Mercurial > hg > xemacs-beta
diff man/new-users-guide/custom1.texi @ 0:376386a54a3c r19-14
Import from CVS: tag r19-14
author | cvs |
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date | Mon, 13 Aug 2007 08:45:50 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/man/new-users-guide/custom1.texi Mon Aug 13 08:45:50 2007 +0200 @@ -0,0 +1,324 @@ +@comment node-name, next, previous, up +@node Customization Basics, Help, Edit, Top +@chapter Customize key bindings and menus +@cindex .emacs +@cindex customize +@findex eval-region + + When you start Emacs, it reads the file @file{~/.emacs} in your home +directory. You can use this file to initialize and customize Emacs to +your liking. This file should contain lisp-code. You can customize your +@file{.emacs} file to create new +menus, disable menus, change key bindings, enable a minor mode, etc. Any +kind of customization affects +only a particular Emacs job that you do them in. If you want to save +your customizations `permanently' i.e. for future use also, you have to +put it in your @samp{.emacs} file. After you make changes to your +@file{.emacs} file and save it, the changes will be effective only after +you start Emacs again i.e. for a new Emacs process. To try out some of +the examples in this section, highlight that region and evaluate the +region by giving the command @kbd{M-x eval-region}. You will be able to +see the results of your customizations in that Emacs session only +(@pxref{Lisp Eval,,,,XEmacs User's Manual}). + +@comment node-name, next, previous, up +@menu +* Customizing key Bindings:: Changing Key Bindings +* Customizing Menus:: Adding, Deleting, Enabling and Disabling Menus +@end menu + +@node Customizing key Bindings, Customizing Menus, Customization Basics, Customization Basics +@section Customize key bindings +@cindex key bindings +@cindex keystrokes + + Most of Emacs commands use key sequences. @xref{Keystrokes,,,,XEmacs +Manual}, for more information about Keys and Commands. In Emacs, the +keys themselves carry no meaning unless they are bound to a +function. For example, @kbd{C-n} moves the cursor to the next line +because its bound to the function @b{next-line}. Similarly, @kbd{C-p} +moves to the previous line because its bound to the function +@b{previous-line}. The functions themselves define a particular +behavior. You can customize the key @kbd{C-n} to move to the previous +line by binding it to @b{previous-line} and @kbd{C-p} to move to the +next line by binding it to @b{next-line}. To bind keys to globally run +commands you need to use the following syntax in your @b{.emacs} file: + +@cindex binding keys +@example +@code{(global-set-key @var{keys} @var{cmd})} +@end example +@noindent + Here, @code{global-set-key} is a function which will bind the +@dfn{keys} to the specified @dfn{cmd}. For example, if you type the +following in your @b{.emacs} file: + +@example +(global-set-key "\C-p" 'next-line) +(global-set-key "\C-n" 'previous-line) +@end example + +@noindent +then @kbd{C-p} will move to the next line and @kbd{C-n} to the previous +line. + +You can also disable a key binding, by using @samp{nil} as the @var{cmd} +in the syntax stated above. Here, @samp{nil} stands for @samp{false} +which means disable a command or turn off a feature. If you want to +enable a command or turn on a particular feature use @samp{t} +which stands for @samp{true}. For example, if you do not wish @kbd{C-x +C-c} to @samp{Exit Emacs} you can type the following expression in your +@file{.emacs} file: + +@example +(global-set-key "\C-x\C-c" nil) +@end example + +@noindent +You might want to have this statement in your @file{.emacs} file because +its easy to hit this command by mistake and it could be annoying to exit +Emacs unintentionally. There is a @b{Exit Emacs} option in the @b{File +menu} which you might want to use instead. To make a particular key +undefined you can also use: + +@example +(global-unset-key "\C-x\C-c") +@end example + +@noindent +Now if you use the command @kbd{C-x C-c}, you will get an error saying +that the command is undefined. + + Some other customizations you could try are: +@itemize @bullet + +@item +@example +(global-set-key 'button3 'beginning-of-buffer) +@end example + +@noindent +Now when you press the third button of your mouse, the cursor will be +placed at the @code{beginning-of-buffer}. + +@item +@example +(global-set-key 'f1 'goto-line) +@end example + +@noindent +If you press the @key{F1} key, you will be prompted for a line +number. After you type the line number and hit @key{RET}, the cursor +will be placed on that line number. + +@item +@example +(global-set-key 'f2 'undo) +@end example + +Pressing @key{F2} will undo the last command. If you have a @key{undo} +key on your keyboard, try binding that key to the undo command. +@end itemize + + + Another syntax for customizing key bindings is: +@code{(define-key @var{keymap} @var{keys} @var{def})} +It defines @var{keys} to run @var{def} in the keymap @var{keymap}. + +@var{keymap} is a keymap object which records the bindings of keys to +the commands that they run. + +@var{keys} is the sequence of keystrokes to bind. + +@var{def} is anything that can be a key's definition: + +Look at the following two examples: + +@example +(define-key global-map "\C-xl" 'make-symbolic-link) +(define-key c-mode-map "\C-xl" 'make-symbolic-link) +@end example + +@findex make-symbolic-link +@noindent +Both the examples bind the key @kbd{C-xl} to run the function +@code{make-symbolic-link} (@pxref{Misc File Ops,,,,XEmacs User's +Manual}). However, the second example will bind the key only for C +mode. @xref{Major Modes,,,,XEmacs User's Manual}, for more +information on Major Modes in XEmacs. + + + +@comment node-name, next, previous, up +@node Customizing Menus, , Customizing key Bindings, Customization Basics +@section Customizing Menus +@cindex customize menus +@cindex delete menus +@cindex disable menus +@findex add-menu-item +@cindex add menus + +You can customize any of the XEmacs Pull-down-Menus. You can create your +own menu, delete an existing one, enable a menu or disable a menu. For +more information on the default menus available to you, @xref{Pull-down +Menus}. + + Some of the functions which are available to you for customization are: +@enumerate + +@item add-menu-item: @var{(menu-name item-name function enabled-p +&optional before)} + +This function will add a menu item to a menu, creating the menu first if +necessary. If the named item already exists, the menu will remain +unchanged. For example, if you add the following example to your +@file{.emacs} file or evaluate it (@pxref{Customization Basics}), + +@example +(add-menu-item '("Edit") "Replace String" replace-string t "Clear") +@end example + +@noindent +a sub-menu @b{Replace String} will be created under @b{Edit} menu before the +sub-menu @b{Clear}. The @b{Edit} menu will now look like: + +@example +Undo C-x u +Cut cut +Copy copy +Paste paste +Replace String +Clear +Start Macro Recording C-x( +End Macro Recording C-x) +Execute Last Macro C-xe +@end example + +@noindent +@b{Replace String} will now execute the function +@code{replace-string}. Select this menu item. Emacs will prompt you for +a string name to be replaced. Type a +string and hit @key{RET}. Now type a new string to replace the old +string and hit @key{RET}. All occurrences of the old string will be +replaced by the new string. In this example, + +@samp{Edit} is the @var{menu-name} which identifies the menu into which +the new menu item should be inserted. + +@samp{Replace String} is the @var{item-name} which names the menu item +to be added. + +@samp{replace-string} is the @var{function} i.e. the command to be +invoked when the menu item "Replace String" is selected. + +@samp{t} is the @var{enabled-p} parameter which controls whether the +menu item is selectable or not. This parameter can be either @code{t} (selectable), @code{nil} (not selectable), or a +form to evaluate. This form is evaluated just before the menu is +displayed, and the menu item will be selectable if the form returns +non-@code{nil}. + +@samp{Clear} is the @var{&optional before} parameter which is the name +of the menu before which the new menu or sub-menu should be added. The +@var{&optional} string means that this parameter is optional. You do not +need to specify this parameter. If you do not specify this parameter in +the example above, the @b{Replace String} menu item will be added at the +end of the list of sub-menus in the @b{Edit} menu i.e. after @b{Execute +Last Macro}. + + If you wish to add a new menu to the menubar, try: + +@example +(add-menu-item nil "Bot" 'end-of-buffer t) +@end example + +@noindent +This will create a new menu @b{Bot} on the menu bar. Selecting this menu +will take you to the end of the buffer. Using @code{nil} for the +parameter @var{menu-name} will create a new menu. Your menu-bar +will now look like: + +@example +File Edit Options Buffers Bot Help +@end example + + The following example will illustrate how you can add sub-menus to the +submenus themselves: + +@example +(add-menu-item '("File" "Management") "Copy File" 'copy-file t) +(add-menu-item '("File" "Management") "Delete File" 'delete-file t) +(add-menu-item '("File" "Management") "Rename File" 'rename-file t) +@end example +@noindent + +This will create a sub-menu @b{Management} under the @b{File} +menu. When you select the submenu @b{Management}, it will contain three +submenus: @b{Copy File}, @b{Delete File} and @b{Rename File}. + +@findex delete-menu-item +@cindex deleting menu items +@item delete-menu-item: @var{(menu-path)} +This function will remove the menu item defined by @var{menu-name} from +the menu hierarchy. Look at the following examples and the comments just +above them which specify what the examples do. + +@example +;; deletes the "Replace String" menu item created earlier +(delete-menu-item '("Edit" "Replace String")) + +;; deletes the "Bot" menu created earlier +(delete-menu-item '("Bot")) + +;; deletes the sub-menu "Copy File" created earlier +(delete-menu-item '("File" "File Management" "Copy File")) + +;; deletes the sub-menu "Delete File" created earlier +(delete-menu-item '("File" "Management" "Delete File")) + +;; deletes the sub-menu "Rename File" created earlier +(delete-menu-item '("File" "Management" "Rename File")) +@end example + + +@findex disable-menu-item +@cindex disabling menu items +@item disable-menu-item: @var{(menu-name)} +Disables the specified menu item. The following example + +@example +(disable-menu-item '("File" "Management" "Copy File")) +@end example + +@noindent +will make the @b{Copy File} item unselectable. This menu-item would +still be there but it will appear faded which would mean that it cannot +be selected. + +@findex enable-menu-item +@cindex enabling menu items +@item enable-menu-item: @var{(menu-name)} +Enables the specified previously disabled menu item. + +@example +(enable-menu-item '("File" "Management" "Copy File")) +@end example + +@noindent +This will enable the sub-menu @b{Copy File}, which was disabled by the +earlier command. + +@findex relabel-menu-items +@cindex relabelling menu items +@item relabel-menu-item: @var{(menu-name new-name)} +Change the string of the menu item specified by @var{menu-name} to +@var{new-name}. + +@example +(relabel-menu-item '("File" "Open...") "Open File") +@end example + +This example will rename the @b{Open...} menu item from the @b{File} +menu to @b{Open File}. + +@end enumerate +