Detect 'home button pressed' event in android service displaying a UI (similar to facebook chatheads)

Question

In facebook chatheads, that are part of the facebook messenger app, I noticed the following behavior: As far as I can see, the chat head itself and the opened chat screen ar

Answer 1

Here is working sample code.

mLinear =  new LinearLayout(getApplicationContext()) {

          //home or recent button
          public void onCloseSystemDialogs(String reason) {
              //The Code Want to Perform. 
          }

          @Override
          public boolean dispatchKeyEvent(KeyEvent event) {
              if (event.getKeyCode() == KeyEvent.KEYCODE_BACK
                || event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_UP
                || event.getKeyCode() == KeyEvent.KEYCODE_VOLUME_DOWN
                || event.getKeyCode() == KeyEvent.KEYCODE_CAMERA ) {

              //The Code Want to Perform.
              }
          return super.dispatchKeyEvent(event);
          }
};

mLinear.setFocusable(true);

View mView = inflate.inflate(R.layout.floating_panel_layout, mLinear);
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);

//params
WindowManager.LayoutParams params = new WindowManager.LayoutParams(
             width,
             height,
             WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
             WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                    | WindowManager.LayoutParams.FLAG_FULLSCREEN
                    | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
                    | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,
              PixelFormat.TRANSLUCENT);
params.gravity = Gravity.LEFT | Gravity.CENTER_VERTICAL;
wm.addView(mView, params);