[ros-dev] Problem drawing the desktop in the updated color

[James Tabor]

Hi,
Timo Kreuzer wrote:
> Hi,
> 
> First, this is going to be a long post, sorry ;-)
> You might have noticed, that I have been working on the desk.cpl 
> appearance tab, wich is working partly.
> Here's the first version: 
> http://www.reactos.org/bugzilla/show_bug.cgi?id=1732
> 
> Some things still don't work. For example the desktop doesn't get 
> repainted in the new color.
> 
>> ------- /Comment #5 
>> <http://www.reactos.org/bugzilla/show_bug.cgi?id=1732#c5> >From 
>> jimtabor 2006-08-05 04:46:36 CET / [reply 
>> <http://www.reactos.org/bugzilla/show_bug.cgi?id=1732#add_comment>] 
>> -------
>>
>>Hi,
>>You can use WM_SYSCOLORCHANGE in the desktop proc if it is used, should be!,
>>user32/misc/desktop.c;
>>
>>static
>>LRESULT
>>WINAPI
>>DesktopWndProc( HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam )
>>{
>>    DPRINT1("Desktop Class Atom!\n");
>>    switch(message)
>>   {
>>    case WM_NCCREATE:
>>         return TRUE;
>>
>>    case WM_CREATE:
>>    /* when I spy I see notify */
>>         SendNotifyMessageW( hwnd, WM_SYSCOLORCHANGE , 0, 0 );
>>    break;
>>
>>    case WM_SYSCOLORCHANGE:
>>    /* update everything, well in theory anyway */
>>         RedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE | RDW_ERASE |
>>RDW_ALLCHILDREN );
>>    break;
>>
>>    default:
>>         return DefWindowProcW(hwnd,message,wParam,lParam);
>>    }
>>    return 0;  /* all other messages are ignored */
>>}
>>
>>Its crude, I'm not sure if it will compile, its off the top of my head ATM.
>>8^D
>>Thanks,
>>James
>>  
>>
> Thanks for helping, James. I tried it, but it doesn't work.
Not surprised at all. We dont use the desktop class when the explorer desktop is opened.

> 1.) Sending WM_SYSCOLORCHANGE on WM_CREATE will probably do nothing, 
> because the desktop has just been created with the initial SysColors, no 
> need to update them.
To init the system colors before the desktop is displayed.

OT Q. Is our explorer desktop a plug in replacement to the windows one?
One way to find out,,, look for explorer desktop replacement projects and read their
source.

> 2.) RedrawWindow calls NtUserRedrawWindow wich calls co_UserRedrawWindow 
> wich calls co_IntPaintWindows wich sends a WM_PAINT message to the 
> desktop window.
Redraw should refresh all of its children including its self and not push the
responsibility off to another app.

> WM_PAINT is then passed to DefWindowProc and passed on to 
> User32DefWindowProc wich does only repaint the icon as it seems.
> So WM_PAINT must be evaluated in DesktopWndProc.
No its not.

> 
> I tried the following:
> 
>>       case WM_PAINT:
>>       {
>>          PAINTSTRUCT ps;
>>          HDC hdc = BeginPaint(hwnd, &ps);
>>          PaintDesktop(hdc);
>>          EndPaint(hwnd, &ps);
>>       }
> 
this could be done in explorer desktop?

> PaintDesktop calls NtUserPaintDesktop, wich then paints the desktop.
> I have also replaced
>   DesktopBrush = (HBRUSH)UserGetClassLongPtr(WndDesktop->Class, 
> GCL_HBRBACKGROUND, FALSE);
> with
>   DesktopBrush = IntGetSysColorBrush(COLOR_BACKGROUND);
> 
> But the desktop is still painted in the original color, whereas the icon 
> text is in the color I have set in the registry.
> 
> I played a little around with the code in NtUserPaintDesktop. I added 
> the following code before the desktop background is painted:
> 
>> if (IntGetSysColor(COLOR_BACKGROUND) == 0) // This is true after 
>> SysColors are loaded from Registry
>> {
>>   DesktopBrush = IntGetSysColorBrush(COLOR_ACTIVECAPTION);
>> }
> 
> And suddenly the desktop is painted in COLOR_ACTIVECAPTION.
> This is strange, because I also added CreateSysColorObjects(); at the 
> beginning of NtUserPaintDesktop.
> 
> Anybody any idea?
> 
> 
No, sorry, not at this moment.

For the Devs, Yes, we plug in explorer by creating the desktop using the
desktop class, So the class proc will get called. Was there a patch?

8^)
Okay,
James