Draw line on image by handgetsture in objective c - ios

Question

I have set image's content mode aspect fit.
Now issue is that, when I'm drawing line on image, that time image's content mode set scaletofill and my image stretched. So I want solution for when I'm drawing line on image, image content mode remain same.
U can download myproject from this link.
I'm using following code:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if(self.tempImage.image==nil)
{
return;
}
colorPicker.hidden = YES;
UITouch *touch = [touches anyObject];
lastPoint = [touch locationInView:self.view];
lastPoint.y -= 20;
_pointsArray = [NSMutableArray array];
[_pointsArray addObject:NSStringFromCGPoint(lastPoint)];
UIGraphicsBeginImageContext(self.view.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.tempImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, brush);
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), self.selectedColor.CGColor);
CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(context, lastPoint.x, lastPoint.y);
CGContextStrokePath(context);
self.tempImage.image = UIGraphicsGetImageFromCurrentImageContext();
[self setupExternalScreen];
UIGraphicsEndImageContext();
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
if(self.tempImage.image==nil)
{
return;
}
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
currentPoint.y -= 20;
UIGraphicsBeginImageContext(self.view.frame.size);
[self.tempImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(context, currentPoint.x, currentPoint.y);
//Now set our brush size and opacity and brush stroke color:
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, brush);
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), self.selectedColor.CGColor);
CGContextSetBlendMode(context,kCGBlendModeNormal);
CGContextStrokePath(context);
self.tempImage.image = UIGraphicsGetImageFromCurrentImageContext();
[self.tempImage setAlpha:opacity];
UIGraphicsEndImageContext();
lastPoint = currentPoint;
[self setupExternalScreen];
[self.pointsArray addObject:NSStringFromCGPoint(lastPoint)];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
if(self.tempImage.image==nil)
{
return;
}
//handle single tap, make _pointsArray has two identical points, draw a line between them
if (_pointsArray.count == 1) {
[_pointsArray addObject:NSStringFromCGPoint(lastPoint)];
}
[self.stack addObject:_pointsArray];
NSLog(#"color -> %# \nwidth->%f", self.selectedColor.description, brush);
NSMutableDictionary *dic = [[NSMutableDictionary alloc] init];
[dic setObject:self.selectedColor forKey:#"color"];
[dic setObject:[NSNumber numberWithFloat:brush] forKey:#"width"];
[self.contextArray addObject:dic];
[self setupExternalScreen];
[self.undoManager registerUndoWithTarget: self
selector: #selector(popDrawing)
object: nil];
}
In this code, view frame set in UIGraphicsBeginImageContext. I think it will possible using subclass of UIImageView. I don't know exact solution.
Please see this Screenshot, u will easily understand my problem
Thanks in advance