How to increase or decrease the size of UIImageView by dragging the right corner of the edge?

Question

I am doing an app which has a feature that resizing UIImageView by dragging the right corner of the UIImageView's edge like zoom in and zoom out. Also we can rotate the image.

How can I achieve this?

Answer 1

In case of resizing UIImage use SPUserResizableView follow link.

For rotation u will add UIRotationGestureRecognizer to resizableview.

Answer 2

Use this code. Here The images are being picked from the PhotoLibrary and then using gestures they are being moved, zoomed etc. I am using all the gestures to help u do virtually anything like panning, pinching and rotating of any image you put.

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{

[picker dismissModalViewControllerAnimated:YES];
imageCollage = [[UIImageView alloc]initWithFrame:CGRectMake(80, 80, 150, 150)];
[imageCollage setUserInteractionEnabled:YES];
imageCollage.image = [info objectForKey:UIImagePickerControllerOriginalImage];

holderView = [[UIView alloc] initWithFrame:CGRectMake(0,0,imageCollage.frame                                                          .size.width, imageCollage.frame.size.height)];
holderView.layer.cornerRadius = 6;
holderView.clipsToBounds = YES;
imageview = [[UIImageView alloc] initWithFrame:[holderView frame]];
[imageview setImage:imageCollage.image];
[holderView addSubview:imageview];

UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scale:)];
[pinchRecognizer setDelegate:self];
[holderView addGestureRecognizer:pinchRecognizer];

UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];
[rotationRecognizer setDelegate:self];
[holderView addGestureRecognizer:rotationRecognizer];

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[holderView addGestureRecognizer:panRecognizer];

DeleteImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];
[DeleteImage setImage:[UIImage imageNamed:@"DeleteRed.png"]];
[holderView addSubview:DeleteImage];
DeleteImage.userInteractionEnabled = YES;

UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapped:)];
[tapRecognizer setNumberOfTapsRequired:1];
[tapRecognizer setDelegate:self];
[DeleteImage addGestureRecognizer:tapRecognizer];

[BaseView addSubview:holderView];

[Trash setImage:[UIImage imageNamed:@"12456977871712665073hrum_trash.svg.med.png"] forState:UIControlStateNormal];
}

   -(void)scale:(id)sender
   {
BaseView.clipsToBounds = YES;
[BaseView bringSubviewToFront:[(UIPinchGestureRecognizer*)sender view]];

if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {

    lastScale = 1.0;
    return;
}   
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);

CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);

[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];

lastScale = [(UIPinchGestureRecognizer*)sender scale];
  }

  -(void)rotate:(id)sender
  {

[BaseView bringSubviewToFront:[(UIRotationGestureRecognizer*)sender view]];

if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {

    lastRotation = 0.0;
    return;
}

CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);

CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);

[[(UIRotationGestureRecognizer*)sender view] setTransform:newTransform];

lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
   }

   -(void)move:(id)sender
  {
[[[(UITapGestureRecognizer*)sender view] layer] removeAllAnimations];
BaseView.clipsToBounds = YES;
[BaseView bringSubviewToFront:[(UIPanGestureRecognizer*)sender view]];
CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:self.view];

if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {

    firstX = [[sender view] center].x;
    firstY = [[sender view] center].y;
}

translatedPoint = CGPointMake(firstX+translatedPoint.x, firstY+translatedPoint.y);

[[sender view] setCenter:translatedPoint];

if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {

    CGFloat finalX = translatedPoint.x + (.20*[(UIPanGestureRecognizer*)sender velocityInView:self.view].x);
    CGFloat finalY = translatedPoint.y + (.20*[(UIPanGestureRecognizer*)sender velocityInView:self.view].y);

    if(UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation])) {

        if(finalX < 0) {

            finalX = 0;
        }

        else if(finalX > 260) {

            finalX = 260;
        }

        if(finalY < 0) {

            finalY = 0;
        }

        else if(finalY > 416) {

            finalY = 416;
        }
    }

    else {

        if(finalX < 0) {

            finalX = 0;
        }

        else if(finalX > 416) {

            finalX = 260;
        }

        if(finalY < 0) {

            finalY = 0;
        }

        else if(finalY > 260) {

            finalY = 416;
        }
    }

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:.35];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
    [[sender view] setCenter:CGPointMake(finalX, finalY)];
    [UIView commitAnimations];
}
   }



      -(void)tapped:(UIGestureRecognizer *)recogniser
      {
    NSLog(@"%@",recogniser.view);
    [Trash setImage:[UIImage imageNamed:@"trash_bin_recycle_quit_terminate_error_cancel_close_exit.png"] forState:UIControlStateNormal];

    [[[recogniser view] superview] removeFromSuperview];
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {

    return ![gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]];
}

Any queries about the code please feel free to ask :)... Happy Coding ..