gtk:window-set-keep-above (window setting)

window -- a gtk:window widget
setting -- a boolean whether to keep window above other windows

Asks to keep the window above, so that it stays on top. Note that you should not assume the window is definitely above afterward, because other entities, for example, the user or window manager, could not keep it above, and not all window managers support keeping windows above. But normally the window will end kept above. Just do not write code that crashes if not.

It is permitted to call this function before showing a window, in which case the window will be kept above when it appears onscreen initially.

You can track the above state via the "window-state-event" signal on the gtk:widget object.

Note that, according to the Extended Window Manager Hints specification, the above state is mainly meant for user preferences and should not be used by applications, for example, for drawing attention to their dialogs.