Bug 965361 - Show firefox watermark when you hide all panels in about:home (r=lucasr)

mobile/android/base/home/HomePager.java

@@ -14,6 +14,7 @@ import org.mozilla.gecko.home.HomeConfig.PanelType;
 import org.mozilla.gecko.util.HardwareUtils;
 
 import android.content.Context;
+import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
@@ -51,6 +52,9 @@ public class HomePager extends ViewPager {
     // Whether or not we need to restart the loader when we show the HomePager.
     private boolean mRestartLoader;
 
+    // Cached original ViewPager background.
+    private final Drawable mOriginalBackground;
+
     // This is mostly used by UI tests to easily fetch
     // specific list views at runtime.
     static final String LIST_TAG_HISTORY = "history";
@@ -122,6 +126,8 @@ public class HomePager extends ViewPager {
         //  ensure there is always a focusable view. This would ordinarily be done via an XML
         //  attribute, but it is not working properly.
         setFocusableInTouchMode(true);
+
+        mOriginalBackground = getBackground();
     }
 
     @Override
@@ -310,9 +316,18 @@ public class HomePager extends ViewPager {
         // Update the adapter with the new panel configs
         adapter.update(enabledPanels);
 
-        // Hide the tab strip if the new configuration contains no panels.
         final int count = enabledPanels.size();
-        mTabStrip.setVisibility(count > 0 ? View.VISIBLE : View.INVISIBLE);
+        if (count == 0) {
+            // Set firefox watermark as background.
+            setBackgroundResource(R.drawable.home_pager_empty_state);
+            // Hide the tab strip as there are no panels.
+            mTabStrip.setVisibility(View.INVISIBLE);
+        } else {
+            mTabStrip.setVisibility(View.VISIBLE);
+            // Restore original background.
+            setBackground(mOriginalBackground);
+        }
+
         // Re-install the adapter with the final state
         // in the pager.
         setAdapter(adapter);

mobile/android/base/resources/drawable/home_pager_empty_state.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android"
+            xmlns:gecko="http://schemas.android.com/apk/res-auto">
+
+    <item android:maxLevel="0" android:drawable="@android:color/white"/>
+
+    <item>
+      <bitmap android:src="@drawable/icon_home_empty_firefox"
+              android:gravity="center"/>
+    </item>
+
+</layer-list>