Disable cutting outside the image

[jloubet]

Hello,

I'm using your library, I want that the picture don't be able to go out of the cut area.

I almost achieve this with the following modifications in the code:

The code is working but have a bug with the pitch, I would like to discuss this with you, please take a look to the code. Thanks!

For the Pan:

- (IBAction)handlePan:(UIPanGestureRecognizer*)recognizer
{
    if([self handleGestureState:recognizer.state]) {
        CGPoint translation = [recognizer translationInView:self.imageView];

        float availableXmove = self.imageView.frame.size.width - self.cropSize.width;
        float availableYmove = self.imageView.frame.size.height - self.cropSize.height;

        if ((availableXmove>0) || (availableYmove>0)){

            float availableXmoveLeft = (availableXmove / 2) - (_totalMoveX + (translation.x * self.scale));
            float availableXmoveRight = (availableXmove / 2) + (_totalMoveX + (translation.x * self.scale));
            float availableYmoveTop = (availableYmove / 2) + (_totalMoveY - (translation.y * self.scale));
            float availableYmoveButton = (availableYmove / 2) - (_totalMoveY - (translation.y * self.scale));

            if ((availableXmoveLeft>=0) && (availableXmoveRight>=0) &&
                (availableYmoveTop>=0) && (availableYmoveButton>=0)){
                //NSLog(@"puedo mover por X o Y");
                float avaliableX = ((availableXmove) / 2);

                _totalMoveX += translation.x * self.scale;

                if ((avaliableX>_totalMoveX) && ((-1*avaliableX)<_totalMoveX)){

                    CGAffineTransform transform = CGAffineTransformTranslate( self.imageView.transform, translation.x, 0);
                    self.imageView.transform = transform;

                    [recognizer setTranslation:CGPointMake(0, 0) inView:self.frameView];

                }else{
                    _totalMoveX -= translation.x * self.scale;
                }

                float avaliableY = ((availableYmove) / 2);

                _totalMoveY -= translation.y * self.scale;
                if ((avaliableY>_totalMoveY) && ((-1*avaliableY)<_totalMoveY)){

                    CGAffineTransform transform = CGAffineTransformTranslate( self.imageView.transform, 0, translation.y);
                    self.imageView.transform = transform;

                    [recognizer setTranslation:CGPointMake(0, 0) inView:self.frameView];

                }else{
                    _totalMoveY += translation.y * self.scale;
                }
            }   
        }else{
            //NSLog(@"Err");
        }   
    }
}

For the Pinch:

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer
{
    if([self handleGestureState:recognizer.state]) {
        if(recognizer.state == UIGestureRecognizerStateBegan){
            self.scaleCenter = self.touchCenter;
        }

        float availableXmove = self.imageView.frame.size.width - self.cropSize.width;
        float availableYmove = self.imageView.frame.size.height - self.cropSize.height;
        availableXmove = availableXmove / 2;
        availableYmove = availableYmove / 2;
        float availableXmoveLeft   = availableXmove - _totalMoveX;
        float availableXmoveRight  = availableXmove + _totalMoveX;
        float availableYmoveTop    = availableYmove + _totalMoveY;
        float availableYmoveButton = availableYmove - _totalMoveY;

        if ((availableXmoveLeft>=0) && (availableXmoveRight>=0) &&
            (availableYmoveTop>=0) && (availableYmoveButton>=0)){
            NSLog(@"ok");

            if ( self.scale*recognizer.scale>=1){
                CGFloat deltaX = 0;//self.scaleCenter.x-self.imageView.bounds.size.width/2.0;
                CGFloat deltaY = 0;//self.scaleCenter.y-self.imageView.bounds.size.height/2.0;

                CGAffineTransform transform =  CGAffineTransformTranslate(self.imageView.transform, deltaX, deltaY);
                transform = CGAffineTransformScale(transform, recognizer.scale, recognizer.scale);
                transform = CGAffineTransformTranslate(transform, -deltaX, -deltaY);

                self.scale *= recognizer.scale;

                self.imageView.transform = transform;

                recognizer.scale = 1;
            }
        }else{
            NSLog(@"Err");
        }
    }
} 

[heitorfr]

Hi. I had this on my pipeline for some time now and finally implemented a 'checkBounds' setting that does what you want. Instead of blocking gestures, it will correct the transformations when gestures are finished. Rotation is not supported though. All the best.

[jloubet]

Heitor, thank you very much, that works great. For rotation validation I think you should use trigonometric function to make the validation. Thanks again.

[heitorfr]

I'll take the challenge when I have some time again ;)