Question

In my app I have a button that if the user clicks than a text box appears on the screen
(I use the setVisibility from GONE to VISIBILE).
the problem I have is when the user presses the BACK button on the device : it closes my app.

Is there any way that when the user presses the BACK button than my code will be called (so I can set the visibility to GONE) ?

Answer 1

The following works since API level 1:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        //Do whatever you want 
        //AND 
        //return true to tell the framework you did handle the back key
        return true;
    }
    //This is not the back key, just ask the framework to behave as usual.
    return super.onKeyDown(keyCode, event);
}

Starting from API level 5 (android 2.0) you can also use:

@Override
public void onBackPressed() {
    // Do something (or nothing) here
    return;
}

See this android developer blog message for a complete overview.