Different coordinates while resizing an imageview iOS - ios

Question

I'm trying to resizing an imageview using these functions:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch* mTouch = [touches anyObject];
if (mTouch.view == [self Logo_01]) {
CGPoint cp = [mTouch locationInView:[self view]];
[[mTouch view]setCenter:CGPointMake(cp.x-xd, cp.y-yd)];
NSLog(#"questo è x");
NSLog(#"lalal %f", cp.y);
if (cp.y > 390) {
[_Logo_01 setHidden:YES];
}
if (cp.y < 130) {
[_Logo_01 setHidden:YES];
}
if (cp.x > 290) {
[_Logo_01 setHidden:YES];
}
if (cp.x < 40) {
[_Logo_01 setHidden:YES];
}
}
when i resize my Logo on the app the image resizes correctly but my center point is wrong
I'm sorry i wronged to post code
this is the code that i use to scale my images:
- (IBAction)ScaleImage1:(UIPinchGestureRecognizer *)recognizer
{
recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale);
recognizer.scale = 1;
CGFloat height = _Logo_01.frame.size.height;
NSLog(#"SIZE ===== %f", height);
if (height > 600) {
[_Logo_01 setHidden:YES];
}
}

Answer 1

try to write same style everywhere (brackets written randomly, spaces, newlines) - it's easier to read and shows that the dev is better.
Logo_01 is just horrible name for UI element. It's good for asset name. Refactor and rename it to eg startingLogoImageView.
Comparing views with == and isEqual works in a different way. One compares pointers, other one objects. Please read about it, as that's a serious bug if that's unintended.
What is xd in setCenter: line? Where is it from?
We try not to use shortcuts in Objective-C. You should name cp touchPoint as it's more obvious what it is in fact. That's the way recommended by Apple and used by devs.
So the code:
// extern NSUInteger const kViewOffsetY; // uncomment this line if you want it accessible via other classes, delete otherwise
NSUInteger const kViewOffsetY = 1;
NSUInteger const kViewOffsetX = 1;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([touch.view isEqual:startingLogoImageView]) {
UIView *touchedView = touch.view;
CGPoint touchPoint = [touch locationInView:self.view];
[touchedView setCenter:CGPointMake(CGRectGetMidX(touchedView.frame) - kViewOffsetX, CGRectGetMidY(touchedView.frame) - kViewOffsetY)];
// where are these values from? you probably should calculate it more dynamically
BOOL shouldHideView = touchPoint.y > 390 || touchPoint.y < 130 || touchPoint.x > 290 || touchPoint.x < 40;
if (shouldHideView) {
[touchedView setHidden:YES];
}
}
}
Why was it working wrong? Because in setCenter: method you were using top left corner (x and y values of view are in top left corner not in the center), while you should use the center point.