Drag multiple UIImageViews in an Array - objective-c

Question

This is what I have so far
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
for (UIImageView *imageView in _imageViewArray) {
CGPoint Location = [touch locationInView:touch.view];
imageView.center = Location;
}
}
The problem I am facing is when I move one image they all jump to the same place.
Thanks to cyberpawn this it what I did it get it to work
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint oldPoint = [touch previousLocationInView:touch.view];
CGPoint newPoint = [touch locationInView:touch.view];
CGPoint diff = CGPointMake(newPoint.x - oldPoint.x, newPoint.y - oldPoint.y);
for (UIImageView *imageView in _imageViewArray) {
if (CGRectContainsPoint(imageView.frame, newPoint)) {
CGPoint cntr = [imageView center];
[imageView setCenter:CGPointMake(cntr.x + diff.x, cntr.y + diff.y)];
}
}
}

Answer 1

Thats because you are moving them all to same location, you need to calculate the difference between touch locations and add that displacement to all views. Below code should solve your problem! Forget touchesBegan and Just override touchesMoved method like that.
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint oldPoint = [touch previousLocationInView:touch.view];
CGPoint newPoint = [touch locationInView:touch.view];
CGPoint diff = CGPointMake(newPoint.x - oldPoint.x, newPoint.y - oldPoint.y);
for (UIImageView *imageView in _imageViewArray) {
CGPoint cntr = [imageView center];
[imageView setCenter:CGPointMake(cntr.x + diff.x, cntr.y + diff.y)];
}
}
If You want to move them separately when any of them is clicked than use below code instead!
float oldX, oldY;
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint pt = [touch locationInView:touch.view];
for (UIImageView *imageView in _imageViewArray) {
if(CGRectContainsPoint(imageView.frame, pt)) {
oldX = imageView.center.x - imageView.frame.origin.x - pt.x;
oldY = imageView.center.y - imageView.frame.origin.y - pt.y;
break;
}
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint pt = [touch locationInView:touch.view];
for (UIImageView *imageView in _imageViewArray) {
if (CGRectContainsPoint(imageView.frame, pt)) {
[self setCenter:CGPointMake(pt.x+oldX, pt.y+oldY)];
}
}
Enjoy Programming!

Answer 2

Here you coded like that only. If you want to move a single image, then you have to find that image and you should move that image alone.