This is Info file ../../info/lispref.info, produced by Makeinfo-1.63 from the input file lispref.texi. Edition History: GNU Emacs Lisp Reference Manual Second Edition (v2.01), May 1993 GNU Emacs Lisp Reference Manual Further Revised (v2.02), August 1993 Lucid Emacs Lisp Reference Manual (for 19.10) First Edition, March 1994 XEmacs Lisp Programmer's Manual (for 19.12) Second Edition, April 1995 GNU Emacs Lisp Reference Manual v2.4, June 1995 XEmacs Lisp Programmer's Manual (for 19.13) Third Edition, July 1995 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. Copyright (C) 1994, 1995 Sun Microsystems, Inc. Copyright (C) 1995 Amdahl Corporation. Copyright (C) 1995 Ben Wing. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the section entitled "GNU General Public License" is included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the section entitled "GNU General Public License" may be included in a translation approved by the Free Software Foundation instead of in the original English.  File: lispref.info, Node: Changing Key Bindings, Next: Key Binding Commands, Prev: Functions for Key Lookup, Up: Keymaps Changing Key Bindings ===================== The way to rebind a key is to change its entry in a keymap. If you change a binding in the global keymap, the change is effective in all buffers (though it has no direct effect in buffers that shadow the global binding with a local one). If you change the current buffer's local map, that usually affects all buffers using the same major mode. The `global-set-key' and `local-set-key' functions are convenient interfaces for these operations (*note Key Binding Commands::.). You can also use `define-key', a more general function; then you must specify explicitly the map to change. In writing the key sequence to rebind, it is good to use the special escape sequences for control and meta characters (*note String Type::.). The syntax `\C-' means that the following character is a control character and `\M-' means that the following character is a meta character. Thus, the string `"\M-x"' is read as containing a single `M-x', `"\C-f"' is read as containing a single `C-f', and `"\M-\C-x"' and `"\C-\M-x"' are both read as containing a single `C-M-x'. You can also use this escape syntax in vectors, as well as others that aren't allowed in strings; one example is `[?\C-\H-x home]'. *Note Character Type::. The key definition and lookup functions accept an alternate syntax for event types in a key sequence that is a vector: you can use a list containing modifier names plus one base event (a character or function key name). For example, `(control ?a)' is equivalent to `?\C-a' and `(hyper control left)' is equivalent to `C-H-left'. One advantage of using a list to represent the event type is that the precise numeric codes for the modifier bits don't appear in compiled files. For the functions below, an error is signaled if KEYMAP is not a keymap or if KEY is not a string or vector representing a key sequence. You can use event types (symbols) as shorthand for events that are lists. - Function: define-key KEYMAP KEY BINDING This function sets the binding for KEY in KEYMAP. (If KEY is more than one event long, the change is actually made in another keymap reached from KEYMAP.) The argument BINDING can be any Lisp object, but only certain types are meaningful. (For a list of meaningful types, see *Note Key Lookup::.) The value returned by `define-key' is BINDING. Every prefix of KEY must be a prefix key (i.e., bound to a keymap) or undefined; otherwise an error is signaled. If some prefix of KEY is undefined, then `define-key' defines it as a prefix key so that the rest of KEY may be defined as specified. Here is an example that creates a sparse keymap and makes a number of bindings in it: (setq map (make-sparse-keymap)) => (keymap) (define-key map "\C-f" 'forward-char) => forward-char map => (keymap (6 . forward-char)) ;; Build sparse submap for `C-x' and bind `f' in that. (define-key map "\C-xf" 'forward-word) => forward-word map => (keymap (24 keymap ; `C-x' (102 . forward-word)) ; `f' (6 . forward-char)) ; `C-f' ;; Bind `C-p' to the `ctl-x-map'. (define-key map "\C-p" ctl-x-map) ;; `ctl-x-map' => [nil ... find-file ... backward-kill-sentence] ;; Bind `C-f' to `foo' in the `ctl-x-map'. (define-key map "\C-p\C-f" 'foo) => 'foo map => (keymap ; Note `foo' in `ctl-x-map'. (16 keymap [nil ... foo ... backward-kill-sentence]) (24 keymap (102 . forward-word)) (6 . forward-char)) Note that storing a new binding for `C-p C-f' actually works by changing an entry in `ctl-x-map', and this has the effect of changing the bindings of both `C-p C-f' and `C-x C-f' in the default global map. - Function: substitute-key-definition OLDDEF NEWDEF KEYMAP &optional OLDMAP This function replaces OLDDEF with NEWDEF for any keys in KEYMAP that were bound to OLDDEF. In other words, OLDDEF is replaced with NEWDEF wherever it appears. The function returns `nil'. For example, this redefines `C-x C-f', if you do it in an XEmacs with standard bindings: (substitute-key-definition 'find-file 'find-file-read-only (current-global-map)) If OLDMAP is non-`nil', then its bindings determine which keys to rebind. The rebindings still happen in NEWMAP, not in OLDMAP. Thus, you can change one map under the control of the bindings in another. For example, (substitute-key-definition 'delete-backward-char 'my-funny-delete my-map global-map) puts the special deletion command in `my-map' for whichever keys are globally bound to the standard deletion command. Here is an example showing a keymap before and after substitution: (setq map '(keymap (?1 . olddef-1) (?2 . olddef-2) (?3 . olddef-1))) => (keymap (49 . olddef-1) (50 . olddef-2) (51 . olddef-1)) (substitute-key-definition 'olddef-1 'newdef map) => nil map => (keymap (49 . newdef) (50 . olddef-2) (51 . newdef)) - Function: suppress-keymap KEYMAP &optional NODIGITS This function changes the contents of the full keymap KEYMAP by making all the printing characters undefined. More precisely, it binds them to the command `undefined'. This makes ordinary insertion of text impossible. `suppress-keymap' returns `nil'. If NODIGITS is `nil', then `suppress-keymap' defines digits to run `digit-argument', and `-' to run `negative-argument'. Otherwise it makes them undefined like the rest of the printing characters. The `suppress-keymap' function does not make it impossible to modify a buffer, as it does not suppress commands such as `yank' and `quoted-insert'. To prevent any modification of a buffer, make it read-only (*note Read Only Buffers::.). Since this function modifies KEYMAP, you would normally use it on a newly created keymap. Operating on an existing keymap that is used for some other purpose is likely to cause trouble; for example, suppressing `global-map' would make it impossible to use most of XEmacs. Most often, `suppress-keymap' is used to initialize local keymaps of modes such as Rmail and Dired where insertion of text is not desirable and the buffer is read-only. Here is an example taken from the file `emacs/lisp/dired.el', showing how the local keymap for Dired mode is set up: ... (setq dired-mode-map (make-keymap)) (suppress-keymap dired-mode-map) (define-key dired-mode-map "r" 'dired-rename-file) (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted) (define-key dired-mode-map "d" 'dired-flag-file-deleted) (define-key dired-mode-map "v" 'dired-view-file) (define-key dired-mode-map "e" 'dired-find-file) (define-key dired-mode-map "f" 'dired-find-file) ...  File: lispref.info, Node: Key Binding Commands, Next: Scanning Keymaps, Prev: Changing Key Bindings, Up: Keymaps Commands for Binding Keys ========================= This section describes some convenient interactive interfaces for changing key bindings. They work by calling `define-key'. People often use `global-set-key' in their `.emacs' file for simple customization. For example, (global-set-key "\C-x\C-\\" 'next-line) or (global-set-key [?\C-x ?\C-\\] 'next-line) or (global-set-key [(control ?x) (control ?\\)] 'next-line) redefines `C-x C-\' to move down a line. (global-set-key [M-mouse-1] 'mouse-set-point) redefines the first (leftmost) mouse button, typed with the Meta key, to set point where you click. - Command: global-set-key KEY DEFINITION This function sets the binding of KEY in the current global map to DEFINITION. (global-set-key KEY DEFINITION) == (define-key (current-global-map) KEY DEFINITION) - Command: global-unset-key KEY This function removes the binding of KEY from the current global map. One use of this function is in preparation for defining a longer key that uses KEY as a prefix--which would not be allowed if KEY has a non-prefix binding. For example: (global-unset-key "\C-l") => nil (global-set-key "\C-l\C-l" 'redraw-display) => nil This function is implemented simply using `define-key': (global-unset-key KEY) == (define-key (current-global-map) KEY nil) - Command: local-set-key KEY DEFINITION This function sets the binding of KEY in the current local keymap to DEFINITION. (local-set-key KEY DEFINITION) == (define-key (current-local-map) KEY DEFINITION) - Command: local-unset-key KEY This function removes the binding of KEY from the current local map. (local-unset-key KEY) == (define-key (current-local-map) KEY nil)  File: lispref.info, Node: Scanning Keymaps, Prev: Key Binding Commands, Up: Keymaps Scanning Keymaps ================ This section describes functions used to scan all the current keymaps for the sake of printing help information. - Function: accessible-keymaps KEYMAP &optional PREFIX This function returns a list of all the keymaps that can be accessed (via prefix keys) from KEYMAP. The value is an association list with elements of the form `(KEY . MAP)', where KEY is a prefix key whose definition in KEYMAP is MAP. The elements of the alist are ordered so that the KEY increases in length. The first element is always `("" . KEYMAP)', because the specified keymap is accessible from itself with a prefix of no events. If PREFIX is given, it should be a prefix key sequence; then `accessible-keymaps' includes only the submaps whose prefixes start with PREFIX. These elements look just as they do in the value of `(accessible-keymaps)'; the only difference is that some elements are omitted. In the example below, the returned alist indicates that the key ESC, which is displayed as `^[', is a prefix key whose definition is the sparse keymap `(keymap (83 . center-paragraph) (115 . foo))'. (accessible-keymaps (current-local-map)) =>(("" keymap (27 keymap ; Note this keymap for ESC is repeated below. (83 . center-paragraph) (115 . center-line)) (9 . tab-to-tab-stop)) ("^[" keymap (83 . center-paragraph) (115 . foo))) These are not all the keymaps you would see in an actual case. - Function: where-is-internal COMMAND &optional KEYMAP FIRSTONLY NOINDIRECT This function returns a list of key sequences (of any length) that are bound to COMMAND in a set of keymaps. The argument COMMAND can be any object; it is compared with all keymap entries using `eq'. If KEYMAP is `nil', then the maps used are the current active keymaps, disregarding `overriding-local-map' (that is, pretending its value is `nil'). If KEYMAP is non-`nil', then the maps searched are KEYMAP and the global keymap. Usually it's best to use `overriding-local-map' as the expression for KEYMAP. Then `where-is-internal' searches precisely the keymaps that are active. To search only the global map, pass `(keymap)' (an empty keymap) as KEYMAP. If FIRSTONLY is `non-ascii', then the value is a single string representing the first key sequence found, rather than a list of all possible key sequences. If FIRSTONLY is `t', then the value is the first key sequence, except that key sequences consisting entirely of ASCII characters (or meta variants of ASCII characters) are preferred to all other key sequences. If NOINDIRECT is non-`nil', `where-is-internal' doesn't follow indirect keymap bindings. This makes it possible to search for an indirect definition itself. This function is used by `where-is' (*note Help: (emacs)Help.). (where-is-internal 'describe-function) => ("\^hf" "\^hd") - Command: describe-bindings PREFIX This function creates a listing of all defined keys and their definitions. It writes the listing in a buffer named `*Help*' and displays it in a window. If PREFIX is non-`nil', it should be a prefix key; then the listing includes only keys that start with PREFIX. The listing describes meta characters as ESC followed by the corresponding non-meta character. When several characters with consecutive ASCII codes have the same definition, they are shown together, as `FIRSTCHAR..LASTCHAR'. In this instance, you need to know the ASCII codes to understand which characters this means. For example, in the default global map, the characters `SPC .. ~' are described by a single line. SPC is ASCII 32, `~' is ASCII 126, and the characters between them include all the normal printing characters, (e.g., letters, digits, punctuation, etc.); all these characters are bound to `self-insert-command'.  File: lispref.info, Node: Menus, Next: Dialog Boxes, Prev: Keymaps, Up: Top Menus ***** * Menu: * Menu Format:: Format of a menu description. * Menubar Format:: How to specify a menubar. * Menubar:: Functions for controlling the menubar. * Modifying Menus:: Modifying a menu description. * Pop-Up Menus:: Functions for specifying pop-up menus. * Menu Filters:: Filter functions for the default menubar. * Buffers Menu:: The menu that displays the list of buffers.  File: lispref.info, Node: Menu Format, Next: Menubar Format, Up: Menus Format of Menus =============== A menu is described using a "menu description", which is a list of menu items, keyword-value pairs, strings, and submenus. The menu description specifies which items are present in the menu, what function each item invokes, and whether the item is selectable or not. Pop-up menus are directly described with a menu description, while menubars are described slightly differently (see below). The first element of a menu must be a string, which is the name of the menu. This is the string that will be displayed in the parent menu or menubar, if any. This string is not displayed in the menu itself, except in the case of the top level pop-up menu, where there is no parent. In this case, the string will be displayed at the top of the menu if `popup-menu-titles' is non-`nil'. Immediately following the first element there may optionally be up to three keyword-value pairs, as follows: `:included FORM' This can be used to control the visibility of a menu. The form is evaluated and the menu will be omitted if the result is `nil'. `:config SYMBOL' This is an efficient shorthand for `:included (memq SYMBOL menubar-configuration)'. See the variable `menubar-configuration'. `:filter FUNCTION' A menu filter is used to sensitize or incrementally create a submenu only when it is selected by the user and not every time the menubar is activated. The filter function is passed the list of menu items in the submenu and must return a list of menu items to be used for the menu. It is called only when the menu is about to be displayed, so other menus may already be displayed. Vile and terrible things will happen if a menu filter function changes the current buffer, window, or frame. It also should not raise, lower, or iconify any frames. Basically, the filter function should have no side-effects. The rest of the menu consists of elements as follows: * A "menu item", which is a vector in the following form: `[ NAME CALLBACK :KEYWORD VALUE :KEYWORD VALUE ... ]' NAME is a string, the name of the menu item; it is the string to display on the menu. It is filtered through the resource database, so it is possible for resources to override what string is actually displayed. CALLBACK is a form that will be invoked when the menu item is selected. If the callback of a menu item is a symbol, then it must name a command. It will be invoked with `call-interactively'. If it is a list, then it is evaluated with `eval'. The valid keywords and their meanings are described below. Note that for compatibility purposes, the form `[ NAME CALLBACK ACTIVE-P ]' is also accepted and is equivalent to `[ NAME CALLBACK :active ACTIVE-P ]' and the form `[ NAME CALLBACK ACTIVE-P SUFFIX]' is accepted and is equivalent to `[ NAME CALLBACK :active ACTIVE-P :suffix SUFFIX]' However, these older forms are deprecated and should generally not be used. * If an element of a menu is a string, then that string will be presented in the menu as unselectable text. * If an element of a menu is a string consisting solely of hyphens, then that item will be presented as a solid horizontal line. * If an element of a menu is a string beginning with `--:', then a particular sort of horizontal line will be displayed, as follows: `"--:singleLine"' A solid horizontal line. This is equivalent to a string consisting solely of hyphens. `"--:doubleLine"' A solid double horizontal line. `"--:singleDashedLine"' A dashed horizontal line. `"--:doubleDashedLine"' A dashed double horizontal line. `"--:noLine"' No line (but a small space is left). `"--:shadowEtchedIn"' A solid horizontal line with a 3-d recessed appearance. `"--:shadowEtchedOut"' A solid horizontal line with a 3-d pushed-out appearance. `"--:shadowDoubleEtchedIn"' A solid double horizontal line with a 3-d recessed appearance. `"--:shadowDoubleEtchedOut"' A solid double horizontal line with a 3-d pushed-out appearance. `"--:shadowEtchedInDash"' A dashed horizontal line with a 3-d recessed appearance. `"--:shadowEtchedOutDash"' A dashed horizontal line with a 3-d pushed-out appearance. `"--:shadowDoubleEtchedInDash"' A dashed double horizontal line with a 3-d recessed appearance. `"--:shadowDoubleEtchedOutDash"' A dashed double horizontal line with a 3-d pushed-out appearance. * If an element of a menu is a list, it is treated as a submenu. The name of that submenu (the first element in the list) will be used as the name of the item representing this menu on the parent. The possible keywords are as follows: :active FORM FORM will be evaluated when the menu that this item is a part of is about to be displayed, and the item will be selectable only if the result is non-`nil'. If the item is unselectable, it will usually be displayed grayed-out to indicate this. :suffix STRING The string is appended to the displayed name. This provides a convenient way of adding the name of a command's "argument" to the menu, like like `Kill Buffer NAME'. :keys STRING Normally, the keyboard equivalents of commands in menus are displayed when the "callback" is a symbol. This can be used to specify keys for more complex menu items. It is passed through `substitute-command-keys' first. :style STYLE Specifies what kind of object this menu item is. STYLE be one of the symbols `nil' A normal menu item. `toggle' A toggle button. `radio' A radio button. `button' A menubar button. The only difference between toggle and radio buttons is how they are displayed. But for consistency, a toggle button should be used when there is one option whose value can be turned on or off, and radio buttons should be used when there is a set of mutally exclusive options. When using a group of radio buttons, you should arrange for no more than one to be marked as selected at a time. :selected FORM Meaningful only when STYLE is `toggle', `radio' or `button'. This specifies whether the button will be in the selected or unselected state. FORM is evaluated, as for `:active'. :included FORM This can be used to control the visibility of a menu item. The form is evaluated and the menu item is only displayed if the result is non-`nil'. Note that this is different from `:active': If `:active' evaluates to `nil', the item will be displayed grayed out, while if `:included' evaluates to `nil', the item will be omitted entirely. :config SYMBOL This is an efficient shorthand for `:included (memq SYMBOL menubar-configuration)'. See the variable `menubar-configuration'. - Variable: menubar-configuration This variable holds a list of symbols, against which the value of the `:config' tag for each menubar item will be compared. If a menubar item has a `:config' tag, then it is omitted from the menubar if that tag is not a member of the `menubar-configuration' list. For example: ("File" :filter file-menu-filter ; file-menu-filter is a function that takes ; one argument (a list of menu items) and ; returns a list of menu items [ "Save As..." write-file t ] [ "Revert Buffer" revert-buffer (buffer-modified-p) ] [ "Read Only" toggle-read-only :style toggle :selected buffer-read-only ] )  File: lispref.info, Node: Menubar Format, Next: Menubar, Prev: Menu Format, Up: Menus Format of the Menubar ===================== A menubar is a list of menus, menu items, and strings. The format is similar to that of a menu, except: * The first item need not be a string, and is not treated specially. * A string consisting solely of hyphens is not treated specially. * If an element of a menubar is `nil', then it is used to represent the division between the set of menubar items which are flush-left and those which are flush-right. (Note: this isn't completely implemented yet.)  File: lispref.info, Node: Menubar, Next: Modifying Menus, Prev: Menubar Format, Up: Menus Menubar ======= - Variable: current-menubar This variable holds the description of the current menubar. This may be buffer-local. When the menubar is changed, the function `set-menubar-dirty-flag' has to be called in order for the menubar to be updated on the screen. - Constant: default-menubar This variable holds the menubar description of the menubar that is visible at startup. This is the value that `current-menubar' has at startup. - Function: set-menubar-dirty-flag This function tells XEmacs that the menubar widget has to be updated. Changes to the menubar will generally not be visible until this function is called. The following convenience functions are provided for setting the menubar. They are equivalent to doing the appropriate action to change `current-menubar', and then calling `set-menubar-dirty-flag'. Note that these functions copy their argument using `copy-sequence'. - Function: set-menubar MENUBAR This function sets the default menubar to be MENUBAR (*note Menu Format::.). This is the menubar that will be visible in buffers that have not defined their own, buffer-local menubar. - Function: set-buffer-menubar MENUBAR This function sets the buffer-local menubar to be MENUBAR. This does not change the menubar in any buffers other than the current one. Miscellaneous: - Variable: menubar-show-keybindings If true, the menubar will display keyboard equivalents. If false, only the command names will be displayed. - Variable: activate-menubar-hook Function or functions called before a menubar menu is pulled down. These functions are called with no arguments, and should interrogate and modify the value of `current-menubar' as desired. The functions on this hook are invoked after the mouse goes down, but before the menu is mapped, and may be used to activate, deactivate, add, or delete items from the menus. However, using a filter (with the `:filter' keyword in a menu description) is generally a more efficient way of accomplishing the same thing, because the filter is invoked only when the actual menu goes down. With a complex menu, there can be a quite noticeable and sometimes aggravating delay if all menu modification is implemented using the `activate-menubar-hook'. See above. These functions may return the symbol `t' to assert that they have made no changes to the menubar. If any other value is returned, the menubar is recomputed. If `t' is returned but the menubar has been changed, then the changes may not show up right away. Returning `nil' when the menubar has not changed is not so bad; more computation will be done, but redisplay of the menubar will still be performed optimally. - Variable: menu-no-selection-hook Function or functions to call when a menu or dialog box is dismissed without a selection having been made.  File: lispref.info, Node: Modifying Menus, Next: Pop-Up Menus, Prev: Menubar, Up: Menus Modifying Menus =============== The following functions are provided to modify the menubar of one of its submenus. Note that these functions modify the menu in-place, rather than copying it and making a new menu. Some of these functions take a "menu path", which is a list of strings identifying the menu to be modified. For example, `("File")' names the top-level "File" menu. `("File" "Foo")' names a hypothetical submenu of "File". Others take a "menu item path", which is similar to a menu path but also specifies a particular item to be modified. For example, `("File" "Save")' means the menu item called "Save" under the top-level "File" menu. `("Menu" "Foo" "Item")' means the menu item called "Item" under the "Foo" submenu of "Menu". - Function: add-submenu MENU-PATH SUBMENU &optional BEFORE This function adds a menu to the menubar or one of its submenus. If the named menu exists already, it is changed. MENU-PATH identifies the menu under which the new menu should be inserted. If MENU-PATH is `nil', then the menu will be added to the menubar itself. SUBMENU is the new menu to add (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this menu should be added, if this menu is not on its parent already. If the menu is already present, it will not be moved. - Function: add-menu-button MENU-PATH MENU-LEAF &optional BEFORE This function adds a menu item to some menu, creating the menu first if necessary. If the named item exists already, it is changed. MENU-PATH identifies the menu under which the new menu item should be inserted. MENU-LEAF is a menubar leaf node (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this item should be added, if this item is not on the menu already. If the item is already present, it will not be moved. - Function: delete-menu-item MENU-ITEM-PATH This function removes the menu item specified by MENU-ITEM-PATH from the menu hierarchy. - Function: enable-menu-item MENU-ITEM-PATH This function makes the menu item specified by MENU-ITEM-PATH be selectable. - Function: disable-menu-item MENU-ITEM-PATH This function makes the menu item specified by MENU-ITEM-PATH be unselectable. - Function: relabel-menu-item MENU-ITEM-PATH NEW-NAME This function changes the string of the menu item specified by MENU-ITEM-PATH. NEW-NAME is the string that the menu item will be printed as from now on. The following function can be used to search for a particular item in a menubar specification, given a path to the item. - Function: find-menu-item MENUBAR MENU-ITEM-PATH &optional PARENT This function searches MENUBAR for the item given by MENU-ITEM-PATH starting from PARENT (`nil' means start at the top of MENUBAR). This function returns `(ITEM . PARENT)', where PARENT is the immediate parent of the item found (a menu description), and ITEM is either a vector, list, or string, depending on the nature of the menu item. This function signals an error if the item is not found. The following deprecated functions are also documented, so that existing code can be understood. You should not use these functions in new code. - Function: add-menu MENU-PATH MENU-NAME MENU-ITEMS &optional BEFORE This function adds a menu to the menubar or one of its submenus. If the named menu exists already, it is changed. This is obsolete; use `add-submenu' instead. MENU-PATH identifies the menu under which the new menu should be inserted. If MENU-PATH is `nil', then the menu will be added to the menubar itself. MENU-NAME is the string naming the menu to be added; MENU-ITEMS is a list of menu items, strings, and submenus. These two arguments are the same as the first and following elements of a menu description (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this menu should be added, if this menu is not on its parent already. If the menu is already present, it will not be moved. - Function: add-menu-item MENU-PATH ITEM-NAME FUNCTION ENABLED-P &optional BEFORE This function adds a menu item to some menu, creating the menu first if necessary. If the named item exists already, it is changed. This is obsolete; use `add-menu-button' instead. MENU-PATH identifies the menu under which the new menu item should be inserted. ITEM-NAME, FUNCTION, and ENABLED-P are the first, second, and third elements of a menu item vector (*note Menu Format::.). BEFORE, if provided, is the name of a menu item before which this item should be added, if this item is not on the menu already. If the item is already present, it will not be moved.  File: lispref.info, Node: Menu Filters, Next: Buffers Menu, Prev: Pop-Up Menus, Up: Menus Menu Filters ============ The following filter functions are provided for use in `default-menubar'. You may want to use them in your own menubar description. - Function: file-menu-filter MENU-ITEMS This function changes the arguments and sensitivity of these File menu items: `Delete Buffer' Has the name of the current buffer appended to it. `Print Buffer' Has the name of the current buffer appended to it. `Pretty-Print Buffer' Has the name of the current buffer appended to it. `Save Buffer' Has the name of the current buffer appended to it, and is sensitive only when the current buffer is modified. `Revert Buffer' Has the name of the current buffer appended to it, and is sensitive only when the current buffer has a file. `Delete Frame' Sensitive only when there is more than one visible frame. - Function: edit-menu-filter MENU-ITEMS This function changes the arguments and sensitivity of these Edit menu items: `Cut' Sensitive only when XEmacs owns the primary X Selection (if `zmacs-regions' is `t', this is equivalent to saying that there is a region selected). `Copy' Sensitive only when XEmacs owns the primary X Selection. `Clear' Sensitive only when XEmacs owns the primary X Selection. `Paste' Sensitive only when there is an owner for the X Clipboard Selection. `Undo' Sensitive only when there is undo information. While in the midst of an undo, this is changed to `Undo More'. - Function: buffers-menu-filter MENU-ITEMS This function sets up the Buffers menu. *Note Buffers Menu:: for more information.  File: lispref.info, Node: Pop-Up Menus, Next: Menu Filters, Prev: Modifying Menus, Up: Menus Pop-Up Menus ============ - Function: popup-menu MENU-DESC This function pops up a menu specified by MENU-DESC, which is a menu description (*note Menu Format::.). The menu is displayed at the current mouse position. - Function: popup-menu-up-p This function returns `t' if a pop-up menu is up, `nil' otherwise. - Variable: popup-menu-titles If true (the default), pop-up menus will have title bars at the top. Some machinery is provided that attempts to provide a higher-level mechanism onto pop-up menus. This only works if you do not redefine the binding for button3. - Command: popup-mode-menu This function pops up a menu of global and mode-specific commands. The menu is computed by combining `global-popup-menu' and `mode-popup-menu'. This is the default binding for button3. You should generally not change this binding. - Variable: global-popup-menu This holds the global popup menu. This is present in all modes. (This is `nil' by default.) - Variable: mode-popup-menu The mode-specific popup menu. Automatically buffer local. This is appended to the default items in `global-popup-menu'. - Constant: default-popup-menu This holds the default value of `mode-popup-menu'. - Variable: activate-popup-menu-hook Function or functions run before a mode-specific popup menu is made visible. These functions are called with no arguments, and should interrogate and modify the value of `global-popup-menu' or `mode-popup-menu' as desired. Note: this hook is only run if you use `popup-mode-menu' for activating the global and mode-specific commands; if you have your own binding for button3, this hook won't be run. The following convenience functions are provided for displaying pop-up menus. - Function: popup-buffer-menu EVENT This function pops up a copy of the `Buffers' menu (from the menubar) where the mouse is clicked. - Function: popup-menubar-menu EVENT This function pops up a copy of menu that also appears in the menubar.  File: lispref.info, Node: Buffers Menu, Prev: Menu Filters, Up: Menus Buffers Menu ============ The following options control how the `Buffers' menu is displayed. This is a list of all (or a subset of) the buffers currently in existence, and is updated dynamically. - User Option: buffers-menu-max-size This user option holds the maximum number of entries which may appear on the `Buffers' menu. If this is 10, then only the ten most-recently-selected buffers will be shown. If this is `nil', then all buffers will be shown. Setting this to a large number or `nil' will slow down menu responsiveness. - Function: format-buffers-menu-line BUFFER This function returns a string to represent BUFFER in the `Buffers' menu. `nil' means the buffer shouldn't be listed. You can redefine this. - User Option: complex-buffers-menu-p If true, the `Buffers' menu will contain several commands, as submenus of each buffer line. If this is false, then there will be only one command: select that buffer. - User Option: buffers-menu-switch-to-buffer-function This user option holds the function to call to select a buffer from the `Buffers' menu. `switch-to-buffer' is a good choice, as is `pop-to-buffer'.  File: lispref.info, Node: Dialog Boxes, Next: Toolbar, Prev: Menus, Up: Top Dialog Boxes ************ * Menu: * Dialog Box Format:: * Dialog Box Functions::  File: lispref.info, Node: Dialog Box Format, Next: Dialog Box Functions, Up: Dialog Boxes Dialog Box Format ================= A dialog box description is a list. * The first element of the list is a string to display in the dialog box. * The rest of the elements are descriptions of the dialog box's buttons. Each one is a vector of three elements: - The first element is the text of the button. - The second element is the "callback". - The third element is `t' or `nil', whether this button is selectable. If the callback of a button is a symbol, then it must name a command. It will be invoked with `call-interactively'. If it is a list, then it is evaluated with `eval'. One (and only one) of the buttons may be `nil'. This marker means that all following buttons should be flushright instead of flushleft. The syntax, more precisely: form := command := callback := command | form active-p := name := partition := 'nil' button := '[' name callback active-p ']' dialog := '(' name [ button ]+ [ partition [ button ]+ ] ')'  File: lispref.info, Node: Dialog Box Functions, Prev: Dialog Box Format, Up: Dialog Boxes Dialog Box Functions ==================== - Function: popup-dialog-box DBOX-DESC This function pops up a dialog box. DBOX-DESC describes how the dialog box will appear (*note Dialog Box Format::.). *Note Yes-or-No Queries::, for functions to ask a yes/no question using a dialog box.  File: lispref.info, Node: Toolbar, Next: Scrollbars, Prev: Dialog Boxes, Up: Top Toolbar ******* * Menu: * Toolbar Intro:: An introduction. * Toolbar Descriptor Format:: How to create a toolbar. * Specifying the Toolbar:: Setting a toolbar. * Other Toolbar Variables:: Controlling the size of toolbars.  File: lispref.info, Node: Toolbar Intro, Next: Toolbar Descriptor Format, Up: Toolbar Toolbar Intro ============= #### Not yet written.  File: lispref.info, Node: Toolbar Descriptor Format, Next: Specifying the Toolbar, Prev: Toolbar Intro, Up: Toolbar Toolbar Descriptor Format ========================= The format of a toolbar descriptor is a list of toolbar button descriptors. Each toolbar button descriptor is a vector in one of the following formats: * `[GLYPH-LIST FUNCTION ENABLED-P HELP]' * `[:style 2D-OR-3D]' * `[:style 2D-OR-3D :size WIDTH-OR-HEIGHT]' * `[:size WIDTH-OR-HEIGHT :style 2D-OR-3D]' Optionally, one of the toolbar-button-descriptors may be `nil' instead of a vector; this signifies the division between the toolbar buttons that are to be displayed flush-left, and the buttons to be displayed flush-right. The first vector format above specifies a normal toolbar button; the others specify blank areas in the toolbar. For the first vector format: * GLYPH-LIST should be a list of one to three glyphs (as created by `make-glyph') or a symbol whose value is such a list. The first glyph, which must be provided, is the glyph used to display the toolbar button when it is in the "up" (not pressed) state. The optional second glyph is for displaying the button when it is in the "down" (pressed) state. The optional third glyph is for when the button is disabled. The function `toolbar-make-button-list' is useful in creating these glyph lists. * Even if you do not provide separate down-state and disabled-state glyphs, the user will still get visual feedback to indicate which state the button is in. Buttons in the up-state are displayed with a shadowed border that gives a raised appearance to the button. Buttons in the down-state are displayed with shadows that give a recessed appearance. Buttons in the disabled state and displayed with no shadows, giving a 2-d effect. * The second element FUNCTION is a function to be called when the toolbar button is activated (i.e. when the mouse is released over the toolbar button, if the press occurred in the toolbar). It can be any form accepted by `call-interactively', since this is how it is invoked. * The third element ENABLED-P specifies whether the toolbar button is enabled (disabled buttons do nothing when they are activated, and are displayed differently; see above). It should be either a boolean or a form that evaluates to a boolean. * The fourth element HELP, if non-`nil', should be a string. This string is displayed in the echo area when the mouse passes over the toolbar button. For the other vector formats (specifying blank areas of the toolbar): * 2D-OR-3D should be one of the symbols `2d' or `3d', indicating whether the area is displayed with shadows (giving it a raised, 3-d appearance) or without shadows (giving it a flat appearance). * WIDTH-OR-HEIGHT specifies the length, in pixels, of the blank area. If omitted, it defaults to a device-specific value (8 pixels for X devices). - Function: toolbar-make-button-list UP &optional DOWN DISABLED This function calls `make-glyph' on each arg and returns a list of the results. This is useful for setting the first argument of a toolbar button descriptor (typically, the result of this function is assigned to a symbol, which is specified as the first argument of the toolbar button descriptor). - Function: check-toolbar-button-syntax BUTTON &optional NOERROR Verify the syntax of entry BUTTON in a toolbar description list. If you want to verify the syntax of a toolbar description list as a whole, use `check-valid-instantiator' with a specifier type of `toolbar'.  File: lispref.info, Node: Specifying the Toolbar, Next: Other Toolbar Variables, Prev: Toolbar Descriptor Format, Up: Toolbar Specifying the Toolbar ====================== In order to specify a toolbar, set one of the variables `default-toolbar', `top-toolbar', `bottom-toolbar', `left-toolbar', or `right-toolbar'. These are specifiers, which means you set them with `set-specifier' and query them with `specifier-specs' or `specifier-instance'. You will get an error if you try to set them using `setq'. *Note Specifiers:: for more information. Most of the time, you will set `default-toolbar', which allows the user to choose where the toolbar should go. - Variable: default-toolbar The position of this toolbar is specified in the function `default-toolbar-position'. If the corresponding position- specific toolbar (e.g. `top-toolbar' if `default-toolbar-position' is `top') does not specify a toolbar in a particular domain, then the value of `default-toolbar' in that domain, of any, will be used instead. Note that the toolbar at any particular position will not be displayed unless its thickness (width or height, depending on orientation) is non-zero. The thickness is controlled by the variables `top-toolbar-height', `bottom-toolbar-height', `left-toolbar-width', and `right-toolbar-width' (*note Other Toolbar Variables::.). By default, only `top-toolbar-height' has a non-zero value. - Function: set-default-toolbar-position POSITION This function sets the position that the `default-toolbar' will be displayed at. Valid positions are the symbols `top', `bottom', `left' and `right'. - Function: default-toolbar-position This function return the position that the `default-toolbar' will be displayed at. You can also explicitly set a toolbar at a particular position. When redisplay determines what to display at a particular position in a particular domain (i.e. window), it first consults the position-specific toolbar. If that does not yield a toolbar descriptor, the `default-toolbar' is consulted if `default-toolbar-position' indicates this position. - Variable: top-toolbar Specifier for toolbar at the top of the frame. - Variable: bottom-toolbar Specifier for toolbar at the bottom of the frame. - Variable: left-toolbar Specifier for toolbar at the left edge of the frame. - Variable: right-toolbar Specifier for toolbar at the right edge of the frame. - Function: toolbar-specifier-p OBJECT This function Returns non-nil if OBJECT is an toolbar specifier. Toolbar specifiers are the actual objects contained in the toolbar variables described above.  File: lispref.info, Node: Other Toolbar Variables, Prev: Specifying the Toolbar, Up: Toolbar Other Toolbar Variables ======================= The variables to control the toolbar height and width are all specifiers. *Note Specifiers::. - Variable: top-toolbar-height Height of top toolbar. - Variable: bottom-toolbar-height Height of bottom toolbar. - Variable: left-toolbar-width Width of left toolbar. - Variable: right-toolbar-width Width of right toolbar. You can also reset the toolbar to what it was when XEmacs started up. - Variable: initial-toolbar-spec The toolbar descriptor used to initialize `default-toolbar' at startup.  File: lispref.info, Node: Scrollbars, Next: Modes, Prev: Toolbar, Up: Top scrollbars ********** Not yet documented.  File: lispref.info, Node: Modes, Next: Documentation, Prev: Scrollbars, Up: Top Major and Minor Modes ********************* A "mode" is a set of definitions that customize XEmacs and can be turned on and off while you edit. There are two varieties of modes: "major modes", which are mutually exclusive and used for editing particular kinds of text, and "minor modes", which provide features that users can enable individually. This chapter describes how to write both major and minor modes, how to indicate them in the modeline, and how they run hooks supplied by the user. For related topics such as keymaps and syntax tables, see *Note Keymaps::, and *Note Syntax Tables::. * Menu: * Major Modes:: Defining major modes. * Minor Modes:: Defining minor modes. * Modeline Format:: Customizing the text that appears in the modeline. * Hooks:: How to use hooks; how to write code that provides hooks.  File: lispref.info, Node: Major Modes, Next: Minor Modes, Up: Modes Major Modes =========== Major modes specialize XEmacs for editing particular kinds of text. Each buffer has only one major mode at a time. The least specialized major mode is called "Fundamental mode". This mode has no mode-specific definitions or variable settings, so each XEmacs command behaves in its default manner, and each option is in its default state. All other major modes redefine various keys and options. For example, Lisp Interaction mode provides special key bindings for LFD (`eval-print-last-sexp'), TAB (`lisp-indent-line'), and other keys. When you need to write several editing commands to help you perform a specialized editing task, creating a new major mode is usually a good idea. In practice, writing a major mode is easy (in contrast to writing a minor mode, which is often difficult). If the new mode is similar to an old one, it is often unwise to modify the old one to serve two purposes, since it may become harder to use and maintain. Instead, copy and rename an existing major mode definition and alter the copy--or define a "derived mode" (*note Derived Modes::.). For example, Rmail Edit mode, which is in `emacs/lisp/rmailedit.el', is a major mode that is very similar to Text mode except that it provides three additional commands. Its definition is distinct from that of Text mode, but was derived from it. Rmail Edit mode is an example of a case where one piece of text is put temporarily into a different major mode so it can be edited in a different way (with ordinary XEmacs commands rather than Rmail). In such cases, the temporary major mode usually has a command to switch back to the buffer's usual mode (Rmail mode, in this case). You might be tempted to present the temporary redefinitions inside a recursive edit and restore the usual ones when the user exits; but this is a bad idea because it constrains the user's options when it is done in more than one buffer: recursive edits must be exited most-recently-entered first. Using alternative major modes avoids this limitation. *Note Recursive Editing::. The standard XEmacs Lisp library directory contains the code for several major modes, in files including `text-mode.el', `texinfo.el', `lisp-mode.el', `c-mode.el', and `rmail.el'. You can look at these libraries to see how modes are written. Text mode is perhaps the simplest major mode aside from Fundamental mode. Rmail mode is a complicated and specialized mode. * Menu: * Major Mode Conventions:: Coding conventions for keymaps, etc. * Example Major Modes:: Text mode and Lisp modes. * Auto Major Mode:: How XEmacs 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.