SysUI: Add no-wallpaper recents theme for low GFX devices

Also add a config flag to control the theme to apply to RecentsActivity.

Bug: 17522143
Change-Id: I8d03e84e37b77698243673f6c4e676b2c53e0d07

3 files changed, 19 insertions, 6 deletions

diff --git a/packages/SystemUI/AndroidManifest.xml b/packages/SystemUI/AndroidManifest.xml
index b94a258c8fb9..3c2a776cd537 100644
--- a/packages/SystemUI/AndroidManifest.xml
+++ b/packages/SystemUI/AndroidManifest.xml
@@ -199,7 +199,7 @@
                   android:excludeFromRecents="true"
                   android:stateNotNeeded="true"
                   android:resumeWhilePausing="true"
-                  android:theme="@style/RecentsTheme">
+                  android:theme="@style/config_recents_activity_theme">
             <intent-filter>
                 <action android:name="com.android.systemui.recents.TOGGLE_RECENTS" />
             </intent-filter>
diff --git a/packages/SystemUI/res/values/config.xml b/packages/SystemUI/res/values/config.xml
index 17b38338a310..a22f77c783c7 100644
--- a/packages/SystemUI/res/values/config.xml
+++ b/packages/SystemUI/res/values/config.xml
@@ -35,6 +35,10 @@
     <!-- The number of app icons we keep in memory -->
     <integer name="config_recents_max_icon_count">20</integer>
 
+
+    <!-- The theme to use for RecentsActivity. -->
+    <item type="style" name="config_recents_activity_theme">@style/RecentsTheme.Wallpaper</item>
+
     <!-- Control whether status bar should distinguish HSPA data icon form UMTS
     data icon on devices -->
     <bool name="config_hspa_data_distinguishable">false</bool>
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index 0456c823e70c..46e7587cb14e 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -20,14 +20,9 @@
         <item name="android:windowAnimationStyle">@style/Animation.RecentsActivity</item>
     </style>
 
-    <!-- Alternate Recents theme -->
     <style name="RecentsTheme" parent="@android:style/Theme">
         <!-- NoTitle -->
         <item name="android:windowNoTitle">true</item>
-        <!-- Wallpaper -->
-        <item name="android:windowBackground">@color/transparent</item>
-        <item name="android:colorBackgroundCacheHint">@null</item>
-        <item name="android:windowShowWallpaper">true</item>
         <!-- Misc -->
         <item name="android:statusBarColor">@android:color/transparent</item>
         <item name="android:navigationBarColor">@android:color/transparent</item>
@@ -36,6 +31,20 @@
         <item name="android:ambientShadowAlpha">0.35</item>
     </style>
 
+
+    <!-- Alternate Recents theme -->
+    <style name="RecentsTheme.Wallpaper">
+        <!-- Wallpaper -->
+        <item name="android:windowBackground">@color/transparent</item>
+        <item name="android:colorBackgroundCacheHint">@null</item>
+        <item name="android:windowShowWallpaper">true</item>
+    </style>
+
+    <!-- Performance optimized alternate Recents theme (no wallpaper) -->
+    <style name="RecentsTheme.NoWallpaper">
+        <item name="android:windowBackground">@android:color/black</item>
+    </style>
+
     <!-- Animations for a non-full-screen window or activity. -->
     <style name="Animation.RecentsActivity" parent="@android:style/Animation.Activity">
         <item name="android:activityOpenEnterAnimation">@anim/recents_launch_from_launcher_enter</item>