How to handle event of push button on non client area

Question

EDIT: I’ve used the following code to draw a push button at the non client area (the title bar) of my window. So my question is: Is possible to handle mouse click event from this button?

bool MainWindow::winEvent(MSG *pMessage, long *result)
{
    UINT m = pMessage->message;
    if(m == WM_NCPAINT || m == WM_ACTIVATE)
    {
        HWND id = winId();
        HDC hDeviceContext = GetWindowDC(id);
        RECT rc = {10, 10, 65, 25};
        DrawFrameControl(hDeviceContext, &rc, DFC_BUTTON, DFCS_BUTTONPUSH);
        ReleaseDC(id, hDeviceContext);
        return true;
    }
    return QWidget::winEvent(pMessage, result);
}

Answer 1

Yes this is quite easy to do. Windows provides several messages specifically for the non-client area. For example you have WM_NCMOUSEMOVE which can be handled just like WM_MOUSEMOVE but specifically for the non-client area. Most of the messages work like their client-area counterparts and usually with the same data structures. Below is a list of non-client area messages.

WM_NCCREATE
WM_NCDESTROY 
WM_NCCALCSIZE
WM_NCHITTEST 
WM_NCPAINT 
WM_NCACTIVATE

WM_NCMOUSEMOVE
WM_NCLBUTTONDOWN
WM_NCLBUTTONUP
WM_NCLBUTTONDBLCLK
WM_NCRBUTTONDOWN
WM_NCRBUTTONUP
WM_NCRBUTTONDBLCLK
WM_NCMBUTTONDOWN
WM_NCMBUTTONUP
WM_NCMBUTTONDBLCLK

WM_NCXBUTTONDOWN
WM_NCXBUTTONUP
WM_NCXBUTTONDBLCLK

WM_NCMOUSEHOVER
WM_NCMOUSELEAVE