On X11, sends an X ClientMessage event to all toplevel windows on
screen.
Toplevel windows are determined by checking for the WM_STATE property,
as described in the Inter-Client Communication Conventions Manual (ICCCM).
If no windows are found with the WM_STATE property set, the message is
sent to all children of the root window.
On Windows, broadcasts a message registered with the name
GDK_WIN32_CLIENT_MESSAGE to all top-level windows. The amount of
data is limited to one long, i.e. four bytes.
Since 2.2
On X11, sends an X ClientMessage event to all toplevel windows on screen. Toplevel windows are determined by checking for the WM_STATE property, as described in the Inter-Client Communication Conventions Manual (ICCCM). If no windows are found with the WM_STATE property set, the message is sent to all children of the root window. On Windows, broadcasts a message registered with the name GDK_WIN32_CLIENT_MESSAGE to all top-level windows. The amount of data is limited to one long, i.e. four bytes. Since 2.2