Re: Drawing aside of -drawRect

[Fred Kiefer]

Tima Vaisburd wrote:
> I have problems with drawing in any method but [NSView -drawRect].
>
> I placed the drawing code directly in the mouse event processing
> handler, like this:
>
> // This is a method of NSView subclass
>
> - (void) mouseDragged:(NSEvent *) event
> {
>         NSPoint sketch_origin = ... ;
>
>         [self lockFocus];
>
>         // NSImage * _sketch, * _mask defined elsewhere
>
>         [_sketch compositeToPoint: sketch_origin operation: NSCompositeCopy];
>
>         [_mask compositeToPoint: sketch_origin 
>                     operation: NSCompositeSourceOver];
>
>         [self unlockFocus];
>     }
> }
>
> Nothing happens when the backing store is buffered or retained.
> What do I miss?

The short answer here is never to draw outside of the drawRect: 
framework. You could always mark the area as needing a refresh and give 
the run loop a chance.
If you still belive that you have to do the drawing here and are sure 
that this is the main thread, what you need to add is
[_window flushWindow];
But don't tell anybody I helped you to draw where you should not. :-)

Cheers
Fred