Re: [2/3] comctl32: Never draw item text with OPAQUE.

[Dimi Paun]

On Fri, March 16, 2007 11:39, Felix Nawothnig wrote:
> This fixes a glitch (blue text background inside a red selected cell))
> in SuperGrid (http://flexo.popuserv.org/SuperGrid.exe) and appears to be
> what native does.
>
> There is no need to use OPAQUE anyway since we always draw the selection
> background seperatly.

But this ends up creating and deleting the brush for each of the cells
we draw... I'm not sure I understand why using OPAQUE here doesn't work.

-- 
Dimi Paun <dimi(a)lattica.com>
Lattica, Inc.

[2/3] comctl32: Never draw item text with OPAQUE.

[Felix Nawothnig]

Dimi Paun wrote:
> But this ends up creating and deleting the brush for each of the cells

Well - yes. But other controls do this too (statusbar for example) and 
considering all the stuff we do during refresh this is hardly a 
bottleneck. And even if it is we should optimize this codepath in gdi32 
instead (by caching solid brushs for example).
> we draw... I'm not sure I understand why using OPAQUE here doesn't work.

Problem is that DrawText() for the subitems will also use the 
background color - which is wrong. To fix this while still using OPAQUE 
we'd need to do something like:

SetBkMode(OPAQUE);
TextOutW(...);
SetBkMode(TRANSPARENT);

But abusing TextOutW() like that just seems wrong to me.

Using DrawText() to draw the background won't work either due to 
LVS_EX_FULLROWSELECT (well, I guess we *could* do it by DrawText()ing 
the first item over the full row and the subitems on top of it but I'd 
prefer to _simplify_ the code, not add more hacks).

Felix

[2/3] comctl32: Never draw item text with OPAQUE.

[Felix Nawothnig]

Felix Nawothnig wrote:
> Well - yes. But other controls do this too (statusbar for example) and 
> considering all the stuff we do during refresh this is hardly a 
> bottleneck. And even if it is we should optimize this codepath in gdi32 
> instead (by caching solid brushs for example).

...looking at the statusbar code again I think using GetSysColorBrush() 
for the three default cases would be even better. If an app overrides 
the colors using CD performance will suffer slightly but that's 
Microsoft's fault by requesting a COLORREF and not a brush for each item.

Felix