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e8af40ee | 1 | ;;; ewoc.el --- utility to maintain a view of a list of objects in a buffer |
5b467bf4 | 2 | |
3731a850 | 3 | ;; Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, |
ceb4c4d3 | 4 | ;; 2000, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. |
5b467bf4 SM |
5 | |
6 | ;; Author: Per Cederqvist <ceder@lysator.liu.se> | |
7 | ;; Inge Wallin <inge@lysator.liu.se> | |
8 | ;; Maintainer: monnier@gnu.org | |
9 | ;; Created: 3 Aug 1992 | |
10 | ;; Keywords: extensions, lisp | |
11 | ||
12 | ;; This file is part of GNU Emacs. | |
13 | ||
14 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
15 | ;; it under the terms of the GNU General Public License as published by | |
16 | ;; the Free Software Foundation; either version 2, or (at your option) | |
17 | ;; any later version. | |
18 | ||
19 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
20 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | ;; GNU General Public License for more details. | |
23 | ||
24 | ;; You should have received a copy of the GNU General Public License | |
25 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
3a35cf56 LK |
26 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
27 | ;; Boston, MA 02110-1301, USA. | |
5b467bf4 SM |
28 | |
29 | ;;; Commentary: | |
30 | ||
31 | ;; Ewoc Was Once Cookie | |
32 | ;; But now it's Emacs' Widget for Object Collections | |
33 | ||
34 | ;; As the name implies this derives from the `cookie' package (part | |
10c471e6 | 35 | ;; of Elib). The changes are pervasive though mostly superficial: |
5b467bf4 | 36 | |
10c471e6 | 37 | ;; - uses CL (and its `defstruct') |
5b467bf4 SM |
38 | ;; - separate from Elib. |
39 | ;; - uses its own version of a doubly-linked list which allows us | |
40 | ;; to merge the elib-wrapper and the elib-node structures into ewoc-node | |
41 | ;; - dropping functions not used by PCL-CVS (the only client of ewoc at the | |
42 | ;; time of writing) | |
43 | ;; - removing unused arguments | |
44 | ;; - renaming: | |
45 | ;; elib-node ==> ewoc--node | |
46 | ;; collection ==> ewoc | |
47 | ;; tin ==> ewoc--node | |
48 | ;; cookie ==> data or element or elem | |
49 | ||
50 | ;; Introduction | |
51 | ;; ============ | |
52 | ;; | |
53 | ;; Ewoc is a package that implements a connection between an | |
54 | ;; dll (a doubly linked list) and the contents of a buffer. | |
55 | ;; Possible uses are dired (have all files in a list, and show them), | |
56 | ;; buffer-list, kom-prioritize (in the LysKOM elisp client) and | |
57 | ;; others. pcl-cvs.el uses ewoc.el. | |
58 | ;; | |
59 | ;; Ewoc can be considered as the `view' part of a model-view-controller. | |
60 | ;; | |
61 | ;; A `element' can be any lisp object. When you use the ewoc | |
62 | ;; package you specify a pretty-printer, a function that inserts | |
63 | ;; a printable representation of the element in the buffer. (The | |
64 | ;; pretty-printer should use "insert" and not | |
65 | ;; "insert-before-markers"). | |
66 | ;; | |
67 | ;; A `ewoc' consists of a doubly linked list of elements, a | |
68 | ;; header, a footer and a pretty-printer. It is displayed at a | |
69 | ;; certain point in a certain buffer. (The buffer and point are | |
70 | ;; fixed when the ewoc is created). The header and the footer | |
71 | ;; are constant strings. They appear before and after the elements. | |
5b467bf4 SM |
72 | ;; |
73 | ;; Ewoc does not affect the mode of the buffer in any way. It | |
74 | ;; merely makes it easy to connect an underlying data representation | |
75 | ;; to the buffer contents. | |
76 | ;; | |
77 | ;; A `ewoc--node' is an object that contains one element. There are | |
10c471e6 SM |
78 | ;; functions in this package that given an ewoc--node extract the data, or |
79 | ;; give the next or previous ewoc--node. (All ewoc--nodes are linked together | |
80 | ;; in a doubly linked list. The `previous' ewoc--node is the one that appears | |
5b467bf4 SM |
81 | ;; before the other in the buffer.) You should not do anything with |
82 | ;; an ewoc--node except pass it to the functions in this package. | |
83 | ;; | |
84 | ;; An ewoc is a very dynamic thing. You can easily add or delete elements. | |
85 | ;; You can apply a function to all elements in an ewoc, etc, etc. | |
86 | ;; | |
87 | ;; Remember that an element can be anything. Your imagination is the | |
88 | ;; limit! It is even possible to have another ewoc as an | |
89 | ;; element. In that way some kind of tree hierarchy can be created. | |
90 | ;; | |
91 | ;; Full documentation will, God willing, soon be available in a | |
92 | ;; Texinfo manual. | |
93 | ||
94 | ;; In the mean time `grep '^(.*ewoc-[^-]' emacs-lisp/ewoc.el' can help | |
95 | ;; you find all the exported functions: | |
a1506d29 | 96 | ;; |
cb3430a1 | 97 | ;; (defun ewoc-create (pretty-printer &optional header footer) |
5b467bf4 | 98 | ;; (defalias 'ewoc-data 'ewoc--node-data) |
10c471e6 | 99 | ;; (defun ewoc-location (node) |
5b467bf4 SM |
100 | ;; (defun ewoc-enter-first (ewoc data) |
101 | ;; (defun ewoc-enter-last (ewoc data) | |
102 | ;; (defun ewoc-enter-after (ewoc node data) | |
103 | ;; (defun ewoc-enter-before (ewoc node data) | |
104 | ;; (defun ewoc-next (ewoc node) | |
105 | ;; (defun ewoc-prev (ewoc node) | |
106 | ;; (defun ewoc-nth (ewoc n) | |
107 | ;; (defun ewoc-map (map-function ewoc &rest args) | |
108 | ;; (defun ewoc-filter (ewoc predicate &rest args) | |
44946a4c | 109 | ;; (defun ewoc-locate (ewoc &optional pos guess) |
5b467bf4 | 110 | ;; (defun ewoc-invalidate (ewoc &rest nodes) |
44946a4c SM |
111 | ;; (defun ewoc-goto-prev (ewoc arg) |
112 | ;; (defun ewoc-goto-next (ewoc arg) | |
5b467bf4 SM |
113 | ;; (defun ewoc-goto-node (ewoc node) |
114 | ;; (defun ewoc-refresh (ewoc) | |
115 | ;; (defun ewoc-collect (ewoc predicate &rest args) | |
116 | ;; (defun ewoc-buffer (ewoc) | |
cb3430a1 SM |
117 | ;; (defun ewoc-get-hf (ewoc) |
118 | ;; (defun ewoc-set-hf (ewoc header footer) | |
5b467bf4 SM |
119 | |
120 | ;; Coding conventions | |
121 | ;; ================== | |
122 | ;; | |
123 | ;; All functions of course start with `ewoc'. Functions and macros | |
124 | ;; starting with the prefix `ewoc--' are meant for internal use, | |
125 | ;; while those starting with `ewoc-' are exported for public use. | |
126 | ;; There are currently no global or buffer-local variables used. | |
127 | ||
128 | ||
129 | ;;; Code: | |
130 | ||
131 | (eval-when-compile (require 'cl)) ;because of CL compiler macros | |
132 | ||
133 | ;; The doubly linked list is implemented as a circular list | |
134 | ;; with a dummy node first and last. The dummy node is used as | |
135 | ;; "the dll" (or rather is the dll handle passed around). | |
136 | ||
137 | (defstruct (ewoc--node | |
138 | (:type vector) ;required for ewoc--node-branch hack | |
139 | (:constructor ewoc--node-create (start-marker data))) | |
140 | left right data start-marker) | |
141 | ||
21311ac9 SM |
142 | (defalias 'ewoc--node-branch 'aref |
143 | "Get the left (CHILD=0) or right (CHILD=1) child of the NODE. | |
144 | ||
145 | \(fn NODE CHILD)") | |
5b467bf4 | 146 | |
5b467bf4 SM |
147 | (defun ewoc--node-next (dll node) |
148 | "Return the node after NODE, or nil if NODE is the last node." | |
149 | (unless (eq (ewoc--node-right node) dll) (ewoc--node-right node))) | |
150 | ||
151 | (defun ewoc--node-prev (dll node) | |
152 | "Return the node before NODE, or nil if NODE is the first node." | |
153 | (unless (eq (ewoc--node-left node) dll) (ewoc--node-left node))) | |
154 | ||
5b467bf4 SM |
155 | (defun ewoc--node-nth (dll n) |
156 | "Return the Nth node from the doubly linked list DLL. | |
157 | N counts from zero. If DLL is not that long, nil is returned. | |
158 | If N is negative, return the -(N+1)th last element. | |
159 | Thus, (ewoc--node-nth dll 0) returns the first node, | |
160 | and (ewoc--node-nth dll -1) returns the last node." | |
161 | ;; Branch 0 ("follow left pointer") is used when n is negative. | |
162 | ;; Branch 1 ("follow right pointer") is used otherwise. | |
163 | (let* ((branch (if (< n 0) 0 1)) | |
164 | (node (ewoc--node-branch dll branch))) | |
165 | (if (< n 0) (setq n (- -1 n))) | |
166 | (while (and (not (eq dll node)) (> n 0)) | |
167 | (setq node (ewoc--node-branch node branch)) | |
168 | (setq n (1- n))) | |
169 | (unless (eq dll node) node))) | |
170 | ||
10c471e6 SM |
171 | (defun ewoc-location (node) |
172 | "Return the start location of NODE." | |
173 | (ewoc--node-start-marker node)) | |
174 | ||
5b467bf4 SM |
175 | \f |
176 | ;;; The ewoc data type | |
177 | ||
178 | (defstruct (ewoc | |
179 | (:constructor nil) | |
180 | (:constructor ewoc--create | |
181 | (buffer pretty-printer header footer dll)) | |
182 | (:conc-name ewoc--)) | |
183 | buffer pretty-printer header footer dll last-node) | |
184 | ||
185 | (defmacro ewoc--set-buffer-bind-dll-let* (ewoc varlist &rest forms) | |
186 | "Execute FORMS with ewoc--buffer selected as current buffer, | |
187 | dll bound to ewoc--dll, and VARLIST bound as in a let*. | |
188 | dll will be bound when VARLIST is initialized, but the current | |
189 | buffer will *not* have been changed. | |
190 | Return value of last form in FORMS." | |
b1c36c0f TTN |
191 | (let ((hnd (make-symbol "ewoc"))) |
192 | `(let* ((,hnd ,ewoc) | |
8a946354 SS |
193 | (dll (ewoc--dll ,hnd)) |
194 | ,@varlist) | |
b1c36c0f TTN |
195 | (with-current-buffer (ewoc--buffer ,hnd) |
196 | ,@forms)))) | |
5b467bf4 SM |
197 | |
198 | (defmacro ewoc--set-buffer-bind-dll (ewoc &rest forms) | |
199 | `(ewoc--set-buffer-bind-dll-let* ,ewoc nil ,@forms)) | |
200 | ||
201 | (defsubst ewoc--filter-hf-nodes (ewoc node) | |
202 | "Evaluate NODE once and return it. | |
203 | BUT if it is the header or the footer in EWOC return nil instead." | |
204 | (unless (or (eq node (ewoc--header ewoc)) | |
205 | (eq node (ewoc--footer ewoc))) | |
206 | node)) | |
207 | ||
7f0ea399 TTN |
208 | (defun ewoc--insert-new-node (node data pretty-printer) |
209 | "Insert before NODE a new node for DATA, displayed by PRETTY-PRINTER. | |
210 | Call PRETTY-PRINTER with point at NODE's start, thus pushing back | |
211 | NODE and leaving the new node's start there. Return the new node." | |
5b467bf4 | 212 | (save-excursion |
7f0ea399 TTN |
213 | (let* ((inhibit-read-only t) |
214 | (m (copy-marker (ewoc--node-start-marker node))) | |
215 | (pos (marker-position m)) | |
216 | (elemnode (ewoc--node-create m data))) | |
217 | (goto-char pos) | |
5b467bf4 SM |
218 | ;; Insert the trailing newline using insert-before-markers |
219 | ;; so that the start position for the next element is updated. | |
220 | (insert-before-markers ?\n) | |
221 | ;; Move back, and call the pretty-printer. | |
222 | (backward-char 1) | |
223 | (funcall pretty-printer data) | |
7f0ea399 TTN |
224 | (setf (marker-position m) pos |
225 | (ewoc--node-left elemnode) (ewoc--node-left node) | |
226 | (ewoc--node-right elemnode) node | |
227 | (ewoc--node-right (ewoc--node-left node)) elemnode | |
228 | (ewoc--node-left node) elemnode) | |
229 | elemnode))) | |
5b467bf4 | 230 | |
cb3430a1 SM |
231 | (defun ewoc--refresh-node (pp node) |
232 | "Redisplay the element represented by NODE using the pretty-printer PP." | |
5b467bf4 | 233 | (let ((inhibit-read-only t)) |
bfbdb5ca TTN |
234 | ;; First, remove the string from the buffer: |
235 | (delete-region (ewoc--node-start-marker node) | |
236 | (1- (marker-position | |
237 | (ewoc--node-start-marker (ewoc--node-right node))))) | |
238 | ;; Calculate and insert the string. | |
239 | (goto-char (ewoc--node-start-marker node)) | |
240 | (funcall pp (ewoc--node-data node)))) | |
5b467bf4 SM |
241 | \f |
242 | ;;; =========================================================================== | |
243 | ;;; Public members of the Ewoc package | |
244 | ||
245 | ||
cb3430a1 | 246 | (defun ewoc-create (pretty-printer &optional header footer) |
5b467bf4 SM |
247 | "Create an empty ewoc. |
248 | ||
cb3430a1 | 249 | The ewoc will be inserted in the current buffer at the current position. |
5b467bf4 SM |
250 | |
251 | PRETTY-PRINTER should be a function that takes one argument, an | |
252 | element, and inserts a string representing it in the buffer (at | |
0111ab41 JB |
253 | point). The string PRETTY-PRINTER inserts may be empty or span |
254 | several lines. A trailing newline will always be inserted | |
255 | automatically. The PRETTY-PRINTER should use `insert', and not | |
256 | `insert-before-markers'. | |
257 | ||
258 | Optional second argument HEADER is a string that will always be | |
259 | present at the top of the ewoc. HEADER should end with a | |
260 | newline. Optional third argument FOOTER is similar, and will | |
cb3430a1 | 261 | be inserted at the bottom of the ewoc." |
2c246c9f TTN |
262 | (let* ((dummy-node (ewoc--node-create 'DL-LIST 'DL-LIST)) |
263 | (dll (progn (setf (ewoc--node-right dummy-node) dummy-node) | |
264 | (setf (ewoc--node-left dummy-node) dummy-node) | |
265 | dummy-node)) | |
266 | (new-ewoc | |
267 | (ewoc--create (current-buffer) | |
268 | pretty-printer nil nil dll)) | |
7f0ea399 TTN |
269 | (pos (point)) |
270 | head foot) | |
5b467bf4 SM |
271 | (ewoc--set-buffer-bind-dll new-ewoc |
272 | ;; Set default values | |
273 | (unless header (setq header "")) | |
274 | (unless footer (setq footer "")) | |
7f0ea399 TTN |
275 | (setf (ewoc--node-start-marker dll) (copy-marker pos) |
276 | foot (ewoc--insert-new-node dll footer 'insert) | |
277 | head (ewoc--insert-new-node foot header 'insert) | |
278 | (ewoc--footer new-ewoc) foot | |
279 | (ewoc--header new-ewoc) head)) | |
5b467bf4 SM |
280 | ;; Return the ewoc |
281 | new-ewoc)) | |
282 | ||
283 | (defalias 'ewoc-data 'ewoc--node-data) | |
284 | ||
285 | (defun ewoc-enter-first (ewoc data) | |
d4ddf783 TTN |
286 | "Enter DATA first in EWOC. |
287 | Return the new node." | |
5b467bf4 SM |
288 | (ewoc--set-buffer-bind-dll ewoc |
289 | (ewoc-enter-after ewoc (ewoc--node-nth dll 0) data))) | |
290 | ||
291 | (defun ewoc-enter-last (ewoc data) | |
d4ddf783 TTN |
292 | "Enter DATA last in EWOC. |
293 | Return the new node." | |
5b467bf4 SM |
294 | (ewoc--set-buffer-bind-dll ewoc |
295 | (ewoc-enter-before ewoc (ewoc--node-nth dll -1) data))) | |
296 | ||
297 | ||
298 | (defun ewoc-enter-after (ewoc node data) | |
10c471e6 | 299 | "Enter a new element DATA after NODE in EWOC. |
d4ddf783 | 300 | Return the new node." |
5b467bf4 SM |
301 | (ewoc--set-buffer-bind-dll ewoc |
302 | (ewoc-enter-before ewoc (ewoc--node-next dll node) data))) | |
303 | ||
304 | (defun ewoc-enter-before (ewoc node data) | |
10c471e6 | 305 | "Enter a new element DATA before NODE in EWOC. |
d4ddf783 | 306 | Return the new node." |
5b467bf4 | 307 | (ewoc--set-buffer-bind-dll ewoc |
7f0ea399 | 308 | (ewoc--insert-new-node node data (ewoc--pretty-printer ewoc)))) |
5b467bf4 SM |
309 | |
310 | (defun ewoc-next (ewoc node) | |
d4ddf783 TTN |
311 | "Return the node in EWOC that follows NODE. |
312 | Return nil if NODE is nil or the last element." | |
5b467bf4 SM |
313 | (when node |
314 | (ewoc--filter-hf-nodes | |
315 | ewoc (ewoc--node-next (ewoc--dll ewoc) node)))) | |
316 | ||
317 | (defun ewoc-prev (ewoc node) | |
d4ddf783 TTN |
318 | "Return the node in EWOC that precedes NODE. |
319 | Return nil if NODE is nil or the first element." | |
5b467bf4 SM |
320 | (when node |
321 | (ewoc--filter-hf-nodes | |
322 | ewoc | |
323 | (ewoc--node-prev (ewoc--dll ewoc) node)))) | |
324 | ||
325 | ||
326 | (defun ewoc-nth (ewoc n) | |
327 | "Return the Nth node. | |
f0529b5b | 328 | N counts from zero. Return nil if there is less than N elements. |
5b467bf4 SM |
329 | If N is negative, return the -(N+1)th last element. |
330 | Thus, (ewoc-nth dll 0) returns the first node, | |
331 | and (ewoc-nth dll -1) returns the last node. | |
332 | Use `ewoc--node-data' to extract the data from the node." | |
333 | ;; Skip the header (or footer, if n is negative). | |
334 | (setq n (if (< n 0) (1- n) (1+ n))) | |
335 | (ewoc--filter-hf-nodes ewoc | |
336 | (ewoc--node-nth (ewoc--dll ewoc) n))) | |
337 | ||
338 | (defun ewoc-map (map-function ewoc &rest args) | |
339 | "Apply MAP-FUNCTION to all elements in EWOC. | |
340 | MAP-FUNCTION is applied to the first element first. | |
341 | If MAP-FUNCTION returns non-nil the element will be refreshed (its | |
342 | pretty-printer will be called once again). | |
343 | ||
0111ab41 JB |
344 | Note that the buffer for EWOC will be the current buffer when |
345 | MAP-FUNCTION is called. MAP-FUNCTION must restore the current | |
346 | buffer before it returns, if it changes it. | |
5b467bf4 SM |
347 | |
348 | If more than two arguments are given, the remaining | |
349 | arguments will be passed to MAP-FUNCTION." | |
350 | (ewoc--set-buffer-bind-dll-let* ewoc | |
351 | ((footer (ewoc--footer ewoc)) | |
352 | (node (ewoc--node-nth dll 1))) | |
bfbdb5ca TTN |
353 | (save-excursion |
354 | (while (not (eq node footer)) | |
355 | (if (apply map-function (ewoc--node-data node) args) | |
356 | (ewoc--refresh-node (ewoc--pretty-printer ewoc) node)) | |
357 | (setq node (ewoc--node-next dll node)))))) | |
5b467bf4 SM |
358 | |
359 | (defun ewoc-filter (ewoc predicate &rest args) | |
360 | "Remove all elements in EWOC for which PREDICATE returns nil. | |
a1506d29 | 361 | Note that the buffer for EWOC will be current-buffer when PREDICATE |
0111ab41 | 362 | is called. PREDICATE must restore the current buffer before it returns |
5b467bf4 | 363 | if it changes it. |
0111ab41 | 364 | The PREDICATE is called with the element as its first argument. If any |
5b467bf4 SM |
365 | ARGS are given they will be passed to the PREDICATE." |
366 | (ewoc--set-buffer-bind-dll-let* ewoc | |
367 | ((node (ewoc--node-nth dll 1)) | |
368 | (footer (ewoc--footer ewoc)) | |
2c246c9f TTN |
369 | (next nil) |
370 | (L nil) (R nil) | |
371 | (inhibit-read-only t)) | |
5b467bf4 SM |
372 | (while (not (eq node footer)) |
373 | (setq next (ewoc--node-next dll node)) | |
374 | (unless (apply predicate (ewoc--node-data node) args) | |
2c246c9f TTN |
375 | ;; If we are about to delete the node pointed at by last-node, |
376 | ;; set last-node to nil. | |
377 | (if (eq (ewoc--last-node ewoc) node) | |
378 | (setf (ewoc--last-node ewoc) nil)) | |
379 | (delete-region (ewoc--node-start-marker node) | |
380 | (ewoc--node-start-marker (ewoc--node-next dll node))) | |
381 | (set-marker (ewoc--node-start-marker node) nil) | |
382 | (setf L (ewoc--node-left node) | |
383 | R (ewoc--node-right node) | |
384 | ;; Link neighbors to each other. | |
385 | (ewoc--node-right L) R | |
386 | (ewoc--node-left R) L | |
387 | ;; Forget neighbors. | |
388 | (ewoc--node-left node) nil | |
389 | (ewoc--node-right node) nil)) | |
5b467bf4 SM |
390 | (setq node next)))) |
391 | ||
44946a4c | 392 | (defun ewoc-locate (ewoc &optional pos guess) |
5b467bf4 | 393 | "Return the node that POS (a buffer position) is within. |
44946a4c | 394 | POS may be a marker or an integer. It defaults to point. |
0111ab41 | 395 | GUESS should be a node that it is likely to be near POS. |
5b467bf4 SM |
396 | |
397 | If POS points before the first element, the first node is returned. | |
398 | If POS points after the last element, the last node is returned. | |
399 | If the EWOC is empty, nil is returned." | |
44946a4c | 400 | (unless pos (setq pos (point))) |
5b467bf4 SM |
401 | (ewoc--set-buffer-bind-dll-let* ewoc |
402 | ((footer (ewoc--footer ewoc))) | |
403 | ||
404 | (cond | |
405 | ;; Nothing present? | |
406 | ((eq (ewoc--node-nth dll 1) (ewoc--node-nth dll -1)) | |
407 | nil) | |
408 | ||
409 | ;; Before second elem? | |
410 | ((< pos (ewoc--node-start-marker (ewoc--node-nth dll 2))) | |
411 | (ewoc--node-nth dll 1)) | |
412 | ||
413 | ;; After one-before-last elem? | |
414 | ((>= pos (ewoc--node-start-marker (ewoc--node-nth dll -2))) | |
415 | (ewoc--node-nth dll -2)) | |
416 | ||
417 | ;; We now know that pos is within a elem. | |
418 | (t | |
419 | ;; Make an educated guess about which of the three known | |
420 | ;; node'es (the first, the last, or GUESS) is nearest. | |
421 | (let* ((best-guess (ewoc--node-nth dll 1)) | |
422 | (distance (abs (- pos (ewoc--node-start-marker best-guess))))) | |
423 | (when guess | |
424 | (let ((d (abs (- pos (ewoc--node-start-marker guess))))) | |
425 | (when (< d distance) | |
426 | (setq distance d) | |
427 | (setq best-guess guess)))) | |
428 | ||
429 | (let* ((g (ewoc--node-nth dll -1)) ;Check the last elem | |
430 | (d (abs (- pos (ewoc--node-start-marker g))))) | |
431 | (when (< d distance) | |
432 | (setq distance d) | |
433 | (setq best-guess g))) | |
434 | ||
435 | (when (ewoc--last-node ewoc) ;Check "previous". | |
436 | (let* ((g (ewoc--last-node ewoc)) | |
437 | (d (abs (- pos (ewoc--node-start-marker g))))) | |
438 | (when (< d distance) | |
439 | (setq distance d) | |
440 | (setq best-guess g)))) | |
441 | ||
442 | ;; best-guess is now a "best guess". | |
443 | ;; Find the correct node. First determine in which direction | |
444 | ;; it lies, and then move in that direction until it is found. | |
a1506d29 | 445 | |
5b467bf4 SM |
446 | (cond |
447 | ;; Is pos after the guess? | |
448 | ((>= pos | |
449 | (ewoc--node-start-marker best-guess)) | |
450 | ;; Loop until we are exactly one node too far down... | |
451 | (while (>= pos (ewoc--node-start-marker best-guess)) | |
452 | (setq best-guess (ewoc--node-next dll best-guess))) | |
453 | ;; ...and return the previous node. | |
454 | (ewoc--node-prev dll best-guess)) | |
455 | ||
456 | ;; Pos is before best-guess | |
457 | (t | |
458 | (while (< pos (ewoc--node-start-marker best-guess)) | |
459 | (setq best-guess (ewoc--node-prev dll best-guess))) | |
460 | best-guess))))))) | |
461 | ||
462 | (defun ewoc-invalidate (ewoc &rest nodes) | |
d4ddf783 TTN |
463 | "Call EWOC's pretty-printer for each element in NODES. |
464 | Delete current text first, thus effecting a \"refresh\"." | |
5b467bf4 | 465 | (ewoc--set-buffer-bind-dll ewoc |
bfbdb5ca TTN |
466 | (save-excursion |
467 | (dolist (node nodes) | |
468 | (ewoc--refresh-node (ewoc--pretty-printer ewoc) node))))) | |
5b467bf4 | 469 | |
44946a4c | 470 | (defun ewoc-goto-prev (ewoc arg) |
d4ddf783 | 471 | "Move point to the ARGth previous element in EWOC. |
5b467bf4 | 472 | Don't move if we are at the first element, or if EWOC is empty. |
d4ddf783 | 473 | Return the node we moved to." |
5b467bf4 | 474 | (ewoc--set-buffer-bind-dll-let* ewoc |
6d84ac85 | 475 | ((node (ewoc-locate ewoc (point)))) |
5b467bf4 | 476 | (when node |
44946a4c SM |
477 | ;; If we were past the last element, first jump to it. |
478 | (when (>= (point) (ewoc--node-start-marker (ewoc--node-right node))) | |
479 | (setq arg (1- arg))) | |
5b467bf4 SM |
480 | (while (and node (> arg 0)) |
481 | (setq arg (1- arg)) | |
482 | (setq node (ewoc--node-prev dll node))) | |
483 | ;; Never step above the first element. | |
484 | (unless (ewoc--filter-hf-nodes ewoc node) | |
485 | (setq node (ewoc--node-nth dll 1))) | |
486 | (ewoc-goto-node ewoc node)))) | |
487 | ||
44946a4c | 488 | (defun ewoc-goto-next (ewoc arg) |
d4ddf783 TTN |
489 | "Move point to the ARGth next element in EWOC. |
490 | Return the node (or nil if we just passed the last node)." | |
5b467bf4 | 491 | (ewoc--set-buffer-bind-dll-let* ewoc |
6d84ac85 | 492 | ((node (ewoc-locate ewoc (point)))) |
5b467bf4 SM |
493 | (while (and node (> arg 0)) |
494 | (setq arg (1- arg)) | |
495 | (setq node (ewoc--node-next dll node))) | |
496 | ;; Never step below the first element. | |
44946a4c SM |
497 | ;; (unless (ewoc--filter-hf-nodes ewoc node) |
498 | ;; (setq node (ewoc--node-nth dll -2))) | |
5b467bf4 SM |
499 | (ewoc-goto-node ewoc node))) |
500 | ||
501 | (defun ewoc-goto-node (ewoc node) | |
d4ddf783 | 502 | "Move point to NODE in EWOC." |
5b467bf4 SM |
503 | (ewoc--set-buffer-bind-dll ewoc |
504 | (goto-char (ewoc--node-start-marker node)) | |
505 | (if goal-column (move-to-column goal-column)) | |
506 | (setf (ewoc--last-node ewoc) node))) | |
507 | ||
508 | (defun ewoc-refresh (ewoc) | |
509 | "Refresh all data in EWOC. | |
510 | The pretty-printer that was specified when the EWOC was created | |
511 | will be called for all elements in EWOC. | |
512 | Note that `ewoc-invalidate' is more efficient if only a small | |
513 | number of elements needs to be refreshed." | |
514 | (ewoc--set-buffer-bind-dll-let* ewoc | |
cb3430a1 | 515 | ((footer (ewoc--footer ewoc))) |
5b467bf4 SM |
516 | (let ((inhibit-read-only t)) |
517 | (delete-region (ewoc--node-start-marker (ewoc--node-nth dll 1)) | |
518 | (ewoc--node-start-marker footer)) | |
519 | (goto-char (ewoc--node-start-marker footer)) | |
340d9945 TTN |
520 | (let ((pp (ewoc--pretty-printer ewoc)) |
521 | (node (ewoc--node-nth dll 1))) | |
5b467bf4 SM |
522 | (while (not (eq node footer)) |
523 | (set-marker (ewoc--node-start-marker node) (point)) | |
340d9945 | 524 | (funcall pp (ewoc--node-data node)) |
5b467bf4 SM |
525 | (insert "\n") |
526 | (setq node (ewoc--node-next dll node))))) | |
527 | (set-marker (ewoc--node-start-marker footer) (point)))) | |
528 | ||
529 | (defun ewoc-collect (ewoc predicate &rest args) | |
530 | "Select elements from EWOC using PREDICATE. | |
531 | Return a list of all selected data elements. | |
0111ab41 JB |
532 | PREDICATE is a function that takes a data element as its first |
533 | argument. The elements on the returned list will appear in the | |
534 | same order as in the buffer. You should not rely on the order of | |
535 | calls to PREDICATE. | |
536 | Note that the buffer the EWOC is displayed in is the current | |
537 | buffer when PREDICATE is called. PREDICATE must restore it if it | |
538 | changes it. | |
5b467bf4 SM |
539 | If more than two arguments are given the |
540 | remaining arguments will be passed to PREDICATE." | |
541 | (ewoc--set-buffer-bind-dll-let* ewoc | |
542 | ((header (ewoc--header ewoc)) | |
543 | (node (ewoc--node-nth dll -2)) | |
544 | result) | |
545 | (while (not (eq node header)) | |
546 | (if (apply predicate (ewoc--node-data node) args) | |
547 | (push (ewoc--node-data node) result)) | |
548 | (setq node (ewoc--node-prev dll node))) | |
6d84ac85 | 549 | (nreverse result))) |
5b467bf4 SM |
550 | |
551 | (defun ewoc-buffer (ewoc) | |
552 | "Return the buffer that is associated with EWOC. | |
d4ddf783 | 553 | Return nil if the buffer has been deleted." |
5b467bf4 SM |
554 | (let ((buf (ewoc--buffer ewoc))) |
555 | (when (buffer-name buf) buf))) | |
556 | ||
cb3430a1 SM |
557 | (defun ewoc-get-hf (ewoc) |
558 | "Return a cons cell containing the (HEADER . FOOTER) of EWOC." | |
559 | (cons (ewoc--node-data (ewoc--header ewoc)) | |
560 | (ewoc--node-data (ewoc--footer ewoc)))) | |
561 | ||
562 | (defun ewoc-set-hf (ewoc header footer) | |
563 | "Set the HEADER and FOOTER of EWOC." | |
564 | (setf (ewoc--node-data (ewoc--header ewoc)) header) | |
565 | (setf (ewoc--node-data (ewoc--footer ewoc)) footer) | |
bfbdb5ca TTN |
566 | (save-excursion |
567 | (ewoc--refresh-node 'insert (ewoc--header ewoc)) | |
568 | (ewoc--refresh-node 'insert (ewoc--footer ewoc)))) | |
cb3430a1 | 569 | |
5b467bf4 SM |
570 | \f |
571 | (provide 'ewoc) | |
572 | ||
573 | ;;; Local Variables: | |
574 | ;;; eval: (put 'ewoc--set-buffer-bind-dll 'lisp-indent-hook 1) | |
575 | ;;; eval: (put 'ewoc--set-buffer-bind-dll-let* 'lisp-indent-hook 2) | |
576 | ;;; End: | |
577 | ||
ab5796a9 | 578 | ;;; arch-tag: d78915b9-9a07-44bf-aac6-04a1fc1bd6d4 |
5b467bf4 | 579 | ;;; ewoc.el ends here |