Lots of progress with dynamic theming, the nav drawer now uses a RecyclerView, AboutDeveloperDialogHelper is now a DialogFragment, RTL support (to suppress Lint warnings), other various small fixes, cleaned up and formatted lot of code (and removed un-used resources), R.string.ok > android.R.string.ok, R.string.cancel > android.R.string.cancel, switched dialog helpers to DialogFragments.

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

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (C) 2014 The Android Open Source Project
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,18 +15,18 @@
   -->
 
 <!-- Layout to be used with only max 3 actions. It has a much larger picture at the left side-->
-<RelativeLayout
+<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/status_bar_latest_event_content"
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="128dp">
+    android:layout_height="128dp"
+    tools:ignore="ContentDescription">
 
     <ImageView
         android:id="@+id/album_art"
         android:layout_width="128dp"
         android:layout_height="128dp"
-        android:scaleType="centerCrop"
-        />
+        android:scaleType="centerCrop" />
 
     <ImageButton
         android:id="@+id/button_quit"
@@ -35,21 +34,25 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
+        android:layout_alignParentEnd="true"
         android:layout_alignParentTop="true"
         android:layout_gravity="center"
         android:background="?android:selectableItemBackground"
         android:padding="8dp"
-        android:src="@drawable/ic_close_white_24dp"/>
+        android:src="@drawable/ic_close_white_24dp" />
 
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_toLeftOf="@+id/button_quit"
+        android:layout_toStartOf="@+id/button_quit"
         android:layout_toRightOf="@+id/album_art"
+        android:layout_toEndOf="@+id/album_art"
         android:gravity="center"
         android:minHeight="@dimen/notification_big_icon_height"
         android:orientation="vertical"
         android:paddingLeft="16dp"
+        android:paddingStart="16dp"
         android:paddingTop="12dp">
 
         <TextView
@@ -57,21 +60,22 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:singleLine="true"
-            android:textAppearance="@style/Theme.MaterialMusic.Notification.Title"/>
+            android:textAppearance="@style/Theme.MaterialMusic.Notification.Title" />
 
         <TextView
             android:id="@+id/song_artist"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:singleLine="true"
-            android:textAppearance="@style/Theme.MaterialMusic.Notification"/>
+            android:textAppearance="@style/Theme.MaterialMusic.Notification" />
 
         <TextView
             android:id="@+id/album_title"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:singleLine="true"
-            android:textAppearance="@style/Theme.MaterialMusic.Notification"/>
+            android:textAppearance="@style/Theme.MaterialMusic.Notification" />
+
     </LinearLayout>
 
     <LinearLayout
@@ -82,26 +86,27 @@
         android:layout_marginEnd="12dp"
         android:layout_marginStart="12dp"
         android:layout_toRightOf="@+id/album_art"
+        android:layout_toEndOf="@+id/album_art"
         android:orientation="horizontal">
 
         <ImageButton
             android:id="@+id/button_prev"
             style="@style/NotificationButton"
             android:padding="8dp"
-            android:src="@drawable/ic_skip_previous_white_48dp"/>
+            android:src="@drawable/ic_skip_previous_white_48dp" />
 
         <ImageButton
             android:id="@+id/button_toggle_play_pause"
             style="@style/NotificationButton"
             android:padding="8dp"
-            android:src="@drawable/ic_play_arrow_white_48dp"
-            />
+            android:src="@drawable/ic_play_arrow_white_48dp" />
 
         <ImageButton
             android:id="@+id/button_next"
             style="@style/NotificationButton"
             android:padding="8dp"
-            android:src="@drawable/ic_skip_next_white_48dp"/>
+            android:src="@drawable/ic_skip_next_white_48dp" />
+
     </LinearLayout>
 
     <ImageView
@@ -110,6 +115,7 @@
         android:layout_height="1dp"
         android:layout_above="@+id/media_actions"
         android:layout_toRightOf="@+id/album_art"
-        android:background="@drawable/notification_template_divider_media"/>
+        android:layout_toEndOf="@+id/album_art"
+        android:background="@drawable/notification_template_divider_media" />
 
 </RelativeLayout>