add grey avatar with first letter of email-guest

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/adapters/items/ParticipantItem.kt

@@ -24,7 +24,7 @@ import com.nextcloud.talk.databinding.RvItemConversationInfoParticipantBinding
 import com.nextcloud.talk.extensions.loadDefaultAvatar
 import com.nextcloud.talk.extensions.loadDefaultGroupCallAvatar
 import com.nextcloud.talk.extensions.loadFederatedUserAvatar
-import com.nextcloud.talk.extensions.loadGuestAvatar
+import com.nextcloud.talk.extensions.loadFirstLetterAvatar
 import com.nextcloud.talk.extensions.loadUserAvatar
 import com.nextcloud.talk.models.domain.ConversationModel
 import com.nextcloud.talk.models.json.participants.Participant
@@ -214,7 +214,9 @@ class ParticipantItem(
                 if (model.displayName.isNullOrEmpty()) {
                     holder.binding.avatarView.loadDefaultAvatar(viewThemeUtils)
                 } else {
-                    holder.binding.avatarView.loadGuestAvatar(user, model.displayName!!, false)
+                    holder.binding.avatarView.loadFirstLetterAvatar(
+                        model.displayName!!.first().toString()
+                    )
                 }
             }
 

app/src/main/java/com/nextcloud/talk/extensions/ImageViewExtensions.kt

@@ -10,12 +10,19 @@
 
 package com.nextcloud.talk.extensions
 
+import android.content.Context
+import android.graphics.Bitmap
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.Paint
+import android.graphics.drawable.BitmapDrawable
 import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.Drawable
 import android.graphics.drawable.LayerDrawable
 import android.util.Log
 import android.widget.ImageView
 import androidx.core.content.ContextCompat
+import androidx.core.content.res.ResourcesCompat
 import coil.annotation.ExperimentalCoilApi
 import coil.imageLoader
 import coil.load
@@ -35,6 +42,7 @@ import com.nextcloud.talk.ui.theme.ViewThemeUtils
 import com.nextcloud.talk.utils.ApiUtils
 import com.nextcloud.talk.utils.DisplayUtils
 import com.nextcloud.talk.utils.TextDrawable
+import java.util.Locale
 
 private const val ROUNDING_PIXEL = 16f
 private const val TAG = "ImageViewExtensions"
@@ -297,6 +305,21 @@ fun ImageView.loadNoteToSelfAvatar(): io.reactivex.disposables.Disposable {
     )
 }
 
+fun ImageView.loadFirstLetterAvatar(letter: String): io.reactivex.disposables.Disposable {
+    val layers = arrayOfNulls<Drawable>(2)
+    layers[0] = ContextCompat.getDrawable(context, R.drawable.ic_launcher_background)
+    layers[1] = createTextDrawable(context, letter.uppercase(Locale.ROOT))
+
+    val layerDrawable = LayerDrawable(layers)
+    val data: Any = layerDrawable
+
+    return DisposableWrapper(
+        load(data) {
+            transformations(CircleCropTransformation())
+        }
+    )
+}
+
 fun ImageView.loadChangelogBotAvatar(): io.reactivex.disposables.Disposable {
     return loadSystemAvatar()
 }
@@ -355,6 +378,32 @@ fun ImageView.loadGuestAvatar(baseUrl: String, name: String, big: Boolean): io.r
     )
 }
 
+@Suppress("MagicNumber")
+private fun createTextDrawable(context: Context, letter: String): Drawable {
+    val size = 100
+    val bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888)
+    val canvas = Canvas(bitmap)
+
+    val paint = Paint().apply {
+        color = ResourcesCompat.getColor(context.resources, R.color.grey_600, null)
+        style = Paint.Style.FILL
+    }
+    canvas.drawRect(0f, 0f, size.toFloat(), size.toFloat(), paint)
+
+    val textPaint = Paint().apply {
+        color = Color.WHITE
+        textSize = size / 2f
+        isAntiAlias = true
+        textAlign = Paint.Align.CENTER
+    }
+
+    val xPos = size / 2f
+    val yPos = (canvas.height / 2 - (textPaint.descent() + textPaint.ascent()) / 2)
+    canvas.drawText(letter.take(1), xPos, yPos, textPaint)
+
+    return BitmapDrawable(context.resources, bitmap)
+}
+
 private class DisposableWrapper(private val disposable: coil.request.Disposable) : io.reactivex.disposables
     .Disposable {