while performing dual operation on UIImageView - ios

Question

This time I am facing problem while performing dual operation on UIImageView means
1) Zoom+Flip the Image
2)Zoom + Reverse the Image
3)Zoom + Flip or Reverse + Rotate(+- 90)deg
so please help to find out the solution of this problem. In thiscase for Zoom I use the GuestureRecognizer for fliping+Revesing+Rotating UIImageView I Use the the UIButton for these operation so how I can handle these operations wiith combination on UIImage
what exact the problem When I Zoom In or Zoom Out the image the at the same time I want to rotate (+-90 deg) or Flip or Reverse the Image at exact zoom In or Zoom Out Position but that time Image get reset then perform the respective operation such rotate, flip ,reverse I wanted to do it simultaneously on UIImage
my code as
if (btnNames == "Rotate R")
{
Angle = deg + 90;
imgview.Transform = CGAffineTransform.MakeRotation (Angle * (float)Math.PI / 180);
return Angle;
} else
{
Angle = deg - 90;
imgview.Transform = CGAffineTransform.MakeRotation (Angle * (float)Math.PI / 180);
return Angle;
}
For Reverse
CGAffineTransform transform = CGAffineTransform.MakeScale (-1, 1);
imgView.Transform = transform;
return true;
============
For Flip
if (flips == false)
{
CGAffineTransform transform = CGAffineTransform.MakeScale (1, -1);
imgView.Transform = transform;
return true;
}
this code i implemented it works fine individually perform to operation. But I want to work simultaneously on UIImage

Answer 1

I would recommend:
Place the UIImage in a UIScrollView with zooming setup
Modify your UIImage's Transform for reverse, rotate, etc.
To setup zooming:
yourScroller.MaximumZoomScale = 5;
yourScroller.MinimumZoomScale = 1;
yourScroller.ViewForZoomingInScrollView = _ => yourImage;
An example for rotation would be:
yourImage.Transform.Rotate (Math.PI / 2)
Play around with it, the UIScrollView should modify the same Transform on the image, so everything should work in tandem.

Answer 2

I'm not sure I really understand what you mean, but it sounds like your trying to do more the one transformations for an image by setting the UIView's transform property like this (example):
myView.transform = scale;
myView.transform = flip;
myView.transform = rotate;
What happens then is, that only the last one of these "is active: on the view.
What you should do is "keeping/saving" the current transformation and appending the new one with CGAffineTransformConcat like:
myView.transform = scale;
myView.transform = CGAffineTransformConcat(myView.transform, flip);
myView.transform = CGAffineTransformConcat(myView.transform,rotate);
Keep in mind that for some transformations order of concatenation matters!

Answer 3

Transformations can be combined by applying them to an existing transformation:
CGAffineTransform transform = CGAffineTransformIdentity;
// Rotate
if (btnNames == "Rotate R") {
Angle = deg + 90;
transform = CGAffineTransformRotate(transform, Angle * (CGFloat)Math.PI / 180);
} else {
Angle = deg - 90;
transform = CGAffineTransformRotate(transform, Angle * (CGFloat)Math.PI / 180);
}
// Reverse
transform = CGAffineTransformScale(transform, -1, 1);
// Flip
if (!flips) {
transform = CGAffineTransformScale(transform, 1, -1);
}
// Apply combined transformation
imgView.transform = transform;