Standard controls on top of NSGradients
-
I have a custom NSView subclass that contains an NSGradient. All this class does is draw a grey vertical gradient like iPhoto and iTunes do.
When I place standard controls on top of one of my custom gradient views, when clicked, they also draw their rects with the same gradient - even though I don't include any code to do that. Do I need to lockFocus or some other aspect of CG on my custom view before I draw my gradient in my view's drawRect: method?
Thanks,
Chuck -
On Apr 5, 2010, at 12:15 PM, Charles Burnstagger wrote:
> When I place standard controls on top of one of my custom gradient views, when clicked, they also draw their rects with the same gradient - even though I don't include any code to do that. Do I need to lockFocus or some other aspect of CG on my custom view before I draw my gradient in my view's drawRect: method?
What happens is when those controls redraw, some part of your view is invalidated, so you are asked to draw again. I suspect that when you draw, you are then using the rect parameter passed to -drawRect: to determine the extends of the gradient – which is incorrect.
The rect parameter passed to -drawRect: is only a hint as to what parts of the view need to be redrawn. You should always do your drawing with respect to your view's bounds.
--
David Duncan
Apple DTS Animation and Printing -
Thanks.
Changing to [ self.theGradient drawInRect:self.bounds angle:90.0 ];
in drawRect:
did the trick.
Chuck
________________________________
From: David Duncan <david.duncan...>
To: Charles Burnstagger <burnstagger...>
Cc: <cocoa-dev...>
Sent: Mon, April 5, 2010 12:23:46 PM
Subject: Re: Standard controls on top of NSGradients
On Apr 5, 2010, at 12:15 PM, Charles Burnstagger wrote:
> When I place standard controls on top of one of my custom gradient views, when clicked, they also draw their rects with the same gradient - even though I don't include any code to do that. Do I need to lockFocus or some other aspect of CG on my custom view before I draw my gradient in my view's drawRect: method?
What happens is when those controls redraw, some part of your view is invalidated, so you are asked to draw again. I suspect that when you draw, you are then using the rect parameter passed to -drawRect: to determine the extends of the gradient – which is incorrect.
The rect parameter passed to -drawRect: is only a hint as to what parts of the view need to be redrawn. You should always do your drawing with respect to your view's bounds.
--
David Duncan
Apple DTS Animation and Printing
