Merge from emacs-24
[emacs.git] / lisp / rfn-eshadow.el
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1 ;;; rfn-eshadow.el --- Highlight `shadowed' part of read-file-name input text
2 ;;
3 ;; Copyright (C) 2000-2014 Free Software Foundation, Inc.
4 ;;
5 ;; Author: Miles Bader <miles@gnu.org>
6 ;; Keywords: convenience minibuffer
7 ;; Package: emacs
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 3 of the License, or
14 ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>.
24 ;;; Commentary:
26 ;; Defines the mode `file-name-shadow-mode'.
28 ;; The `read-file-name' function passes its result through
29 ;; `substitute-in-file-name', so any part of the string preceding
30 ;; multiple slashes (or a drive indicator on MS-DOS/MS-Windows) is
31 ;; ignored.
33 ;; If `file-name-shadow-mode' is active, any part of the
34 ;; minibuffer text that would be ignored because of this is given the
35 ;; properties in `file-name-shadow-properties', which may
36 ;; be used to make the ignored text invisible, dim, etc.
39 ;;; Code:
42 ;;; Customization
44 (defconst file-name-shadow-properties-custom-type
45 '(list
46 (checklist :inline t
47 (const :tag "Invisible"
48 :doc "Make shadowed part of filename invisible"
49 :format "%t%n%h"
50 :inline t
51 (invisible t intangible t))
52 (list :inline t
53 :format "%v"
54 :tag "Face"
55 :doc "Display shadowed part of filename using a different face"
56 (const :format "" face)
57 (face :value file-name-shadow))
58 (list :inline t
59 :format "%t: %v%h"
60 :tag "Brackets"
61 ;; Note the 4 leading spaces in the doc string;
62 ;; this is hack to get around the fact that the
63 ;; newline after the second string widget comes
64 ;; from the string widget, and doesn't indent
65 ;; correctly. We could use a :size attribute to
66 ;; make the second string widget not have a
67 ;; terminating newline, but this makes it impossible
68 ;; to enter trailing whitespace, and it's desirable
69 ;; that it be possible.
70 :doc " Surround shadowed part of filename with brackets"
71 (const :format "" before-string)
72 (string :format "%v" :size 4 :value "{")
73 (const :format "" after-string)
74 ;; see above about why the 2nd string doesn't use :size
75 (string :format " and: %v" :value "} "))
76 (list :inline t
77 :format "%t: %v%n%h"
78 :tag "String"
79 :doc "Display a string instead of the shadowed part of filename"
80 (const :format "" display)
81 (string :format "%v" :size 15 :value "<...ignored...>"))
82 (const :tag "Avoid"
83 :doc "Try to keep cursor out of shadowed part of filename"
84 :format "%t%n%h"
85 :inline t
86 (field shadow)))
87 (repeat :inline t
88 :tag "Other Properties"
89 (list :inline t
90 :format "%v"
91 (symbol :tag "Property")
92 (sexp :tag "Value")))))
94 (defcustom file-name-shadow-properties
95 ;; FIXME: should we purecopy this?
96 '(face file-name-shadow field shadow)
97 "Properties given to the `shadowed' part of a filename in the minibuffer.
98 Only used when `file-name-shadow-mode' is active.
99 If Emacs is not running under a window system,
100 `file-name-shadow-tty-properties' is used instead."
101 :type file-name-shadow-properties-custom-type
102 :group 'minibuffer
103 :version "22.1")
105 (defcustom file-name-shadow-tty-properties
106 (purecopy '(before-string "{" after-string "} " field shadow))
107 "Properties given to the `shadowed' part of a filename in the minibuffer.
108 Only used when `file-name-shadow-mode' is active and Emacs
109 is not running under a window-system; if Emacs is running under a window
110 system, `file-name-shadow-properties' is used instead."
111 :type file-name-shadow-properties-custom-type
112 :group 'minibuffer
113 :version "22.1")
115 (defface file-name-shadow
116 '((t :inherit shadow))
117 "Face used by `file-name-shadow-mode' for the shadow."
118 :group 'minibuffer
119 :version "22.1")
121 (defvar rfn-eshadow-setup-minibuffer-hook nil
122 "Minibuffer setup functions from other packages.")
124 (defvar rfn-eshadow-update-overlay-hook nil
125 "Customer overlay functions from other packages")
128 ;;; Internal variables
130 ;; A list of minibuffers to which we've added a post-command-hook.
131 (defvar rfn-eshadow-frobbed-minibufs nil)
133 ;; An overlay covering the shadowed part of the filename (local to the
134 ;; minibuffer).
135 (defvar rfn-eshadow-overlay)
136 (make-variable-buffer-local 'rfn-eshadow-overlay)
139 ;;; Hook functions
141 ;; This function goes on minibuffer-setup-hook
142 (defun rfn-eshadow-setup-minibuffer ()
143 "Set up a minibuffer for `file-name-shadow-mode'.
144 The prompt and initial input should already have been inserted."
145 (when minibuffer-completing-file-name
146 (setq rfn-eshadow-overlay
147 (make-overlay (minibuffer-prompt-end) (minibuffer-prompt-end)))
148 ;; Give rfn-eshadow-overlay the user's props.
149 (let ((props
150 (if window-system
151 file-name-shadow-properties
152 file-name-shadow-tty-properties)))
153 (while props
154 (overlay-put rfn-eshadow-overlay (pop props) (pop props))))
155 ;; Turn on overlay evaporation so that we don't have to worry about
156 ;; odd effects when the overlay sits empty at the beginning of the
157 ;; minibuffer.
158 (overlay-put rfn-eshadow-overlay 'evaporate t)
159 ;; Add our post-command hook, and make sure can remove it later.
160 (add-to-list 'rfn-eshadow-frobbed-minibufs (current-buffer))
161 (add-hook 'post-command-hook #'rfn-eshadow-update-overlay nil t)
162 ;; Run custom hook
163 (run-hooks 'rfn-eshadow-setup-minibuffer-hook)))
165 (defsubst rfn-eshadow-sifn-equal (goal pos)
166 (equal goal (condition-case nil
167 (substitute-in-file-name
168 (buffer-substring-no-properties pos (point-max)))
169 ;; `substitute-in-file-name' can fail on partial input.
170 (error nil))))
172 ;; post-command-hook to update overlay
173 (defun rfn-eshadow-update-overlay ()
174 "Update `rfn-eshadow-overlay' to cover shadowed part of minibuffer input.
175 This is intended to be used as a minibuffer `post-command-hook' for
176 `file-name-shadow-mode'; the minibuffer should have already
177 been set up by `rfn-eshadow-setup-minibuffer'."
178 (condition-case nil
179 (let* ((non-essential t)
180 (goal (substitute-in-file-name (minibuffer-contents)))
181 (mid (overlay-end rfn-eshadow-overlay))
182 (start (minibuffer-prompt-end))
183 (end (point-max)))
184 (unless
185 ;; Catch the common case where the shadow does not need to move.
186 (and mid
187 (or (eq mid end)
188 (not (rfn-eshadow-sifn-equal goal (1+ mid))))
189 (or (eq mid start)
190 (rfn-eshadow-sifn-equal goal mid)))
191 ;; Binary search for the greatest position still equivalent to
192 ;; the whole.
193 (while (or (< (1+ start) end)
194 (if (and (< (1+ end) (point-max))
195 (rfn-eshadow-sifn-equal goal (1+ end)))
196 ;; (SIFN end) != goal, but (SIFN (1+end)) == goal,
197 ;; We've reached a discontinuity: this can happen
198 ;; e.g. if `end' point to "/:...".
199 (setq start (1+ end) end (point-max))))
200 (setq mid (/ (+ start end) 2))
201 (if (rfn-eshadow-sifn-equal goal mid)
202 (setq start mid)
203 (setq end mid)))
204 (move-overlay rfn-eshadow-overlay (minibuffer-prompt-end) start))
205 ;; Run custom hook
206 (run-hooks 'rfn-eshadow-update-overlay-hook))
207 ;; `substitute-in-file-name' can fail on partial input.
208 (error nil)))
210 (define-minor-mode file-name-shadow-mode
211 "Toggle file-name shadowing in minibuffers (File-Name Shadow mode).
212 With a prefix argument ARG, enable File-Name Shadow mode if ARG
213 is positive, and disable it otherwise. If called from Lisp,
214 enable the mode if ARG is omitted or nil.
216 File-Name Shadow mode is a global minor mode. When enabled, any
217 part of a filename being read in the minibuffer that would be
218 ignored (because the result is passed through
219 `substitute-in-file-name') is given the properties in
220 `file-name-shadow-properties', which can be used to make that
221 portion dim, invisible, or otherwise less visually noticeable."
222 :global t
223 ;; We'd like to use custom-initialize-set here so the setup is done
224 ;; before dumping, but at the point where the defcustom is evaluated,
225 ;; the corresponding function isn't defined yet, so
226 ;; custom-initialize-set signals an error.
227 :initialize 'custom-initialize-delay
228 :init-value t
229 :group 'minibuffer
230 :version "22.1"
231 (if file-name-shadow-mode
232 ;; Enable the mode
233 (add-hook 'minibuffer-setup-hook 'rfn-eshadow-setup-minibuffer)
234 ;; Disable the mode
235 (remove-hook 'minibuffer-setup-hook 'rfn-eshadow-setup-minibuffer)
236 ;; Remove our entry from any post-command-hook variable's it's still in
237 (dolist (minibuf rfn-eshadow-frobbed-minibufs)
238 (with-current-buffer minibuf
239 (remove-hook 'post-command-hook #'rfn-eshadow-update-overlay t)))
240 (setq rfn-eshadow-frobbed-minibufs nil)))
243 (provide 'rfn-eshadow)
245 ;;; rfn-eshadow.el ends here