Question

I have a view control and inside I plan to place some controls like buttons textbox etc… I can drag my view along the x axis like:

1)

2)

with the following code:

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event allTouches] anyObject];

    if( [touch view] == ViewMain)
    {
        CGPoint location = [touch locationInView:self.view];
        displaceX = location.x - ViewMain.center.x;        
        displaceY = ViewMain.center.y;        
        startPosX = location.x - displaceX;
    }

    CurrentTime = [[NSDate date] timeIntervalSince1970];

}


- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{



    UITouch *touch = [[event allTouches] anyObject];

    if( [touch view] == ViewMain)
    {
        CGPoint location = [touch locationInView:self.view];
        location.x =location.x - displaceX;
        location.y = displaceY;
        ViewMain.center = location;
    }  


}

-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

    double time = [[NSDate date] timeIntervalSince1970]-CurrentTime;


    UITouch *touch = [[event allTouches] anyObject];

    if( [touch view] == ViewMain)
    {
        CGPoint location = [touch locationInView:self.view];
        location.x =location.x - displaceX;
        location.y = displaceY;
        ViewMain.center = location;
        double speed = (ViewMain.center.x-startPosX)/(time*2);
        NSLog(@"speed: %f", speed);

    }
}

not that I have to add the global variables:

float displaceX = 0;
float displaceY = 0;
float startPosX = 0;
float startPosY = 0;
double CurrentTime;

the reason why I created those variables is so that when I start dragging the view the view moves from the point where I touch it instead of from the middle.

Anyways if I touch a button or image the view will not drag even though the images have transparency on the background. I want to be able to still be able to drag the view regardless if there is an image on top of the view. I where thinking that maybe I need to place a large transparent view on top of everything but I need to have buttons, images etc. I want to be able to drag a view just like you can with:

note that I was able to drag the view regardless of wither I first touched an app/image or text. How could I do that?

Answer 1

I think your problem is that if you touch a UIButton or a UIImageView with interaction enabled, it doesn’t pass the touch along.
For the images, uncheck the User Interaction Enabledproperty in IB.
For the buttons that are causing touchesBegan:withEvent:, etc. to not get called, then look at the following link: Is there a way to pass touches through on the iPhone?.