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[emacs.git] / lisp / fringe.el
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1 ;;; fringe.el --- fringe setup and control
3 ;; Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
5 ;; Author: Simon Josefsson <simon@josefsson.org>
6 ;; Maintainer: FSF
7 ;; Keywords: frames
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
26 ;;; Commentary:
28 ;; This file contains code to initialize the built-in fringe bitmaps
29 ;; as well as helpful functions for customizing the appearance of the
30 ;; fringe.
32 ;; The code is influenced by scroll-bar.el and avoid.el. The author
33 ;; gratefully acknowledge comments and suggestions made by Miles
34 ;; Bader, Eli Zaretski, Richard Stallman, Pavel Janík and others which
35 ;; improved this package.
37 ;;; Code:
39 (defgroup fringe nil
40 "Window fringes."
41 :version "22.1"
42 :group 'frames)
44 ;; Define the built-in fringe bitmaps and setup default mappings
46 (when (boundp 'fringe-bitmaps)
47 (let ((bitmaps '(question-mark
48 left-arrow right-arrow up-arrow down-arrow
49 left-curly-arrow right-curly-arrow
50 left-triangle right-triangle
51 top-left-angle top-right-angle
52 bottom-left-angle bottom-right-angle
53 left-bracket right-bracket
54 filled-rectangle hollow-rectangle
55 filled-square hollow-square
56 vertical-bar horizontal-bar
57 empty-line))
58 (bn 1))
59 (while bitmaps
60 (push (car bitmaps) fringe-bitmaps)
61 (put (car bitmaps) 'fringe bn)
62 (setq bitmaps (cdr bitmaps)
63 bn (1+ bn))))
65 (setq-default fringe-indicator-alist
66 '((truncation . (left-arrow right-arrow))
67 (continuation . (left-curly-arrow right-curly-arrow))
68 (overlay-arrow . right-triangle)
69 (up . up-arrow)
70 (down . down-arrow)
71 (top . (top-left-angle top-right-angle))
72 (bottom . (bottom-left-angle bottom-right-angle
73 top-right-angle top-left-angle))
74 (top-bottom . (left-bracket right-bracket
75 top-right-angle top-left-angle))
76 (empty-line . empty-line)
77 (unknown . question-mark)))
79 (setq-default fringe-cursor-alist
80 '((box . filled-rectangle)
81 (hollow . hollow-rectangle)
82 (bar . vertical-bar)
83 (hbar . horizontal-bar)
84 (hollow-small . hollow-square))))
87 (defmacro fringe-bitmap-p (symbol)
88 "Return non-nil if SYMBOL is a fringe bitmap."
89 `(get ,symbol 'fringe))
92 ;; Control presence of fringes
94 (defvar fringe-mode)
96 (defun set-fringe-mode-1 (ignore value)
97 "Call `set-fringe-mode' with VALUE.
98 See `fringe-mode' for valid values and their effect.
99 This is usually invoked when setting `fringe-mode' via customize."
100 (set-fringe-mode value))
102 (defun set-fringe-mode (value)
103 "Set `fringe-mode' to VALUE and put the new value into effect.
104 See `fringe-mode' for possible values and their effect."
105 (setq fringe-mode value)
107 ;; Apply it to default-frame-alist.
108 (let ((parameter (assq 'left-fringe default-frame-alist)))
109 (if (consp parameter)
110 (setcdr parameter (if (consp fringe-mode)
111 (car fringe-mode)
112 fringe-mode))
113 (setq default-frame-alist
114 (cons (cons 'left-fringe (if (consp fringe-mode)
115 (car fringe-mode)
116 fringe-mode))
117 default-frame-alist))))
118 (let ((parameter (assq 'right-fringe default-frame-alist)))
119 (if (consp parameter)
120 (setcdr parameter (if (consp fringe-mode)
121 (cdr fringe-mode)
122 fringe-mode))
123 (setq default-frame-alist
124 (cons (cons 'right-fringe (if (consp fringe-mode)
125 (cdr fringe-mode)
126 fringe-mode))
127 default-frame-alist))))
129 ;; Apply it to existing frames.
130 (let ((frames (frame-list)))
131 (while frames
132 (modify-frame-parameters
133 (car frames)
134 (list (cons 'left-fringe (if (consp fringe-mode)
135 (car fringe-mode)
136 fringe-mode))
137 (cons 'right-fringe (if (consp fringe-mode)
138 (cdr fringe-mode)
139 fringe-mode))))
140 (setq frames (cdr frames)))))
142 ;; For initialization of fringe-mode, take account of changes
143 ;; made explicitly to default-frame-alist.
144 (defun fringe-mode-initialize (symbol value)
145 (let* ((left-pair (assq 'left-fringe default-frame-alist))
146 (right-pair (assq 'right-fringe default-frame-alist))
147 (left (cdr left-pair))
148 (right (cdr right-pair)))
149 (if (or left-pair right-pair)
150 ;; If there's something in default-frame-alist for fringes,
151 ;; don't change it, but reflect that into the value of fringe-mode.
152 (progn
153 (setq fringe-mode (cons left right))
154 (if (equal fringe-mode '(nil . nil))
155 (setq fringe-mode nil))
156 (if (equal fringe-mode '(0 . 0))
157 (setq fringe-mode 0)))
158 ;; Otherwise impose the user-specified value of fringe-mode.
159 (custom-initialize-reset symbol value))))
161 (defcustom fringe-mode nil
162 "*Specify appearance of fringes on all frames.
163 This variable can be nil (the default) meaning the fringes should have
164 the default width (8 pixels), it can be an integer value specifying
165 the width of both left and right fringe (where 0 means no fringe), or
166 a cons cell where car indicates width of left fringe and cdr indicates
167 width of right fringe (where again 0 can be used to indicate no
168 fringe).
169 To set this variable in a Lisp program, use `set-fringe-mode' to make
170 it take real effect.
171 Setting the variable with a customization buffer also takes effect.
172 If you only want to modify the appearance of the fringe in one frame,
173 you can use the interactive function `set-fringe-style'."
174 :type '(choice (const :tag "Default width" nil)
175 (const :tag "No fringes" 0)
176 (const :tag "Only right" (0 . nil))
177 (const :tag "Only left" (nil . 0))
178 (const :tag "Half width" (5 . 5))
179 (const :tag "Minimal" (1 . 1))
180 (integer :tag "Specific width")
181 (cons :tag "Different left/right sizes"
182 (integer :tag "Left width")
183 (integer :tag "Right width")))
184 :group 'fringe
185 :require 'fringe
186 :initialize 'fringe-mode-initialize
187 :set 'set-fringe-mode-1)
189 (defun fringe-query-style (&optional all-frames)
190 "Query user for fringe style.
191 Returns values suitable for left-fringe and right-fringe frame parameters.
192 If ALL-FRAMES, the negation of the fringe values in
193 `default-frame-alist' is used when user enters the empty string.
194 Otherwise the negation of the fringe value in the currently selected
195 frame parameter is used."
196 (let ((mode (intern (completing-read
197 (concat
198 "Select fringe mode for "
199 (if all-frames "all frames" "selected frame")
200 " (type ? for list): ")
201 '(("none") ("default") ("left-only")
202 ("right-only") ("half") ("minimal"))
203 nil t))))
204 (cond ((eq mode 'none) 0)
205 ((eq mode 'default) nil)
206 ((eq mode 'left-only) '(nil . 0))
207 ((eq mode 'right-only) '(0 . nil))
208 ((eq mode 'half) '(5 . 5))
209 ((eq mode 'minimal) '(1 . 1))
210 ((eq mode (intern ""))
211 (if (eq 0 (cdr (assq 'left-fringe
212 (if all-frames
213 default-frame-alist
214 (frame-parameters (selected-frame))))))
216 0)))))
218 (defun fringe-mode (&optional mode)
219 "Set the default appearance of fringes on all frames.
221 When called interactively, query the user for MODE. Valid values
222 for MODE include `none', `default', `left-only', `right-only',
223 `minimal' and `half'.
225 When used in a Lisp program, MODE can be a cons cell where the
226 integer in car specifies the left fringe width and the integer in
227 cdr specifies the right fringe width. MODE can also be a single
228 integer that specifies both the left and the right fringe width.
229 If a fringe width specification is nil, that means to use the
230 default width (8 pixels). This command may round up the left and
231 right width specifications to ensure that their sum is a multiple
232 of the character width of a frame. It never rounds up a fringe
233 width of 0.
235 Fringe widths set by `set-window-fringes' override the default
236 fringe widths set by this command. This command applies to all
237 frames that exist and frames to be created in the future. If you
238 want to set the default appearance of fringes on the selected
239 frame only, see the command `set-fringe-style'."
240 (interactive (list (fringe-query-style 'all-frames)))
241 (set-fringe-mode mode))
243 (defun set-fringe-style (&optional mode)
244 "Set the default appearance of fringes on the selected frame.
246 When called interactively, query the user for MODE. Valid values
247 for MODE include `none', `default', `left-only', `right-only',
248 `minimal' and `half'.
250 When used in a Lisp program, MODE can be a cons cell where the
251 integer in car specifies the left fringe width and the integer in
252 cdr specifies the right fringe width. MODE can also be a single
253 integer that specifies both the left and the right fringe width.
254 If a fringe width specification is nil, that means to use the
255 default width (8 pixels). This command may round up the left and
256 right width specifications to ensure that their sum is a multiple
257 of the character width of a frame. It never rounds up a fringe
258 width of 0.
260 Fringe widths set by `set-window-fringes' override the default
261 fringe widths set by this command. If you want to set the
262 default appearance of fringes on all frames, see the command
263 `fringe-mode'."
264 (interactive (list (fringe-query-style)))
265 (modify-frame-parameters
266 (selected-frame)
267 (list (cons 'left-fringe (if (consp mode) (car mode) mode))
268 (cons 'right-fringe (if (consp mode) (cdr mode) mode)))))
270 (defsubst fringe-columns (side &optional real)
271 "Return the width, measured in columns, of the fringe area on SIDE.
272 If optional argument REAL is non-nil, return a real floating point
273 number instead of a rounded integer value.
274 SIDE must be the symbol `left' or `right'."
275 (funcall (if real '/ 'ceiling)
276 (or (funcall (if (eq side 'left) 'car 'cadr)
277 (window-fringes))
279 (float (frame-char-width))))
281 (provide 'fringe)
283 ;;; arch-tag: 6611ef60-0869-47ed-8b93-587ee7d3ff5d
284 ;;; fringe.el ends here