How to cancel an Dialog themed like Activity when touched outside the window?

Just to point out that there is a way to get dialog-like "touch outside to cancel" behaviour from an Activity themed as a dialog, though I've not fully investigated whether it has unwanted side effects.

Within your Activity's onCreate() method, before creating the view, you're going to set two flags on the window: One to make it 'non-modal', to allow views other than your activity's views to receive events. The second is to receive notification that one of those events has taken place, which will send you an ACTION_OUTSDIE move event.

If you set the theme on the activity to the dialog theme, you'll get the behaviour you want.

It looks something like this:

public class MyActivity extends Activity {

 @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Make us non-modal, so that others can receive touch events.
    getWindow().setFlags(LayoutParams.FLAG_NOT_TOUCH_MODAL, LayoutParams.FLAG_NOT_TOUCH_MODAL);

    // ...but notify us that it happened.
    getWindow().setFlags(LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH, LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH);

    // Note that flag changes must happen *before* the content view is set.
    setContentView(R.layout.my_dialog_view);
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    // If we've received a touch notification that the user has touched
    // outside the app, finish the activity.
    if (MotionEvent.ACTION_OUTSIDE == event.getAction()) {
      finish();
      return true;
    }

    // Delegate everything else to Activity.
    return super.onTouchEvent(event);
  }
}

I couldn't get the top answer here to work on a Samsung tab running 3.1, so I did this:

@Override
public boolean onTouchEvent(MotionEvent event) {
    float x = event.getX();
    float y = event.getY();
    int xmargin = (ViewUtils.getScreenWidth() - Constants.PRODUCT_DIALOG_WIDTH) / 2;
    int ymargin = (ViewUtils.getScreenHeight() - Constants.PRODUCT_DIALOG_HEIGHT) / 2;

    if (
            x < xmargin                              || 
            x > ViewUtils.getScreenWidth() - xmargin ||
            y < ymargin                              || 
            y > ViewUtils.getScreenHeight() - ymargin
        ) {
            finish();
            return true;
    }
    return super.onTouchEvent(event);
}

You'll need to replace Constants.PRODUCT_DIALOG_WIDTH and Constants.PRODUCT_DIALOG_HEIGHT with the width/height of your dialog. Mine was used in a number of places so I made them constants.

You'll also need to implement your own method to get the the screen width and height, which you can find easily on this here site. Don't forget to account for the Android header in that!

It's kind of ugly, and I'm not proud, but it works.

You can reference the dialog.java code from android source:

public boolean onTouchEvent(MotionEvent event) {
    if (mCancelable && mCanceledOnTouchOutside && event.getAction() == MotionEvent.ACTION_DOWN && isOutOfBounds(event)) {
        cancel();
        return true;
    }
    return false;
}

private boolean isOutOfBounds(MotionEvent event) {
    final int x = (int) event.getX();
    final int y = (int) event.getY();
    final int slop = ViewConfiguration.get(mContext).getScaledWindowTouchSlop();
    final View decorView = getWindow().getDecorView();
    return (x < -slop) || (y < -slop) || (x > (decorView.getWidth()+slop)) || (y > (decorView.getHeight()+slop));
}

Just modify it to :

public boolean onTouchEvent(MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_DOWN && isOutOfBounds(event)) {
        finish();
        return true;
    }
    return false;
}

private boolean isOutOfBounds(MotionEvent event) {
    final int x = (int) event.getX();
    final int y = (int) event.getY();
    final int slop = ViewConfiguration.get(this).getScaledWindowTouchSlop();
    final View decorView = getWindow().getDecorView();
    return (x < -slop) || (y < -slop) || (x > (decorView.getWidth() + slop)) || (y > decorView.getHeight() + slop));
}

can solve your problem.