Question

I have two views

• the top view has some opaque and some transparent regions
• the bottom view has some clickable buttons.

The top view is completely covering the bottom view, but since top view has transparent areas, bottom view can still be seen.

BUT, i cannot detect button clicks on the bottom view anymore since topview is blocking it, what should I do?

Is there anyway to let top view pass the touches to bottom view?

Answer 1

My solution for my own question, hope it helps someone.

In the front view, listen for touchesEnded:withEvent delegate.

When this delegate fires, you knows that a user is touching the front view.

Next you need to check whether the finger position touches special areas in the BOTTOM view.

What to do is:

1) Convert the point to relative to the bottom view:

UITouch *touch = [touches anyObject];
CGPoint touchPointInLowerView = [touch locationInView:self.lowerViewController.view];
BOOL isLowerButtonClicked = [self.lowerViewController isFingerOnYourButton:touchPointInLowerView];
if(isLowerButtonClicked)
{
 // lower button clicked
}

2) In the lower view

- (BOOL) isFingerOnYourButton:(CGPoint)point
{
 return CGRectContainsPoint(self.aButton.frame, point);
}  

voila. In this way, we can detect clicks in bottom view even it is blocked by another interactive view on top.