comctl32/button: Implement NM_CUSTOMDRAW for themed Push Buttons.

dlls/comctl32/button.c

@@ -1904,19 +1904,50 @@ static void PB_ThemedPaint(HTHEME theme, const BUTTON_INFO *infoPtr, HDC hDC, in
     HFONT font = infoPtr->font;
     HFONT hPrevFont = font ? SelectObject(hDC, font) : NULL;
     WCHAR *text = get_button_text(infoPtr);
+    NMCUSTOMDRAW nmcd;
+    LRESULT cdrf;
+    HWND parent;
 
     GetClientRect(infoPtr->hwnd, &bgRect);
     GetThemeBackgroundContentRect(theme, hDC, BP_PUSHBUTTON, state, &bgRect, &textRect);
+    init_custom_draw(&nmcd, infoPtr, hDC, &bgRect);
+
+    parent = GetParent(infoPtr->hwnd);
+    if (!parent) parent = infoPtr->hwnd;
+
+    /* Send erase notifications */
+    cdrf = SendMessageW(parent, WM_NOTIFY, nmcd.hdr.idFrom, (LPARAM)&nmcd);
+    if (cdrf & CDRF_SKIPDEFAULT) goto cleanup;
 
     if (IsThemeBackgroundPartiallyTransparent(theme, BP_PUSHBUTTON, state))
         DrawThemeParentBackground(infoPtr->hwnd, hDC, NULL);
     DrawThemeBackground(theme, hDC, BP_PUSHBUTTON, state, &bgRect, NULL);
+
+    if (cdrf & CDRF_NOTIFYPOSTERASE)
+    {
+        nmcd.dwDrawStage = CDDS_POSTERASE;
+        SendMessageW(parent, WM_NOTIFY, nmcd.hdr.idFrom, (LPARAM)&nmcd);
+    }
+
+    /* Send paint notifications */
+    nmcd.dwDrawStage = CDDS_PREPAINT;
+    cdrf = SendMessageW(parent, WM_NOTIFY, nmcd.hdr.idFrom, (LPARAM)&nmcd);
+    if (cdrf & CDRF_SKIPDEFAULT) goto cleanup;
+
     if (text)
     {
-        DrawThemeText(theme, hDC, BP_PUSHBUTTON, state, text, lstrlenW(text), dtFlags, 0, &textRect);
+        if (!(cdrf & CDRF_DOERASE))
+            DrawThemeText(theme, hDC, BP_PUSHBUTTON, state, text, lstrlenW(text), dtFlags, 0, &textRect);
         heap_free(text);
     }
 
+    if (cdrf & CDRF_NOTIFYPOSTPAINT)
+    {
+        nmcd.dwDrawStage = CDDS_POSTPAINT;
+        SendMessageW(parent, WM_NOTIFY, nmcd.hdr.idFrom, (LPARAM)&nmcd);
+    }
+    if (cdrf & CDRF_SKIPPOSTPAINT) goto cleanup;
+
     if (focused)
     {
         MARGINS margins;
@@ -1932,6 +1963,7 @@ static void PB_ThemedPaint(HTHEME theme, const BUTTON_INFO *infoPtr, HDC hDC, in
         DrawFocusRect( hDC, &focusRect );
     }
 
+cleanup:
     if (hPrevFont) SelectObject(hDC, hPrevFont);
 }