Fix last change in etags.c, which failed the test suite
[emacs.git] / lisp / emacs-lisp / tabulated-list.el
blob5d10b55d14c30a3742b09dd65160f7d651622693
1 ;;; tabulated-list.el --- generic major mode for tabulated lists -*- lexical-binding: t -*-
3 ;; Copyright (C) 2011-2015 Free Software Foundation, Inc.
5 ;; Author: Chong Yidong <cyd@stupidchicken.com>
6 ;; Keywords: extensions, lisp
7 ;; Version: 1.0
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 ;; This file defines Tabulated List mode, a generic major mode for
27 ;; displaying lists of tabulated data, intended for other major modes
28 ;; to inherit from. It provides several utility routines, e.g. for
29 ;; pretty-printing lines of tabulated data to fit into the appropriate
30 ;; columns.
32 ;; For usage information, see the documentation of `tabulated-list-mode'.
34 ;; This package originated from Tom Tromey's Package Menu mode,
35 ;; extended and generalized to be used by other modes.
37 ;;; Code:
39 ;; The reason `tabulated-list-format' and other variables are
40 ;; permanent-local is to make it convenient to switch to a different
41 ;; major mode, switch back, and have the original Tabulated List data
42 ;; still valid. See, for example, ebuff-menu.el.
44 (defvar-local tabulated-list-format nil
45 "The format of the current Tabulated List mode buffer.
46 This should be a vector of elements (NAME WIDTH SORT . PROPS),
47 where:
48 - NAME is a string describing the column.
49 This is the label for the column in the header line.
50 Different columns must have non-`equal' names.
51 - WIDTH is the width to reserve for the column.
52 For the final element, its numerical value is ignored.
53 - SORT specifies how to sort entries by this column.
54 If nil, this column cannot be used for sorting.
55 If t, sort by comparing the string value printed in the column.
56 Otherwise, it should be a predicate function suitable for
57 `sort', accepting arguments with the same form as the elements
58 of `tabulated-list-entries'.
59 - PROPS is a plist of additional column properties.
60 Currently supported properties are:
61 - `:right-align': If non-nil, the column should be right-aligned.
62 - `:pad-right': Number of additional padding spaces to the
63 right of the column (defaults to 1 if omitted).")
64 (put 'tabulated-list-format 'permanent-local t)
66 (defvar-local tabulated-list-use-header-line t
67 "Whether the Tabulated List buffer should use a header line.")
69 (defvar-local tabulated-list-entries nil
70 "Entries displayed in the current Tabulated List buffer.
71 This should be either a function, or a list.
72 If a list, each element has the form (ID [DESC1 ... DESCN]),
73 where:
74 - ID is nil, or a Lisp object uniquely identifying this entry,
75 which is used to keep the cursor on the \"same\" entry when
76 rearranging the list. Comparison is done with `equal'.
78 - Each DESC is a column descriptor, one for each column
79 specified in `tabulated-list-format'. A descriptor is either
80 a string, which is printed as-is, or a list (LABEL . PROPS),
81 which means to use `insert-text-button' to insert a text
82 button with label LABEL and button properties PROPS.
83 The string, or button label, must not contain any newline.
85 If `tabulated-list-entries' is a function, it is called with no
86 arguments and must return a list of the above form.")
87 (put 'tabulated-list-entries 'permanent-local t)
89 (defvar-local tabulated-list-padding 0
90 "Number of characters preceding each Tabulated List mode entry.
91 By default, lines are padded with spaces, but you can use the
92 function `tabulated-list-put-tag' to change this.")
93 (put 'tabulated-list-padding 'permanent-local t)
95 (defvar tabulated-list-revert-hook nil
96 "Hook run before reverting a Tabulated List buffer.
97 This is commonly used to recompute `tabulated-list-entries'.")
99 (defvar-local tabulated-list-printer 'tabulated-list-print-entry
100 "Function for inserting a Tabulated List entry at point.
101 It is called with two arguments, ID and COLS. ID is a Lisp
102 object identifying the entry, and COLS is a vector of column
103 descriptors, as documented in `tabulated-list-entries'.")
105 (defvar-local tabulated-list-sort-key nil
106 "Sort key for the current Tabulated List mode buffer.
107 If nil, no additional sorting is performed.
108 Otherwise, this should be a cons cell (NAME . FLIP).
109 NAME is a string matching one of the column names in
110 `tabulated-list-format' (the corresponding SORT entry in
111 `tabulated-list-format' then specifies how to sort). FLIP, if
112 non-nil, means to invert the resulting sort.")
113 (put 'tabulated-list-sort-key 'permanent-local t)
115 (defsubst tabulated-list-get-id (&optional pos)
116 "Return the entry ID of the Tabulated List entry at POS.
117 The value is an ID object from `tabulated-list-entries', or nil.
118 POS, if omitted or nil, defaults to point."
119 (get-text-property (or pos (point)) 'tabulated-list-id))
121 (defsubst tabulated-list-get-entry (&optional pos)
122 "Return the Tabulated List entry at POS.
123 The value is a vector of column descriptors, or nil if there is
124 no entry at POS. POS, if omitted or nil, defaults to point."
125 (get-text-property (or pos (point)) 'tabulated-list-entry))
127 (defun tabulated-list-put-tag (tag &optional advance)
128 "Put TAG in the padding area of the current line.
129 TAG should be a string, with length <= `tabulated-list-padding'.
130 If ADVANCE is non-nil, move forward by one line afterwards."
131 (unless (stringp tag)
132 (error "Invalid argument to `tabulated-list-put-tag'"))
133 (unless (> tabulated-list-padding 0)
134 (error "Unable to tag the current line"))
135 (save-excursion
136 (beginning-of-line)
137 (when (tabulated-list-get-entry)
138 (let ((beg (point))
139 (inhibit-read-only t))
140 (forward-char tabulated-list-padding)
141 (insert-and-inherit
142 (let ((width (string-width tag)))
143 (if (<= width tabulated-list-padding)
144 (concat tag
145 (make-string (- tabulated-list-padding width) ?\s))
146 (truncate-string-to-width tag tabulated-list-padding))))
147 (delete-region beg (+ beg tabulated-list-padding)))))
148 (if advance
149 (forward-line)))
151 (defvar tabulated-list-mode-map
152 (let ((map (copy-keymap special-mode-map)))
153 (set-keymap-parent map button-buffer-map)
154 (define-key map "n" 'next-line)
155 (define-key map "p" 'previous-line)
156 (define-key map "S" 'tabulated-list-sort)
157 (define-key map [follow-link] 'mouse-face)
158 (define-key map [mouse-2] 'mouse-select-window)
159 map)
160 "Local keymap for `tabulated-list-mode' buffers.")
162 (defvar tabulated-list-sort-button-map
163 (let ((map (make-sparse-keymap)))
164 (define-key map [header-line mouse-1] 'tabulated-list-col-sort)
165 (define-key map [header-line mouse-2] 'tabulated-list-col-sort)
166 (define-key map [mouse-1] 'tabulated-list-col-sort)
167 (define-key map [mouse-2] 'tabulated-list-col-sort)
168 (define-key map "\C-m" 'tabulated-list-sort)
169 (define-key map [follow-link] 'mouse-face)
170 map)
171 "Local keymap for `tabulated-list-mode' sort buttons.")
173 (defvar tabulated-list-glyphless-char-display
174 (let ((table (make-char-table 'glyphless-char-display nil)))
175 (set-char-table-parent table glyphless-char-display)
176 ;; Some text terminals can't display the Unicode arrows; be safe.
177 (aset table 9650 (cons nil "^"))
178 (aset table 9660 (cons nil "v"))
179 table)
180 "The `glyphless-char-display' table in Tabulated List buffers.")
182 (defvar tabulated-list--header-string nil
183 "Holds the header if `tabulated-list-use-header-line' is nil.
184 Populated by `tabulated-list-init-header'.")
185 (defvar tabulated-list--header-overlay nil)
187 (defun tabulated-list-init-header ()
188 "Set up header line for the Tabulated List buffer."
189 ;; FIXME: Should share code with tabulated-list-print-col!
190 (let ((x (max tabulated-list-padding 0))
191 (button-props `(help-echo "Click to sort by column"
192 mouse-face highlight
193 keymap ,tabulated-list-sort-button-map))
194 (cols nil))
195 (push (propertize " " 'display `(space :align-to ,x)) cols)
196 (dotimes (n (length tabulated-list-format))
197 (let* ((col (aref tabulated-list-format n))
198 (label (nth 0 col))
199 (width (nth 1 col))
200 (props (nthcdr 3 col))
201 (pad-right (or (plist-get props :pad-right) 1))
202 (right-align (plist-get props :right-align))
203 (next-x (+ x pad-right width)))
204 (push
205 (cond
206 ;; An unsortable column
207 ((not (nth 2 col))
208 (propertize label 'tabulated-list-column-name label))
209 ;; The selected sort column
210 ((equal (car col) (car tabulated-list-sort-key))
211 (apply 'propertize
212 (concat label
213 (cond
214 ((> (+ 2 (length label)) width) "")
215 ((cdr tabulated-list-sort-key) " ▲")
216 (t " ▼")))
217 'face 'bold
218 'tabulated-list-column-name label
219 button-props))
220 ;; Unselected sortable column.
221 (t (apply 'propertize label
222 'tabulated-list-column-name label
223 button-props)))
224 cols)
225 (when right-align
226 (let ((shift (- width (string-width (car cols)))))
227 (when (> shift 0)
228 (setq cols
229 (cons (car cols)
230 (cons (propertize (make-string shift ?\s)
231 'display
232 `(space :align-to ,(+ x shift)))
233 (cdr cols))))
234 (setq x (+ x shift)))))
235 (if (>= pad-right 0)
236 (push (propertize " "
237 'display `(space :align-to ,next-x)
238 'face 'fixed-pitch)
239 cols))
240 (setq x next-x)))
241 (setq cols (apply 'concat (nreverse cols)))
242 (if tabulated-list-use-header-line
243 (setq header-line-format cols)
244 (setq header-line-format nil)
245 (setq-local tabulated-list--header-string cols))))
247 (defun tabulated-list-print-fake-header ()
248 "Insert a fake Tabulated List \"header line\" at the start of the buffer.
249 Do nothing if `tabulated-list--header-string' is nil."
250 (when tabulated-list--header-string
251 (goto-char (point-min))
252 (let ((inhibit-read-only t))
253 (insert tabulated-list--header-string "\n")
254 (if tabulated-list--header-overlay
255 (move-overlay tabulated-list--header-overlay (point-min) (point))
256 (setq-local tabulated-list--header-overlay
257 (make-overlay (point-min) (point))))
258 (overlay-put tabulated-list--header-overlay 'face 'underline))))
260 (defun tabulated-list-revert (&rest ignored)
261 "The `revert-buffer-function' for `tabulated-list-mode'.
262 It runs `tabulated-list-revert-hook', then calls `tabulated-list-print'."
263 (interactive)
264 (unless (derived-mode-p 'tabulated-list-mode)
265 (error "The current buffer is not in Tabulated List mode"))
266 (run-hooks 'tabulated-list-revert-hook)
267 (tabulated-list-print t))
269 (defun tabulated-list--column-number (name)
270 (let ((len (length tabulated-list-format))
271 (n 0)
272 found)
273 (while (and (< n len) (null found))
274 (if (equal (car (aref tabulated-list-format n)) name)
275 (setq found n))
276 (setq n (1+ n)))
277 (or found
278 (error "No column named %s" name))))
280 (defun tabulated-list-print (&optional remember-pos)
281 "Populate the current Tabulated List mode buffer.
282 This sorts the `tabulated-list-entries' list if sorting is
283 specified by `tabulated-list-sort-key'. It then erases the
284 buffer and inserts the entries with `tabulated-list-printer'.
286 Optional argument REMEMBER-POS, if non-nil, means to move point
287 to the entry with the same ID element as the current line."
288 (let ((inhibit-read-only t)
289 (entries (if (functionp tabulated-list-entries)
290 (funcall tabulated-list-entries)
291 tabulated-list-entries))
292 entry-id saved-pt saved-col)
293 (and remember-pos
294 (setq entry-id (tabulated-list-get-id))
295 (setq saved-col (current-column)))
296 (erase-buffer)
297 (unless tabulated-list-use-header-line
298 (tabulated-list-print-fake-header))
299 ;; Sort the entries, if necessary.
300 (when (and tabulated-list-sort-key
301 (car tabulated-list-sort-key))
302 (let* ((sort-column (car tabulated-list-sort-key))
303 (n (tabulated-list--column-number sort-column))
304 (sorter (nth 2 (aref tabulated-list-format n))))
305 ;; Is the specified column sortable?
306 (when sorter
307 (when (eq sorter t)
308 (setq sorter ; Default sorter checks column N:
309 (lambda (A B)
310 (setq A (aref (cadr A) n))
311 (setq B (aref (cadr B) n))
312 (string< (if (stringp A) A (car A))
313 (if (stringp B) B (car B))))))
314 (setq entries (sort entries sorter))
315 (if (cdr tabulated-list-sort-key)
316 (setq entries (nreverse entries)))
317 (unless (functionp tabulated-list-entries)
318 (setq tabulated-list-entries entries)))))
319 ;; Print the resulting list.
320 (dolist (elt entries)
321 (and entry-id
322 (equal entry-id (car elt))
323 (setq saved-pt (point)))
324 (apply tabulated-list-printer elt))
325 (set-buffer-modified-p nil)
326 ;; If REMEMBER-POS was specified, move to the "old" location.
327 (if saved-pt
328 (progn (goto-char saved-pt)
329 (move-to-column saved-col)
330 (when (eq (window-buffer) (current-buffer))
331 (recenter)))
332 (goto-char (point-min)))))
334 (defun tabulated-list-print-entry (id cols)
335 "Insert a Tabulated List entry at point.
336 This is the default `tabulated-list-printer' function. ID is a
337 Lisp object identifying the entry to print, and COLS is a vector
338 of column descriptors."
339 (let ((beg (point))
340 (x (max tabulated-list-padding 0))
341 (ncols (length tabulated-list-format))
342 (inhibit-read-only t))
343 (if (> tabulated-list-padding 0)
344 (insert (make-string x ?\s)))
345 (dotimes (n ncols)
346 (setq x (tabulated-list-print-col n (aref cols n) x)))
347 (insert ?\n)
348 ;; Ever so slightly faster than calling `put-text-property' twice.
349 (add-text-properties
350 beg (point)
351 `(tabulated-list-id ,id tabulated-list-entry ,cols))))
353 (defun tabulated-list-print-col (n col-desc x)
354 "Insert a specified Tabulated List entry at point.
355 N is the column number, COL-DESC is a column descriptor (see
356 `tabulated-list-entries'), and X is the column number at point.
357 Return the column number after insertion."
358 ;; TODO: don't truncate to `width' if the next column is align-right
359 ;; and has some space left.
360 (let* ((format (aref tabulated-list-format n))
361 (name (nth 0 format))
362 (width (nth 1 format))
363 (props (nthcdr 3 format))
364 (pad-right (or (plist-get props :pad-right) 1))
365 (right-align (plist-get props :right-align))
366 (label (if (stringp col-desc) col-desc (car col-desc)))
367 (label-width (string-width label))
368 (help-echo (concat (car format) ": " label))
369 (opoint (point))
370 (not-last-col (< (1+ n) (length tabulated-list-format))))
371 ;; Truncate labels if necessary (except last column).
372 (and not-last-col
373 (> label-width width)
374 (setq label (truncate-string-to-width label width nil nil t)
375 label-width width))
376 (setq label (bidi-string-mark-left-to-right label))
377 (when (and right-align (> width label-width))
378 (let ((shift (- width label-width)))
379 (insert (propertize (make-string shift ?\s)
380 'display `(space :align-to ,(+ x shift))))
381 (setq width (- width shift))
382 (setq x (+ x shift))))
383 (if (stringp col-desc)
384 (insert (if (get-text-property 0 'help-echo label)
385 label
386 (propertize label 'help-echo help-echo)))
387 (apply 'insert-text-button label (cdr col-desc)))
388 (let ((next-x (+ x pad-right width)))
389 ;; No need to append any spaces if this is the last column.
390 (when not-last-col
391 (when (> pad-right 0) (insert (make-string pad-right ?\s)))
392 (insert (propertize
393 (make-string (- next-x x label-width pad-right) ?\s)
394 'display `(space :align-to ,next-x))))
395 (put-text-property opoint (point) 'tabulated-list-column-name name)
396 next-x)))
398 (defun tabulated-list-delete-entry ()
399 "Delete the Tabulated List entry at point.
400 Return a list (ID COLS), where ID is the ID of the deleted entry
401 and COLS is a vector of its column descriptors. Move point to
402 the beginning of the deleted entry. Return nil if there is no
403 entry at point.
405 This function only changes the buffer contents; it does not alter
406 `tabulated-list-entries'."
407 ;; Assume that each entry occupies one line.
408 (let* ((id (tabulated-list-get-id))
409 (cols (tabulated-list-get-entry))
410 (inhibit-read-only t))
411 (when cols
412 (delete-region (line-beginning-position) (1+ (line-end-position)))
413 (list id cols))))
415 (defun tabulated-list-set-col (col desc &optional change-entry-data)
416 "Change the Tabulated List entry at point, setting COL to DESC.
417 COL is the column number to change, or the name of the column to change.
418 DESC is the new column descriptor, which is inserted via
419 `tabulated-list-print-col'.
421 If CHANGE-ENTRY-DATA is non-nil, modify the underlying entry data
422 by setting the appropriate slot of the vector originally used to
423 print this entry. If `tabulated-list-entries' has a list value,
424 this is the vector stored within it."
425 (let* ((opoint (point))
426 (eol (line-end-position))
427 (pos (line-beginning-position))
428 (id (tabulated-list-get-id pos))
429 (entry (tabulated-list-get-entry pos))
430 (prop 'tabulated-list-column-name)
431 (inhibit-read-only t)
432 name)
433 (cond ((numberp col)
434 (setq name (car (aref tabulated-list-format col))))
435 ((stringp col)
436 (setq name col
437 col (tabulated-list--column-number col)))
438 (t
439 (error "Invalid column %s" col)))
440 (unless entry
441 (error "No Tabulated List entry at position %s" opoint))
442 (unless (equal (get-text-property pos prop) name)
443 (while (and (setq pos
444 (next-single-property-change pos prop nil eol))
445 (< pos eol)
446 (not (equal (get-text-property pos prop) name)))))
447 (when (< pos eol)
448 (delete-region pos (next-single-property-change pos prop nil eol))
449 (goto-char pos)
450 (tabulated-list-print-col col desc (current-column))
451 (if change-entry-data
452 (aset entry col desc))
453 (put-text-property pos (point) 'tabulated-list-id id)
454 (put-text-property pos (point) 'tabulated-list-entry entry)
455 (goto-char opoint))))
457 (defun tabulated-list-col-sort (&optional e)
458 "Sort Tabulated List entries by the column of the mouse click E."
459 (interactive "e")
460 (let* ((pos (event-start e))
461 (obj (posn-object pos)))
462 (with-current-buffer (window-buffer (posn-window pos))
463 (tabulated-list--sort-by-column-name
464 (get-text-property (if obj (cdr obj) (posn-point pos))
465 'tabulated-list-column-name
466 (car obj))))))
468 (defun tabulated-list-sort (&optional n)
469 "Sort Tabulated List entries by the column at point.
470 With a numeric prefix argument N, sort the Nth column."
471 (interactive "P")
472 (let ((name (if n
473 (car (aref tabulated-list-format n))
474 (get-text-property (point)
475 'tabulated-list-column-name))))
476 (tabulated-list--sort-by-column-name name)))
478 (defun tabulated-list--sort-by-column-name (name)
479 (when (and name (derived-mode-p 'tabulated-list-mode))
480 ;; Flip the sort order on a second click.
481 (if (equal name (car tabulated-list-sort-key))
482 (setcdr tabulated-list-sort-key
483 (not (cdr tabulated-list-sort-key)))
484 (setq tabulated-list-sort-key (cons name nil)))
485 (tabulated-list-init-header)
486 (tabulated-list-print t)))
488 ;;; The mode definition:
490 (define-derived-mode tabulated-list-mode special-mode "Tabulated"
491 "Generic major mode for browsing a list of items.
492 This mode is usually not used directly; instead, other major
493 modes are derived from it, using `define-derived-mode'.
495 In this major mode, the buffer is divided into multiple columns,
496 which are labeled using the header line. Each non-empty line
497 belongs to one \"entry\", and the entries can be sorted according
498 to their column values.
500 An inheriting mode should usually do the following in their body:
502 - Set `tabulated-list-format', specifying the column format.
503 - Set `tabulated-list-revert-hook', if the buffer contents need
504 to be specially recomputed prior to `revert-buffer'.
505 - Maybe set a `tabulated-list-entries' function (see below).
506 - Maybe set `tabulated-list-printer' (see below).
507 - Maybe set `tabulated-list-padding'.
508 - Call `tabulated-list-init-header' to initialize `header-line-format'
509 according to `tabulated-list-format'.
511 An inheriting mode is usually accompanied by a \"list-FOO\"
512 command (e.g. `list-packages', `list-processes'). This command
513 creates or switches to a buffer and enables the major mode in
514 that buffer. If `tabulated-list-entries' is not a function, the
515 command should initialize it to a list of entries for displaying.
516 Finally, it should call `tabulated-list-print'.
518 `tabulated-list-print' calls the printer function specified by
519 `tabulated-list-printer', once for each entry. The default
520 printer is `tabulated-list-print-entry', but a mode that keeps
521 data in an ewoc may instead specify a printer function (e.g., one
522 that calls `ewoc-enter-last'), with `tabulated-list-print-entry'
523 as the ewoc pretty-printer."
524 (setq-local truncate-lines t)
525 (setq-local buffer-read-only t)
526 (setq-local buffer-undo-list t)
527 (setq-local revert-buffer-function #'tabulated-list-revert)
528 (setq-local glyphless-char-display tabulated-list-glyphless-char-display)
529 ;; Avoid messing up the entries' display just because the first
530 ;; column of the first entry happens to begin with a R2L letter.
531 (setq bidi-paragraph-direction 'left-to-right))
533 (put 'tabulated-list-mode 'mode-class 'special)
535 (provide 'tabulated-list)
537 ;; Local Variables:
538 ;; coding: utf-8
539 ;; End:
541 ;;; tabulated-list.el ends here