Info Catalog elisp: Hooks elisp: Modes elisp: Minor Modes

elisp: Major Modes

 
 22.2 Major Modes
 ================
 
 Major modes specialize Emacs for editing or interacting with particular
 kinds of text.  Each buffer has exactly one major mode at a time.  Every
 major mode is associated with a “major mode command”, whose name should
 end in ‘-mode’.  This command takes care of switching to that mode in
 the current buffer, by setting various buffer-local variables such as a
 local keymap.  Major Mode Conventions.  Note that unlike minor
 modes there is no way to “turn off” a major mode, instead the buffer
 must be switched to a different one.
 
    The least specialized major mode is called “Fundamental mode”, which
 has no mode-specific definitions or variable settings.
 
  -- Command: fundamental-mode
      This is the major mode command for Fundamental mode.  Unlike other
      mode commands, it does _not_ run any mode hooks (Major Mode
      Conventions), since you are not supposed to customize this mode.
 
    The easiest way to write a major mode is to use the macro
 ‘define-derived-mode’, which sets up the new mode as a variant of an
 existing major mode.  Derived Modes.  We recommend using
 ‘define-derived-mode’ even if the new mode is not an obvious derivative
 of another mode, as it automatically enforces many coding conventions
 for you.  Basic Major Modes, for common modes to derive from.
 
    The standard GNU Emacs Lisp directory tree contains the code for
 several major modes, in files such as ‘text-mode.el’, ‘texinfo.el’,
 ‘lisp-mode.el’, and ‘rmail.el’.  You can study these libraries to see
 how modes are written.
 
  -- User Option: major-mode
      The buffer-local value of this variable holds the symbol for the
      current major mode.  Its default value holds the default major mode
      for new buffers.  The standard default value is ‘fundamental-mode’.
 
      If the default value is ‘nil’, then whenever Emacs creates a new
      buffer via a command such as ‘C-x b’ (‘switch-to-buffer’), the new
      buffer is put in the major mode of the previously current buffer.
      As an exception, if the major mode of the previous buffer has a
      ‘mode-class’ symbol property with value ‘special’, the new buffer
      is put in Fundamental mode (Major Mode Conventions).
 

Menu

 
· Major Mode Conventions  Coding conventions for keymaps, etc.
· Auto Major Mode         How Emacs chooses the major mode automatically.
· Mode Help               Finding out how to use a mode.
· Derived Modes           Defining a new major mode based on another major
                               mode.
· Basic Major Modes       Modes that other modes are often derived from.
· Mode Hooks              Hooks run at the end of major mode functions.
· Tabulated List Mode     Parent mode for buffers containing tabulated data.
· Generic Modes           Defining a simple major mode that supports
                               comment syntax and Font Lock mode.
· Example Major Modes     Text mode and Lisp modes.
 

Info Catalog elisp: Hooks elisp: Modes elisp: Minor Modes