Aha. I know what this is.
 
A few Windows controls draw themselves (or parts of themselves) outside the 
WM_PAINT DefWndProc. Most should draw in WM_PAINT, but a very few (like 
RichEdits, if I remember correctly) draw when some other messages are posted, 
such as "i have been modified" messages etc. In other words, they handle their 
own redrawing by sending themselves messages internally. I'd have to spend some 
time on MSDN checking out where RichEdits actually draw themselves, but I don't 
have time to dig into that right at this minute.
 
There will obviously need to be a few special cases for controls that don't 
work quite as expected. Are you resizing the richedit control with the window 
(scaling it in the window's xxx_Resize handler), or is it just the window on 
it's own that you are resizing? What happens if you InvalidateRect on the 
richedit control whenever the window is being resized? You say you're left with 
an empty grey control. Is the grey a different grey to the window background? 
If you're left with a dark grey box that at least tells me that SOMETHING is 
being done on WM_PRINT, probably - as you said - just the groundwork for 
subsequent drawing of the control contents.
 
I believe the grid control you mentioned is one of Laurent's modules and it 
uses some third party opensource grid control code written in C, I think he 
links to it on his site so I can have a look through that code and find out 
just why that particular control isn't drawing right. One hopes that WM_PRINT 
is implemented there.
 
23 windows?!
 
Steve

-----Original Message-----
From: Jez White [mailto:[EMAIL PROTECTED]
Sent: 17 December 2003 11:53
To: Stephen Pick; guihackers
Subject: Re: [perl-win32-gui-hackers] -noflicker Feedback/bugs


Hi, 

Unfortunately I never received the original email from the list - spam filters 
are at work stopping me receiving some of the posts. I've rejoined under a 
different email address. 

My app is fairly complex, with hundreds of controls and 23 windows. The fact 
that -noflicker works so well is impressive. 

The symptoms of the RichEdit control are similar to Grid in that the contents 
aren't visible until the control is changed (say by moving the scroll bar). On 
a resize you can *sometimes* (difficult to reproduce on a consistent basis) see 
the flash of the original contents of the RichEdit - all you are left with is 
an empty grey control. By the looks of things the RichEdit draws itself in two 
phases, the first it greys out the contents, and paints the bounding box, and 
in the second it paints the contents. Does this make any sense? 

I'd be happy to supply examples. I'll try the suggestions you made. 

Cheers, 

jez. 

----- Original Message ----- 
From: Stephen  <mailto:[EMAIL PROTECTED]> Pick 
To: Jez White <mailto:[EMAIL PROTECTED]>  ; guihackers 
<mailto:perl-win32-gui-hackers@lists.sourceforge.net>  
Sent: Wednesday, December 17, 2003 10:49 AM
Subject: RE: [perl-win32-gui-hackers] -noflicker Feedback/bugs

Yes yes yes.
 
As was posted in the mail regarding the -noflicker option, as was written in 
the documentation for the noflicker option, and as was noted in the changelog 
for the noflicker option: IT BREAKS STUFF. If it didnt, it wouldnt be an option.
 
I'm gratified to see that most of the stuff it's broken for you is nonstandard 
Win32::GUI stuff (I mean, not part of Win32::GUI itself but add-ons). I'm 
surprised that it breaks RichEdit, but not surprised that it breaks Graphics.
 
The -noflicker option should be considered an alpha fix, something that I'm 
working on. You may be able to solve the problem you experience with 
disappearing richedit controls by calling InvalidateRect on them, or adding 
PRF_OWNED to the delivery of the WM_PRINT message in the CommonMsgLoops section 
of the GUI_MessageLoops.cpp file.
 
Incidentally, the reason it breaks Graphics is because Graphics is just a DC, 
and thus is not "drawn" into a parent DC, but is stand-alone. WM_PRINT won't 
capture the contents of other DCs, it simply tells a widget to draw itself into 
the given DC, and one can't draw a DC into a DC.
 
As far as RichEdit goes, I'm guessing it simply doesnt support WM_PRINT at all. 
It will require some looking into, and if all else fails making a compromise by 
just making the RichEdit and Graphics controls flicker like they used to.
 
Steve

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Jez White
Sent: 16 December 2003 14:11
To: guihackers
Subject: [perl-win32-gui-hackers] -noflicker Feedback/bugs


All, 
 
I've been testing with the latest source and I've found various issues with the 
-noflicker option. 
 
All the following controls resize correctly, but the contents aren't visible 
until the user interacts with the control (say moving a scroll bar). The 
contents of the control is windows grey.
 
* Win32::GUI::Grid 
* Win32::GUI::Scintilla 
* RichEdit
 
The following controls resize correctly, and the contents are correct but the 
control still flickers.
 
* Win32::GUI::AxWindow
* Graphic control
 
I've had a look through the source - but didn't get anywhere. I can provide 
examples if needed.
 
Other than the issues, a great option. Nice work.
 
Cheers,
 
jez.
 

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