Owner drawn button flicker hell

[Christian Graus]

I'm not using MFC, and I'm storing bitmaps inside my own button classes, which encapsulate the HWND of the button. If I respond to the WM_DRAWITEM message, and draw my buttons, they flicker like crazy if the window is being resized ( and they are moved ). The ones that stay put also flicker as they are redrawn. I've been trying to get a wndproc happening to subclass the buttons, but that seems not to want to work. Does anyone have any other suggestions ? Christian After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOz

I live in Bob's HungOut now

[Rick Dangerous]

Whenever your window is being resized, your main window is receiving a WM_ERASEBKGND message. This message by default erases all the controls on the window which then need to be redrawn. This is bad for flicker. One was around this would be to use the following routine to only fill in that windows area by excluding the areas of the controls on the window so they are not erased:

int dont_erase_indexes[] =
{
IDC_DPAS_LAMP,
IDC_INSTRUMENT_TYPE,
IDC_LABEL1,
IDC_LABEL2,
IDC_DESTINATION,
IDC_CURRENT_STATUS,
IDC_LOG,
IDC_GRAPH,
IDC_DOWNLOAD_STATUS,
IDC_DOWNLOAD_PROGRESS,
ID_AUTO_LOAD,
IDC_UPLOAD_ASSAYS,
IDC_AUTO_UPLOAD,
IDC_BROWSE_FOR_FOLDER
} ;

BOOL CYourWindow::OnEraseBkgnd(CDC* pDC)
{
static int dont_erase_indexes[] =
{// this is a list of the ID's of the controls on the parent window
IDC_DPAS_LAMP,
IDC_INSTRUMENT_TYPE,
IDC_LABEL1,
IDC_LABEL2,
IDC_DESTINATION,
IDC_CURRENT_STATUS,
IDC_LOG,
IDC_GRAPH,
IDC_DOWNLOAD_STATUS,
IDC_DOWNLOAD_PROGRESS,
ID_AUTO_LOAD,
IDC_UPLOAD_ASSAYS,
IDC_AUTO_UPLOAD,
IDC_BROWSE_FOR_FOLDER
} ;
CRect clip ;
pDC->SaveDC() ;
for (int i = 0 ; i < sizeof(dont_erase_indexes) / sizeof(int) ; i++)
{
GetDlgItem(dont_erase_indexes[i])->GetWindowRect(&clip); // get rect of the control
ScreenToClient(&clip);
pDC->ExcludeClipRect(&clip);
}
pDC->GetClipBox(&clip);
pDC->FillSolidRect(clip, GetSysColor(COLOR_BTNFACE));
pDC->RestoreDC(-1) ;
return FALSE;
}

Hope this helps out Roger Bin Allen :-D

[Christian Graus]

Hey, cool. I did not know about this stuff, thank you *very* much. Christian After all, there's nothing wrong with an elite as long as I'm allowed to be part of it!! - Mike Burston Oct 23, 2001

Sonork ID 100.10002:MeanManOz

I live in Bob's HungOut now