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Window Close Button MessageBox with GLUT

ruzip (103)
Is there a way to attach a messagebox confirmation if a GLUT Window close button is triggered?

Currently this works but it disables GLUT keyboard events:

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LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
	int choice;
    switch (uMsg) {
        case WM_CLOSE:
            // Display the message box
            choice = MessageBox(NULL, "Quit?", "MyWindow", MB_YESNO | MB_ICONQUESTION);
            if (choice == IDYES) {
                // Close the window
                DestroyWindow(hWnd);
                exit(0);
            }
            // Do nothing if the user selects "No" or closes the message box without making a choice
            return 0;
        default:
            return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
}

...
...

hWnd = FindWindow(NULL, "MyWindow");
WNDPROC oldProc = (WNDPROC)SetWindowLongPtr(hWnd, GWLP_WNDPROC, (LONG_PTR)WindowProc);


I'm using GLUT since this is overall intended for cross-platform and this extra part is just specific for Windows.
Last edited on
kigar64551 (814)
Have you tried forwarding the messages to oldProc(), instead of DefWindowProc(), in your WindowProc() ???

Probably GLUT has installed its own WNDPROC and you are kicking that one out of chain!

Also I think that obtaining the window handle with FindWindow() where only the title is specified, is not really reliable. Normally you should have the HWND of the window that you created yourself in a more direct way.
Last edited on
ruzip (103)
Thanks kigar, solved.. also got a suggestion to use hWnd = GetActiveWindow() instead.
kigar64551 (814)
Try with global __glutCurrentWindow variable:

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extern GLUTwindow *__glutCurrentWindow;
__glutCurrentWindow->win // <-- should be HWND on Win32
__glutCurrentWindow->renderWin // <-- should be HWND on Win32
Last edited on
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