[Emacs-diffs] Changes to emacs/lispref/os.texi,v

[Richard M. Stallman]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     Richard M. Stallman <rms>       06/08/20 12:09:37

Index: os.texi
===================================================================
RCS file: /cvsroot/emacs/emacs/lispref/os.texi,v
retrieving revision 1.89
retrieving revision 1.90
diff -u -b -r1.89 -r1.90
--- os.texi     12 Aug 2006 12:55:07 -0000      1.89
+++ os.texi     20 Aug 2006 12:09:37 -0000      1.90
@@ -28,6 +28,8 @@
 * Processor Run Time::  Getting the run time used by Emacs.
 * Time Calculations::   Adding, subtracting, comparing times, etc.
 * Timers::             Setting a timer to call a function at a certain time.
+* Idle Timers::         Setting a timer to call a function when Emacs has
+                          been idle for a certain length of time.
 * Terminal Input::      Accessing and recording terminal input.
 * Terminal Output::     Controlling and recording terminal output.
 * Sound Output::        Playing sounds on the computer's speaker.
@@ -1473,6 +1475,21 @@
 a timer to avoid waiting too long for an answer.  @xref{Yes-or-No
 Queries}.
 
address@hidden cancel-timer timer
+This cancels the requested action for @var{timer}, which should be a
+timer---usually, one previously returned by @code{run-at-time} or
address@hidden  This cancels the effect of that call to
+one of these functions; the arrival of the specified time will not
+cause anything special to happen.
address@hidden defun
+
address@hidden Idle Timers
address@hidden Idle Timers
+
+  Here is how to set up a timer that runs when Emacs is idle for a
+certain length of time.  Aside from how to set them nup, idle timers
+work just like ordinary timers.
+
 @deffn Command run-with-idle-timer secs repeat function &rest args
 Set up a timer which runs when Emacs has been idle for @var{secs}
 seconds.  The value of @var{secs} may be an integer or a floating point
@@ -1508,11 +1525,49 @@
 input.  Then it becomes idle again, and all the idle timers that are
 set up to repeat will subsequently run another time, one by one.
 
address@hidden cancel-timer timer
-Cancel the requested action for @var{timer}, which should be a value
-previously returned by @code{run-at-time} or @code{run-with-idle-timer}.
-This cancels the effect of that call to one of these functions; the
-arrival of the specified time will not cause anything special to happen.
address@hidden Emacs 19 feature
address@hidden current-idle-time
+This function returns the length of time Emacs has been idle, as a
+list of three integers: @code{(@var{high} @var{low} @var{microsec})}.
+The integers @var{high} and @var{low} combine to give the number of
+seconds of idleness, which is
address@hidden
address@hidden * 2**16 + @var{low}.
address@hidden ifnottex
address@hidden
+$high*2^{16}+low$.
address@hidden tex
+
+The third element, @var{microsec}, gives the microseconds since the
+start of the current second (or 0 for systems that return time with
+the resolution of only one second).
+
+The main use of this function is when an idle timer function wants to
+``take a break'' for a while.  It can set up another idle timer to
+call the same function again, after a few seconds more idleness.
+Here's an example:
+
address@hidden
+(defvar resume-timer nil
+  "Timer that `timer-function' used to reschedule itself, or nil.")
+
+(defun timer-function ()
+  ;; @r{If the user types a command while @code{resume-timer}}
+  ;; @r{is active, the next time this function is called from}
+  ;; @r{its main idle timer, deactivate @code{resume-timer}.}
+  (when resume-timer
+    (cancel-timer resume-timer))
+  address@hidden the work for a while}...
+  (when @var{taking-a-break}
+    (setq resume-timer
+          (run-with-idle-timer
+            ;; Compute an idle time @var{break-length} 
+            ;; more than the current value.
+            (time-add (current-idle-time)
+                      (seconds-to-time @var{break-length}))
+            nil
+            'timer-function))))
address@hidden smallexample
 @end defun
 
 @node Terminal Input