Move a UIView with my finger

Question

I'm trying to move a UIView (let's call it viewA), which is located on top of another UIView (let's call it viewB). viewB has the size of the iPad screen, and view A is much much smaller.

I manage to move things, but the whole screen moves (viewA + viewB), not only viewA.

Here is my code for viewA class:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
        UITouch *touch = [[event allTouches] anyObject];
        CGPoint touchLocation = [touch locationInView:self->view];
        if (CGRectContainsPoint(self.window.frame, touchLocation)) {
            dragging = YES;
            oldY = touchLocation.y;
        }
    }    


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self->view];
    if (dragging) {
        CGRect frame = self.window.frame;
        frame.origin.y =  self.window.frame.origin.y + touchLocation.y - oldY;
        self.window.frame = frame;
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    dragging = NO;
} 

What I do not understand, is that, I implemented these methods in the viewA class. "Self" should concern this viewA, right? So why does the whole page move when my finger move on the screen?

Answer 1

You are moving the entire window, which contains all the views, you should only move the view you want, viewA in your case.