UIImageView Rotation and zooming in iPhone Sdk - ios5

Question

i'm implementing zooming and rotation using UIImageview in my project,
i'm facing problem in zoom in and zoom out after rotating the image,
Here is my code follows:
in .h file
#interface ViewController : UIViewController{
float degrees;
float height;
float width;
float moveLeft;
float moveRight;
}
#property(nonatomic,retain)UIImageView *imageView;
-(IBAction)rotationLeft:(id)sender;
-(IBAction)rotationRight:(id)sender;
-(IBAction)zoomIn:(id)sender;
-(IBAction)zoomOut:(id)sender;
-(IBAction)moveLeft:(id)sender;
-(IBAction)moveRight:(id)sender;
in .m file
- (void)viewDidLoad
{
[super viewDidLoad];
height=50;
width=50;
degrees=20;
moveLeft=20;
moveRight=20;
imageView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:#"1.png"]];
imageView.frame=CGRectMake(100, 100,width, height);
[self.view addSubview:imageView];
// Do any additional setup after loading the view, typically from a nib.
}
-(IBAction)rotationLeft:(id)sender{
//the value in degrees
imageView.transform = CGAffineTransformMakeRotation(degrees*M_PI/180);
degrees=degrees+25;
}
-(IBAction)rotationRight:(id)sender{
//the value in degrees
degrees=degrees-25;
imageView.transform = CGAffineTransformMakeRotation(degrees*M_PI/180);
}
-(IBAction)zoomIn:(id)sender{
height=height-15;
width=width-15;
imageView.frame=CGRectMake(100, 100,width, height);
}
-(IBAction)zoomOut:(id)sender{
height=height+15;
width=width+15;
imageView.frame=CGRectMake(100, 100,width, height);
}
Please find the attached image for your reference.

Answer 1

you should use CGAffineTransformMakeScale for zooming purposes, instead of forcing the frame.
define somewhere a global foal x = 1; then:
-(IBAction)zoomIn:(id)sender{
x += 0.3;
imageView.transform = CGAffineTransformMakeScale(x, x);
}
-(IBAction)zoomOut:(id)sender{
x -= 0.3;
imageView.transform = CGAffineTransformMakeScale(x, x);
}

Answer 2

I would recommend scaling the image using a very similar method to the rotation code that you have:
CGAffineTransformMakeScale(CGFloat sx, CGFloat sy);
Just send it more than 1.0 to scale up and less than 1.0 to scale down;

Answer 3

Below code worked for me perfect!!!
-(IBAction)rotationLeft:(id)sender{
//the value in degrees
degrees=degrees+25;
CGAffineTransform t;
t=CGAffineTransformMakeScale(x, x);
// imageView.transform = CGAffineTransformMakeRotation(degrees*M_PI/180,x,x);
imageView.transform=CGAffineTransformRotate(t, degrees*M_PI/180);
}
-(IBAction)rotationRight:(id)sender{
degrees=degrees-25;
CGAffineTransform t;
t=CGAffineTransformMakeScale(x, x);
imageView.transform=CGAffineTransformRotate(t, degrees*M_PI/180);
}
-(IBAction)zoomIn:(id)sender{
x += 0.3;
CGAffineTransform t;
t=CGAffineTransformMakeRotation(degrees*M_PI/180);
imageView.transform=CGAffineTransformScale(t, x, x);
}
-(IBAction)zoomOut:(id)sender{
x -= 0.3;
CGAffineTransform t;
t=CGAffineTransformMakeRotation(degrees*M_PI/180);
imageView.transform=CGAffineTransformScale(t, x, x);
}