How to resize the UIView when CGAffineTransformIdentity

Question

I am doing an app which has a feature to rotate and re size a view. i have implemented this feature but i do face an issue.

My problem

The View

Answer 1

Since you don't use UIView animations you can save current view's transform, set view's transform to identity, resize the view and reapply saved transform:

UIView *v;
CGAffineTransform t = v.transform;
v.transform = CGAffineTransformIdentity;
CGFloat scale = 2.0f;
v.frame = CGRectMake(v.frame.origin.x, v.frame.origin.y, v.frame.size.width*scale , v.frame.size.height*scale);
v.transform = t;

(EDIT)About your resizing:

If you define your rectangle with 4 vectors (points) A,B,C,D where (A+C)*.5 = (B+D)*.5 = rectangle_center Then for moving point C to position C' would also move B and D to B' and D':

A' = A
C' = C' //touch input
B' = A + (normalized(B-A) * dotProduct((C'-A), normalized(B-A)))
D' = A + (normalized(D-A) * dotProduct((C'-A), normalized(D-A)))

After that:

• transform your view to identity
• set frame to (.0f, .0f, length(A-D), length(A-C))
• set center to (A+D)*.5f
• get rotation to create view's transform through atanf(height/width) and few "if's" OR fill/create transform with base vectors that are normalized(D-A) and normalized(B-A)

You can do that for any point in a rectangle.