Handling Back button in custom View

Question

In a word game for Android with DrawerLayout the left and right navigation drawers are closed by the following code in the MainActivity:

@Override
public void onBackPressed() {
    if (mDrawerLayout.isDrawerOpen(mLeftDrawer)) {
        mDrawerLayout.closeDrawer(mLeftDrawer);
    } else if (mDrawerLayout.isDrawerOpen(mRightDrawer)) {
        mDrawerLayout.closeDrawer(mRightDrawer);
    } else {
        super.onBackPressed();
    }
}

This works well (the left screenshot) -

However I am also trying to detect Back button press in my custom View (which overrides onDraw method to draw scrollable game board and letter tiles) by the following methods - (to allow app user cancelling tile swapping or recalling unplayed tiles from the game board) - but none of them is called:

@Override
public boolean dispatchKeyEventPreIme(KeyEvent event) {
    if (mSwapping && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
        cancelSwapLetters();
        return true;
    }

    return super.dispatchKeyEventPreIme(event);
}

@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
    if (mSwapping && keyCode == KeyEvent.KEYCODE_BACK) {
        cancelSwapLetters();
        return true;
    }

    return super.onKeyPreIme(keyCode, event);
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (mSwapping && keyCode == KeyEvent.KEYCODE_BACK) {
        cancelSwapLetters();
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

I have put breakpoints in the above methods, but none of them are hit.

Please advise me, how to solve this problem.

Answer 1

This code helped me get back press event in a fragment try this code :

getView().setFocusableInTouchMode(true);
        getView().requestFocus();
        getView().setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {

                if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {

                    if(you handled back press) return true;
                    else return false;
            }
        });