Back button and last activity

Question

My app chains some activities.

if you press the back button, you go back through old activities then you suddenly quit the application !

so I need to show a message like "do you really want to exit" if it's the last activity on stack

I know how to override the back button but i can't figure how to know how many activity are in history

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
        // Is it the last activity on stack ? 
        // so show confirm dialog
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

Please help.

Answer 1

you can achieve that using the finish() function

public void finish() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("do you really want to exit?");
        builder.setCancelable(false);
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                quit();
            }
        });
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                dialog.cancel();
            }
        });
        AlertDialog alert = builder.create();
        alert.show();
    }

    public void quit() {
        super.finish();
    };