How can I control imageView's moving by PanGestureRecognizer? - ios

Question

I want to move imageView by PanGestureRecognizer like this
(imageView can be scaled)
If imageView's position is (0,0), it can't move.
If imageView's position x is over 60, it can't move more.
If imageView's position y is over 80, it can't move more.
When imageView's scale is restored(1.0), it's position is (0,0).
It is difficult to restrict imageView's moving and position.
What should I do?
Here is my code.
img = [UIImage imageNamed:[NSString stringWithFormat:#"a.jpg"]];
imgView = [[UIImageView alloc]initWithImage:img];
imgView.frame = CGRectMake(0,0, self.view.frame.size.width, 448);
imgView.userInteractionEnabled = YES;
[self.view imgView];
- (void)panAction : (UIPanGestureRecognizer *)sender {
CGPoint CGP = imgView.center;
if(newScale != 1.0 && CGP.x-160 != 0 && CGP.y-224 != 50){
CGPoint p = [sender translationInView:self.view];
CGPoint movedPoint = CGPointMake(imgView.center.x + p.x, imgView.center.y + p.y);
imgView.center = movedPoint;
[sender setTranslation:CGPointZero inView:self.view];
}
}
-(void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer {
if([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
// Reset the last scale, necessary if there are multiple objects with different scales
lastScale = [gestureRecognizer scale];
}
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan ||
[gestureRecognizer state] == UIGestureRecognizerStateChanged) {
CGFloat currentScale = [[[gestureRecognizer view].layer valueForKeyPath:#"transform.scale"] floatValue];
// Constants to adjust the max/min values of zoom
const CGFloat kMaxScale = 2.0;
const CGFloat kMinScale = 1.0;
newScale = 1 - (lastScale - [gestureRecognizer scale]);
newScale = MIN(newScale, kMaxScale / currentScale);
newScale = MAX(newScale, kMinScale / currentScale);
CGAffineTransform transform = CGAffineTransformScale([[gestureRecognizer view] transform], newScale, newScale);
[gestureRecognizer view].transform = transform;
lastScale = [gestureRecognizer scale]; // Store the previous scale factor for the next pinch gesture call
}
}

Answer 1

You must use the following condition check in your Pan Gesture action:
For you information, as you move the object, this panAction() method is called regularly at each pixel move.
- (void)panAction : (UIPanGestureRecognizer *)sender {
if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan)
{
//Do something whatever you need to be done while the pan gesture starts
}
if ([(UIPanGestureRecognizer *)sender state] == UIGestureRecognizerStateChanged)
{
//Do something whatever you need to be done while the imageView object is in the moving state
}
if ([(UIPanGestureRecognizer *)sender state] == UIGestureRecognizerStateEnded){
//Do something you need to do as you end the pan gesture.
}
}