Tomek Tomek - 4 months ago 62
Android Question

Activity has leaked window - Android

Look at these pieces of code:

Custom views and window attributes on Android

Problem

When I click 'Home button',

exception
is thrown:
Activity
has leaked window... from this line:

localWindowManager.addView(colourView, layoutParams);


Question(s)

Do you know what can cause it?

Problem doesn't occur, when I close application with back button.

Exception/Error Logs

W/InputManagerService( 96): Starting input on non-focused client com.android.internal.view.IInputMethodClient$Stub$Proxy@40908148 (uid=10056 pid=1368)
D/CordovaActivity( 1368): CordovaActivity.onDestroy()
D/CordovaWebView( 1368): >>> loadUrlNow()
E/WindowManager( 1368): Activity com.phonegap.helloworld.HelloWorld has leaked window pl.edu.uj.tcs.student.xxx.Display$Layer@40589368 that was originally added here
E/WindowManager( 1368): android.view.WindowLeaked: Activity com.phonegap.helloworld.HelloWorld has leaked window pl.edu.uj.tcs.student.xxx.Display$Layer@40589368 that was originally added here
E/WindowManager( 1368): at android.view.ViewRoot.<init>(ViewRoot.java:258)
E/WindowManager( 1368): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
E/WindowManager( 1368): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
E/WindowManager( 1368): at android.view.Window$LocalWindowManager.addView(Window.java:424)
E/WindowManager( 1368): at pl.edu.uj.tcs.student.xxx.Display.setColorsViews(Display.java:181)
E/WindowManager( 1368): at pl.edu.uj.tcs.student.xxx.Display$3.run(Display.java:139)
E/WindowManager( 1368): at android.os.Handler.handleCallback(Handler.java:587)
E/WindowManager( 1368): at android.os.Handler.dispatchMessage(Handler.java:92)
E/WindowManager( 1368): at android.os.Looper.loop(Looper.java:130)
E/WindowManager( 1368): at android.app.ActivityThread.main(ActivityThread.java:3683)
E/WindowManager( 1368): at java.lang.reflect.Method.invokeNative(NativeMethod)
E/WindowManager( 1368): at java.lang.reflect.Method.invoke(Method.java:507)
E/WindowManager( 1368): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
E/WindowManager( 1368): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
E/WindowManager( 1368): at dalvik.system.NativeStart.main(Native Method)

D/CordovaActivity( 1368): onMessage(onPageStarted,about:blank)
D/CordovaWebViewClient( 1368): onPageFinished(about:blank)
D/CordovaActivity( 1368): onMessage(onPageFinished,about:blank)
D/CordovaActivity( 1368): onMessage(exit,null)
I/power ( 96): *** set_screen_state 0


EDIT:

How can I add something to onPause(), onStop() etc. functions in Cordova Activity?

EDIT 2:

Why is that a problem? Because all I create is class that extends CordovaPlugin and small auxilary classes. That's all. I'm not able (I suppose) to modify Activity class body. All I can do is get reference to it by calling
cordova.getActivity()
function.

Answer

What is a leak in programming?

The memory that you acquire and do not release lead to the memory leak.Similar happens with the (windows/dialogs).

What's happening here?

You are trying to add a window and while it shows up it is on the foreground,but when you are pressing the home button it gets paused and then gets stopped (Try to put a toast in onStop() and onPause()).

Since you did not tell the system to remove your view , hence it remains attached to the window that now has disappeared/detached from the application. Hence according to the system your customView occupied the space which it did not release.

Solution

Inside your onStop() or onPause()andonDestroy() make sure you dismiss your view(dismiss() if it's a dialog) or remove it(remove()if added using window Manager).

Add the dismiss or remove functions inside your on unload function as you mentioned that on pressing back button you get this error.On exiting an app its onUnload() method gets called.

Suggestion(Ignore if not in context)

As i can observe you are trying to make a System alert window that comes over anything beneath it.Adding such kind of pop ups in the activity is risky as it may cause leakage problems. You may actually add such kind of window via a Service so it outlives your activity and shows up everywhere on the device (if that is what you need).

Check this out

Update 2-The Cordova lifecycle

Why don't you try to override onUnload method in your CordovaPlugin class.I tried finding but the docs are mentioning the existence of onPause and onResume methods.If you got onUnload in the CordovaPlugin class then remove the view you are making in your view class runOnUiThread method.