CODEWITHSUNDEEP
objective-ccocoa
Bret
Bret

Reputation: 912

Does each CALayer have it's own CGContextRef?

I'm trying to figure out the best way to do hit detection on a CALayer containing a non-rectangular path. I am aware of the CGContextPathContainsPoint function but im not sure how to get a reference to the appropriate CGContextRef when I need to do hit detection (like mouse down). Is it safe to retain a reference to the CGContextRef that is passed to the (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx delegate method for purposes of hit detection? I'm not sure if the same CGContextRef could potentially be modified by other layers.

Upvotes: 0

Views: 993

Answers (2)

Omkar
Omkar

Reputation: 1118

Use CAShapeLayer instead CALayer, if you are dealing with drawing shapes over layer. CAShapeLayer contains CGPath, so you don't need to maintain CGPath in your CALayer.

Upvotes: 1

Peter Hosey
Peter Hosey

Reputation: 96323

Have the layer own a CGPath and hit-test that. Then you don't have to worry about whether it's safe to retain the context, and you don't have to re-plot the path every time, either.

Upvotes: 3

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