Don't produce ram-expensive Bitmap just for letter

Instead save a very small object with the string in it and draw every
time. Drawing a single letter is not noticibly slower than blitting a
bitmap of the same size. It may even be faster, and certainly saves RAM.

(cherry picked from commit c996da3a0eefc197b8ea887790bdf8d73736b1ed)

src/main/java/eu/siacs/conversations/services/AvatarService.java

@@ -4,7 +4,9 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.ColorFilter;
 import android.graphics.Paint;
+import android.graphics.PixelFormat;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
@@ -545,14 +547,7 @@ public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 	}*/
 
 	public Drawable get(final String name, String seed, final int size, boolean cachedOnly) {
-		final String KEY = key(seed == null ? name : name+"\0"+seed, size);
+		return getImpl(name, seed, size);
-		Drawable bitmap = mXmppConnectionService.getDrawableCache().get(KEY);
-		if (bitmap != null || cachedOnly) {
-			return bitmap;
-		}
-		bitmap = getImpl(name, seed, size);
-		mXmppConnectionService.getDrawableCache().put(KEY, bitmap);
-		return bitmap;
 	}
 
 	public static Drawable get(final Jid jid, final int size) {
@@ -563,8 +558,7 @@ public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 		Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
 		Canvas canvas = new Canvas(bitmap);
 		final String trimmedName = name == null ? "" : name.trim();
-		drawTile(canvas, trimmedName, seed, 0, 0, size, size);
+		return new TextDrawable(name, seed, size);
-		return new BitmapDrawable(bitmap);
 	}
 
 	private String key(String name, int size) {
@@ -693,4 +687,47 @@ public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 		@ColorInt int getAvatarBackgroundColor();
 		String getAvatarName();
 	}
+
+	public static class TextDrawable extends Drawable {
+		protected final String name;
+		protected final String seed;
+		protected final int size;
+
+		public TextDrawable(final String name, final String seed, final int size) {
+			this.name = name;
+			this.seed = seed;
+			this.size = size;
+		}
+
+		@Override
+		public void draw(Canvas canvas) {
+			final var r = getBounds();
+			drawTile(canvas, name, seed, r.left, r.top, r.right, r.bottom);
+		}
+
+		@Override
+		public void setAlpha(int alpha) {
+			// TODO?
+		}
+
+		@Override
+		public void setColorFilter(ColorFilter cf) {
+			// TODO?
+		}
+
+		@Override
+		public int getOpacity() {
+			return PixelFormat.TRANSLUCENT;
+		}
+
+		@Override
+		public int getIntrinsicWidth() {
+			return size;
+		}
+
+		@Override
+		public int getIntrinsicHeight() {
+			return size;
+		}
+	}
 }

src/main/java/eu/siacs/conversations/services/XmppConnectionService.java

@@ -1484,15 +1484,17 @@ public class XmppConnectionService extends Service {
         }
         updateMemorizingTrustManager();
         final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
-        final int cacheSize = maxMemory / 7;
+        final int cacheSize = maxMemory / 8;
         this.mDrawableCache = new LruCache<String, Drawable>(cacheSize) {
             @Override
             protected int sizeOf(final String key, final Drawable drawable) {
                 if (drawable instanceof BitmapDrawable) {
-                    Bitmap bitmap =  ((BitmapDrawable) drawable).getBitmap();
+                    Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
                     if (bitmap == null) return 1024;
 
                     return bitmap.getByteCount() / 1024;
+                } else if (drawable instanceof AvatarService.TextDrawable) {
+                    return 50;
                 } else {
                     return drawable.getIntrinsicWidth() * drawable.getIntrinsicHeight() * 40 / 1024;
                 }