function unmaps the specified window and causes the X server to generate an
If the specified window is already unmapped,
has no effect.
Normal exposure processing on formerly obscured windows is performed.
Any child window will no longer be visible until another map call is
made on the parent.
In other words, the subwindows are still mapped but are not visible
until the parent is mapped.
Unmapping a window will generate
events on windows that were formerly obscured by it.
can generate a
function unmaps all subwindows for the specified window in bottom-to-top
It causes the X server to generate an
event on each subwindow and
events on formerly obscured windows.
Using this function is much more efficient than unmapping multiple windows
one at a time because the server needs to perform much of the work
only once, for all of the windows, rather than for each window.