Info Catalog elisp: Focus Events elisp: Input Events elisp: Event Examples

elisp: Misc Events

 
 20.7.10 Miscellaneous System Events
 -----------------------------------
 
 A few other event types represent occurrences within the system.
 
 ‘(delete-frame (FRAME))’
      This kind of event indicates that the user gave the window manager
      a command to delete a particular window, which happens to be an
      Emacs frame.
 
      The standard definition of the ‘delete-frame’ event is to delete
      FRAME.
 
 ‘(iconify-frame (FRAME))’
      This kind of event indicates that the user iconified FRAME using
      the window manager.  Its standard definition is ‘ignore’; since the
      frame has already been iconified, Emacs has no work to do.  The
      purpose of this event type is so that you can keep track of such
      events if you want to.
 
 ‘(make-frame-visible (FRAME))’
      This kind of event indicates that the user deiconified FRAME using
      the window manager.  Its standard definition is ‘ignore’; since the
      frame has already been made visible, Emacs has no work to do.
 
 ‘(wheel-up POSITION)’
 ‘(wheel-down POSITION)’
      These kinds of event are generated by moving a mouse wheel.  The
      POSITION element is a mouse position list (Click Events),
      specifying the position of the mouse cursor when the event
      occurred.
 
      This kind of event is generated only on some kinds of systems.  On
      some systems, ‘mouse-4’ and ‘mouse-5’ are used instead.  For
      portable code, use the variables ‘mouse-wheel-up-event’ and
      ‘mouse-wheel-down-event’ defined in ‘mwheel.el’ to determine what
      event types to expect for the mouse wheel.
 
 ‘(drag-n-drop POSITION FILES)’
      This kind of event is generated when a group of files is selected
      in an application outside of Emacs, and then dragged and dropped
      onto an Emacs frame.
 
      The element POSITION is a list describing the position of the
      event, in the same format as used in a mouse-click event (
      Click Events), and FILES is the list of file names that were
      dragged and dropped.  The usual way to handle this event is by
      visiting these files.
 
      This kind of event is generated, at present, only on some kinds of
      systems.
 
 ‘help-echo’
      This kind of event is generated when a mouse pointer moves onto a
      portion of buffer text which has a ‘help-echo’ text property.  The
      generated event has this form:
 
           (help-echo FRAME HELP WINDOW OBJECT POS)
 
      The precise meaning of the event parameters and the way these
      parameters are used to display the help-echo text are described in
      Text help-echo.
 
 ‘sigusr1’
 ‘sigusr2’
      These events are generated when the Emacs process receives the
      signals ‘SIGUSR1’ and ‘SIGUSR2’.  They contain no additional data
      because signals do not carry additional information.  They can be
      useful for debugging (Error Debugging).
 
      To catch a user signal, bind the corresponding event to an
      interactive command in the ‘special-event-map’ (Active
      Keymaps).  The command is called with no arguments, and the
      specific signal event is available in ‘last-input-event’.  For
      example:
 
           (defun sigusr-handler ()
             (interactive)
             (message "Caught signal %S" last-input-event))
 
           (define-key special-event-map [sigusr1] 'sigusr-handler)
 
      To test the signal handler, you can make Emacs send a signal to
      itself:
 
           (signal-process (emacs-pid) 'sigusr1)
 
 ‘language-change’
      This kind of event is generated on MS-Windows when the input
      language has changed.  This typically means that the keyboard keys
      will send to Emacs characters from a different language.  The
      generated event has this form:
 
           (language-change FRAME CODEPAGE LANGUAGE-ID)
 
      Here FRAME is the frame which was current when the input language
      changed; CODEPAGE is the new codepage number; and LANGUAGE-ID is
      the numerical ID of the new input language.  The coding-system
      (Coding Systems) that corresponds to CODEPAGE is
      ‘cpCODEPAGE’ or ‘windows-CODEPAGE’.  To convert LANGUAGE-ID to a
      string (e.g., to use it for various language-dependent features,
      such as ‘set-language-environment’), use the ‘w32-get-locale-info’
      function, like this:
 
           ;; Get the abbreviated language name, such as "ENU" for English
           (w32-get-locale-info language-id)
           ;; Get the full English name of the language,
           ;; such as "English (United States)"
           (w32-get-locale-info language-id 4097)
           ;; Get the full localized name of the language
           (w32-get-locale-info language-id t)
 
    If one of these events arrives in the middle of a key sequence—that
 is, after a prefix key—then Emacs reorders the events so that this event
 comes either before or after the multi-event key sequence, not within
 it.
 

Info Catalog elisp: Focus Events elisp: Input Events elisp: Event Examples