Bug 568927 - Hide task on window minimize on Android, r=mwu,alexp

embedding/android/AndroidManifest.xml.in

@@ -17,7 +17,8 @@
         <activity android:name="App"
                   android:label="@MOZ_APP_DISPLAYNAME@"
                   android:configChanges="keyboard|keyboardHidden|orientation|mcc|mnc"
-                  android:windowSoftInputMode="stateUnspecified|adjustResize">
+                  android:windowSoftInputMode="stateUnspecified|adjustResize"
+                  android:launchMode="singleInstance">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />

embedding/android/GeckoAppShell.java

@@ -214,6 +214,10 @@ class GeckoAppShell
         }
     }
 
+    public static void moveTaskToBack() {
+        GeckoApp.mAppContext.moveTaskToBack(true);
+    }
+
     public static void returnIMEQueryResult(String result, int selectionStart, int selectionEnd) {
         GeckoApp.surfaceView.inputConnection.mSelectionStart = selectionStart;
         GeckoApp.surfaceView.inputConnection.mSelectionEnd = selectionEnd;

widget/src/android/AndroidBridge.cpp

@@ -100,6 +100,7 @@ AndroidBridge::Init(JNIEnv *jEnv,
     jGetHandlersForMimeType = (jmethodID) jEnv->GetStaticMethodID(jGeckoAppShellClass, "getHandlersForMimeType", "(Ljava/lang/String;)[Ljava/lang/String;");
     jOpenUriExternal = (jmethodID) jEnv->GetStaticMethodID(jGeckoAppShellClass, "openUriExternal", "(Ljava/lang/String;Ljava/lang/String;)Z");
     jGetMimeTypeFromExtension = (jmethodID) jEnv->GetStaticMethodID(jGeckoAppShellClass, "getMimeTypeFromExtension", "(Ljava/lang/String;)Ljava/lang/String;");
+    jMoveTaskToBack = (jmethodID) jEnv->GetStaticMethodID(jGeckoAppShellClass, "moveTaskToBack", "()V");
     InitAndroidJavaWrappers(jEnv);
 
     // jEnv should NOT be cached here by anything -- the jEnv here
@@ -260,6 +261,12 @@ AndroidBridge::GetMimeTypeFromExtension(const nsCString& aFileExt, nsCString& aM
     aMimeType.Assign(NS_ConvertUTF16toUTF8(jniStr.get()));
 }
 
+void
+AndroidBridge::MoveTaskToBack()
+{
+    mJNIEnv->CallStaticVoidMethod(mGeckoAppShellClass, jMoveTaskToBack);
+}
+
 void
 AndroidBridge::SetSurfaceView(jobject obj)
 {

widget/src/android/AndroidBridge.h

@@ -110,6 +110,8 @@ public:
 
     void GetMimeTypeFromExtension(const nsCString& aFileExt, nsCString& aMimeType);
 
+    void MoveTaskToBack();
+
     struct AutoLocalJNIFrame {
         AutoLocalJNIFrame(int nEntries = 128) : mEntries(nEntries) {
             AndroidBridge::Bridge()->JNI()->PushLocalFrame(mEntries);
@@ -159,6 +161,7 @@ protected:
     jmethodID jGetHandlersForMimeType;
     jmethodID jOpenUriExternal;
     jmethodID jGetMimeTypeFromExtension;
+    jmethodID jMoveTaskToBack;
 };
 
 }

widget/src/android/nsWindow.cpp

@@ -411,6 +411,11 @@ nsWindow::PlaceBehind(nsTopLevelWidgetZPlacement aPlacement,
 NS_IMETHODIMP
 nsWindow::SetSizeMode(PRInt32 aMode)
 {
+    switch (aMode) {
+        case nsSizeMode_Minimized:
+            AndroidBridge::Bridge()->MoveTaskToBack();
+            break;
+    }
     return NS_OK;
 }