Re: PlotIconRefInContext doesn't work

FROM : Uli Kusterer
DATE : Sun May 18 00:16:38 2008

> On May 17, 2008, at 12:37 AM, Mike wrote:
>

>> It's a local NSRect which I assume is interchangeable with CGRect 
>> as they are the same.
>>
>> I fill in the rect at the top of the method with the Rect of the 
>> item in the window from IB and then I hide the item before drawing 
>> to prevent my stuff from being drawn over.
>>
>> CGContextFillRect doesn't do anything either. Just a blank space as 
>> with PlotIconRefInContext.



  Can't find the start of this thread, so this may have already been 
covered, but:

  Have you checked whether the coordinate system of the port is 
flipped? You can flip the Y axis of a context, and then drawings 
relative to the lower left edge of the context will actually be drawn 
relative to the upper left, and can end up offscreen depending on what 
drawing call you're using (some drawing calls aren't intended for 
flipped rects, and always draw upwards or downwards from a point 
instead of flipping the rect correctly, which is why you have e.g. 
CGContextDrawImage() and HIViewDrawCGImage()).

  There's also some cases where CG and Cocoa may disagree on whether a 
context is flipped or not, or someone applied an affine transform to a 
port that causes your drawing to end up off screen.

Cheers,
-- Uli Kusterer
"The Witnesses of TeachText are everywhere..."
http://www.zathras.de