Add error view showing on first loading in fragment view (#590)

app/src/main/java/io/github/wulkanowy/ui/base/BaseActivity.kt

@@ -22,7 +22,8 @@ import io.github.wulkanowy.utils.FragmentLifecycleLogger
 import io.github.wulkanowy.utils.getThemeAttrColor
 import javax.inject.Inject
 
-abstract class BaseActivity<T : BasePresenter<out BaseView>> : AppCompatActivity(), BaseView, HasAndroidInjector {
+abstract class BaseActivity<T : BasePresenter<out BaseView>> : AppCompatActivity(), BaseView,
+    HasAndroidInjector {
 
     @Inject
     lateinit var androidInjector: DispatchingAndroidInjector<Any>
@@ -53,13 +54,15 @@ abstract class BaseActivity<T : BasePresenter<out BaseView>> : AppCompatActivity
     override fun showError(text: String, error: Throwable) {
         if (messageContainer != null) {
             Snackbar.make(messageContainer!!, text, LENGTH_LONG)
-                .setAction(R.string.all_details) {
+                .setAction(R.string.all_details) { showErrorDetailsDialog(error) }
-                    ErrorDialog.newInstance(error).show(supportFragmentManager, error.toString())
-                }
                 .show()
         } else showMessage(text)
     }
 
+    override fun showErrorDetailsDialog(error: Throwable) {
+        ErrorDialog.newInstance(error).show(supportFragmentManager, error.toString())
+    }
+
     override fun showMessage(text: String) {
         if (messageContainer != null) Snackbar.make(messageContainer!!, text, LENGTH_LONG).show()
         else Toast.makeText(this, text, Toast.LENGTH_LONG).show()

app/src/main/java/io/github/wulkanowy/ui/base/BaseDialogFragment.kt

@@ -0,0 +1,27 @@
+package io.github.wulkanowy.ui.base
+
+import android.widget.Toast
+import dagger.android.support.DaggerAppCompatDialogFragment
+
+abstract class BaseDialogFragment : DaggerAppCompatDialogFragment(), BaseView {
+
+    override fun showError(text: String, error: Throwable) {
+        showMessage(text)
+    }
+
+    override fun showMessage(text: String) {
+        Toast.makeText(context, text, Toast.LENGTH_LONG).show()
+    }
+
+    override fun showExpiredDialog() {
+        (activity as? BaseActivity<*>)?.showExpiredDialog()
+    }
+
+    override fun openClearLoginView() {
+        (activity as? BaseActivity<*>)?.openClearLoginView()
+    }
+
+    override fun showErrorDetailsDialog(error: Throwable) {
+        ErrorDialog.newInstance(error).show(childFragmentManager, error.toString())
+    }
+}

app/src/main/java/io/github/wulkanowy/ui/base/BaseFragment.kt

@@ -13,15 +13,17 @@ abstract class BaseFragment : DaggerFragment(), BaseView {
     override fun showError(text: String, error: Throwable) {
         if (messageContainer != null) {
             Snackbar.make(messageContainer!!, text, LENGTH_LONG)
-                .setAction(R.string.all_details) {
+                .setAction(R.string.all_details) { if (isAdded) showErrorDetailsDialog(error) }
-                    if (isAdded) ErrorDialog.newInstance(error).show(childFragmentManager, error.toString())
-                }
                 .show()
         } else {
             (activity as? BaseActivity<*>)?.showError(text, error)
         }
     }
 
+    override fun showErrorDetailsDialog(error: Throwable) {
+        ErrorDialog.newInstance(error).show(childFragmentManager, error.toString())
+    }
+
     override fun showMessage(text: String) {
         if (messageContainer != null) {
             Snackbar.make(messageContainer!!, text, LENGTH_LONG).show()

app/src/main/java/io/github/wulkanowy/ui/base/BaseView.kt

@@ -9,4 +9,6 @@ interface BaseView {
     fun showExpiredDialog()
 
     fun openClearLoginView()
+
+    fun showErrorDetailsDialog(error: Throwable)
 }

app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountDialog.kt

@@ -7,18 +7,17 @@ import android.view.ViewGroup
 import android.widget.Toast
 import android.widget.Toast.LENGTH_LONG
 import androidx.appcompat.app.AlertDialog
-import dagger.android.support.DaggerAppCompatDialogFragment
 import eu.davidea.flexibleadapter.FlexibleAdapter
 import eu.davidea.flexibleadapter.common.SmoothScrollLinearLayoutManager
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.R
-import io.github.wulkanowy.ui.base.BaseActivity
+import io.github.wulkanowy.ui.base.BaseDialogFragment
 import io.github.wulkanowy.ui.modules.login.LoginActivity
 import io.github.wulkanowy.utils.setOnItemClickListener
 import kotlinx.android.synthetic.main.dialog_account.*
 import javax.inject.Inject
 
-class AccountDialog : DaggerAppCompatDialogFragment(), AccountView {
+class AccountDialog : BaseDialogFragment(), AccountView {
 
     @Inject
     lateinit var presenter: AccountPresenter
@@ -77,14 +76,6 @@ class AccountDialog : DaggerAppCompatDialogFragment(), AccountView {
         }
     }
 
-    override fun showExpiredDialog() {
-        (activity as? BaseActivity<*>)?.showExpiredDialog()
-    }
-
-    override fun openClearLoginView() {
-        (activity as? BaseActivity<*>)?.openClearLoginView()
-    }
-
     override fun showConfirmDialog() {
         context?.let {
             AlertDialog.Builder(it)
@@ -105,4 +96,3 @@ class AccountDialog : DaggerAppCompatDialogFragment(), AccountView {
         super.onDestroy()
     }
 }
-

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceFragment.kt

@@ -6,6 +6,9 @@ import android.view.Menu
 import android.view.MenuInflater
 import android.view.MenuItem
 import android.view.View
+import android.view.View.GONE
+import android.view.View.INVISIBLE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import com.wdullaer.materialdatetimepicker.date.DatePickerDialog
 import eu.davidea.flexibleadapter.FlexibleAdapter
@@ -73,6 +76,9 @@ class AttendanceFragment : BaseFragment(), AttendanceView, MainView.MainChildVie
         }
 
         attendanceSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        attendanceErrorRetry.setOnClickListener { presenter.onRetry() }
+        attendanceErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+
         attendancePreviousButton.setOnClickListener { presenter.onPreviousDay() }
         attendanceNavDate.setOnClickListener { presenter.onPickDate() }
         attendanceNextButton.setOnClickListener { presenter.onNextDay() }
@@ -114,11 +120,19 @@ class AttendanceFragment : BaseFragment(), AttendanceView, MainView.MainChildVie
     }
 
     override fun showEmpty(show: Boolean) {
-        attendanceEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        attendanceEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        attendanceError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        attendanceErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        attendanceProgress.visibility = if (show) View.VISIBLE else View.GONE
+        attendanceProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -126,7 +140,7 @@ class AttendanceFragment : BaseFragment(), AttendanceView, MainView.MainChildVie
     }
 
     override fun showContent(show: Boolean) {
-        attendanceRecycler.visibility = if (show) View.VISIBLE else View.GONE
+        attendanceRecycler.visibility = if (show) VISIBLE else GONE
     }
 
     override fun hideRefresh() {
@@ -134,11 +148,11 @@ class AttendanceFragment : BaseFragment(), AttendanceView, MainView.MainChildVie
     }
 
     override fun showPreButton(show: Boolean) {
-        attendancePreviousButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        attendancePreviousButton.visibility = if (show) VISIBLE else INVISIBLE
     }
 
     override fun showNextButton(show: Boolean) {
-        attendanceNextButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        attendanceNextButton.visibility = if (show) VISIBLE else INVISIBLE
     }
 
     override fun showAttendanceDialog(lesson: Attendance) {

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendancePresenter.kt

@@ -1,5 +1,6 @@
 package io.github.wulkanowy.ui.modules.attendance
 
+import android.annotation.SuppressLint
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.data.repositories.attendance.AttendanceRepository
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
@@ -37,10 +38,13 @@ class AttendancePresenter @Inject constructor(
     lateinit var currentDate: LocalDate
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: AttendanceView, date: Long?) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Attendance view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
         if (currentDate.isHolidays) setBaseDateOnHolidays()
         reloadView()
@@ -70,6 +74,18 @@ class AttendancePresenter @Inject constructor(
         loadData(currentDate, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentDate, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onViewReselected() {
         Timber.i("Attendance view is reselected")
         view?.also { view ->
@@ -139,18 +155,29 @@ class AttendancePresenter @Inject constructor(
                     view?.apply {
                         updateData(it)
                         showEmpty(it.isEmpty())
+                        showErrorView(false)
                         showContent(it.isNotEmpty())
                     }
                     analytics.logEvent("load_attendance", "items" to it.size, "force_refresh" to forceRefresh)
                 }) {
                     Timber.i("Loading attendance result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     errorHandler.dispatch(it)
                 }
             )
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun reloadView() {
         Timber.i("Reload attendance view with the date ${currentDate.toFormattedString()}")
         view?.apply {
@@ -158,11 +185,13 @@ class AttendancePresenter @Inject constructor(
             enableSwipe(false)
             showContent(false)
             showEmpty(false)
+            showErrorView(false)
             clearData()
             reloadNavigation()
         }
     }
 
+    @SuppressLint("DefaultLocale")
     private fun reloadNavigation() {
         view?.apply {
             showPreButton(!currentDate.minusDays(1).isHolidays)

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceView.kt

@@ -24,6 +24,10 @@ interface AttendanceView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryFragment.kt

@@ -57,6 +57,8 @@ class AttendanceSummaryFragment : BaseFragment(), AttendanceSummaryView, MainVie
         }
 
         attendanceSummarySwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        attendanceSummaryErrorRetry.setOnClickListener { presenter.onRetry() }
+        attendanceSummaryErrorDetails.setOnClickListener { presenter.onDetailsClick() }
 
         subjectsAdapter = ArrayAdapter(requireContext(), android.R.layout.simple_spinner_item, mutableListOf())
         subjectsAdapter.setDropDownViewResource(R.layout.item_attendance_summary_subject)
@@ -93,6 +95,14 @@ class AttendanceSummaryFragment : BaseFragment(), AttendanceSummaryView, MainVie
         attendanceSummaryEmpty.visibility = if (show) VISIBLE else GONE
     }
 
+    override fun showErrorView(show: Boolean) {
+        attendanceSummaryError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        attendanceSummaryErrorMessage.text = message
+    }
+
     override fun showProgress(show: Boolean) {
         attendanceSummaryProgress.visibility = if (show) VISIBLE else GONE
     }

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryPresenter.kt

@@ -33,10 +33,13 @@ class AttendanceSummaryPresenter @Inject constructor(
     var currentSubjectId = -1
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: AttendanceSummaryView, subjectId: Int?) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Attendance summary view was initialized with subject id ${subjectId ?: -1}")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(subjectId ?: -1)
         loadSubjects()
     }
@@ -46,6 +49,18 @@ class AttendanceSummaryPresenter @Inject constructor(
         loadData(currentSubjectId, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentSubjectId, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onSubjectSelected(name: String?) {
         Timber.i("Select attendance summary subject $name")
         view?.run {
@@ -53,6 +68,7 @@ class AttendanceSummaryPresenter @Inject constructor(
             showProgress(true)
             enableSwipe(false)
             showEmpty(false)
+            showErrorView(false)
             clearView()
         }
         (subjects.singleOrNull { it.name == name }?.realId ?: -1).let {
@@ -89,13 +105,23 @@ class AttendanceSummaryPresenter @Inject constructor(
                     analytics.logEvent("load_attendance_summary", "items" to it.first.size, "force_refresh" to forceRefresh, "item_id" to subjectId)
                 }) {
                     Timber.i("Loading attendance summary result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     errorHandler.dispatch(it)
                 }
             )
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun loadSubjects() {
         Timber.i("Loading attendance summary subjects started")
         disposable.add(studentRepository.getCurrentStudent()

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryView.kt

@@ -18,6 +18,10 @@ interface AttendanceSummaryView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun updateDataSet(data: List<AttendanceSummaryItem>, header: AttendanceSummaryScrollableHeader)
 
     fun updateSubjects(data: ArrayList<String>)

app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamFragment.kt

@@ -61,6 +61,9 @@ class ExamFragment : BaseFragment(), ExamView, MainView.MainChildView, MainView.
         }
 
         examSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        examErrorRetry.setOnClickListener { presenter.onRetry() }
+        examErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+
         examPreviousButton.setOnClickListener { presenter.onPreviousWeek() }
         examNextButton.setOnClickListener { presenter.onNextWeek() }
 
@@ -95,6 +98,14 @@ class ExamFragment : BaseFragment(), ExamView, MainView.MainChildView, MainView.
         examEmpty.visibility = if (show) VISIBLE else GONE
     }
 
+    override fun showErrorView(show: Boolean) {
+        examError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        examErrorMessage.text = message
+    }
+
     override fun showProgress(show: Boolean) {
         examProgress.visibility = if (show) VISIBLE else GONE
     }

app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamPresenter.kt

@@ -36,10 +36,13 @@ class ExamPresenter @Inject constructor(
     lateinit var currentDate: LocalDate
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: ExamView, date: Long?) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Exam view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
         if (currentDate.isHolidays) setBaseDateOnHolidays()
         reloadView()
@@ -60,6 +63,18 @@ class ExamPresenter @Inject constructor(
         loadData(currentDate, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentDate, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onExamItemSelected(item: AbstractFlexibleItem<*>?) {
         if (item is ExamItem) {
             Timber.i("Select exam item ${item.exam.id}")
@@ -116,17 +131,28 @@ class ExamPresenter @Inject constructor(
                     view?.apply {
                         updateData(it)
                         showEmpty(it.isEmpty())
+                        showErrorView(false)
                         showContent(it.isNotEmpty())
                     }
                     analytics.logEvent("load_exam", "items" to it.size, "force_refresh" to forceRefresh)
                 }) {
                     Timber.i("Loading exam result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     errorHandler.dispatch(it)
                 })
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun createExamItems(items: Map<LocalDate, List<Exam>>): List<ExamItem> {
         return items.flatMap {
             ExamHeader(it.key).let { header ->
@@ -142,6 +168,7 @@ class ExamPresenter @Inject constructor(
             enableSwipe(false)
             showContent(false)
             showEmpty(false)
+            showErrorView(false)
             clearData()
             reloadNavigation()
         }

app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamView.kt

@@ -21,6 +21,10 @@ interface ExamView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeFragment.kt

@@ -13,6 +13,7 @@ import androidx.appcompat.app.AlertDialog
 import io.github.wulkanowy.R
 import io.github.wulkanowy.ui.base.BaseFragment
 import io.github.wulkanowy.ui.base.BaseFragmentPagerAdapter
+import io.github.wulkanowy.ui.base.ErrorDialog
 import io.github.wulkanowy.ui.modules.grade.details.GradeDetailsFragment
 import io.github.wulkanowy.ui.modules.grade.statistics.GradeStatisticsFragment
 import io.github.wulkanowy.ui.modules.grade.summary.GradeSummaryFragment
@@ -83,7 +84,8 @@ class GradeFragment : BaseFragment(), GradeView, MainView.MainChildView, MainVie
             setElevationCompat(context.dpToPx(4f))
         }
 
-        gradeSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        gradeErrorRetry.setOnClickListener { presenter.onRetry() }
+        gradeErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
@@ -104,22 +106,18 @@ class GradeFragment : BaseFragment(), GradeView, MainView.MainChildView, MainVie
         gradeProgress.visibility = if (show) VISIBLE else INVISIBLE
     }
 
-    override fun showEmpty(show: Boolean) {
+    override fun showErrorView(show: Boolean) {
-        gradeEmpty.visibility = if (show) VISIBLE else INVISIBLE
+        gradeError.visibility = if (show) VISIBLE else INVISIBLE
     }
 
-    override fun showRefresh(show: Boolean) {
+    override fun setErrorDetails(message: String) {
-        gradeSwipe.isRefreshing = show
+        gradeErrorMessage.text = message
     }
 
     override fun showSemesterSwitch(show: Boolean) {
         semesterSwitchMenu?.isVisible = show
     }
 
-    override fun enableSwipe(enable: Boolean) {
-        gradeSwipe.isEnabled = enable
-    }
-
     override fun showSemesterDialog(selectedIndex: Int) {
         val choices = arrayOf(
             getString(R.string.grade_semester, 1),

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt

@@ -25,14 +25,14 @@ class GradePresenter @Inject constructor(
 
     private val loadedSemesterId = mutableMapOf<Int, Int>()
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: GradeView, savedIndex: Int?) {
         super.onAttachView(view)
         selectedIndex = savedIndex ?: 0
-        view.run {
+        view.initView()
-            initView()
-            enableSwipe(false)
-        }
         Timber.i("Grade view was initialized with $selectedIndex index")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -71,7 +71,7 @@ class GradePresenter @Inject constructor(
         view?.apply {
             showContent(true)
             showProgress(false)
-            showEmpty(false)
+            showErrorView(false)
             loadedSemesterId[currentPageIndex] = semesterId
         }
     }
@@ -80,10 +80,18 @@ class GradePresenter @Inject constructor(
         if (semesters.isNotEmpty()) loadChild(index)
     }
 
-    fun onSwipeRefresh() {
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
         loadData()
     }
 
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     private fun loadData() {
         Timber.i("Loading grade data started")
         disposable.add(studentRepository.getCurrentStudent()
@@ -96,25 +104,28 @@ class GradePresenter @Inject constructor(
             }
             .subscribeOn(schedulers.backgroundThread)
             .observeOn(schedulers.mainThread)
-            .doFinally { view?.showRefresh(false) }
+            .doFinally { view?.showProgress(false) }
             .subscribe({
                 view?.run {
                     Timber.i("Loading grade result: Attempt load index $currentPageIndex")
                     loadChild(currentPageIndex)
-                    enableSwipe(false)
+                    showErrorView(false)
                     showSemesterSwitch(true)
                 }
             }) {
                 Timber.i("Loading grade result: An exception occurred")
                 errorHandler.dispatch(it)
-                view?.run {
-                    showProgress(false)
-                    showEmpty(true)
-                    enableSwipe(true)
-                }
             })
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        lastError = error
+        view?.run {
+            showErrorView(true)
+            setErrorDetails(message)
+        }
+    }
+
     private fun loadChild(index: Int, forceRefresh: Boolean = false) {
         semesters.first { it.semesterName == selectedIndex }.semesterId.also {
             if (forceRefresh || loadedSemesterId[index] != it) {

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeView.kt

@@ -12,16 +12,14 @@ interface GradeView : BaseView {
 
     fun showProgress(show: Boolean)
 
-    fun showEmpty(show: Boolean)
+    fun showErrorView(show: Boolean)
 
-    fun showRefresh(show: Boolean)
+    fun setErrorDetails(message: String)
 
     fun showSemesterSwitch(show: Boolean)
 
     fun showSemesterDialog(selectedIndex: Int)
 
-    fun enableSwipe(enable: Boolean)
-
     fun notifyChildLoadData(index: Int, semesterId: Int, forceRefresh: Boolean)
 
     fun notifyChildParentReselected(index: Int)

app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsFragment.kt

@@ -18,6 +18,7 @@ import eu.davidea.flexibleadapter.items.IFlexible
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.ui.base.BaseFragment
+import io.github.wulkanowy.ui.base.ErrorDialog
 import io.github.wulkanowy.ui.modules.grade.GradeFragment
 import io.github.wulkanowy.ui.modules.grade.GradeView
 import io.github.wulkanowy.ui.modules.main.MainActivity
@@ -90,6 +91,8 @@ class GradeDetailsFragment : BaseFragment(), GradeDetailsView, GradeView.GradeCh
             )
         }
         gradeDetailsSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        gradeDetailsErrorRetry.setOnClickListener { presenter.onRetry() }
+        gradeDetailsErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
@@ -141,6 +144,14 @@ class GradeDetailsFragment : BaseFragment(), GradeDetailsView, GradeView.GradeCh
         gradeDetailsEmpty.visibility = if (show) VISIBLE else INVISIBLE
     }
 
+    override fun showErrorView(show: Boolean) {
+        gradeDetailsError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        gradeDetailsErrorMessage.text = message
+    }
+
     override fun showRefresh(show: Boolean) {
         gradeDetailsSwipe.isRefreshing = show
     }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsPresenter.kt

@@ -1,6 +1,5 @@
 package io.github.wulkanowy.ui.modules.grade.details
 
-import android.widget.Toast
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.data.repositories.grade.GradeRepository
@@ -31,9 +30,12 @@ class GradeDetailsPresenter @Inject constructor(
 
     private var currentSemesterId = 0
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: GradeDetailsView) {
         super.onAttachView(view)
         view.initView()
+        errorHandler.showErrorMessage = ::showErrorViewOnError
     }
 
     fun onParentViewLoadData(semesterId: Int, forceRefresh: Boolean) {
@@ -90,6 +92,18 @@ class GradeDetailsPresenter @Inject constructor(
         view?.notifyParentRefresh()
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        view?.notifyParentRefresh()
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onParentViewReselected() {
         view?.run {
             if (!isViewEmpty) {
@@ -140,21 +154,32 @@ class GradeDetailsPresenter @Inject constructor(
             }
             .subscribe({
                 Timber.i("Loading grade details result: Success")
-                newGradesAmount  = it.sumBy { gradeDetailsHeader -> gradeDetailsHeader.newGrades }
+                newGradesAmount = it.sumBy { gradeDetailsHeader -> gradeDetailsHeader.newGrades }
                 updateMarkAsDoneButton()
                 view?.run {
                     showEmpty(it.isEmpty())
+                    showErrorView(false)
                     showContent(it.isNotEmpty())
                     updateData(it)
                 }
                 analytics.logEvent("load_grade_details", "items" to it.size, "force_refresh" to forceRefresh)
             }) {
                 Timber.i("Loading grade details result: An exception occurred")
-                view?.run { showEmpty(isViewEmpty) }
                 errorHandler.dispatch(it)
             })
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun createGradeItems(items: Map<String, List<Grade>>, averages: Map<String, Double>): List<GradeDetailsHeader> {
         val isGradeExpandable = preferencesRepository.isGradeExpandable
         val gradeColorTheme = preferencesRepository.gradeColorTheme

app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsView.kt

@@ -38,6 +38,10 @@ interface GradeDetailsView : BaseView {
 
     fun showProgress(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun enableSwipe(enable: Boolean)
 
     fun showRefresh(show: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsFragment.kt

@@ -111,9 +111,11 @@ class GradeStatisticsFragment : BaseFragment(), GradeStatisticsView, GradeView.G
             setOnItemSelectedListener<TextView> { presenter.onSubjectSelected(it?.text?.toString()) }
         }
 
-        gradeStatisticsSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
-
         gradeStatisticsSubjectsContainer.setElevationCompat(requireContext().dpToPx(1f))
+
+        gradeStatisticsSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        gradeStatisticsErrorRetry.setOnClickListener { presenter.onRetry() }
+        gradeStatisticsErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun updateSubjects(data: ArrayList<String>) {
@@ -228,6 +230,14 @@ class GradeStatisticsFragment : BaseFragment(), GradeStatisticsView, GradeView.G
         gradeStatisticsEmpty.visibility = if (show) View.VISIBLE else View.INVISIBLE
     }
 
+    override fun showErrorView(show: Boolean) {
+        gradeStatisticsError.visibility = if (show) View.VISIBLE else View.GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        gradeStatisticsErrorMessage.text = message
+    }
+
     override fun showProgress(show: Boolean) {
         gradeStatisticsProgress.visibility = if (show) View.VISIBLE else View.GONE
     }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt

@@ -30,6 +30,8 @@ class GradeStatisticsPresenter @Inject constructor(
 
     private var currentSubjectName: String = "Wszystkie"
 
+    private lateinit var lastError: Throwable
+
     var currentType: ViewType = ViewType.PARTIAL
         private set
 
@@ -37,6 +39,7 @@ class GradeStatisticsPresenter @Inject constructor(
         super.onAttachView(view)
         currentType = type ?: ViewType.PARTIAL
         view.initView()
+        errorHandler.showErrorMessage = ::showErrorViewOnError
     }
 
     fun onParentViewLoadData(semesterId: Int, forceRefresh: Boolean) {
@@ -51,6 +54,7 @@ class GradeStatisticsPresenter @Inject constructor(
             enableSwipe(false)
             showRefresh(false)
             showBarContent(false)
+            showErrorView(false)
             showEmpty(false)
             clearView()
         }
@@ -62,6 +66,18 @@ class GradeStatisticsPresenter @Inject constructor(
         view?.notifyParentRefresh()
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        view?.notifyParentRefresh()
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onSubjectSelected(name: String?) {
         Timber.i("Select grade stats subject $name")
         view?.run {
@@ -70,6 +86,7 @@ class GradeStatisticsPresenter @Inject constructor(
             showProgress(true)
             enableSwipe(false)
             showEmpty(false)
+            showErrorView(false)
             clearView()
         }
         (subjects.singleOrNull { it.name == name }?.name)?.let {
@@ -86,6 +103,7 @@ class GradeStatisticsPresenter @Inject constructor(
             showProgress(true)
             enableSwipe(false)
             showEmpty(false)
+            showErrorView(false)
             clearView()
         }
         loadDataByType(currentSemesterId, currentSubjectName, type)
@@ -146,12 +164,12 @@ class GradeStatisticsPresenter @Inject constructor(
                     showEmpty(it.isEmpty())
                     showBarContent(false)
                     showPieContent(it.isNotEmpty())
+                    showErrorView(false)
                     updatePieData(it, preferencesRepository.gradeColorTheme)
                 }
                 analytics.logEvent("load_grade_statistics", "items" to it.size, "force_refresh" to forceRefresh)
             }) {
                 Timber.e("Loading grade stats result: An exception occurred")
-                view?.run { showEmpty(isPieViewEmpty) }
                 errorHandler.dispatch(it)
             })
     }
@@ -177,12 +195,12 @@ class GradeStatisticsPresenter @Inject constructor(
                     showEmpty(false)
                     showPieContent(false)
                     showBarContent(true)
+                    showErrorView(false)
                     updateBarData(it)
                 }
                 analytics.logEvent("load_grade_points_statistics", "force_refresh" to forceRefresh)
             }, {
                 Timber.e("Loading grade points stats result: An exception occurred")
-                view?.run { showEmpty(isBarViewEmpty) }
                 errorHandler.dispatch(it)
             }, {
                 Timber.d("Loading grade points stats result: No point stats found")
@@ -193,4 +211,15 @@ class GradeStatisticsPresenter @Inject constructor(
             })
         )
     }
+
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isBarViewEmpty || isPieViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsView.kt

@@ -32,6 +32,10 @@ interface GradeStatisticsView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryFragment.kt

@@ -56,6 +56,8 @@ class GradeSummaryFragment : BaseFragment(), GradeSummaryView, GradeView.GradeCh
             adapter = gradeSummaryAdapter
         }
         gradeSummarySwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        gradeSummaryErrorRetry.setOnClickListener { presenter.onRetry() }
+        gradeSummaryErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun updateData(data: List<GradeSummaryItem>, header: GradeSummaryScrollableHeader) {
@@ -82,6 +84,14 @@ class GradeSummaryFragment : BaseFragment(), GradeSummaryView, GradeView.GradeCh
         gradeSummaryEmpty.visibility = if (show) VISIBLE else INVISIBLE
     }
 
+    override fun showErrorView(show: Boolean) {
+        gradeSummaryError.visibility = if (show) VISIBLE else INVISIBLE
+    }
+
+    override fun setErrorDetails(message: String) {
+        gradeSummaryErrorMessage.text = message
+    }
+
     override fun showProgress(show: Boolean) {
         gradeSummaryProgress.visibility = if (show) VISIBLE else GONE
     }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryPresenter.kt

@@ -25,9 +25,12 @@ class GradeSummaryPresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<GradeSummaryView>(errorHandler, studentRepository, schedulers) {
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: GradeSummaryView) {
         super.onAttachView(view)
         view.initView()
+        errorHandler.showErrorMessage = ::showErrorViewOnError
     }
 
     fun onParentViewLoadData(semesterId: Int, forceRefresh: Boolean) {
@@ -56,21 +59,44 @@ class GradeSummaryPresenter @Inject constructor(
                 view?.run {
                     showEmpty(gradeSummaryItems.isEmpty())
                     showContent(gradeSummaryItems.isNotEmpty())
+                    showErrorView(false)
                     updateData(gradeSummaryItems, gradeSummaryHeader)
                 }
                 analytics.logEvent("load_grade_summary", "items" to gradeSummaryItems.size, "force_refresh" to forceRefresh)
             }) {
                 Timber.i("Loading grade summary result: An exception occurred")
-                view?.run { showEmpty(isViewEmpty) }
                 errorHandler.dispatch(it)
             })
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     fun onSwipeRefresh() {
         Timber.i("Force refreshing the grade summary")
         view?.notifyParentRefresh()
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        view?.notifyParentRefresh()
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onParentViewReselected() {
         view?.run {
             if (!isViewEmpty) resetView()

app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryView.kt

@@ -26,6 +26,10 @@ interface GradeSummaryView : BaseView {
 
     fun showContent(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showEmpty(show: Boolean)
 
     fun notifyParentDataLoaded(semesterId: Int)

app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkFragment.kt

@@ -3,6 +3,8 @@ package io.github.wulkanowy.ui.modules.homework
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
+import android.view.View.GONE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import eu.davidea.flexibleadapter.FlexibleAdapter
 import eu.davidea.flexibleadapter.common.FlexibleItemDecoration
@@ -34,6 +36,8 @@ class HomeworkFragment : BaseFragment(), HomeworkView, MainView.TitledView {
 
     override val titleStringId get() = R.string.homework_title
 
+    override val isViewEmpty get() = homeworkAdapter.isEmpty
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.fragment_homework, container, false)
     }
@@ -41,7 +45,7 @@ class HomeworkFragment : BaseFragment(), HomeworkView, MainView.TitledView {
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
         messageContainer = homeworkRecycler
-        presenter.onAttachView(this, savedInstanceState?.getLong(HomeworkFragment.SAVED_DATE_KEY))
+        presenter.onAttachView(this, savedInstanceState?.getLong(SAVED_DATE_KEY))
     }
 
     override fun initView() {
@@ -56,6 +60,9 @@ class HomeworkFragment : BaseFragment(), HomeworkView, MainView.TitledView {
         }
 
         homeworkSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        homeworkErrorRetry.setOnClickListener { presenter.onRetry() }
+        homeworkErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+
         homeworkPreviousButton.setOnClickListener { presenter.onPreviousDay() }
         homeworkNextButton.setOnClickListener { presenter.onNextDay() }
 
@@ -74,18 +81,24 @@ class HomeworkFragment : BaseFragment(), HomeworkView, MainView.TitledView {
         homeworkNavDate.text = date
     }
 
-    override fun isViewEmpty() = homeworkAdapter.isEmpty
-
     override fun hideRefresh() {
         homeworkSwipe.isRefreshing = false
     }
 
     override fun showEmpty(show: Boolean) {
-        homeworkEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        homeworkEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        homeworkError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        homeworkErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        homeworkProgress.visibility = if (show) View.VISIBLE else View.GONE
+        homeworkProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -93,15 +106,15 @@ class HomeworkFragment : BaseFragment(), HomeworkView, MainView.TitledView {
     }
 
     override fun showContent(show: Boolean) {
-        homeworkRecycler.visibility = if (show) View.VISIBLE else View.GONE
+        homeworkRecycler.visibility = if (show) VISIBLE else GONE
     }
 
     override fun showPreButton(show: Boolean) {
-        homeworkPreviousButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        homeworkPreviousButton.visibility = if (show) VISIBLE else View.INVISIBLE
     }
 
     override fun showNextButton(show: Boolean) {
-        homeworkNextButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        homeworkNextButton.visibility = if (show) VISIBLE else View.INVISIBLE
     }
 
     override fun showTimetableDialog(homework: Homework) {

app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkPresenter.kt

@@ -35,10 +35,13 @@ class HomeworkPresenter @Inject constructor(
     lateinit var currentDate: LocalDate
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: HomeworkView, date: Long?) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Homework view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
         if (currentDate.isHolidays) setBaseDateOnHolidays()
         reloadView()
@@ -59,6 +62,18 @@ class HomeworkPresenter @Inject constructor(
         loadData(currentDate, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentDate, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onHomeworkItemSelected(item: AbstractFlexibleItem<*>?) {
         if (item is HomeworkItem) {
             Timber.i("Select homework item ${item.homework.id}")
@@ -105,17 +120,29 @@ class HomeworkPresenter @Inject constructor(
                     view?.apply {
                         updateData(it)
                         showEmpty(it.isEmpty())
+                        showErrorView(false)
                         showContent(it.isNotEmpty())
                     }
                     analytics.logEvent("load_homework", "items" to it.size, "force_refresh" to forceRefresh)
                 }) {
                     Timber.i("Loading homework result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty()) }
+
                     errorHandler.dispatch(it)
                 })
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun createHomeworkItem(items: Map<LocalDate, List<Homework>>): List<HomeworkItem> {
         return items.flatMap {
             HomeworkHeader(it.key).let { header ->
@@ -131,6 +158,7 @@ class HomeworkPresenter @Inject constructor(
             enableSwipe(false)
             showContent(false)
             showEmpty(false)
+            showErrorView(false)
             clearData()
             reloadNavigation()
         }

app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkView.kt

@@ -5,6 +5,8 @@ import io.github.wulkanowy.ui.base.BaseView
 
 interface HomeworkView : BaseView {
 
+    val isViewEmpty: Boolean
+
     fun initView()
 
     fun updateData(data: List<HomeworkItem>)
@@ -13,12 +15,14 @@ interface HomeworkView : BaseView {
 
     fun updateNavigationWeek(date: String)
 
-    fun isViewEmpty(): Boolean
-
     fun hideRefresh()
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberFragment.kt

@@ -3,6 +3,8 @@ package io.github.wulkanowy.ui.modules.luckynumber
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
+import android.view.View.GONE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.LuckyNumber
@@ -23,17 +25,22 @@ class LuckyNumberFragment : BaseFragment(), LuckyNumberView, MainView.TitledView
     override val titleStringId: Int
         get() = R.string.lucky_number_title
 
+    override val isViewEmpty get() = luckyNumberText.text.isBlank()
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.fragment_lucky_number, container, false)
     }
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
+        messageContainer = luckyNumberSwipe
         presenter.onAttachView(this)
     }
 
     override fun initView() {
         luckyNumberSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        luckyNumberErrorRetry.setOnClickListener { presenter.onRetry() }
+        luckyNumberErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun updateData(data: LuckyNumber) {
@@ -45,11 +52,19 @@ class LuckyNumberFragment : BaseFragment(), LuckyNumberView, MainView.TitledView
     }
 
     override fun showEmpty(show: Boolean) {
-        luckyNumberEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        luckyNumberEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        luckyNumberError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        luckyNumberErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        luckyNumberProgress.visibility = if (show) View.VISIBLE else View.GONE
+        luckyNumberProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -57,11 +72,7 @@ class LuckyNumberFragment : BaseFragment(), LuckyNumberView, MainView.TitledView
     }
 
     override fun showContent(show: Boolean) {
-        luckyNumberContent.visibility = if (show) View.VISIBLE else View.GONE
+        luckyNumberContent.visibility = if (show) VISIBLE else GONE
-    }
-
-    override fun isViewEmpty(): Boolean {
-        return luckyNumberText.text.isBlank()
     }
 
     override fun onDestroyView() {

app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberPresenter.kt

@@ -19,6 +19,8 @@ class LuckyNumberPresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<LuckyNumberView>(errorHandler, studentRepository, schedulers) {
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: LuckyNumberView) {
         super.onAttachView(view)
         view.run {
@@ -27,6 +29,7 @@ class LuckyNumberPresenter @Inject constructor(
             enableSwipe(false)
         }
         Timber.i("Lucky number view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -52,25 +55,49 @@ class LuckyNumberPresenter @Inject constructor(
                         updateData(it)
                         showContent(true)
                         showEmpty(false)
+                        showErrorView(false)
                     }
                     analytics.logEvent("load_lucky_number", "lucky_number" to it.luckyNumber, "force_refresh" to forceRefresh)
                 }, {
                     Timber.i("Loading lucky number result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty()) }
                     errorHandler.dispatch(it)
                 }, {
                     Timber.i("Loading lucky number result: No lucky number found")
                     view?.run {
                         showContent(false)
                         showEmpty(true)
+                        showEmpty(false)
                     }
                 })
             )
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     fun onSwipeRefresh() {
         Timber.i("Force refreshing the lucky number")
         loadData(true)
     }
+
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberView.kt

@@ -5,6 +5,8 @@ import io.github.wulkanowy.ui.base.BaseView
 
 interface LuckyNumberView : BaseView {
 
+    val isViewEmpty: Boolean
+
     fun initView()
 
     fun updateData(data: LuckyNumber)
@@ -13,11 +15,13 @@ interface LuckyNumberView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)
 
     fun showContent(show: Boolean)
-
-    fun isViewEmpty(): Boolean
 }

app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewFragment.kt

@@ -65,6 +65,10 @@ class MessagePreviewFragment : BaseFragment(), MessagePreviewView, MainView.Titl
         presenter.onAttachView(this, (savedInstanceState ?: arguments)?.getLong(MESSAGE_ID_KEY) ?: 0L)
     }
 
+    override fun initView() {
+        messagePreviewErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+    }
+
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
         inflater.inflate(R.menu.action_menu_message_preview, menu)
         menuReplyButton = menu.findItem(R.id.messagePreviewMenuReply)
@@ -126,8 +130,16 @@ class MessagePreviewFragment : BaseFragment(), MessagePreviewView, MainView.Titl
         menuDeleteButton?.setTitle(R.string.message_move_to_bin)
     }
 
-    override fun showMessageError() {
+    override fun showErrorView(show: Boolean) {
-        messagePreviewError.visibility = VISIBLE
+        messagePreviewError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        messagePreviewErrorMessage.text = message
+    }
+
+    override fun setErrorRetryCallback(callback: () -> Unit) {
+        messagePreviewErrorRetry.setOnClickListener { callback() }
     }
 
     override fun openMessageReply(message: Message?) {

app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewPresenter.kt

@@ -23,11 +23,29 @@ class MessagePreviewPresenter @Inject constructor(
 
     private var message: Message? = null
 
+    private lateinit var lastError: Throwable
+
+    private var retryCallback: () -> Unit = {}
+
     fun onAttachView(view: MessagePreviewView, id: Long) {
         super.onAttachView(view)
+        view.initView()
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(id)
     }
 
+    private fun onMessageLoadRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(messageId)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     private fun loadData(id: Long) {
         Timber.i("Loading message $id preview started")
         messageId = id
@@ -55,7 +73,7 @@ class MessagePreviewPresenter @Inject constructor(
                     analytics.logEvent("load_message_preview", "length" to message.content?.length)
                 }) {
                     Timber.i("Loading message $id preview result: An exception occurred ")
-                    view?.showMessageError()
+                    retryCallback = { onMessageLoadRetry() }
                     errorHandler.dispatch(it)
                 })
         }
@@ -85,6 +103,7 @@ class MessagePreviewPresenter @Inject constructor(
                         showContent(false)
                         showProgress(true)
                         showOptions(false)
+                        showErrorView(false)
                     }
                 }
                 .doFinally {
@@ -97,15 +116,24 @@ class MessagePreviewPresenter @Inject constructor(
                         popView()
                     }
                 }, { error ->
-                    view?.showMessageError()
+                    retryCallback = { onMessageDelete() }
                     errorHandler.dispatch(error)
                 }, {
-                    view?.showMessageError()
+                    view?.showErrorView(true)
                 })
             )
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            lastError = error
+            setErrorDetails(message)
+            showErrorView(true)
+            setErrorRetryCallback { retryCallback() }
+        }
+    }
+
     fun onMessageDelete(): Boolean {
         deleteMessage()
         return true

app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewView.kt

@@ -9,6 +9,8 @@ interface MessagePreviewView : BaseView {
 
     val deleteMessageSuccessString: String
 
+    fun initView()
+
     fun setSubject(subject: String)
 
     fun setRecipient(recipient: String)
@@ -23,19 +25,23 @@ interface MessagePreviewView : BaseView {
 
     fun showContent(show: Boolean)
 
+    fun notifyParentMessageDeleted(message: Message)
+
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
+    fun setErrorRetryCallback(callback: () -> Unit)
+
     fun showOptions(show: Boolean)
 
     fun setDeletedOptionsLabels()
 
     fun setNotDeletedOptionsLabels()
 
-    fun showMessageError()
-
     fun openMessageReply(message: Message?)
 
     fun openMessageForward(message: Message?)
 
     fun popView()
-
-    fun notifyParentMessageDeleted(message: Message)
 }

app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt

@@ -72,6 +72,8 @@ class MessageTabFragment : BaseFragment(), MessageTabView {
             )
         }
         messageTabSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        messageTabErrorRetry.setOnClickListener { presenter.onRetry() }
+        messageTabErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun updateData(data: List<MessageItem>) {
@@ -102,6 +104,14 @@ class MessageTabFragment : BaseFragment(), MessageTabView {
         messageTabEmpty.visibility = if (show) VISIBLE else INVISIBLE
     }
 
+    override fun showErrorView(show: Boolean) {
+        messageTabError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        messageTabErrorMessage.text = message
+    }
+
     override fun showRefresh(show: Boolean) {
         messageTabSwipe.isRefreshing = show
     }

app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt

@@ -23,9 +23,12 @@ class MessageTabPresenter @Inject constructor(
 
     lateinit var folder: MessageFolder
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: MessageTabView, folder: MessageFolder) {
         super.onAttachView(view)
         view.initView()
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         this.folder = folder
     }
 
@@ -34,6 +37,18 @@ class MessageTabPresenter @Inject constructor(
         onParentViewLoadData(true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onDeleteMessage() {
         loadData(false)
     }
@@ -78,17 +93,28 @@ class MessageTabPresenter @Inject constructor(
                     view?.run {
                         showEmpty(it.isEmpty())
                         showContent(it.isNotEmpty())
+                        showErrorView(false)
                         updateData(it)
                     }
                     analytics.logEvent("load_messages", "items" to it.size, "folder" to folder.name)
                 }) {
                     Timber.i("Loading $folder message result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     errorHandler.dispatch(it)
                 })
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun updateMessage(message: Message) {
         Timber.i("Attempt to update message ${message.id}")
         disposable.add(messageRepository.updateMessage(message)

app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabView.kt

@@ -26,6 +26,10 @@ interface MessageTabView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showRefresh(show: Boolean)
 
     fun openMessage(messageId: Long)

app/src/main/java/io/github/wulkanowy/ui/modules/mobiledevice/MobileDeviceFragment.kt

@@ -61,6 +61,8 @@ class MobileDeviceFragment : BaseFragment(), MobileDeviceView, MainView.TitledVi
             onDeviceUnregisterListener = presenter::onUnregisterDevice
         }
         mobileDevicesSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        mobileDevicesErrorRetry.setOnClickListener { presenter.onRetry() }
+        mobileDevicesErrorDetails.setOnClickListener { presenter.onDetailsClick() }
         mobileDeviceAddButton.setOnClickListener { presenter.onRegisterDevice() }
     }
 
@@ -105,6 +107,14 @@ class MobileDeviceFragment : BaseFragment(), MobileDeviceView, MainView.TitledVi
         mobileDevicesEmpty.visibility = if (show) VISIBLE else GONE
     }
 
+    override fun showErrorView(show: Boolean) {
+        mobileDevicesError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        mobileDevicesErrorMessage.text = message
+    }
+
     override fun enableSwipe(enable: Boolean) {
         mobileDevicesSwipe.isEnabled = enable
     }

app/src/main/java/io/github/wulkanowy/ui/modules/mobiledevice/MobileDevicePresenter.kt

@@ -20,10 +20,13 @@ class MobileDevicePresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<MobileDeviceView>(errorHandler, studentRepository, schedulers) {
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: MobileDeviceView) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Mobile device view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -31,6 +34,18 @@ class MobileDevicePresenter @Inject constructor(
         loadData(true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     private fun loadData(forceRefresh: Boolean = false) {
         Timber.i("Loading mobile devices data started")
         disposable.add(studentRepository.getCurrentStudent()
@@ -51,15 +66,26 @@ class MobileDevicePresenter @Inject constructor(
                     updateData(it)
                     showContent(it.isNotEmpty())
                     showEmpty(it.isEmpty())
+                    showErrorView(false)
                 }
                 analytics.logEvent("load_devices", "items" to it.size, "force_refresh" to forceRefresh)
             }) {
                 Timber.i("Loading mobile devices result: An exception occurred")
-                view?.run { showEmpty(isViewEmpty) }
                 errorHandler.dispatch(it)
             })
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     fun onRegisterDevice() {
         view?.showTokenDialog()
     }

app/src/main/java/io/github/wulkanowy/ui/modules/mobiledevice/MobileDeviceView.kt

@@ -25,6 +25,10 @@ interface MobileDeviceView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showUndo(position: Int, device: MobileDevice)
 
     fun showTokenDialog()

app/src/main/java/io/github/wulkanowy/ui/modules/mobiledevice/token/MobileDeviceTokenDialog.kt

@@ -12,15 +12,13 @@ import android.view.View.VISIBLE
 import android.view.ViewGroup
 import android.widget.Toast
 import androidx.core.content.getSystemService
-import dagger.android.support.DaggerDialogFragment
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.pojos.MobileDeviceToken
-import io.github.wulkanowy.data.repositories.mobiledevice.MobileDeviceRemote
+import io.github.wulkanowy.ui.base.BaseDialogFragment
-import io.github.wulkanowy.ui.base.BaseActivity
 import kotlinx.android.synthetic.main.dialog_mobile_device.*
 import javax.inject.Inject
 
-class MobileDeviceTokenDialog : DaggerDialogFragment(), MobileDeviceTokenVIew {
+class MobileDeviceTokenDialog : BaseDialogFragment(), MobileDeviceTokenVIew {
 
     @Inject
     lateinit var presenter: MobileDeviceTokenPresenter
@@ -66,6 +64,12 @@ class MobileDeviceTokenDialog : DaggerDialogFragment(), MobileDeviceTokenVIew {
         })
     }
 
+    private fun clickCopy(text: String) {
+        val clip = ClipData.newPlainText("wulkanowy", text)
+        activity?.getSystemService<ClipboardManager>()?.setPrimaryClip(clip)
+        Toast.makeText(context, R.string.all_copied, Toast.LENGTH_LONG).show()
+    }
+
     override fun hideLoading() {
         mobileDeviceDialogProgress.visibility = GONE
     }
@@ -78,30 +82,8 @@ class MobileDeviceTokenDialog : DaggerDialogFragment(), MobileDeviceTokenVIew {
         dismiss()
     }
 
-    override fun showError(text: String, error: Throwable) {
-        showMessage(text)
-    }
-
-    override fun showMessage(text: String) {
-        Toast.makeText(context, text, Toast.LENGTH_LONG).show()
-    }
-
-    override fun showExpiredDialog() {
-        (activity as? BaseActivity<*>)?.showExpiredDialog()
-    }
-
-    override fun openClearLoginView() {
-        (activity as? BaseActivity<*>)?.openClearLoginView()
-    }
-
     override fun onDestroyView() {
         presenter.onDetachView()
         super.onDestroyView()
     }
-
-    fun clickCopy(text: String) {
-        val clip = ClipData.newPlainText("wulkanowy", text)
-        activity?.getSystemService<ClipboardManager>()?.setPrimaryClip(clip)
-        Toast.makeText(context, R.string.all_copied, Toast.LENGTH_LONG).show()
-    }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteFragment.kt

@@ -60,6 +60,8 @@ class NoteFragment : BaseFragment(), NoteView, MainView.TitledView {
             )
         }
         noteSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        noteErrorRetry.setOnClickListener { presenter.onRetry() }
+        noteErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun showNoteDialog(note: Note) {
@@ -82,6 +84,14 @@ class NoteFragment : BaseFragment(), NoteView, MainView.TitledView {
         noteEmpty.visibility = if (show) VISIBLE else GONE
     }
 
+    override fun showErrorView(show: Boolean) {
+        noteError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        noteErrorMessage.text = message
+    }
+
     override fun showProgress(show: Boolean) {
         noteProgress.visibility = if (show) VISIBLE else GONE
     }

app/src/main/java/io/github/wulkanowy/ui/modules/note/NotePresenter.kt

@@ -21,10 +21,13 @@ class NotePresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<NoteView>(errorHandler, studentRepository, schedulers) {
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: NoteView) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Note view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -33,6 +36,18 @@ class NotePresenter @Inject constructor(
         loadData(true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     private fun loadData(forceRefresh: Boolean = false) {
         Timber.i("Loading note data started")
         disposable.add(studentRepository.getCurrentStudent()
@@ -53,17 +68,28 @@ class NotePresenter @Inject constructor(
                 view?.apply {
                     updateData(it)
                     showEmpty(it.isEmpty())
+                    showErrorView(false)
                     showContent(it.isNotEmpty())
                 }
                 analytics.logEvent("load_note", "items" to it.size, "force_refresh" to forceRefresh)
             }, {
                 Timber.i("Loading note result: An exception occurred")
-                view?.run { showEmpty(isViewEmpty) }
                 errorHandler.dispatch(it)
             })
         )
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     fun onNoteItemSelected(item: AbstractFlexibleItem<*>?) {
         if (item is NoteItem) {
             Timber.i("Select note item ${item.note.id}")

app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteView.kt

@@ -18,6 +18,10 @@ interface NoteView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/school/SchoolFragment.kt

@@ -3,6 +3,8 @@ package io.github.wulkanowy.ui.modules.schoolandteachers.school
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
+import android.view.View.GONE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.School
@@ -22,6 +24,8 @@ class SchoolFragment : BaseFragment(), SchoolView, MainView.TitledView, SchoolAn
 
     override val titleStringId get() = R.string.school_title
 
+    override val isViewEmpty get() = schoolName.text.isBlank()
+
     companion object {
         fun newInstance() = SchoolFragment()
     }
@@ -37,6 +41,8 @@ class SchoolFragment : BaseFragment(), SchoolView, MainView.TitledView, SchoolAn
 
     override fun initView() {
         schoolSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        schoolErrorRetry.setOnClickListener { presenter.onRetry() }
+        schoolErrorDetails.setOnClickListener { presenter.onDetailsClick() }
 
         schoolAddressButton.setOnClickListener { presenter.onAddressSelected() }
         schoolTelephoneButton.setOnClickListener { presenter.onTelephoneSelected() }
@@ -45,24 +51,27 @@ class SchoolFragment : BaseFragment(), SchoolView, MainView.TitledView, SchoolAn
     override fun updateData(data: School) {
         schoolName.text = data.name
         schoolAddress.text = data.address.ifBlank { "-" }
-        schoolAddressButton.visibility = if (data.address.isNotBlank()) View.VISIBLE else View.GONE
+        schoolAddressButton.visibility = if (data.address.isNotBlank()) VISIBLE else GONE
         schoolTelephone.text = data.contact.ifBlank { "-" }
-        schoolTelephoneButton.visibility = if (data.contact.isNotBlank()) View.VISIBLE else View.GONE
+        schoolTelephoneButton.visibility = if (data.contact.isNotBlank()) VISIBLE else GONE
         schoolHeadmaster.text = data.headmaster
         schoolPedagogue.text = data.pedagogue
     }
 
-
+    override fun showEmpty(show: Boolean) {
-    override fun isViewEmpty(): Boolean {
+        schoolEmpty.visibility = if (show) VISIBLE else GONE
-        return schoolName.text.isBlank()
     }
 
-    override fun showEmpty(show: Boolean) {
+    override fun showErrorView(show: Boolean) {
-        schoolEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        schoolError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        schoolErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        schoolProgress.visibility = if (show) View.VISIBLE else View.GONE
+        schoolProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -70,7 +79,7 @@ class SchoolFragment : BaseFragment(), SchoolView, MainView.TitledView, SchoolAn
     }
 
     override fun showContent(show: Boolean) {
-        schoolContent.visibility = if (show) View.VISIBLE else View.GONE
+        schoolContent.visibility = if (show) VISIBLE else GONE
     }
 
     override fun hideRefresh() {

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/school/SchoolPresenter.kt

@@ -23,10 +23,13 @@ class SchoolPresenter @Inject constructor(
 
     private var contact: String? = null
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: SchoolView) {
         super.onAttachView(view)
         view.initView()
         Timber.i("School view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -34,12 +37,24 @@ class SchoolPresenter @Inject constructor(
         loadData(true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onParentViewLoadData(forceRefresh: Boolean) {
         loadData(forceRefresh)
     }
 
     fun onAddressSelected() {
-        address?.let{ view?.openMapsLocation(it) }
+        address?.let { view?.openMapsLocation(it) }
     }
 
     fun onTelephoneSelected() {
@@ -68,21 +83,31 @@ class SchoolPresenter @Inject constructor(
                     updateData(it)
                     showContent(true)
                     showEmpty(false)
+                    showErrorView(false)
                 }
                 analytics.logEvent("load_school", "force_refresh" to forceRefresh)
             }, {
                 Timber.i("Loading school result: An exception occurred")
-                view?.run {
-                    showContent(!isViewEmpty())
-                    showEmpty(isViewEmpty())
-                }
                 errorHandler.dispatch(it)
             }, {
                 Timber.i("Loading school result: No school info found")
                 view?.run {
-                    showContent(!isViewEmpty())
+                    showContent(!isViewEmpty)
-                    showEmpty(isViewEmpty())
+                    showEmpty(isViewEmpty)
+                    showErrorView(false)
                 }
             }))
     }
+
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+                showContent(false)
+            } else showError(message, error)
+        }
+    }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/school/SchoolView.kt

@@ -6,14 +6,18 @@ import io.github.wulkanowy.ui.modules.schoolandteachers.SchoolAndTeachersChildVi
 
 interface SchoolView : BaseView, SchoolAndTeachersChildView {
 
+    val isViewEmpty: Boolean
+
     fun initView()
 
     fun updateData(data: School)
 
-    fun isViewEmpty(): Boolean
-
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/teacher/TeacherFragment.kt

@@ -3,6 +3,8 @@ package io.github.wulkanowy.ui.modules.schoolandteachers.teacher
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
+import android.view.View.GONE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import eu.davidea.flexibleadapter.FlexibleAdapter
 import eu.davidea.flexibleadapter.common.FlexibleItemDecoration
@@ -16,7 +18,8 @@ import io.github.wulkanowy.ui.modules.schoolandteachers.SchoolAndTeachersFragmen
 import kotlinx.android.synthetic.main.fragment_teacher.*
 import javax.inject.Inject
 
-class TeacherFragment : BaseFragment(), TeacherView, MainView.TitledView, SchoolAndTeachersChildView {
+class TeacherFragment : BaseFragment(), TeacherView, MainView.TitledView,
+    SchoolAndTeachersChildView {
 
     @Inject
     lateinit var presenter: TeacherPresenter
@@ -55,6 +58,8 @@ class TeacherFragment : BaseFragment(), TeacherView, MainView.TitledView, School
             )
         }
         teacherSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+        teacherErrorRetry.setOnClickListener { presenter.onRetry() }
+        teacherErrorDetails.setOnClickListener { presenter.onDetailsClick() }
     }
 
     override fun updateData(data: List<TeacherItem>) {
@@ -70,11 +75,19 @@ class TeacherFragment : BaseFragment(), TeacherView, MainView.TitledView, School
     }
 
     override fun showEmpty(show: Boolean) {
-        teacherEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        teacherEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        teacherError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        teacherErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        teacherProgress.visibility = if (show) View.VISIBLE else View.GONE
+        teacherProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -82,7 +95,7 @@ class TeacherFragment : BaseFragment(), TeacherView, MainView.TitledView, School
     }
 
     override fun showContent(show: Boolean) {
-        teacherRecycler.visibility = if (show) View.VISIBLE else View.GONE
+        teacherRecycler.visibility = if (show) VISIBLE else GONE
     }
 
     override fun hideRefresh() {

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/teacher/TeacherPresenter.kt

@@ -19,10 +19,13 @@ class TeacherPresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<TeacherView>(errorHandler, studentRepository, schedulers) {
 
+    private lateinit var lastError: Throwable
+
     override fun onAttachView(view: TeacherView) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Teacher view was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData()
     }
 
@@ -30,6 +33,18 @@ class TeacherPresenter @Inject constructor(
         loadData(true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onParentViewLoadData(forceRefresh: Boolean) {
         loadData(forceRefresh)
     }
@@ -56,12 +71,23 @@ class TeacherPresenter @Inject constructor(
                     updateData(it)
                     showContent(it.isNotEmpty())
                     showEmpty(it.isEmpty())
+                    showErrorView(false)
                 }
                 analytics.logEvent("load_teachers", "items" to it.size, "force_refresh" to forceRefresh)
             }) {
                 Timber.i("Loading teachers result: An exception occurred")
-                view?.run { showEmpty(isViewEmpty) }
                 errorHandler.dispatch(it)
             })
     }
+
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/schoolandteachers/teacher/TeacherView.kt

@@ -27,4 +27,8 @@ interface TeacherView : BaseView, SchoolAndTeachersChildView {
     fun showContent(show: Boolean)
 
     fun showEmpty(show: Boolean)
+
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
 }

app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsFragment.kt

@@ -9,6 +9,7 @@ import com.yariksoffice.lingver.Lingver
 import dagger.android.support.AndroidSupportInjection
 import io.github.wulkanowy.R
 import io.github.wulkanowy.ui.base.BaseActivity
+import io.github.wulkanowy.ui.base.ErrorDialog
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.utils.AppInfo
 import javax.inject.Inject
@@ -82,6 +83,10 @@ class SettingsFragment : PreferenceFragmentCompat(),
         (activity as? BaseActivity<*>)?.openClearLoginView()
     }
 
+    override fun showErrorDetailsDialog(error: Throwable) {
+        ErrorDialog.newInstance(error).show(childFragmentManager, error.toString())
+    }
+
     override fun onResume() {
         super.onResume()
         preferenceScreen.sharedPreferences.registerOnSharedPreferenceChangeListener(this)

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableFragment.kt

@@ -6,6 +6,8 @@ import android.view.Menu
 import android.view.MenuInflater
 import android.view.MenuItem
 import android.view.View
+import android.view.View.GONE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import com.wdullaer.materialdatetimepicker.date.DatePickerDialog
 import eu.davidea.flexibleadapter.FlexibleAdapter
@@ -74,8 +76,11 @@ class TimetableFragment : BaseFragment(), TimetableView, MainView.MainChildView,
         }
 
         timetableSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        timetableErrorRetry.setOnClickListener { presenter.onRetry() }
+        timetableErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+
         timetablePreviousButton.setOnClickListener { presenter.onPreviousDay() }
-        timetableNavDate.setOnClickListener {presenter.onPickDate() }
+        timetableNavDate.setOnClickListener { presenter.onPickDate() }
         timetableNextButton.setOnClickListener { presenter.onNextDay() }
 
         timetableNavContainer.setElevationCompat(requireContext().dpToPx(8f))
@@ -119,11 +124,19 @@ class TimetableFragment : BaseFragment(), TimetableView, MainView.MainChildView,
     }
 
     override fun showEmpty(show: Boolean) {
-        timetableEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        timetableEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        timetableError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        timetableErrorMessage.text = message
     }
 
     override fun showProgress(show: Boolean) {
-        timetableProgress.visibility = if (show) View.VISIBLE else View.GONE
+        timetableProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -131,15 +144,15 @@ class TimetableFragment : BaseFragment(), TimetableView, MainView.MainChildView,
     }
 
     override fun showContent(show: Boolean) {
-        timetableRecycler.visibility = if (show) View.VISIBLE else View.GONE
+        timetableRecycler.visibility = if (show) VISIBLE else GONE
     }
 
     override fun showPreButton(show: Boolean) {
-        timetablePreviousButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        timetablePreviousButton.visibility = if (show) VISIBLE else View.INVISIBLE
     }
 
     override fun showNextButton(show: Boolean) {
-        timetableNextButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        timetableNextButton.visibility = if (show) VISIBLE else View.INVISIBLE
     }
 
     override fun showTimetableDialog(lesson: Timetable) {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetablePresenter.kt

@@ -37,10 +37,13 @@ class TimetablePresenter @Inject constructor(
     lateinit var currentDate: LocalDate
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: TimetableView, date: Long?) {
         super.onAttachView(view)
         view.initView()
         Timber.i("Timetable was initialized")
+        errorHandler.showErrorMessage = ::showErrorViewOnError
         loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
         if (currentDate.isHolidays) setBaseDateOnHolidays()
         reloadView()
@@ -70,6 +73,18 @@ class TimetablePresenter @Inject constructor(
         loadData(currentDate, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentDate, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onViewReselected() {
         Timber.i("Timetable view is reselected")
         view?.also { view ->
@@ -135,17 +150,28 @@ class TimetablePresenter @Inject constructor(
                     view?.apply {
                         updateData(it)
                         showEmpty(it.isEmpty())
+                        showErrorView(false)
                         showContent(it.isNotEmpty())
                     }
                     analytics.logEvent("load_timetable", "items" to it.size, "force_refresh" to forceRefresh)
                 }) {
                     Timber.i("Loading timetable result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     errorHandler.dispatch(it)
                 })
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun reloadView() {
         Timber.i("Reload timetable view with the date ${currentDate.toFormattedString()}")
         view?.apply {
@@ -153,6 +179,7 @@ class TimetablePresenter @Inject constructor(
             enableSwipe(false)
             showContent(false)
             showEmpty(false)
+            showErrorView(false)
             clearData()
             reloadNavigation()
         }

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableView.kt

@@ -24,6 +24,10 @@ interface TimetableView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showProgress(show: Boolean)
 
     fun enableSwipe(enable: Boolean)

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsFragment.kt

@@ -3,6 +3,9 @@ package io.github.wulkanowy.ui.modules.timetable.completed
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
+import android.view.View.GONE
+import android.view.View.INVISIBLE
+import android.view.View.VISIBLE
 import android.view.ViewGroup
 import com.wdullaer.materialdatetimepicker.date.DatePickerDialog
 import eu.davidea.flexibleadapter.FlexibleAdapter
@@ -58,6 +61,9 @@ class CompletedLessonsFragment : BaseFragment(), CompletedLessonsView, MainView.
         }
 
         completedLessonsSwipe.setOnRefreshListener(presenter::onSwipeRefresh)
+        completedLessonErrorRetry.setOnClickListener { presenter.onRetry() }
+        completedLessonErrorDetails.setOnClickListener { presenter.onDetailsClick() }
+
         completedLessonsPreviousButton.setOnClickListener { presenter.onPreviousDay() }
         completedLessonsNavDate.setOnClickListener { presenter.onPickDate() }
         completedLessonsNextButton.setOnClickListener { presenter.onNextDay() }
@@ -82,7 +88,15 @@ class CompletedLessonsFragment : BaseFragment(), CompletedLessonsView, MainView.
     }
 
     override fun showEmpty(show: Boolean) {
-        completedLessonsEmpty.visibility = if (show) View.VISIBLE else View.GONE
+        completedLessonsEmpty.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showErrorView(show: Boolean) {
+        completedLessonError.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun setErrorDetails(message: String) {
+        completedLessonErrorMessage.text = message
     }
 
     override fun showFeatureDisabled() {
@@ -91,7 +105,7 @@ class CompletedLessonsFragment : BaseFragment(), CompletedLessonsView, MainView.
     }
 
     override fun showProgress(show: Boolean) {
-        completedLessonsProgress.visibility = if (show) View.VISIBLE else View.GONE
+        completedLessonsProgress.visibility = if (show) VISIBLE else GONE
     }
 
     override fun enableSwipe(enable: Boolean) {
@@ -99,15 +113,15 @@ class CompletedLessonsFragment : BaseFragment(), CompletedLessonsView, MainView.
     }
 
     override fun showContent(show: Boolean) {
-        completedLessonsRecycler.visibility = if (show) View.VISIBLE else View.GONE
+        completedLessonsRecycler.visibility = if (show) VISIBLE else GONE
     }
 
     override fun showPreButton(show: Boolean) {
-        completedLessonsPreviousButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        completedLessonsPreviousButton.visibility = if (show) VISIBLE else INVISIBLE
     }
 
     override fun showNextButton(show: Boolean) {
-        completedLessonsNextButton.visibility = if (show) View.VISIBLE else View.INVISIBLE
+        completedLessonsNextButton.visibility = if (show) VISIBLE else INVISIBLE
     }
 
     override fun showCompletedLessonDialog(completedLesson: CompletedLesson) {

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsPresenter.kt

@@ -1,5 +1,6 @@
 package io.github.wulkanowy.ui.modules.timetable.completed
 
+import android.annotation.SuppressLint
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.data.repositories.completedlessons.CompletedLessonsRepository
 import io.github.wulkanowy.data.repositories.semester.SemesterRepository
@@ -34,17 +35,20 @@ class CompletedLessonsPresenter @Inject constructor(
     lateinit var currentDate: LocalDate
         private set
 
+    private lateinit var lastError: Throwable
+
     fun onAttachView(view: CompletedLessonsView, date: Long?) {
         super.onAttachView(view)
         Timber.i("Completed lessons is attached")
         view.initView()
-        loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
+        completedLessonsErrorHandler.showErrorMessage = ::showErrorViewOnError
-        if (currentDate.isHolidays) setBaseDateOnHolidays()
-        reloadView()
         completedLessonsErrorHandler.onFeatureDisabled = {
             this.view?.showFeatureDisabled()
             Timber.i("Completed lessons feature disabled by school")
         }
+        loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
+        if (currentDate.isHolidays) setBaseDateOnHolidays()
+        reloadView()
     }
 
     fun onPreviousDay() {
@@ -71,6 +75,18 @@ class CompletedLessonsPresenter @Inject constructor(
         loadData(currentDate, true)
     }
 
+    fun onRetry() {
+        view?.run {
+            showErrorView(false)
+            showProgress(true)
+        }
+        loadData(currentDate, true)
+    }
+
+    fun onDetailsClick() {
+        view?.showErrorDetailsDialog(lastError)
+    }
+
     fun onCompletedLessonsItemSelected(item: AbstractFlexibleItem<*>?) {
         if (item is CompletedLessonItem) {
             Timber.i("Select completed lessons item ${item.completedLesson.id}")
@@ -117,17 +133,28 @@ class CompletedLessonsPresenter @Inject constructor(
                     view?.apply {
                         updateData(it)
                         showEmpty(it.isEmpty())
+                        showErrorView(false)
                         showContent(it.isNotEmpty())
                     }
                     analytics.logEvent("load_completed_lessons", "items" to it.size, "force_refresh" to forceRefresh)
                 }) {
                     Timber.i("Loading completed lessons result: An exception occurred")
-                    view?.run { showEmpty(isViewEmpty) }
                     completedLessonsErrorHandler.dispatch(it)
                 })
         }
     }
 
+    private fun showErrorViewOnError(message: String, error: Throwable) {
+        view?.run {
+            if (isViewEmpty) {
+                lastError = error
+                setErrorDetails(message)
+                showErrorView(true)
+                showEmpty(false)
+            } else showError(message, error)
+        }
+    }
+
     private fun reloadView() {
         Timber.i("Reload completed lessons view with the date ${currentDate.toFormattedString()}")
         view?.apply {
@@ -135,11 +162,13 @@ class CompletedLessonsPresenter @Inject constructor(
             enableSwipe(false)
             showContent(false)
             showEmpty(false)
+            showErrorView(false)
             clearData()
             reloadNavigation()
         }
     }
 
+    @SuppressLint("DefaultLocale")
     private fun reloadNavigation() {
         view?.apply {
             showPreButton(!currentDate.minusDays(1).isHolidays)

app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsView.kt

@@ -20,6 +20,10 @@ interface CompletedLessonsView : BaseView {
 
     fun showEmpty(show: Boolean)
 
+    fun showErrorView(show: Boolean)
+
+    fun setErrorDetails(message: String)
+
     fun showFeatureDisabled()
 
     fun showProgress(show: Boolean)

app/src/main/res/drawable/ic_error.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FFF"
+      android:pathData="M11,15h2v2h-2zM11,7h2v6h-2zM11.99,2C6.47,2 2,6.48 2,12s4.47,10 9.99,10C17.52,22 22,17.52 22,12S17.52,2 11.99,2zM12,20c-4.42,0 -8,-3.58 -8,-8s3.58,-8 8,-8 8,3.58 8,8 -3.58,8 -8,8z"/>
+</vector>

app/src/main/res/layout/fragment_attendance.xml

@@ -2,7 +2,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.attendance.AttendanceFragment">
 
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
@@ -25,7 +26,8 @@
             <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/attendanceRecycler"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" />
+                android:layout_height="match_parent"
+                tools:listitem="@layout/item_attendance" />
         </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
         <LinearLayout
@@ -53,6 +55,57 @@
                 android:text="@string/attendance_no_items"
                 android:textSize="20sp" />
         </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/attendanceError"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="invisible"
+            tools:ignore="UseCompoundDrawables"
+            tools:visibility="invisible">
+
+            <ImageView
+                android:layout_width="100dp"
+                android:layout_height="100dp"
+                app:srcCompat="@drawable/ic_error"
+                app:tint="?colorOnBackground"
+                tools:ignore="contentDescription" />
+
+            <TextView
+                android:id="@+id/attendanceErrorMessage"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:gravity="center"
+                android:padding="8dp"
+                android:text="@string/error_unknown"
+                android:textSize="20sp" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:gravity="center"
+                android:orientation="horizontal">
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/attendanceErrorDetails"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:text="@string/all_details" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/attendanceErrorRetry"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/all_retry" />
+            </LinearLayout>
+        </LinearLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <io.github.wulkanowy.ui.widgets.MaterialLinearLayout

app/src/main/res/layout/fragment_attendance_summary.xml

@@ -82,4 +82,55 @@
             android:text="@string/attendance_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/attendanceSummaryError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/attendanceSummaryErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/attendanceSummaryErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/attendanceSummaryErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_exam.xml

@@ -2,7 +2,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.exam.ExamFragment">
 
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
@@ -25,7 +26,8 @@
             <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/examRecycler"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" />
+                android:layout_height="match_parent"
+                tools:listitem="@layout/header_exam" />
         </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
         <LinearLayout
@@ -53,6 +55,57 @@
                 android:text="@string/exam_no_items"
                 android:textSize="20sp" />
         </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/examError"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="invisible"
+            tools:ignore="UseCompoundDrawables"
+            tools:visibility="invisible">
+
+            <ImageView
+                android:layout_width="100dp"
+                android:layout_height="100dp"
+                app:srcCompat="@drawable/ic_error"
+                app:tint="?colorOnBackground"
+                tools:ignore="contentDescription" />
+
+            <TextView
+                android:id="@+id/examErrorMessage"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:gravity="center"
+                android:padding="8dp"
+                android:text="@string/error_unknown"
+                android:textSize="20sp" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:gravity="center"
+                android:orientation="horizontal">
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/examErrorDetails"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:text="@string/all_details" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/examErrorRetry"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/all_retry" />
+            </LinearLayout>
+        </LinearLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <io.github.wulkanowy.ui.widgets.MaterialLinearLayout
@@ -60,8 +113,8 @@
         android:layout_width="match_parent"
         android:layout_height="48dp"
         android:layout_gravity="bottom"
-        android:orientation="horizontal"
         android:gravity="center"
+        android:orientation="horizontal"
         tools:ignore="UnusedAttribute">
 
         <ImageButton
@@ -70,14 +123,14 @@
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:background="?attr/selectableItemBackgroundBorderless"
+            android:contentDescription="@string/all_prev"
             android:paddingLeft="12dp"
             android:paddingTop="8dp"
             android:paddingRight="12dp"
             android:paddingBottom="8dp"
             android:scaleType="fitStart"
             android:tint="?colorPrimary"
-            app:srcCompat="@drawable/ic_chevron_left"
+            app:srcCompat="@drawable/ic_chevron_left" />
-            android:contentDescription="@string/all_prev"/>
 
         <TextView
             android:id="@+id/examNavDate"
@@ -94,13 +147,13 @@
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:background="?attr/selectableItemBackgroundBorderless"
+            android:contentDescription="@string/all_next"
             android:paddingLeft="12dp"
             android:paddingTop="8dp"
             android:paddingRight="12dp"
             android:paddingBottom="8dp"
             android:scaleType="fitEnd"
             android:tint="?colorPrimary"
-            app:srcCompat="@drawable/ic_chevron_right"
+            app:srcCompat="@drawable/ic_chevron_right" />
-            android:contentDescription="@string/all_next" />
     </io.github.wulkanowy.ui.widgets.MaterialLinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_grade.xml

@@ -17,19 +17,13 @@
         tools:ignore="UnusedAttribute"
         tools:visibility="visible" />
 
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    <androidx.viewpager.widget.ViewPager
-        android:id="@+id/gradeSwipe"
+        android:id="@+id/gradeViewPager"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:layout_marginTop="48dp">
+        android:layout_marginTop="48dp"
-
+        android:visibility="invisible"
-        <androidx.viewpager.widget.ViewPager
+        tools:visibility="visible" />
-            android:id="@+id/gradeViewPager"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:visibility="invisible"
-            tools:visibility="visible" />
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
     <me.zhanghai.android.materialprogressbar.MaterialProgressBar
         android:id="@+id/gradeProgress"
@@ -41,7 +35,7 @@
         tools:visibility="invisible" />
 
     <LinearLayout
-        android:id="@+id/gradeEmpty"
+        android:id="@+id/gradeError"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:gravity="center"
@@ -53,16 +47,41 @@
         <ImageView
             android:layout_width="100dp"
             android:layout_height="100dp"
-            app:srcCompat="@drawable/ic_main_grade"
+            app:srcCompat="@drawable/ic_error"
             app:tint="?colorOnBackground"
             tools:ignore="contentDescription" />
 
         <TextView
+            android:id="@+id/gradeErrorMessage"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="20dp"
             android:gravity="center"
-            android:text="@string/grade_no_items"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
             android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
     </LinearLayout>
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

app/src/main/res/layout/fragment_grade_details.xml

@@ -13,7 +13,8 @@
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/gradeDetailsRecycler"
             android:layout_width="match_parent"
-            android:layout_height="match_parent" />
+            android:layout_height="match_parent"
+            tools:listitem="@layout/item_grade_details" />
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
     <me.zhanghai.android.materialprogressbar.MaterialProgressBar
@@ -49,4 +50,55 @@
             android:text="@string/grade_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/gradeDetailsError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/gradeDetailsErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeDetailsErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeDetailsErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_grade_statistics.xml

@@ -138,6 +138,58 @@
                             android:text="@string/grade_no_items"
                             android:textSize="20sp" />
                     </LinearLayout>
+
+
+                    <LinearLayout
+                        android:id="@+id/gradeStatisticsError"
+                        android:layout_width="match_parent"
+                        android:layout_height="match_parent"
+                        android:gravity="center"
+                        android:orientation="vertical"
+                        android:visibility="invisible"
+                        tools:ignore="UseCompoundDrawables"
+                        tools:visibility="invisible">
+
+                        <ImageView
+                            android:layout_width="100dp"
+                            android:layout_height="100dp"
+                            app:srcCompat="@drawable/ic_error"
+                            app:tint="?colorOnBackground"
+                            tools:ignore="contentDescription" />
+
+                        <TextView
+                            android:id="@+id/gradeStatisticsErrorMessage"
+                            android:layout_width="wrap_content"
+                            android:layout_height="wrap_content"
+                            android:layout_marginTop="20dp"
+                            android:gravity="center"
+                            android:padding="8dp"
+                            android:text="@string/error_unknown"
+                            android:textSize="20sp" />
+
+                        <LinearLayout
+                            android:layout_width="match_parent"
+                            android:layout_height="wrap_content"
+                            android:layout_marginTop="16dp"
+                            android:gravity="center"
+                            android:orientation="horizontal">
+
+                            <com.google.android.material.button.MaterialButton
+                                android:id="@+id/gradeStatisticsErrorDetails"
+                                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                                android:layout_width="wrap_content"
+                                android:layout_height="wrap_content"
+                                android:layout_marginEnd="8dp"
+                                android:layout_marginRight="8dp"
+                                android:text="@string/all_details" />
+
+                            <com.google.android.material.button.MaterialButton
+                                android:id="@+id/gradeStatisticsErrorRetry"
+                                android:layout_width="wrap_content"
+                                android:layout_height="wrap_content"
+                                android:text="@string/all_retry" />
+                        </LinearLayout>
+                    </LinearLayout>
                 </FrameLayout>
             </LinearLayout>
         </androidx.core.widget.NestedScrollView>

app/src/main/res/layout/fragment_grade_summary.xml

@@ -13,7 +13,8 @@
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/gradeSummaryRecycler"
             android:layout_width="match_parent"
-            android:layout_height="match_parent" />
+            android:layout_height="match_parent"
+            tools:listitem="@layout/item_grade_summary" />
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
     <me.zhanghai.android.materialprogressbar.MaterialProgressBar
@@ -49,4 +50,55 @@
             android:text="@string/grade_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/gradeSummaryError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/gradeSummaryErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeSummaryErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/gradeSummaryErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_homework.xml

@@ -2,7 +2,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.homework.HomeworkFragment">
 
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
@@ -25,7 +26,8 @@
             <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/homeworkRecycler"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" />
+                android:layout_height="match_parent"
+                tools:listitem="@layout/item_homework" />
         </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
         <LinearLayout
@@ -53,6 +55,57 @@
                 android:text="@string/homework_no_items"
                 android:textSize="20sp" />
         </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/homeworkError"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="invisible"
+            tools:ignore="UseCompoundDrawables"
+            tools:visibility="invisible">
+
+            <ImageView
+                android:layout_width="100dp"
+                android:layout_height="100dp"
+                app:srcCompat="@drawable/ic_error"
+                app:tint="?colorOnBackground"
+                tools:ignore="contentDescription" />
+
+            <TextView
+                android:id="@+id/homeworkErrorMessage"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:gravity="center"
+                android:padding="8dp"
+                android:text="@string/error_unknown"
+                android:textSize="20sp" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:gravity="center"
+                android:orientation="horizontal">
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/homeworkErrorDetails"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:text="@string/all_details" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/homeworkErrorRetry"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/all_retry" />
+            </LinearLayout>
+        </LinearLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <io.github.wulkanowy.ui.widgets.MaterialLinearLayout
@@ -60,8 +113,8 @@
         android:layout_width="match_parent"
         android:layout_height="48dp"
         android:layout_gravity="bottom"
-        android:orientation="horizontal"
         android:gravity="center"
+        android:orientation="horizontal"
         tools:ignore="UnusedAttribute">
 
         <ImageButton
@@ -70,14 +123,14 @@
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:background="?attr/selectableItemBackgroundBorderless"
+            android:contentDescription="@string/all_prev"
             android:paddingLeft="12dp"
             android:paddingTop="8dp"
             android:paddingRight="12dp"
             android:paddingBottom="8dp"
             android:scaleType="fitStart"
             android:tint="?colorPrimary"
-            app:srcCompat="@drawable/ic_chevron_left"
+            app:srcCompat="@drawable/ic_chevron_left" />
-            android:contentDescription="@string/all_prev"/>
 
         <TextView
             android:id="@+id/homeworkNavDate"
@@ -94,13 +147,13 @@
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:background="?attr/selectableItemBackgroundBorderless"
+            android:contentDescription="@string/all_next"
             android:paddingLeft="12dp"
             android:paddingTop="8dp"
             android:paddingRight="12dp"
             android:paddingBottom="8dp"
             android:scaleType="fitEnd"
             android:tint="?colorPrimary"
-            app:srcCompat="@drawable/ic_chevron_right"
+            app:srcCompat="@drawable/ic_chevron_right" />
-            android:contentDescription="@string/all_next" />
     </io.github.wulkanowy.ui.widgets.MaterialLinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_lucky_number.xml

@@ -67,4 +67,55 @@
             android:text="@string/lucky_number_empty"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/luckyNumberError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/luckyNumberErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/luckyNumberErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/luckyNumberErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

app/src/main/res/layout/fragment_message_preview.xml

@@ -54,30 +54,56 @@
         </LinearLayout>
     </androidx.core.widget.NestedScrollView>
 
+
     <LinearLayout
         android:id="@+id/messagePreviewError"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:gravity="center"
         android:orientation="vertical"
-        android:padding="10dp"
         android:visibility="invisible"
-        tools:ignore="UseCompoundDrawables">
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
 
         <ImageView
             android:layout_width="100dp"
             android:layout_height="100dp"
-            app:srcCompat="@drawable/ic_more_messages"
+            app:srcCompat="@drawable/ic_error"
             app:tint="?colorOnBackground"
             tools:ignore="contentDescription" />
 
         <TextView
+            android:id="@+id/messagePreviewErrorMessage"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="20dp"
             android:gravity="center"
-            android:text="@string/message_preview_error"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
             android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/messagePreviewErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/messagePreviewErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
     </LinearLayout>
 
     <me.zhanghai.android.materialprogressbar.MaterialProgressBar

app/src/main/res/layout/fragment_message_tab.xml

@@ -12,7 +12,8 @@
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/messageTabRecycler"
             android:layout_width="match_parent"
-            android:layout_height="match_parent" />
+            android:layout_height="match_parent"
+            tools:listitem="@layout/item_message" />
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
     <me.zhanghai.android.materialprogressbar.MaterialProgressBar
@@ -47,4 +48,55 @@
             android:text="@string/message_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/messageTabError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/messageTabErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/messageTabErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/messageTabErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_mobile_device.xml

@@ -14,6 +14,18 @@
         android:indeterminate="true"
         tools:visibility="invisible" />
 
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/mobileDevicesSwipe"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/mobileDevicesRecycler"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            tools:listitem="@layout/item_mobile_device" />
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
     <LinearLayout
         android:id="@+id/mobileDevicesEmpty"
         android:layout_width="match_parent"
@@ -42,17 +54,56 @@
             tools:ignore="contentDescription" />
     </LinearLayout>
 
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    <LinearLayout
-        android:id="@+id/mobileDevicesSwipe"
+        android:id="@+id/mobileDevicesError"
         android:layout_width="match_parent"
-        android:layout_height="match_parent">
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
 
-        <androidx.recyclerview.widget.RecyclerView
+        <ImageView
-            android:id="@+id/mobileDevicesRecycler"
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/mobileDevicesErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
             android:layout_width="match_parent"
-            android:layout_height="match_parent"
+            android:layout_height="wrap_content"
-            tools:listitem="@layout/item_mobile_device" />
+            android:layout_marginTop="16dp"
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/mobileDevicesErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/mobileDevicesErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/mobileDeviceAddButton"

app/src/main/res/layout/fragment_note.xml

@@ -48,4 +48,55 @@
             android:text="@string/note_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/noteError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/noteErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/noteErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/noteErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_school.xml

@@ -232,4 +232,55 @@
             android:text="@string/school_no_info"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/schoolError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/schoolErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/schoolErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/schoolErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_teacher.xml

@@ -49,4 +49,55 @@
             android:text="@string/teacher_no_items"
             android:textSize="20sp" />
     </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/teacherError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible"
+        tools:ignore="UseCompoundDrawables"
+        tools:visibility="invisible">
+
+        <ImageView
+            android:layout_width="100dp"
+            android:layout_height="100dp"
+            app:srcCompat="@drawable/ic_error"
+            app:tint="?colorOnBackground"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:id="@+id/teacherErrorMessage"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:padding="8dp"
+            android:text="@string/error_unknown"
+            android:textSize="20sp" />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:gravity="center"
+            android:orientation="horizontal">
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/teacherErrorDetails"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="8dp"
+                android:layout_marginRight="8dp"
+                android:text="@string/all_details" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/teacherErrorRetry"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/all_retry" />
+        </LinearLayout>
+    </LinearLayout>
 </FrameLayout>

app/src/main/res/layout/fragment_timetable.xml

@@ -2,7 +2,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.timetable.TimetableFragment">
 
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
@@ -25,7 +26,8 @@
             <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/timetableRecycler"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" />
+                android:layout_height="match_parent"
+                tools:listitem="@layout/item_timetable" />
         </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
         <LinearLayout
@@ -53,6 +55,57 @@
                 android:text="@string/timetable_no_items"
                 android:textSize="20sp" />
         </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/timetableError"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="invisible"
+            tools:ignore="UseCompoundDrawables"
+            tools:visibility="invisible">
+
+            <ImageView
+                android:layout_width="100dp"
+                android:layout_height="100dp"
+                app:srcCompat="@drawable/ic_error"
+                app:tint="?colorOnBackground"
+                tools:ignore="contentDescription" />
+
+            <TextView
+                android:id="@+id/timetableErrorMessage"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:gravity="center"
+                android:padding="8dp"
+                android:text="@string/error_unknown"
+                android:textSize="20sp" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:gravity="center"
+                android:orientation="horizontal">
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/timetableErrorDetails"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:text="@string/all_details" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/timetableErrorRetry"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/all_retry" />
+            </LinearLayout>
+        </LinearLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <io.github.wulkanowy.ui.widgets.MaterialLinearLayout

app/src/main/res/layout/fragment_timetable_completed.xml

@@ -57,6 +57,57 @@
                 android:text="@string/completed_lessons_no_items"
                 android:textSize="20sp" />
         </LinearLayout>
+
+        <LinearLayout
+            android:id="@+id/completedLessonError"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="invisible"
+            tools:ignore="UseCompoundDrawables"
+            tools:visibility="invisible">
+
+            <ImageView
+                android:layout_width="100dp"
+                android:layout_height="100dp"
+                app:srcCompat="@drawable/ic_error"
+                app:tint="?colorOnBackground"
+                tools:ignore="contentDescription" />
+
+            <TextView
+                android:id="@+id/completedLessonErrorMessage"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="20dp"
+                android:gravity="center"
+                android:padding="8dp"
+                android:text="@string/error_unknown"
+                android:textSize="20sp" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:gravity="center"
+                android:orientation="horizontal">
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/completedLessonErrorDetails"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:text="@string/all_details" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/completedLessonErrorRetry"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/all_retry" />
+            </LinearLayout>
+        </LinearLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <io.github.wulkanowy.ui.widgets.MaterialLinearLayout

app/src/main/res/layout/item_homework.xml

@@ -32,7 +32,7 @@
         android:layout_toRightOf="@id/homeworkItemSubject"
         android:gravity="end"
         android:textSize="13sp"
-        tools:text="@tools:sample/lorem" />
+        tools:text="@tools:sample/full_names" />
 
     <TextView
         android:id="@+id/homeworkItemContent"
@@ -46,5 +46,5 @@
         android:layout_marginBottom="15dp"
         android:lineSpacingMultiplier="1.2"
         android:textSize="14sp"
-        tools:text="@tools:sample/lorem/random" />
+        tools:text="@tools:sample/lorem" />
 </RelativeLayout>

app/src/main/res/values-pl/strings.xml

@@ -270,6 +270,7 @@
 
     <!--Generic-->
     <string name="all_content">Treść</string>
+    <string name="all_retry">Ponów</string>
     <string name="all_description">Opis</string>
     <string name="all_no_description">Brak opisu</string>
     <string name="all_teacher">Nauczyciel</string>

app/src/main/res/values/strings.xml

@@ -256,6 +256,7 @@
 
     <!--Generic-->
     <string name="all_content">Content</string>
+    <string name="all_retry">Retry</string>
     <string name="all_description">Description</string>
     <string name="all_no_description">No description</string>
     <string name="all_teacher">Teacher</string>