Method UpdateMenuBars

source/script_gui.cpp:2611–2638

void GuiType::UpdateMenuBars(HMENU aMenu)
// Caller has changed aMenu and wants the change visibly reflected in any windows that that
// use aMenu as a menu bar.  For example, if a menu item has been disabled, the grey-color
// won't show up immediately unless the window is refreshed.
{
	for (GuiType* gui = g_firstGui; gui; gui = gui->mNextGui)
	{
		//if (gui->mHwnd) // Always non-NULL for any item in the list.
		if (GetMenu(gui->mHwnd) == aMenu && IsWindowVisible(gui->mHwnd))
		{
			// Neither of the below two calls by itself is enough for all types of changes.
			// Thought it's possible that every type of change only needs one or the other, both
			// are done for simplicity:
			// This first line is necessary at least for cases where the height of the menu bar
			// (the number of rows needed to display all its items) has changed as a result
			// of the caller's change.  In addition, I believe SetWindowPos() must be called
			// before RedrawWindow() to prevent artifacts in some cases:
			SetWindowPos(gui->mHwnd, NULL, 0, 0, 0, 0, SWP_DRAWFRAME|SWP_FRAMECHANGED|SWP_NOMOVE|SWP_NOSIZE|SWP_NOZORDER|SWP_NOACTIVATE);
			// This line is necessary at least when a single new menu item has been added:
			RedrawWindow(gui->mHwnd, NULL, NULL, RDW_INVALIDATE|RDW_FRAME|RDW_UPDATENOW);
			// RDW_UPDATENOW: Seems best so that the window is in an visible updated state when function
			// returns.  This is because if the menu bar happens to be two rows or its size is changed
			// in any other way, the window dimensions themselves might change, and the caller might
			// rely on such a change being visibly finished for PixelGetColor, etc.
			//Not enough: UpdateWindow(gui->mHwnd);
		}
	}
}