Variable: mouse-leave-buffer-hook
mouse-leave-buffer-hook is a variable defined in callint.c.
Value
(hmouse-save-region)
Documentation
Hook run when the user mouse-clicks in a window.
It can be run both before and after switching windows, or even when not actually switching windows.
Its purpose is to give temporary modes such as Isearch mode a way to turn themselves off when a mouse command switches windows.
Source Code
// Defined in /usr/src/emacs/src/callint.c
DEFVAR_LISP ("mouse-leave-buffer-hook", Vmouse_leave_buffer_hook,
doc: /* Hook run when the user mouse-clicks in a window.
It can be run both before and after switching windows, or even when
not actually switching windows.
Its purpose is to give temporary modes such as Isearch mode
a way to turn themselves off when a mouse command switches windows. */);