[Architecture] Add base MVP classes

app/src/main/java/pl/szczodrzynski/edziennik/ui/base/BaseFragment.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) Kacper Ziubryniewicz 2019-11-4
+ */
+
+package pl.szczodrzynski.edziennik.ui.base
+
+import android.widget.Toast
+import androidx.fragment.app.Fragment
+
+abstract class BaseFragment<T : BasePresenter<out BaseView>> : Fragment(), BaseView {
+
+    abstract val presenter: T
+
+    override fun showMessage(text: String) {
+        Toast.makeText(activity, text, Toast.LENGTH_SHORT).show()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        presenter.onDetachView()
+    }
+}

app/src/main/java/pl/szczodrzynski/edziennik/ui/base/BasePresenter.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) Kacper Ziubryniewicz 2019-11-4
+ */
+
+package pl.szczodrzynski.edziennik.ui.base
+
+open class BasePresenter<T : BaseView> {
+
+    var view: T? = null
+
+    open fun onAttachView(view: T) {
+        this.view = view
+    }
+
+    open fun onDetachView() {
+        view = null
+    }
+}

app/src/main/java/pl/szczodrzynski/edziennik/ui/base/BaseView.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) Kacper Ziubryniewicz 2019-11-4
+ */
+
+package pl.szczodrzynski.edziennik.ui.base
+
+interface BaseView {
+
+    fun showMessage(text: String)
+}