Updates the background of the clear all button for low ram devices

When the background changes on device, update the background color of
the clear all button on low ram devices to match.

Test: manual - change wallpaper color to dark/light, open recents
Change-Id: Ie91bc2eeb77307aa63055334a1ff1727026e5094
Fixes: 65261858
diff --git a/packages/SystemUI/res/values/attrs.xml b/packages/SystemUI/res/values/attrs.xml
index 745d6015..a923f0b 100644
--- a/packages/SystemUI/res/values/attrs.xml
+++ b/packages/SystemUI/res/values/attrs.xml
@@ -34,6 +34,7 @@
         <attr name="recentItemLayout" format="reference" />
         <!-- Style for the "Clear all" button. -->
         <attr name="clearAllStyle" format="reference" />
+        <attr name="clearAllBackgroundColor" format="reference" />
     </declare-styleable>
     <declare-styleable name="DeadZone">
         <attr name="minSize" format="dimension" />
diff --git a/packages/SystemUI/res/values/colors.xml b/packages/SystemUI/res/values/colors.xml
index f72f379..f244d88 100644
--- a/packages/SystemUI/res/values/colors.xml
+++ b/packages/SystemUI/res/values/colors.xml
@@ -60,6 +60,11 @@
     <!-- The background color for the freeform workspace. -->
     <color name="recents_freeform_workspace_bg_color">#33FFFFFF</color>
 
+    <!-- The background color for clear all button on light backgrounds if not transparent. -->
+    <color name="recents_clear_all_button_bg_light_color">#CCFFFFFF</color>
+    <!-- The background color for clear all button on dark backgrounds if not transparent. -->
+    <color name="recents_clear_all_button_bg_dark_color">#CC000000</color>
+
     <color name="keyguard_affordance">#ffffffff</color>
 
     <!-- The color of the legacy notification background -->
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index 2199fff..90c5977 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -34,11 +34,13 @@
         <item name="android:windowShowWallpaper">true</item>
         <item name="android:windowDisablePreview">true</item>
         <item name="clearAllStyle">@style/ClearAllButtonDefaultMargins</item>
+        <item name="clearAllBackgroundColor">@color/recents_clear_all_button_bg_dark_color</item>
         <item name="wallpaperTextColor">@*android:color/primary_text_material_dark</item>
         <item name="wallpaperTextColorSecondary">@*android:color/secondary_text_material_dark</item>
     </style>
 
     <style name="RecentsTheme.Wallpaper.Light">
+        <item name="clearAllBackgroundColor">@color/recents_clear_all_button_bg_light_color</item>
         <item name="wallpaperTextColor">@*android:color/primary_text_material_light</item>
         <item name="wallpaperTextColorSecondary">@*android:color/secondary_text_material_light</item>
     </style>
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
index 71f06cb..09e712c 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
@@ -205,6 +205,10 @@
                         mStackButtonShadowDistance.x, mStackButtonShadowDistance.y,
                         mStackButtonShadowColor);
             }
+            if (Recents.getConfiguration().isLowRamDevice) {
+                int bgColor = Utils.getColorAttr(mContext, R.attr.clearAllBackgroundColor);
+                mStackActionButton.setBackgroundColor(bgColor);
+            }
         }
 
         // Let's also require dark status and nav bars if the text is dark