Detecting tap inside a bezier path

Question

I have a UIView which is added as a subview to my view controller. I have drawn a bezier path on that view. My drawRect implementation is below

- (void)drawR         


        

Answer 1

A solution in Swift 3.1 (porting over the Apple recommended solution from here)

func containsPoint(_ point: CGPoint, path: UIBezierPath, inFillArea: Bool) -> Bool {

        UIGraphicsBeginImageContext(self.size)

        let context: CGContext? = UIGraphicsGetCurrentContext()
        let pathToTest = path.cgPath
        var isHit = false

        var mode: CGPathDrawingMode = CGPathDrawingMode.stroke

        if inFillArea {

            // check if UIBezierPath uses EO fill
            if path.usesEvenOddFillRule {
                mode = CGPathDrawingMode.eoFill
            } else {
                mode = CGPathDrawingMode.fill
            }
        } // else mode == stroke

        context?.saveGState()
        context?.addPath(pathToTest)

        isHit = (context?.pathContains(point, mode: mode))!
        context?.restoreGState()

        return isHit
        }

Answer 2

Detecting tap inside a bezier path in swift :-

It's simple in latest swift ,follow these steps and you will get your UIBezierPath touch event.

Step 1 :- Initialize Tap Event on view where your UIBeizerPath Added.

///Catch layer by tap detection let tapRecognizer:UITapGestureRecognizer = UITapGestureRecognizer.init(target: self, action: #selector(YourClass.tapDetected(_:))) viewSlices.addGestureRecognizer(tapRecognizer)

Step 2 :- Make "tapDetected" method

  //MARK:- Hit TAP
public func tapDetected(tapRecognizer:UITapGestureRecognizer){
    let tapLocation:CGPoint = tapRecognizer.locationInView(viewSlices)
    self.hitTest(CGPointMake(tapLocation.x, tapLocation.y))


}

Step 3 :- Make "hitTest" final method

  public func hitTest(tapLocation:CGPoint){
        let path:UIBezierPath = yourPath
        if path.containsPoint(tapLocation){
            //tap detected do what ever you want ..;)
        }else{
             //ooops you taped on other position in view
        }
    }

Update: Swift 4

Step 1 :- Initialize Tap Event on view where your UIBeizerPath Added.

///Catch layer by tap detection
let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(YourClass.tapDetected(tapRecognizer:)))
viewSlices.addGestureRecognizer(tapRecognizer)

Step 2 :- Make "tapDetected" method

public func tapDetected(tapRecognizer:UITapGestureRecognizer){
    let tapLocation:CGPoint = tapRecognizer.location(in: viewSlices)
    self.hitTest(tapLocation: CGPoint(x: tapLocation.x, y: tapLocation.y))
}

Step 3 :- Make "hitTest" final method

private func hitTest(tapLocation:CGPoint){
    let path:UIBezierPath = yourPath

    if path.contains(tapLocation){
        //tap detected do what ever you want ..;)
    }else{
        //ooops you taped on other position in view
    }
}

Answer 3

There is a function CGPathContainsPoint() it may be useful in your case.

Also be careful if you get gesture point from superview, the coordinate may not be correct with your test. You have a method to convertPoint from or to a particular view's coordinate system:

- (CGPoint)convertPoint:(CGPoint)point toView:(UIView *)view
- (CGPoint)convertPoint:(CGPoint)point fromView:(UIView *)view

Answer 4

Try UIBezierPath's method :

func contains(_ point: CGPoint) -> Bool

Returns a Boolean value indicating whether the area enclosed by the receiver contains the specified point.