iPhone smooth move and pinch of UIImageView
- by Jacob
I have an image view that I'm wanting to be able to move around, and pinch to stretch it. It's all working, but it's kinda jumpy when I start to do any pinch movements. The position will jump back and forth between the two fingers.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
startLocation = [[touches anyObject] locationInView:mouth_handle];
if([touches count] == 2) {
NSArray *twoTouches = [touches allObjects];
UITouch *first = [twoTouches objectAtIndex:0];
UITouch *second = [twoTouches objectAtIndex:1];
initialDistance = distanceBetweenPoints([first locationInView:mouth_handle],[second locationInView:mouth_handle]);
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint pt = [[touches anyObject] locationInView:mouth_handle];
CGRect frame = [mouth_handle frame];
frame.origin.x += pt.x - startLocation.x;
frame.origin.y += pt.y - startLocation.y;
frame.origin.x = (frame.origin.x < 58) ? 58 : frame.origin.x;
frame.origin.x = (frame.origin.x > (260 - mouth_handle.frame.size.width)) ? (260 - mouth_handle.frame.size.width) : frame.origin.x;
frame.origin.y = (frame.origin.y < 300) ? 300 : frame.origin.y;
frame.origin.y = (frame.origin.y > 377) ? 377 : frame.origin.y;
if(frame.origin.x - prevDistanceX > 2 && frame.origin.x - prevDistanceX < -2)
frame.origin.x = prevDistanceX;
if(frame.origin.y - prevDistanceY > 2 && frame.origin.y - prevDistanceY < -2)
frame.origin.y = prevDistanceY;
prevDistanceX = frame.origin.x;
prevDistanceY = frame.origin.y;
CGFloat handleWidth = mouth_handle.frame.size.width;
if([touches count] == 2) {
NSArray *twoTouches = [touches allObjects];
UITouch *first = [twoTouches objectAtIndex:0];
UITouch *second = [twoTouches objectAtIndex:1];
CGFloat currentDistance = distanceBetweenPoints([first locationInView:mouth_handle],[second locationInView:mouth_handle]);
handleWidth = mouth_handle.frame.size.width + (currentDistance - initialDistance);
handleWidth = (handleWidth < 60) ? 60 : handleWidth;
handleWidth = (handleWidth > 150) ? 150 : handleWidth;
if(initialDistance == 0) {
initialDistance = currentDistance;
}
initialDistance = currentDistance;
}
mouth_handle.frame = CGRectMake(frame.origin.x, frame.origin.y, handleWidth, 15);
}
Any thoughts on how to make this smoother?
