CODEWITHSUNDEEP
iosuiviewuigesturerecognizeruibezierpath
Reza.Ab
Reza.Ab

Reputation: 1215

Why touchesbegan: never gets called on a UIView after UIPinchGestureRecognizer is used?

I'm developing a drawing app which lets user to draw a UIbezierpath on a UIView (InsideView) subviewed by it's superView (self.view). I'm using conventional drawing codes in the InsideView like touchesBegan:, touchesMoved:, touchesEnded:and I'm handling pinch zoom code handlePinch:(UIPinchGestureRecognizer *)recognizer: inside the viewController class (which is InsideView's superView).

When I draw first, I can do the pinch zoom after it but when I do the pinch zoom first, the drawing code (touchesBegan etc) doesn't get called after UIPinchGestureRecognizer is fired and it doesnt draw anything on InsideView. What am I doing wrong? Thanks in advance.

//Code in the InsideView (which is a UIView subclass and is a subview for self.view)

- (id)initWithFrame:(CGRect)frame{              
                 self = [super initWithFrame:frame];
                 if (self) {
                             path = [UIBezierPath bezierPath];
                             [path setLineWidth:7.0];
                             pointsArray = [NSMutableArray array];
                             finish = NO;
                             }
                   return self;   
}   
-(void)drawRect:(CGRect)rect{
                        [[UIColor redColor] setStroke];
                        [path stroke];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

                    UITouch *touch = [touches anyObject];
                    CGPoint p = [touch locationInView:self];
                    [path moveToPoint:p];
                    [pointsArray addObject:[NSValue valueWithCGPoint:p]];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{

                    UITouch *touch = [touches anyObject];
                    CGPoint p = [touch locationInView:self];
                    [path addLineToPoint:p];
                    [self setNeedsDisplay];
                    [pointsArray addObject:[NSValue valueWithCGPoint:p]];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

                    [path closePath];

                    //Smoothing the path.
                    path.miterLimit=-10;
                    [self setNeedsDisplay];
                    finish = YES;
}

//Code in the viewController (InsideView's superView)
- (void)viewDidLoad {
        [super viewDidLoad];
        InsideView* sV = [InsideView new];
        [sV setFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
        [self.view addSubview:sV];

        //Pinch
        UIPinchGestureRecognizer*pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)];
        pinch.delegate =self;
        [sV addGestureRecognizer:pinch];
}
- (void)handlePinch:(UIPinchGestureRecognizer *)recognizer{

        if ([recognizer numberOfTouches] < 2)
            return;
        if (recognizer.state == UIGestureRecognizerStateBegan) {
            lastScale = 1.0;
            lastPoint = [recognizer locationInView:self.view];
        }
        // Scale
        CGFloat scale = 1.0 - (lastScale - recognizer.scale);
        [sV.layer setAffineTransform:
         CGAffineTransformScale([sV.layer affineTransform],
                                scale,
                                scale)];
        lastScale = recognizer.scale;
        // Translate
        CGPoint point = [recognizer locationInView:self.view];

        [sV.layer setAffineTransform:
         CGAffineTransformTranslate([sV.layer affineTransform],
                                    point.x - lastPoint.x,
                                    point.y - lastPoint.y)];
        lastPoint = [recognizer locationInView:self.view];
}
-(void)handlePinchWithGestureRecognizer:(UIPinchGestureRecognizer *)pinchGestureRecognizer{
        sV.transform = CGAffineTransformScale(sV.transform, pinchGestureRecognizer.scale, pinchGestureRecognizer.scale);
        pinchGestureRecognizer.scale = 1.0;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
        return YES;
}

Upvotes: 0

Views: 523

Answers (1)

ddb
ddb

Reputation: 2435

I've developed a UIViewController where I used them together without any problem,s maybe a solution could be to move this logic from UIView to the UIViewController. So at viewDidLoad you can define the pinch recognizer like this

UIPinchGestureRecognizer* pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)];
[self.view addGestureRecognizer:pinch];

of course also the method handlePinch: should be moved to the UIViewController, together with touchesBegan:withEvent:, touchesMoved:withEvent:, touchesEnded:withEvent: methods

what you should change in these methods is that you should change

self

to

self.yourSpecificCurrentUIView

Upvotes: 2

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