Resize UIView to fit a CGPath - ios

Question

I have a UIView subclass on which the user can add a random CGPath. The CGPath is added by processing UIPanGestures.
I would like to resize the UIView to the minimal rect possible that contains the CGPath. In my UIView subclass, I have overridden sizeThatFits to return the minimal size as such:
- (CGSize) sizeThatFits:(CGSize)size {
CGRect box = CGPathGetBoundingBox(sigPath);
return box.size;
}
This works as expected and the UIView is resized to the value returned, but the CGPath is also "resized" proportionally resulting in a different path that what the user had originally drawn. As an example, this is the view with a path as drawn by the user:
And this is the view with the path after resizing:
How can I resize my UIView and not "resize" the path?

Answer 1

Use the CGPathGetBoundingBox. From Apple documentation:
Returns the bounding box containing all points in a graphics path. The
bounding box is the smallest rectangle completely enclosing all points
in the path, including control points for Bézier and quadratic curves.
Here a small proof-of-concept drawRect methods. Hope it helps you!
- (void)drawRect:(CGRect)rect {
//Get the CGContext from this view
CGContextRef context = UIGraphicsGetCurrentContext();
//Clear context rect
CGContextClearRect(context, rect);
//Set the stroke (pen) color
CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);
//Set the width of the pen mark
CGContextSetLineWidth(context, 1.0);
CGPoint startPoint = CGPointMake(50, 50);
CGPoint arrowPoint = CGPointMake(60, 110);
//Start at this point
CGContextMoveToPoint(context, startPoint.x, startPoint.y);
CGContextAddLineToPoint(context, startPoint.x+100, startPoint.y);
CGContextAddLineToPoint(context, startPoint.x+100, startPoint.y+90);
CGContextAddLineToPoint(context, startPoint.x+50, startPoint.y+90);
CGContextAddLineToPoint(context, arrowPoint.x, arrowPoint.y);
CGContextAddLineToPoint(context, startPoint.x+40, startPoint.y+90);
CGContextAddLineToPoint(context, startPoint.x, startPoint.y+90);
CGContextAddLineToPoint(context, startPoint.x, startPoint.y);
//Draw it
//CGContextStrokePath(context);
CGPathRef aPathRef = CGContextCopyPath(context);
// Close the path
CGContextClosePath(context);
CGRect boundingBox = CGPathGetBoundingBox(aPathRef);
NSLog(#"your minimal enclosing rect: %.2f %.2f %.2f %.2f", boundingBox.origin.x, boundingBox.origin.y, boundingBox.size.width, boundingBox.size.height);
}