Question

Iam using a custom layer for drawing on my UIView. And to invalidate and update the layer I need to set my view to be the delegate of my CALayer. When this is done it draws my text correctly but when the view receives touches the app crashes.
What I am a doing wrong?

- (void) layoutSubView {
    if (drawLayer == nil) {
        drawLayer = [[CALayer alloc] init];
        [drawLayer setDelegate:self];
        [[self layer] addSublayer:drawLayer];
    }
    [drawLayer setFrame:[self bounds]]; 
    [drawLayer setNeedsDisplay];
}

Above is my code to setup the CALayer, and below is the overridden drawLayer method.

- (void) drawLayer:(CALayer *)layer 
     inContext:(CGContextRef)ctx {

        if (layer == drawLayer) {
        UIGraphicsPushContext(ctx);
        [self drawTitle:ctx];
        UIGraphicsPopContext();
    }
}

Here is the stack.

Answer 1

You can’t use a UIView object to be the delegate of a layer other than its own layer. Its stated here. You will need to assign some other object as its delegate.