[UI/Messages] Improve HTML lists presentation.

app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/messages/MessagesUtils.kt

@@ -1,17 +1,21 @@
 package pl.szczodrzynski.edziennik.ui.modules.messages
 
 import android.content.Context
-import android.graphics.*
+import android.graphics.Bitmap
-import android.os.Build
+import android.graphics.Canvas
-import android.text.Html
+import android.graphics.Paint
+import android.graphics.RectF
 import android.text.Spanned
 import androidx.core.graphics.ColorUtils
-import pl.szczodrzynski.edziennik.*
+import pl.szczodrzynski.edziennik.App
+import pl.szczodrzynski.edziennik.R
 import pl.szczodrzynski.edziennik.data.db.entity.Message
 import pl.szczodrzynski.edziennik.data.db.full.MessageFull
+import pl.szczodrzynski.edziennik.fixName
+import pl.szczodrzynski.edziennik.getNameInitials
 import pl.szczodrzynski.edziennik.utils.Colors
 import pl.szczodrzynski.edziennik.utils.Utils
-import pl.szczodrzynski.navlib.blendColors
+import pl.szczodrzynski.edziennik.utils.html.BetterHtml
 import kotlin.math.roundToInt
 
 object MessagesUtils {
@@ -179,39 +183,6 @@ object MessagesUtils {
 
     @JvmStatic
     fun htmlToSpannable(context: Context, html: String): Spanned {
-        val hexPattern = "(#[a-fA-F0-9]{6})"
+        return BetterHtml.fromHtml(context, html)
-        val colorRegex = "(?:color=\"$hexPattern\")|(?:style=\"color: ?${hexPattern})"
-                .toRegex(RegexOption.IGNORE_CASE)
-
-        var text = html
-                .replace("\\[META:[A-z0-9]+;[0-9-]+]".toRegex(), "")
-                .replace("background-color: ?$hexPattern;".toRegex(), "")
-
-        val colorBackground = android.R.attr.colorBackground.resolveAttr(context)
-        val textColorPrimary = android.R.attr.textColorPrimary.resolveAttr(context) and 0xffffff
-
-        colorRegex.findAll(text).forEach { result ->
-            val group = result.groups.drop(1).firstOrNull { it != null } ?: return@forEach
-
-            val color = Color.parseColor(group.value)
-            var newColor = 0xff000000.toInt() or color
-
-            var blendAmount = 1
-            var numIterations = 0
-
-            while (numIterations < 100 && ColorUtils.calculateContrast(colorBackground, newColor) < 4.5f) {
-                blendAmount += 2
-                newColor = blendColors(color, blendAmount shl 24 or textColorPrimary)
-                numIterations++
-            }
-
-            text = text.replaceRange(group.range, "#" + (newColor and 0xffffff).toString(16))
-        }
-
-        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            Html.fromHtml(text, Html.FROM_HTML_MODE_LEGACY)
-        } else {
-            Html.fromHtml(text)
-        }
     }
 }

app/src/main/java/pl/szczodrzynski/edziennik/utils/html/BetterHtml.kt

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-3-17.
+ */
+
+package pl.szczodrzynski.edziennik.utils.html
+
+import android.content.Context
+import android.graphics.Color
+import android.os.Build
+import android.text.Html
+import android.text.SpannableStringBuilder
+import android.text.Spanned
+import android.text.style.BulletSpan
+import androidx.core.graphics.ColorUtils
+import pl.szczodrzynski.edziennik.dp
+import pl.szczodrzynski.edziennik.resolveAttr
+import pl.szczodrzynski.navlib.blendColors
+
+object BetterHtml {
+
+    @JvmStatic
+    fun fromHtml(context: Context, html: String): Spanned {
+        val hexPattern = "(#[a-fA-F0-9]{6})"
+        val colorRegex = "(?:color=\"$hexPattern\")|(?:style=\"color: ?${hexPattern})"
+                .toRegex(RegexOption.IGNORE_CASE)
+
+        var text = html
+                .replace("\\[META:[A-z0-9]+;[0-9-]+]".toRegex(), "")
+                .replace("background-color: ?$hexPattern;".toRegex(), "")
+
+        val colorBackground = android.R.attr.colorBackground.resolveAttr(context)
+        val textColorPrimary = android.R.attr.textColorPrimary.resolveAttr(context) and 0xffffff
+
+        colorRegex.findAll(text).forEach { result ->
+            val group = result.groups.drop(1).firstOrNull { it != null } ?: return@forEach
+
+            val color = Color.parseColor(group.value)
+            var newColor = 0xff000000.toInt() or color
+
+            var blendAmount = 1
+            var numIterations = 0
+
+            while (numIterations < 100 && ColorUtils.calculateContrast(colorBackground, newColor) < 4.5f) {
+                blendAmount += 2
+                newColor = blendColors(color, blendAmount shl 24 or textColorPrimary)
+                numIterations++
+            }
+
+            text = text.replaceRange(group.range, "#" + (newColor and 0xffffff).toString(16))
+        }
+
+        /*val olRegex = """<ol>(.+?)</\s*?ol>"""
+                .toRegex(setOf(RegexOption.DOT_MATCHES_ALL, RegexOption.IGNORE_CASE))
+        olRegex.findAll(text).forEach {
+            text.replaceRange(
+                    it.range,
+                    text.slice(it.range).replace("li>", "_li>")
+            )
+        }*/
+
+        @Suppress("DEPRECATION")
+        val htmlSpannable = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            Html.fromHtml(
+                    text,
+                    Html.FROM_HTML_SEPARATOR_LINE_BREAK_LIST_ITEM or Html.FROM_HTML_SEPARATOR_LINE_BREAK_LIST or Html.FROM_HTML_SEPARATOR_LINE_BREAK_DIV,
+                    null,
+                    LiTagHandler()
+            )
+        } else {
+            Html.fromHtml(text, null, LiTagHandler())
+        }
+
+        val spannableBuilder = SpannableStringBuilder(htmlSpannable)
+        val bulletSpans = spannableBuilder.getSpans(0, spannableBuilder.length, BulletSpan::class.java)
+        bulletSpans.forEach {
+            val start = spannableBuilder.getSpanStart(it)
+            val end = spannableBuilder.getSpanEnd(it)
+            spannableBuilder.removeSpan(it)
+            spannableBuilder.setSpan(
+                    ImprovedBulletSpan(bulletRadius = 3.dp, startWidth = 24.dp, gapWidth = 8.dp),
+                    start,
+                    end,
+                    Spanned.SPAN_INCLUSIVE_EXCLUSIVE
+            )
+        }
+
+        return spannableBuilder
+    }
+}

app/src/main/java/pl/szczodrzynski/edziennik/utils/html/ImprovedBulletSpan.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-3-17.
+ */
+
+/**
+ * https://github.com/davidbilik/bullet-span-sample/blob/master/app/src/main/java/cz/davidbilik/bulletsample/ImprovedBulletSpan.kt
+ */
+
+package pl.szczodrzynski.edziennik.utils.html
+
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.Path
+import android.graphics.Path.Direction
+import android.text.Layout
+import android.text.Spanned
+import android.text.style.LeadingMarginSpan
+
+/**
+ * Copy of [android.text.style.BulletSpan] from android SDK 28 with removed internal code
+ */
+class ImprovedBulletSpan(
+        val bulletRadius: Int = STANDARD_BULLET_RADIUS,
+        val startWidth: Int = STANDARD_GAP_WIDTH,
+        val gapWidth: Int = STANDARD_GAP_WIDTH,
+        val color: Int = STANDARD_COLOR
+) : LeadingMarginSpan {
+
+    companion object {
+        // Bullet is slightly bigger to avoid aliasing artifacts on mdpi devices.
+        private const val STANDARD_BULLET_RADIUS = 4
+        private const val STANDARD_GAP_WIDTH = 2
+        private const val STANDARD_COLOR = 0
+    }
+
+    private var mBulletPath: Path? = null
+
+    override fun getLeadingMargin(first: Boolean): Int {
+        return startWidth + 2 * bulletRadius + gapWidth
+    }
+
+    override fun drawLeadingMargin(
+            canvas: Canvas, paint: Paint, x: Int, dir: Int,
+            top: Int, baseline: Int, bottom: Int,
+            text: CharSequence, start: Int, end: Int,
+            first: Boolean,
+            layout: Layout?
+    ) {
+        if ((text as Spanned).getSpanStart(this) == start) {
+            val style = paint.style
+            paint.style = Paint.Style.FILL
+
+            val yPosition = if (layout != null) {
+                val line = layout.getLineForOffset(start)
+                layout.getLineBaseline(line).toFloat() - bulletRadius * 2f
+            } else {
+                (top + bottom) / 2f
+            }
+
+            val xPosition = startWidth + (x + dir * bulletRadius).toFloat()
+
+            if (canvas.isHardwareAccelerated) {
+                if (mBulletPath == null) {
+                    mBulletPath = Path()
+                    mBulletPath!!.addCircle(0.0f, 0.0f, bulletRadius.toFloat(), Direction.CW)
+                }
+
+                canvas.save()
+                canvas.translate(xPosition, yPosition)
+                canvas.drawPath(mBulletPath!!, paint)
+                canvas.restore()
+            } else {
+                canvas.drawCircle(xPosition, yPosition, bulletRadius.toFloat(), paint)
+            }
+
+            paint.style = style
+        }
+    }
+}

app/src/main/java/pl/szczodrzynski/edziennik/utils/html/LiTagHandler.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-3-17.
+ */
+
+/**
+ * https://github.com/davidbilik/bullet-span-sample/blob/master/app/src/main/java/cz/davidbilik/bulletsample/LiTagHandler.kt
+ */
+
+package pl.szczodrzynski.edziennik.utils.html
+
+import android.text.Editable
+import android.text.Html
+import android.text.Spannable
+import android.text.Spanned
+import android.text.style.BulletSpan
+import org.xml.sax.XMLReader
+
+/**
+ * [Html.TagHandler] implementation that processes <ul> and <li> tags and creates bullets.
+ *
+ * Note: This class is only applied on SDK < 25 and processes only one-level list, nested lists do not work.
+ */
+class LiTagHandler : Html.TagHandler {
+    /**
+     * Helper marker class. Idea stolen from [Html.fromHtml] implementation
+     */
+    class Bullet
+
+    override fun handleTag(opening: Boolean, tag: String, output: Editable, xmlReader: XMLReader) {
+        if (tag == "li" && opening) {
+            output.setSpan(Bullet(), output.length, output.length, Spannable.SPAN_INCLUSIVE_EXCLUSIVE)
+        }
+        if (tag == "li" && !opening) {
+            output.append("\n")
+            val lastMark = output.getSpans(0, output.length, Bullet::class.java).lastOrNull()
+            lastMark?.let {
+                val start = output.getSpanStart(it)
+                output.removeSpan(it)
+                if (start != output.length) {
+                    output.setSpan(BulletSpan(), start, output.length, Spanned.SPAN_INCLUSIVE_EXCLUSIVE)
+                }
+            }
+        }
+    }
+}