[cairo] mixing native OSX widgets with a cairo canvas

[Vladimir Vukicevic]

On Jan 16, 2008, at 5:20 PM, Bobby Powers wrote:

> hello!
>
> I am starting to work on my pet project, and it requires people to  
> be able to add text labels to different parts of a cairo canvas on  
> MacOS X.  I could just draw a text input box and flash a vertical  
> line as a cursor, but I know that Firefox 3 mixes native widgets  
> with a cairo canvas to lay out pages, and I was hoping to do the  
> same.  I've tried adding UI elements as subviews, but it didn't seem  
> to work.  Does anyone have any suggestions?  I downloaded the source  
> for the latest FF3 beta, but I must admit I was a little overwhelmed  
> and couldn't find anything.

We basically grab the CGContext from the quartz surface, recreate the  
cairo_t state, and then make HITheme calls to draw the widget bits.   
Check out http://mxr.mozilla.org/seamonkey/source/widget/src/cocoa/nsNativeThemeCocoa.mm 
  -- specifically the nsNativeThemeCocoa::DrawWidgetBackground method  
(called "draw background" because the background is the native part,  
and then we draw things like text on top of it).

     - Vlad