Simple Drag Drop with Zoom and Rotate in xCode

Today i am very happy to put this Post as This is the heart of iPhone/iPod/iPad main event. i.e. Zooming Image or Rotating it.

You just need to follow the main thing as below.

1. Put your any View component inside a UIScrollView. You can do this by following code.

//Make a simple view

UIScrollView *viewForImage = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];

[viewForImage addSubview:imageView];

in above code "imageView" is my runtime UIImageView. (You can put your view component here)

2. Now inherit UIGestureRecognizerDelegate in your class ".h" file as below.

@interface SecondTabViewController :  UIViewController < UIGestureRecognizerDelegate>

3. Now add your every UIScrollView for Gesture Recognizer as follow.

[self addGestureRecognizersToPiece:viewForImage];

4. Now Just copy paste the below method in your class ".m" as this code is from Apple itself.

// adds a set of gesture recognizers to one of our piece subviews

- (void)addGestureRecognizersToPiece:(UIView *)piece

{

    UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotatePiece:)];

    [piece addGestureRecognizer:rotationGesture];

    

    UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scalePiece:)];

    [pinchGesture setDelegate:self];

    [piece addGestureRecognizer:pinchGesture];

    

    UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panPiece:)];

    [panGesture setMaximumNumberOfTouches:2];

    [panGesture setDelegate:self];

    [piece addGestureRecognizer:panGesture];

}

- (void)panPiece:(UIPanGestureRecognizer *)gestureRecognizer

{

    UIView *piece = [gestureRecognizer view];

    

    [self adjustAnchorPointForGestureRecognizer:gestureRecognizer];

    

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {

        CGPoint translation = [gestureRecognizer translationInView:[piece superview]];

        

        [piece setCenter:CGPointMake([piece center].x + translation.x, [piece center].y + translation.y)];

        [gestureRecognizer setTranslation:CGPointZero inView:[piece superview]];

    }

}

// rotate the piece by the current rotation

// reset the gesture recognizer's rotation to 0 after applying so the next callback is a delta from the current rotation

- (void)rotatePiece:(UIRotationGestureRecognizer *)gestureRecognizer

{

    [self adjustAnchorPointForGestureRecognizer:gestureRecognizer];

    

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {

        [gestureRecognizer view].transform = CGAffineTransformRotate([[gestureRecognizer view] transform], [gestureRecognizer rotation]);

        [gestureRecognizer setRotation:0];

    }

}

// scale the piece by the current scale

// reset the gesture recognizer's rotation to 0 after applying so the next callback is a delta from the current scale

- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer

{

    [self adjustAnchorPointForGestureRecognizer:gestureRecognizer];

    

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {

        [gestureRecognizer view].transform = CGAffineTransformScale([[gestureRecognizer view] transform], [gestureRecognizer scale], [gestureRecognizer scale]);

        [gestureRecognizer setScale:1];

    }

}

- (void)adjustAnchorPointForGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer

{

    if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {

        UIView *piece = gestureRecognizer.view;

        CGPoint locationInView = [gestureRecognizer locationInView:piece];

        CGPoint locationInSuperview = [gestureRecognizer locationInView:piece.superview];

        

        piece.layer.anchorPoint = CGPointMake(locationInView.x / piece.bounds.size.width, locationInView.y / piece.bounds.size.height);

        piece.center = locationInSuperview;

    }

}

Will provide you the link for the above sample code by Apple. I forget this now.