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1 @comment node-name, next, previous, up
2 @node Customization Basics, Help, Edit, Top
3 @chapter Customize key bindings and menus
4 @cindex .emacs
5 @cindex customize
6 @findex eval-region
7
8 When you start Emacs, it reads the file @file{~/.emacs} in your home
9 directory. You can use this file to initialize and customize Emacs to
10 your liking. This file should contain lisp-code. You can customize your
11 @file{.emacs} file to create new
12 menus, disable menus, change key bindings, enable a minor mode, etc. Any
13 kind of customization affects
14 only a particular Emacs job that you do them in. If you want to save
15 your customizations `permanently' i.e. for future use also, you have to
16 put it in your @samp{.emacs} file. After you make changes to your
17 @file{.emacs} file and save it, the changes will be effective only after
18 you start Emacs again i.e. for a new Emacs process. To try out some of
19 the examples in this section, highlight that region and evaluate the
20 region by giving the command @kbd{M-x eval-region}. You will be able to
21 see the results of your customizations in that Emacs session only
22 (@pxref{Lisp Eval,,,,XEmacs User's Manual}).
23
24 @comment node-name, next, previous, up
25 @menu
26 * Customizing key Bindings:: Changing Key Bindings
27 * Customizing Menus:: Adding, Deleting, Enabling and Disabling Menus
28 @end menu
29
30 @node Customizing key Bindings, Customizing Menus, Customization Basics, Customization Basics
31 @section Customize key bindings
32 @cindex key bindings
33 @cindex keystrokes
34
35 Most of Emacs commands use key sequences. @xref{Keystrokes,,,,XEmacs
36 Manual}, for more information about Keys and Commands. In Emacs, the
37 keys themselves carry no meaning unless they are bound to a
38 function. For example, @kbd{C-n} moves the cursor to the next line
39 because its bound to the function @b{next-line}. Similarly, @kbd{C-p}
40 moves to the previous line because its bound to the function
41 @b{previous-line}. The functions themselves define a particular
42 behavior. You can customize the key @kbd{C-n} to move to the previous
43 line by binding it to @b{previous-line} and @kbd{C-p} to move to the
44 next line by binding it to @b{next-line}. To bind keys to globally run
45 commands you need to use the following syntax in your @b{.emacs} file:
46
47 @cindex binding keys
48 @example
49 @code{(global-set-key @var{keys} @var{cmd})}
50 @end example
51 @noindent
52 Here, @code{global-set-key} is a function which will bind the
53 @dfn{keys} to the specified @dfn{cmd}. For example, if you type the
54 following in your @b{.emacs} file:
55
56 @example
57 (global-set-key "\C-p" 'next-line)
58 (global-set-key "\C-n" 'previous-line)
59 @end example
60
61 @noindent
62 then @kbd{C-p} will move to the next line and @kbd{C-n} to the previous
63 line.
64
65 You can also disable a key binding, by using @samp{nil} as the @var{cmd}
66 in the syntax stated above. Here, @samp{nil} stands for @samp{false}
67 which means disable a command or turn off a feature. If you want to
68 enable a command or turn on a particular feature use @samp{t}
69 which stands for @samp{true}. For example, if you do not wish @kbd{C-x
70 C-c} to @samp{Exit Emacs} you can type the following expression in your
71 @file{.emacs} file:
72
73 @example
74 (global-set-key "\C-x\C-c" nil)
75 @end example
76
77 @noindent
78 You might want to have this statement in your @file{.emacs} file because
79 its easy to hit this command by mistake and it could be annoying to exit
80 Emacs unintentionally. There is a @b{Exit Emacs} option in the @b{File
81 menu} which you might want to use instead. To make a particular key
82 undefined you can also use:
83
84 @example
85 (global-unset-key "\C-x\C-c")
86 @end example
87
88 @noindent
89 Now if you use the command @kbd{C-x C-c}, you will get an error saying
90 that the command is undefined.
91
92 Some other customizations you could try are:
93 @itemize @bullet
94
95 @item
96 @example
97 (global-set-key 'button3 'beginning-of-buffer)
98 @end example
99
100 @noindent
101 Now when you press the third button of your mouse, the cursor will be
102 placed at the @code{beginning-of-buffer}.
103
104 @item
105 @example
106 (global-set-key 'f1 'goto-line)
107 @end example
108
109 @noindent
110 If you press the @key{F1} key, you will be prompted for a line
111 number. After you type the line number and hit @key{RET}, the cursor
112 will be placed on that line number.
113
114 @item
115 @example
116 (global-set-key 'f2 'undo)
117 @end example
118
119 Pressing @key{F2} will undo the last command. If you have a @key{undo}
120 key on your keyboard, try binding that key to the undo command.
121 @end itemize
122
123
124 Another syntax for customizing key bindings is:
125 @code{(define-key @var{keymap} @var{keys} @var{def})}
126 It defines @var{keys} to run @var{def} in the keymap @var{keymap}.
127
128 @var{keymap} is a keymap object which records the bindings of keys to
129 the commands that they run.
130
131 @var{keys} is the sequence of keystrokes to bind.
132
133 @var{def} is anything that can be a key's definition:
134
135 Look at the following two examples:
136
137 @example
138 (define-key global-map "\C-xl" 'make-symbolic-link)
139 (define-key c-mode-map "\C-xl" 'make-symbolic-link)
140 @end example
141
142 @findex make-symbolic-link
143 @noindent
144 Both the examples bind the key @kbd{C-xl} to run the function
145 @code{make-symbolic-link} (@pxref{Misc File Ops,,,,XEmacs User's
146 Manual}). However, the second example will bind the key only for C
147 mode. @xref{Major Modes,,,,XEmacs User's Manual}, for more
148 information on Major Modes in XEmacs.
149
150
151
152 @comment node-name, next, previous, up
153 @node Customizing Menus, , Customizing key Bindings, Customization Basics
154 @section Customizing Menus
155 @cindex customize menus
156 @cindex delete menus
157 @cindex disable menus
158 @findex add-menu-item
159 @cindex add menus
160
161 You can customize any of the XEmacs Pull-down-Menus. You can create your
162 own menu, delete an existing one, enable a menu or disable a menu. For
163 more information on the default menus available to you, @xref{Pull-down
164 Menus}.
165
166 Some of the functions which are available to you for customization are:
167 @enumerate
168
169 @item add-menu-item: @var{(menu-name item-name function enabled-p
170 &optional before)}
171
172 This function will add a menu item to a menu, creating the menu first if
173 necessary. If the named item already exists, the menu will remain
174 unchanged. For example, if you add the following example to your
175 @file{.emacs} file or evaluate it (@pxref{Customization Basics}),
176
177 @example
178 (add-menu-item '("Edit") "Replace String" replace-string t "Clear")
179 @end example
180
181 @noindent
182 a sub-menu @b{Replace String} will be created under @b{Edit} menu before the
183 sub-menu @b{Clear}. The @b{Edit} menu will now look like:
184
185 @example
186 Undo C-x u
187 Cut cut
188 Copy copy
189 Paste paste
190 Replace String
191 Clear
192 Start Macro Recording C-x(
193 End Macro Recording C-x)
194 Execute Last Macro C-xe
195 @end example
196
197 @noindent
198 @b{Replace String} will now execute the function
199 @code{replace-string}. Select this menu item. Emacs will prompt you for
200 a string name to be replaced. Type a
201 string and hit @key{RET}. Now type a new string to replace the old
202 string and hit @key{RET}. All occurrences of the old string will be
203 replaced by the new string. In this example,
204
205 @samp{Edit} is the @var{menu-name} which identifies the menu into which
206 the new menu item should be inserted.
207
208 @samp{Replace String} is the @var{item-name} which names the menu item
209 to be added.
210
211 @samp{replace-string} is the @var{function} i.e. the command to be
212 invoked when the menu item "Replace String" is selected.
213
214 @samp{t} is the @var{enabled-p} parameter which controls whether the
215 menu item is selectable or not. This parameter can be either @code{t} (selectable), @code{nil} (not selectable), or a
216 form to evaluate. This form is evaluated just before the menu is
217 displayed, and the menu item will be selectable if the form returns
218 non-@code{nil}.
219
220 @samp{Clear} is the @var{&optional before} parameter which is the name
221 of the menu before which the new menu or sub-menu should be added. The
222 @var{&optional} string means that this parameter is optional. You do not
223 need to specify this parameter. If you do not specify this parameter in
224 the example above, the @b{Replace String} menu item will be added at the
225 end of the list of sub-menus in the @b{Edit} menu i.e. after @b{Execute
226 Last Macro}.
227
228 If you wish to add a new menu to the menubar, try:
229
230 @example
231 (add-menu-item nil "Bot" 'end-of-buffer t)
232 @end example
233
234 @noindent
235 This will create a new menu @b{Bot} on the menu bar. Selecting this menu
236 will take you to the end of the buffer. Using @code{nil} for the
237 parameter @var{menu-name} will create a new menu. Your menu-bar
238 will now look like:
239
240 @example
241 File Edit Options Buffers Bot Help
242 @end example
243
244 The following example will illustrate how you can add sub-menus to the
245 submenus themselves:
246
247 @example
248 (add-menu-item '("File" "Management") "Copy File" 'copy-file t)
249 (add-menu-item '("File" "Management") "Delete File" 'delete-file t)
250 (add-menu-item '("File" "Management") "Rename File" 'rename-file t)
251 @end example
252 @noindent
253
254 This will create a sub-menu @b{Management} under the @b{File}
255 menu. When you select the submenu @b{Management}, it will contain three
256 submenus: @b{Copy File}, @b{Delete File} and @b{Rename File}.
257
258 @findex delete-menu-item
259 @cindex deleting menu items
260 @item delete-menu-item: @var{(menu-path)}
261 This function will remove the menu item defined by @var{menu-name} from
262 the menu hierarchy. Look at the following examples and the comments just
263 above them which specify what the examples do.
264
265 @example
266 ;; deletes the "Replace String" menu item created earlier
267 (delete-menu-item '("Edit" "Replace String"))
268
269 ;; deletes the "Bot" menu created earlier
270 (delete-menu-item '("Bot"))
271
272 ;; deletes the sub-menu "Copy File" created earlier
273 (delete-menu-item '("File" "File Management" "Copy File"))
274
275 ;; deletes the sub-menu "Delete File" created earlier
276 (delete-menu-item '("File" "Management" "Delete File"))
277
278 ;; deletes the sub-menu "Rename File" created earlier
279 (delete-menu-item '("File" "Management" "Rename File"))
280 @end example
281
282
283 @findex disable-menu-item
284 @cindex disabling menu items
285 @item disable-menu-item: @var{(menu-name)}
286 Disables the specified menu item. The following example
287
288 @example
289 (disable-menu-item '("File" "Management" "Copy File"))
290 @end example
291
292 @noindent
293 will make the @b{Copy File} item unselectable. This menu-item would
294 still be there but it will appear faded which would mean that it cannot
295 be selected.
296
297 @findex enable-menu-item
298 @cindex enabling menu items
299 @item enable-menu-item: @var{(menu-name)}
300 Enables the specified previously disabled menu item.
301
302 @example
303 (enable-menu-item '("File" "Management" "Copy File"))
304 @end example
305
306 @noindent
307 This will enable the sub-menu @b{Copy File}, which was disabled by the
308 earlier command.
309
310 @findex relabel-menu-items
311 @cindex relabelling menu items
312 @item relabel-menu-item: @var{(menu-name new-name)}
313 Change the string of the menu item specified by @var{menu-name} to
314 @var{new-name}.
315
316 @example
317 (relabel-menu-item '("File" "Open...") "Open File")
318 @end example
319
320 This example will rename the @b{Open...} menu item from the @b{File}
321 menu to @b{Open File}.
322
323 @end enumerate
324