Make list-processes support display-line-numbers
[emacs.git] / lisp / emacs-lisp / tabulated-list.el
blob6844c25b1aa14c1ec78d8bc80b66ed1b5b484a6f
1 ;;; tabulated-list.el --- generic major mode for tabulated lists -*- lexical-binding: t -*-
3 ;; Copyright (C) 2011-2017 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 tabulated-list--near-rows)
107 (defvar-local tabulated-list-sort-key nil
108 "Sort key for the current Tabulated List mode buffer.
109 If nil, no additional sorting is performed.
110 Otherwise, this should be a cons cell (NAME . FLIP).
111 NAME is a string matching one of the column names in
112 `tabulated-list-format' (the corresponding SORT entry in
113 `tabulated-list-format' then specifies how to sort). FLIP, if
114 non-nil, means to invert the resulting sort.")
115 (put 'tabulated-list-sort-key 'permanent-local t)
117 (defsubst tabulated-list-get-id (&optional pos)
118 "Return the entry ID of the Tabulated List entry at POS.
119 The value is an ID object from `tabulated-list-entries', or nil.
120 POS, if omitted or nil, defaults to point."
121 (get-text-property (or pos (point)) 'tabulated-list-id))
123 (defsubst tabulated-list-get-entry (&optional pos)
124 "Return the Tabulated List entry at POS.
125 The value is a vector of column descriptors, or nil if there is
126 no entry at POS. POS, if omitted or nil, defaults to point."
127 (get-text-property (or pos (point)) 'tabulated-list-entry))
129 (defun tabulated-list-put-tag (tag &optional advance)
130 "Put TAG in the padding area of the current line.
131 TAG should be a string, with length <= `tabulated-list-padding'.
132 If ADVANCE is non-nil, move forward by one line afterwards."
133 (unless (stringp tag)
134 (error "Invalid argument to `tabulated-list-put-tag'"))
135 (unless (> tabulated-list-padding 0)
136 (error "Unable to tag the current line"))
137 (save-excursion
138 (beginning-of-line)
139 (when (tabulated-list-get-entry)
140 (let ((beg (point))
141 (inhibit-read-only t))
142 (forward-char tabulated-list-padding)
143 (insert-and-inherit
144 (let ((width (string-width tag)))
145 (if (<= width tabulated-list-padding)
146 (concat tag
147 (make-string (- tabulated-list-padding width) ?\s))
148 (truncate-string-to-width tag tabulated-list-padding))))
149 (delete-region beg (+ beg tabulated-list-padding)))))
150 (if advance
151 (forward-line)))
153 (defvar tabulated-list-mode-map
154 (let ((map (copy-keymap special-mode-map)))
155 (set-keymap-parent map button-buffer-map)
156 (define-key map "n" 'next-line)
157 (define-key map "p" 'previous-line)
158 (define-key map "S" 'tabulated-list-sort)
159 (define-key map [follow-link] 'mouse-face)
160 (define-key map [mouse-2] 'mouse-select-window)
161 map)
162 "Local keymap for `tabulated-list-mode' buffers.")
164 (defvar tabulated-list-sort-button-map
165 (let ((map (make-sparse-keymap)))
166 (define-key map [header-line mouse-1] 'tabulated-list-col-sort)
167 (define-key map [header-line mouse-2] 'tabulated-list-col-sort)
168 (define-key map [mouse-1] 'tabulated-list-col-sort)
169 (define-key map [mouse-2] 'tabulated-list-col-sort)
170 (define-key map "\C-m" 'tabulated-list-sort)
171 (define-key map [follow-link] 'mouse-face)
172 map)
173 "Local keymap for `tabulated-list-mode' sort buttons.")
175 (defvar tabulated-list-glyphless-char-display
176 (let ((table (make-char-table 'glyphless-char-display nil)))
177 (set-char-table-parent table glyphless-char-display)
178 ;; Some text terminals can't display the Unicode arrows; be safe.
179 (aset table 9650 (cons nil "^"))
180 (aset table 9660 (cons nil "v"))
181 table)
182 "The `glyphless-char-display' table in Tabulated List buffers.")
184 (defvar tabulated-list--header-string nil
185 "Holds the header if `tabulated-list-use-header-line' is nil.
186 Populated by `tabulated-list-init-header'.")
187 (defvar tabulated-list--header-overlay nil)
189 (defun tabulated-list-line-number-width ()
190 "Return the width taken by display-line-numbers in the current buffer."
191 ;; line-number-display-width returns the value for the selected
192 ;; window, which might not be the window in which the current buffer
193 ;; is displayed.
194 (if (not display-line-numbers)
196 (let ((cbuf-window (get-buffer-window (current-buffer))))
197 (if (window-live-p cbuf-window)
198 (with-selected-window cbuf-window
199 (+ (line-number-display-width) 2))
200 4))))
202 (defun tabulated-list-init-header ()
203 "Set up header line for the Tabulated List buffer."
204 ;; FIXME: Should share code with tabulated-list-print-col!
205 (let ((x (max tabulated-list-padding 0))
206 (button-props `(help-echo "Click to sort by column"
207 mouse-face header-line-highlight
208 keymap ,tabulated-list-sort-button-map))
209 (cols nil))
210 (if display-line-numbers
211 (setq x (+ x (tabulated-list-line-number-width))))
212 (push (propertize " " 'display `(space :align-to ,x)) cols)
213 (dotimes (n (length tabulated-list-format))
214 (let* ((col (aref tabulated-list-format n))
215 (label (nth 0 col))
216 (width (nth 1 col))
217 (props (nthcdr 3 col))
218 (pad-right (or (plist-get props :pad-right) 1))
219 (right-align (plist-get props :right-align))
220 (next-x (+ x pad-right width)))
221 (push
222 (cond
223 ;; An unsortable column
224 ((not (nth 2 col))
225 (propertize label 'tabulated-list-column-name label))
226 ;; The selected sort column
227 ((equal (car col) (car tabulated-list-sort-key))
228 (apply 'propertize
229 (concat label
230 (cond
231 ((> (+ 2 (length label)) width) "")
232 ((cdr tabulated-list-sort-key) " ▲")
233 (t " ▼")))
234 'face 'bold
235 'tabulated-list-column-name label
236 button-props))
237 ;; Unselected sortable column.
238 (t (apply 'propertize label
239 'tabulated-list-column-name label
240 button-props)))
241 cols)
242 (when right-align
243 (let ((shift (- width (string-width (car cols)))))
244 (when (> shift 0)
245 (setq cols
246 (cons (car cols)
247 (cons (propertize (make-string shift ?\s)
248 'display
249 `(space :align-to ,(+ x shift)))
250 (cdr cols))))
251 (setq x (+ x shift)))))
252 (if (>= pad-right 0)
253 (push (propertize " "
254 'display `(space :align-to ,next-x)
255 'face 'fixed-pitch)
256 cols))
257 (setq x next-x)))
258 (setq cols (apply 'concat (nreverse cols)))
259 (if tabulated-list-use-header-line
260 (setq header-line-format cols)
261 (setq header-line-format nil)
262 (setq-local tabulated-list--header-string cols))))
264 (defun tabulated-list-print-fake-header ()
265 "Insert a fake Tabulated List \"header line\" at the start of the buffer.
266 Do nothing if `tabulated-list--header-string' is nil."
267 (when tabulated-list--header-string
268 (goto-char (point-min))
269 (let ((inhibit-read-only t))
270 (insert tabulated-list--header-string "\n")
271 (if tabulated-list--header-overlay
272 (move-overlay tabulated-list--header-overlay (point-min) (point))
273 (setq-local tabulated-list--header-overlay
274 (make-overlay (point-min) (point))))
275 (overlay-put tabulated-list--header-overlay 'face 'underline))))
277 (defsubst tabulated-list-header-overlay-p (&optional pos)
278 "Return non-nil if there is a fake header.
279 Optional arg POS is a buffer position where to look for a fake header;
280 defaults to `point-min'."
281 (overlays-at (or pos (point-min))))
283 (defun tabulated-list-revert (&rest ignored)
284 "The `revert-buffer-function' for `tabulated-list-mode'.
285 It runs `tabulated-list-revert-hook', then calls `tabulated-list-print'."
286 (interactive)
287 (unless (derived-mode-p 'tabulated-list-mode)
288 (error "The current buffer is not in Tabulated List mode"))
289 (run-hooks 'tabulated-list-revert-hook)
290 (tabulated-list-print t))
292 (defun tabulated-list--column-number (name)
293 (let ((len (length tabulated-list-format))
294 (n 0)
295 found)
296 (while (and (< n len) (null found))
297 (if (equal (car (aref tabulated-list-format n)) name)
298 (setq found n))
299 (setq n (1+ n)))
300 (or found
301 (error "No column named %s" name))))
303 (defun tabulated-list--get-sorter ()
304 "Return a sorting predicate for the current tabulated-list.
305 Return nil if `tabulated-list-sort-key' specifies an unsortable
306 column. Negate the predicate that would be returned if
307 `tabulated-list-sort-key' has a non-nil cdr."
308 (when (and tabulated-list-sort-key
309 (car tabulated-list-sort-key))
310 (let* ((sort-column (car tabulated-list-sort-key))
311 (n (tabulated-list--column-number sort-column))
312 (sorter (nth 2 (aref tabulated-list-format n))))
313 (when (eq sorter t); Default sorter checks column N:
314 (setq sorter (lambda (A B)
315 (let ((a (aref (cadr A) n))
316 (b (aref (cadr B) n)))
317 (string< (if (stringp a) a (car a))
318 (if (stringp b) b (car b)))))))
319 ;; Reversed order.
320 (if (cdr tabulated-list-sort-key)
321 (lambda (a b) (not (funcall sorter a b)))
322 sorter))))
324 (defsubst tabulated-list--col-local-max-widths (col)
325 "Return maximum entry widths at column COL around current row.
326 Check the current row, the previous one and the next row."
327 (apply #'max (mapcar (lambda (x)
328 (let ((nt (elt x col)))
329 (string-width (if (stringp nt) nt (car nt)))))
330 tabulated-list--near-rows)))
332 (defun tabulated-list-print (&optional remember-pos update)
333 "Populate the current Tabulated List mode buffer.
334 This sorts the `tabulated-list-entries' list if sorting is
335 specified by `tabulated-list-sort-key'. It then erases the
336 buffer and inserts the entries with `tabulated-list-printer'.
338 Optional argument REMEMBER-POS, if non-nil, means to move point
339 to the entry with the same ID element as the current line and
340 recenter window line accordingly.
342 Non-nil UPDATE argument means to use an alternative printing
343 method which is faster if most entries haven't changed since the
344 last print. The only difference in outcome is that tags will not
345 be removed from entries that haven't changed (see
346 `tabulated-list-put-tag'). Don't use this immediately after
347 changing `tabulated-list-sort-key'."
348 (let ((inhibit-read-only t)
349 (entries (if (functionp tabulated-list-entries)
350 (funcall tabulated-list-entries)
351 tabulated-list-entries))
352 (sorter (tabulated-list--get-sorter))
353 entry-id saved-pt saved-col window-line)
354 (and remember-pos
355 (setq entry-id (tabulated-list-get-id))
356 (setq saved-col (current-column))
357 (when (eq (window-buffer) (current-buffer))
358 (setq window-line
359 (count-screen-lines (window-start) (point)))))
360 ;; Sort the entries, if necessary.
361 (when sorter
362 (setq entries (sort entries sorter)))
363 (unless (functionp tabulated-list-entries)
364 (setq tabulated-list-entries entries))
365 ;; Without a sorter, we have no way to just update.
366 (when (and update (not sorter))
367 (setq update nil))
368 (if update (goto-char (point-min))
369 ;; Redo the buffer, unless we're just updating.
370 (erase-buffer)
371 (unless tabulated-list-use-header-line
372 (tabulated-list-print-fake-header)))
373 ;; Finally, print the resulting list.
374 (while entries
375 (let* ((elt (car entries))
376 (tabulated-list--near-rows
377 (list
378 (or (tabulated-list-get-entry (point-at-bol 0)) (cadr elt))
379 (cadr elt)
380 (or (cadr (cadr entries)) (cadr elt))))
381 (id (car elt)))
382 (and entry-id
383 (equal entry-id id)
384 (setq entry-id nil
385 saved-pt (point)))
386 ;; If the buffer this empty, simply print each elt.
387 (if (or (not update) (eobp))
388 (apply tabulated-list-printer elt)
389 (while (let ((local-id (tabulated-list-get-id)))
390 ;; If we find id, then nothing to update.
391 (cond ((equal id local-id)
392 (forward-line 1)
393 nil)
394 ;; If this entry sorts after id (or it's the
395 ;; end), then just insert id and move on.
396 ((or (not local-id)
397 (funcall sorter elt
398 ;; FIXME: Might be faster if
399 ;; don't construct this list.
400 (list local-id (tabulated-list-get-entry))))
401 (apply tabulated-list-printer elt)
402 nil)
403 ;; We find an entry that sorts before id,
404 ;; it needs to be deleted.
405 (t t)))
406 (let ((old (point)))
407 (forward-line 1)
408 (delete-region old (point))))))
409 (setq entries (cdr entries)))
410 (set-buffer-modified-p nil)
411 ;; If REMEMBER-POS was specified, move to the "old" location.
412 (if saved-pt
413 (progn (goto-char saved-pt)
414 (move-to-column saved-col)
415 (when window-line
416 (recenter window-line)))
417 (goto-char (point-min)))))
419 (defun tabulated-list-print-entry (id cols)
420 "Insert a Tabulated List entry at point.
421 This is the default `tabulated-list-printer' function. ID is a
422 Lisp object identifying the entry to print, and COLS is a vector
423 of column descriptors."
424 (let ((beg (point))
425 (x (max tabulated-list-padding 0))
426 (ncols (length tabulated-list-format))
427 (lnum-width (tabulated-list-line-number-width))
428 (inhibit-read-only t))
429 (if display-line-numbers
430 (setq x (+ x lnum-width)))
431 (if (> tabulated-list-padding 0)
432 (insert (make-string (- x lnum-width) ?\s)))
433 (let ((tabulated-list--near-rows ; Bind it if not bound yet (Bug#25506).
434 (or (bound-and-true-p tabulated-list--near-rows)
435 (list (or (tabulated-list-get-entry (point-at-bol 0))
436 cols)
437 cols))))
438 (dotimes (n ncols)
439 (setq x (tabulated-list-print-col n (aref cols n) x))))
440 (insert ?\n)
441 ;; Ever so slightly faster than calling `put-text-property' twice.
442 (add-text-properties
443 beg (point)
444 `(tabulated-list-id ,id tabulated-list-entry ,cols))))
446 (defun tabulated-list-print-col (n col-desc x)
447 "Insert a specified Tabulated List entry at point.
448 N is the column number, COL-DESC is a column descriptor (see
449 `tabulated-list-entries'), and X is the column number at point.
450 Return the column number after insertion."
451 (let* ((format (aref tabulated-list-format n))
452 (name (nth 0 format))
453 (width (nth 1 format))
454 (props (nthcdr 3 format))
455 (pad-right (or (plist-get props :pad-right) 1))
456 (right-align (plist-get props :right-align))
457 (label (if (stringp col-desc) col-desc (car col-desc)))
458 (label-width (string-width label))
459 (help-echo (concat (car format) ": " label))
460 (opoint (point))
461 (not-last-col (< (1+ n) (length tabulated-list-format)))
462 available-space)
463 (when not-last-col
464 (let* ((next-col-format (aref tabulated-list-format (1+ n)))
465 (next-col-right-align (plist-get (nthcdr 3 next-col-format)
466 :right-align))
467 (next-col-width (nth 1 next-col-format)))
468 (setq available-space
469 (if (and (not right-align)
470 next-col-right-align)
472 (+ width next-col-width)
473 (min next-col-width
474 (tabulated-list--col-local-max-widths (1+ n))))
475 width))))
476 ;; Truncate labels if necessary (except last column).
477 ;; Don't truncate to `width' if the next column is align-right
478 ;; and has some space left, truncate to `available-space' instead.
479 (when (and not-last-col
480 (> label-width available-space)
481 (setq label (truncate-string-to-width
482 label available-space nil nil t)
483 label-width available-space)))
484 (setq label (bidi-string-mark-left-to-right label))
485 (when (and right-align (> width label-width))
486 (let ((shift (- width label-width)))
487 (insert (propertize (make-string shift ?\s)
488 'display `(space :align-to ,(+ x shift))))
489 (setq width (- width shift))
490 (setq x (+ x shift))))
491 (if (stringp col-desc)
492 (insert (if (get-text-property 0 'help-echo label)
493 label
494 (propertize label 'help-echo help-echo)))
495 (apply 'insert-text-button label (cdr col-desc)))
496 (let ((next-x (+ x pad-right width)))
497 ;; No need to append any spaces if this is the last column.
498 (when not-last-col
499 (when (> pad-right 0) (insert (make-string pad-right ?\s)))
500 (insert (propertize
501 (make-string (- width (min width label-width)) ?\s)
502 'display `(space :align-to ,next-x))))
503 (put-text-property opoint (point) 'tabulated-list-column-name name)
504 next-x)))
506 (defun tabulated-list-delete-entry ()
507 "Delete the Tabulated List entry at point.
508 Return a list (ID COLS), where ID is the ID of the deleted entry
509 and COLS is a vector of its column descriptors. Move point to
510 the beginning of the deleted entry. Return nil if there is no
511 entry at point.
513 This function only changes the buffer contents; it does not alter
514 `tabulated-list-entries'."
515 ;; Assume that each entry occupies one line.
516 (let* ((id (tabulated-list-get-id))
517 (cols (tabulated-list-get-entry))
518 (inhibit-read-only t))
519 (when cols
520 (delete-region (line-beginning-position) (1+ (line-end-position)))
521 (list id cols))))
523 (defun tabulated-list-set-col (col desc &optional change-entry-data)
524 "Change the Tabulated List entry at point, setting COL to DESC.
525 COL is the column number to change, or the name of the column to change.
526 DESC is the new column descriptor, which is inserted via
527 `tabulated-list-print-col'.
529 If CHANGE-ENTRY-DATA is non-nil, modify the underlying entry data
530 by setting the appropriate slot of the vector originally used to
531 print this entry. If `tabulated-list-entries' has a list value,
532 this is the vector stored within it."
533 (let* ((opoint (point))
534 (eol (line-end-position))
535 (pos (line-beginning-position))
536 (id (tabulated-list-get-id pos))
537 (entry (tabulated-list-get-entry pos))
538 (prop 'tabulated-list-column-name)
539 (inhibit-read-only t)
540 name)
541 (cond ((numberp col)
542 (setq name (car (aref tabulated-list-format col))))
543 ((stringp col)
544 (setq name col
545 col (tabulated-list--column-number col)))
547 (error "Invalid column %s" col)))
548 (unless entry
549 (error "No Tabulated List entry at position %s" opoint))
550 (unless (equal (get-text-property pos prop) name)
551 (while (and (setq pos
552 (next-single-property-change pos prop nil eol))
553 (< pos eol)
554 (not (equal (get-text-property pos prop) name)))))
555 (when (< pos eol)
556 (delete-region pos (next-single-property-change pos prop nil eol))
557 (goto-char pos)
558 (let ((tabulated-list--near-rows
559 (list
560 (tabulated-list-get-entry (point-at-bol 0))
561 entry
562 (or (tabulated-list-get-entry (point-at-bol 2)) entry))))
563 (tabulated-list-print-col col desc (current-column)))
564 (if change-entry-data
565 (aset entry col desc))
566 (put-text-property pos (point) 'tabulated-list-id id)
567 (put-text-property pos (point) 'tabulated-list-entry entry)
568 (goto-char opoint))))
570 (defun tabulated-list-col-sort (&optional e)
571 "Sort Tabulated List entries by the column of the mouse click E."
572 (interactive "e")
573 (let* ((pos (event-start e))
574 (obj (posn-object pos)))
575 (with-current-buffer (window-buffer (posn-window pos))
576 (tabulated-list--sort-by-column-name
577 (get-text-property (if obj (cdr obj) (posn-point pos))
578 'tabulated-list-column-name
579 (car obj))))))
581 (defun tabulated-list-sort (&optional n)
582 "Sort Tabulated List entries by the column at point.
583 With a numeric prefix argument N, sort the Nth column."
584 (interactive "P")
585 (let ((name (if n
586 (car (aref tabulated-list-format n))
587 (get-text-property (point)
588 'tabulated-list-column-name))))
589 (if (nth 2 (assoc name (append tabulated-list-format nil)))
590 (tabulated-list--sort-by-column-name name)
591 (user-error "Cannot sort by %s" name))))
593 (defun tabulated-list--sort-by-column-name (name)
594 (when (and name (derived-mode-p 'tabulated-list-mode))
595 ;; Flip the sort order on a second click.
596 (if (equal name (car tabulated-list-sort-key))
597 (setcdr tabulated-list-sort-key
598 (not (cdr tabulated-list-sort-key)))
599 (setq tabulated-list-sort-key (cons name nil)))
600 (tabulated-list-init-header)
601 (tabulated-list-print t)))
603 ;;; The mode definition:
605 (define-derived-mode tabulated-list-mode special-mode "Tabulated"
606 "Generic major mode for browsing a list of items.
607 This mode is usually not used directly; instead, other major
608 modes are derived from it, using `define-derived-mode'.
610 In this major mode, the buffer is divided into multiple columns,
611 which are labeled using the header line. Each non-empty line
612 belongs to one \"entry\", and the entries can be sorted according
613 to their column values.
615 An inheriting mode should usually do the following in their body:
617 - Set `tabulated-list-format', specifying the column format.
618 - Set `tabulated-list-revert-hook', if the buffer contents need
619 to be specially recomputed prior to `revert-buffer'.
620 - Maybe set a `tabulated-list-entries' function (see below).
621 - Maybe set `tabulated-list-printer' (see below).
622 - Maybe set `tabulated-list-padding'.
623 - Call `tabulated-list-init-header' to initialize `header-line-format'
624 according to `tabulated-list-format'.
626 An inheriting mode is usually accompanied by a \"list-FOO\"
627 command (e.g. `list-packages', `list-processes'). This command
628 creates or switches to a buffer and enables the major mode in
629 that buffer. If `tabulated-list-entries' is not a function, the
630 command should initialize it to a list of entries for displaying.
631 Finally, it should call `tabulated-list-print'.
633 `tabulated-list-print' calls the printer function specified by
634 `tabulated-list-printer', once for each entry. The default
635 printer is `tabulated-list-print-entry', but a mode that keeps
636 data in an ewoc may instead specify a printer function (e.g., one
637 that calls `ewoc-enter-last'), with `tabulated-list-print-entry'
638 as the ewoc pretty-printer."
639 (setq-local truncate-lines t)
640 (setq-local buffer-undo-list t)
641 (setq-local revert-buffer-function #'tabulated-list-revert)
642 (setq-local glyphless-char-display tabulated-list-glyphless-char-display)
643 ;; Avoid messing up the entries' display just because the first
644 ;; column of the first entry happens to begin with a R2L letter.
645 (setq bidi-paragraph-direction 'left-to-right)
646 ;; This is for if/when they turn on display-line-numbers
647 (add-hook 'display-line-numbers-mode-hook #'tabulated-list-revert nil t))
649 (put 'tabulated-list-mode 'mode-class 'special)
651 (provide 'tabulated-list)
653 ;;; tabulated-list.el ends here