How to add a floating view to Android Window manager and listen to System/Hardware back button events

Question

I have a service which displays a floating view on the window manager (using WINDOW_TYPE_ALERT permission). I'm able to display it and perform actions. But, I have two specific questions:

1. Regarding the implementation of the floating view
2. How to listen to system back button event so that I can dismiss the view.

Implementation:

In the manifest I added permissions for:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

I have a broadcast receiver which will listen for Alarm events. Upon receiving the event, I'm starting a service to display the floating view. The following is the code I'm using to create the view.

LayoutParams layOutParams = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
                WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
                PixelFormat.TRANSLUCENT);

Whenever a user performs any action on the view, I'm removing the view from window manager and killing the service.

What I would like to know is - if this is the right way to approach the problem or are there any better ways to do it? And, should I make changes to the LayoutParams or keep them as is?

Secondly, I would also like to dismiss this floating view when there is SYSTEM BACK/HARDWARE BACK button press event. Any pointers on how to do this would be helpful.

Attaching a screenshot of the floating view for better understanding:

Lowestoft

just show a dialog, it will handle events for you #5469505 – Willette

@veon can you please tell me where to add the dialog? – Lowestoft

Answer 1

In terms of back button detection - I made it to work in a following way (everything happens in service onCreate code):

1. Wrap your desired view into ViewGroup (LinearLayout, Relative or other)
2. override dispatchKeyEvent like this in wrapper view:

mView = new RelativeLayout(this) {
        @Override
        public boolean dispatchKeyEvent(KeyEvent event) {
            if (event.getKeyCode()==KeyEvent.KEYCODE_BACK) {
                // < your action >
                return true;
            }
            return super.dispatchKeyEvent(event);
        }
};

3. add wrapper view to the window manager, and be sure that WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE is not set on wrapper layout params.

Kerseymere

How did you get this to work? I can't touch anything / scroll. – Povertystricken

Answer 2

Have a look at Standout Library , which is good for handling floating windows , it seems it is also not handling back press event , contacting developer might help.

And one more way is you can try opening activity with semi transparent background/theme to get the similar effect used in floating window in Any.do and backpress event can be handled

Inconsolable

Thanks for the answer, you definitely pointed me in the right direction. To get this completely working exactly like Any.do I had to do the following: We have to launch the activity with launch mode "singleInstance" . We have to mention it in manifest file like this android:launchMode="singleInstance" – Lowestoft

Answer 3

Do you want the HOME button to also dismiss your UI? If you do, it sounds like it is better to have an activity that opens on a transparent background, instead of an alert window. To do this use the following style as the theme for your activity

<style name="Transparent">
    <item name="android:windowFrame">@null</item>
    <item name="android:windowBackground">@color/transparent</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
    <item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
    <item name="android:windowFullscreen">true</item>
</style>

Racket

Answer 4

Regarding the Back button - You should override the "onBackPressed()" inside your view and do whatever you want

@Override
public boolean onBackPressed() {
    // Remove your view from the window...
}

Anyway, I'm using an SDK called Tooleap, to display floating windows in a straight-forward way.

Trevelyan

onBackPressed() is not a View method and so cannot be overridden. You can however override dispatchKeyEvent(KeyEvent event) and look for back presses. – Apophyllite

Answer 5

FOR WORKING "onBackpressed" BUTTON FOLLOW BELOW INSTRUCTION

1.Go to FlotingFolder.java file in example (Not library).

2.Find below method

@Override
public int getFlags(int id) {
    if (APP_SELECTOR_ID == id) {
        return super.getFlags(id);
    } else {
        return super.getFlags(id) | StandOutFlags.FLAG_BODY_MOVE_ENABLE
                | StandOutFlags.FLAG_WINDOW_EDGE_LIMITS_ENABLE
                | StandOutFlags.FLAG_WINDOW_FOCUSABLE_DISABLE;
    }
}

3. Then remove - "StandOutFlags.FLAG_WINDOW_FOCUSABLE_DISABLE" from the above method

Now onBackPressed will work.

Galvanoscope