Win32 Tab Control grey background - c++

Question

I am trying to make make my ui in win32 everywhere white. The problem is that my tab control's background is not white , so the not the tab itself, but the party next to the tabs is grey.
I am handling WM_CTLCOLORSTATIC for the static controls, but it does not seems to work for the tab control.
case WM_CTLCOLORSTATIC:
{
HDC hEdit = (HDC)w_param;
SetBkMode(hEdit, TRANSPARENT);
SetTextColor(hEdit, RGB(0, 0, 0));
SetBkColor(hEdit, RGB(255, 255, 255));
// Do not return a brush created by CreateSolidBrush(...) because you'll get a memory leak
return (INT_PTR)GetStockObject(WHITE_BRUSH);
}
I hope there is an 'easy' way to make my entire ui white :)
Grz

Answer 1

You can not capture a message to draw on the grey background. The system draws everything in the WM_PRINTCLIENT. There is however a nice hack! The idea is from this post.
I do this (in my WM_PAINT handler):
Create a memory DC to draw into
Send a WM_PRINTCLIENT message to the tab control to get it to draw the tabs into your memory DC
Create a region which mirrors the shape of the tabs
Fill the parts of the memory DC outside this region (RGN_DIFF) with the desired background brush
Blt the result into the DC returned by BeginPaint
Call EndPaint and return, without calling the tab control's own WndProc of course :)
Step 3 is a bit fiddly as you have to know the location and shape of the tabs, but other
than that it's a pretty clean solution (see image below the following sample code). You
could probably use TransparentBlt to replace the system background colour instead.
I am using TransparentBlt in this solution:
create hdcMemTab, step 1
HBITMAP hBitmap, hBitmapOld ; //keep them till the end of the program
HDC hdcMemTab; //keep it till the end of the program
HDC hdc;
Rect rt;
hdc = CreateIC(TEXT("DISPLAY"), NULL, NULL, NULL);
hdcMemTab = CreateCompatibleDC(hdc);
GetWindowRect(hwnd_Tab, &rt);
rt.right = rt.right - rt.left;
rt.bottom = rt.bottom - rt.top;
rt.left = 0;
rt.top = 0;
hBitmap = CreateCompatibleBitmap(hdc, rt.right, rt.bottom);
hBitmapOld = SelectObject(hdcMemTab, hBitmap);
DeleteDC(hdc);
In WM_PAINT of the subclassed tab control:
RECT rt, rtTab;
HDC hdc = BeginPaint(hwnd, &ps);
GetWindowRect(hwnd_Tab, &rt);
rt.right = rt.right - rt.left;
rt.bottom = rt.bottom - rt.top;
rt.left = 0;
rt.top = 0;
//step 2
SendMessage(hwnd_Tab, WM_PRINTCLIENT, (WPARAM)hdcMemTab, PRF_CLIENT);
FillRect(hdc, &rt, gBrushWhite); //gBrushWhite has the desired background color
HRGN hRgn = CreateRectRgn(0, 0, 0, 0);
int n_items = TabCtrl_GetItemCount(hwnd_Tab);
//get tabs region, step 3
for(i = 0; i < n_items; i++){
TabCtrl_GetItemRect(hwnd_Tab, i, &rtTab);
HRGN hTabRgn = CreateRectRgn(rtTab.left, rtTab.top, rtTab.right, rt.bottom);
CombineRgn(hRgn, hRgn, hTabRgn, RGN_OR);
DeleteObject(hTabRgn);
}
GetRgnBox(hRgn, &rtTab);
DeleteObject(hRgn);
//step 5
TransparentBlt(hdc, 0, 0, rt.right, rt.bottom, hdcMemTab, 0, 0, rt.right, rt.bottom, RGB(240, 240, 240)); //(240, 240, 240) is the grey color
BitBlt(hdc, rtTab.left, rtTab.top, rtTab.right - 5, rtTab.bottom, hdcMemTab, rtTab.left, rtTab.top, SRCCOPY);
EndPaint(hwnd, &ps);
//step 6
return 0;

Answer 2

Sorry about my english. What I do is return 0 in WM_PRINTCLIENT message without doing anything, I mean, preventing WM_PRINTCLIENT from calling DefWindowProc. This causes the tabcontrol header to have the same background color as its parent window. The same goes for the TrackBar.
I only have it tested on windows 10, I would like to know if it works for win 7 too.