Objective C - OS X - Issue adding NSShadow to NSImageView

Question

I am trying to add a shadow to a NSImageView on an MAC application.

I created a custom NSImageView class "ShadowView.h" and modified the drawRect: like so:

- (void)drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];

    NSShadow *shadow = [[NSShadow alloc] init];
    [shadow setShadowBlurRadius:5];
    [shadow setShadowOffset:NSMakeSize(30.0, 3.0)];
    [shadow setShadowColor:[NSColor redColor]];
    [shadow set];

    [self setWantsLayer:YES];
    [self setShadow:shadow];
}

However nothing happens. Also, when I debug I can see the above code being called. I looked at this question from 5 years ago but it seems to not work anymore

Adding a Shadow to a NSImageView

Thank you!

Answer 1

When adding a shadow to a view, that view's superview also needs to have layer-backing enabled. If it doesn't, the view's shadow gets clipped at its own bounds, as seen in this sample app:

Make sure you call -setWantsLayer:YES on your view's superview (or check the "Core Animation Layer" checkbox in Interface Builder) in order to make sure the shadow is completely visible: