Fix a bug in the state cache mechanism. Refactor this a bit.
[emacs.git] / lisp / tree-widget.el
blob2f73aee3ed44f79475d5c8ab704f1f4f727e99a2
1 ;;; tree-widget.el --- Tree widget
3 ;; Copyright (C) 2004-2013 Free Software Foundation, Inc.
5 ;; Author: David Ponce <david@dponce.com>
6 ;; Maintainer: David Ponce <david@dponce.com>
7 ;; Created: 16 Feb 2001
8 ;; Keywords: extensions
10 ;; This file is part of GNU Emacs
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;;; Commentary:
27 ;; This library provide a tree widget useful to display data
28 ;; structures organized in a hierarchical order.
30 ;; The following properties are specific to the tree widget:
32 ;; :open
33 ;; Set to non-nil to expand the tree. By default the tree is
34 ;; collapsed.
36 ;; :node
37 ;; Specify the widget used to represent the value of a tree node.
38 ;; By default this is an `item' widget which displays the
39 ;; tree-widget :tag property value if defined, or a string
40 ;; representation of the tree-widget value.
42 ;; :keep
43 ;; Specify a list of properties to keep when the tree is collapsed
44 ;; so they can be recovered when the tree is expanded. This
45 ;; property can be used in child widgets too.
47 ;; :expander (obsoletes :dynargs)
48 ;; Specify a function to be called to dynamically provide the
49 ;; tree's children in response to an expand request. This function
50 ;; will be passed the tree widget and must return a list of child
51 ;; widgets. Child widgets returned by the :expander function are
52 ;; stored in the :args property of the tree widget.
54 ;; :expander-p
55 ;; Specify a predicate which must return non-nil to indicate that
56 ;; the :expander function above has to be called. By default, to
57 ;; speed up successive expand requests, the :expander-p predicate
58 ;; return non-nil when the :args value is nil. So, by default, to
59 ;; refresh child values, it is necessary to set the :args property
60 ;; to nil, then redraw the tree.
62 ;; :open-icon (default `tree-widget-open-icon')
63 ;; :close-icon (default `tree-widget-close-icon')
64 ;; :empty-icon (default `tree-widget-empty-icon')
65 ;; :leaf-icon (default `tree-widget-leaf-icon')
66 ;; Those properties define the icon widgets associated to tree
67 ;; nodes. Icon widgets must derive from the `tree-widget-icon'
68 ;; widget. The :tag and :glyph-name property values are
69 ;; respectively used when drawing the text and graphic
70 ;; representation of the tree. The :tag value must be a string
71 ;; that represent a node icon, like "[+]" for example. The
72 ;; :glyph-name value must the name of an image found in the current
73 ;; theme, like "close" for example (see also the variable
74 ;; `tree-widget-theme').
76 ;; :guide (default `tree-widget-guide')
77 ;; :end-guide (default `tree-widget-end-guide')
78 ;; :no-guide (default `tree-widget-no-guide')
79 ;; :handle (default `tree-widget-handle')
80 ;; :no-handle (default `tree-widget-no-handle')
81 ;; Those properties define `item'-like widgets used to draw the
82 ;; tree guide lines. The :tag property value is used when drawing
83 ;; the text representation of the tree. The graphic look and feel
84 ;; is given by the images named "guide", "no-guide", "end-guide",
85 ;; "handle", and "no-handle" found in the current theme (see also
86 ;; the variable `tree-widget-theme').
88 ;; These are the default :tag values for icons, and guide lines:
90 ;; open-icon "[-]"
91 ;; close-icon "[+]"
92 ;; empty-icon "[X]"
93 ;; leaf-icon ""
94 ;; guide " |"
95 ;; no-guide " "
96 ;; end-guide " `"
97 ;; handle "-"
98 ;; no-handle " "
100 ;; The text representation of a tree looks like this:
102 ;; [-] 1 (open-icon :node)
103 ;; |-[+] 1.0 (guide+handle+close-icon :node)
104 ;; |-[X] 1.1 (guide+handle+empty-icon :node)
105 ;; `-[-] 1.2 (end-guide+handle+open-icon :node)
106 ;; |- 1.2.1 (no-guide+no-handle+guide+handle+leaf-icon leaf)
107 ;; `- 1.2.2 (no-guide+no-handle+end-guide+handle+leaf-icon leaf)
109 ;; By default, images will be used instead of strings to draw a
110 ;; nice-looking tree. See the `tree-widget-image-enable',
111 ;; `tree-widget-themes-directory', and `tree-widget-theme' options for
112 ;; more details.
114 ;;; History:
117 ;;; Code:
118 (require 'wid-edit)
120 ;;; Customization
122 (defgroup tree-widget nil
123 "Customization support for the Tree Widget library."
124 :version "22.1"
125 :group 'widgets)
127 (defcustom tree-widget-image-enable (if (fboundp 'display-images-p)
128 (display-images-p))
129 "Non-nil means that tree-widget will try to use images."
130 :type 'boolean
131 :group 'tree-widget)
133 (defvar tree-widget-themes-load-path
134 '(load-path
135 (let ((dir (if (fboundp 'locate-data-directory)
136 (locate-data-directory "tree-widget") ;; XEmacs
137 data-directory)))
138 (and dir (list dir (expand-file-name "images" dir))))
140 "List of locations in which to search for the themes sub-directory.
141 Each element is an expression that will be recursively evaluated until
142 it returns a single directory or a list of directories.
143 The default is to search in the `load-path' first, then in the
144 \"images\" sub directory in the data directory, then in the data
145 directory.
146 The data directory is the value of the variable `data-directory' on
147 Emacs, and what `(locate-data-directory \"tree-widget\")' returns on
148 XEmacs.")
150 (defcustom tree-widget-themes-directory "tree-widget"
151 "Name of the directory in which to look for an image theme.
152 When nil use the directory where the tree-widget library is located.
153 When it is a relative name, search in all occurrences of that sub
154 directory in the path specified by `tree-widget-themes-load-path'.
155 The default is to use the \"tree-widget\" relative name."
156 :type '(choice (const :tag "Default" "tree-widget")
157 (const :tag "Where is this library" nil)
158 (directory :format "%{%t%}:\n%v"))
159 :group 'tree-widget)
161 (defcustom tree-widget-theme nil
162 "Name of the theme in which to look for images.
163 This is a sub directory of the themes directory specified by the
164 `tree-widget-themes-directory' option.
165 The default theme is \"default\". When an image is not found in a
166 theme, it is searched in its parent theme.
168 A complete theme must at least contain images with these file names
169 with a supported extension (see also `tree-widget-image-formats'):
171 \"guide\"
172 A vertical guide line.
173 \"no-guide\"
174 An invisible vertical guide line.
175 \"end-guide\"
176 End of a vertical guide line.
177 \"handle\"
178 Horizontal guide line that joins the vertical guide line to an icon.
179 \"no-handle\"
180 An invisible handle.
182 Plus images whose name is given by the :glyph-name property of the
183 icon widgets used to draw the tree. By default these images are used:
185 \"open\"
186 Icon associated to an expanded tree.
187 \"close\"
188 Icon associated to a collapsed tree.
189 \"empty\"
190 Icon associated to an expanded tree with no child.
191 \"leaf\"
192 Icon associated to a leaf node."
193 :type '(choice (const :tag "Default" nil)
194 (string :tag "Name"))
195 :group 'tree-widget)
197 (defcustom tree-widget-image-properties-emacs
198 '(:ascent center :mask (heuristic t))
199 "Default properties of Emacs images."
200 :type 'plist
201 :group 'tree-widget)
203 (defcustom tree-widget-image-properties-xemacs
205 "Default properties of XEmacs images."
206 :type 'plist
207 :group 'tree-widget)
209 (defcustom tree-widget-space-width 0.5
210 "Amount of space between an icon image and a node widget.
211 Must be a valid space :width display property."
212 :group 'tree-widget
213 :type 'sexp)
215 ;;; Image support
217 (eval-and-compile ;; Emacs/XEmacs compatibility stuff
218 (cond
219 ;; XEmacs
220 ((featurep 'xemacs)
221 (defsubst tree-widget-use-image-p ()
222 "Return non-nil if image support is currently enabled."
223 (and tree-widget-image-enable
224 widget-glyph-enable
225 (console-on-window-system-p)))
226 (defsubst tree-widget-create-image (type file &optional props)
227 "Create an image of type TYPE from FILE, and return it.
228 Give the image the specified properties PROPS."
229 (apply 'make-glyph `([,type :file ,file ,@props])))
230 (defsubst tree-widget-image-formats ()
231 "Return the alist of image formats/file name extensions.
232 See also the option `widget-image-file-name-suffixes'."
233 (delq nil
234 (mapcar
235 #'(lambda (fmt)
236 (and (valid-image-instantiator-format-p (car fmt)) fmt))
237 widget-image-file-name-suffixes)))
239 ;; Emacs
241 (defsubst tree-widget-use-image-p ()
242 "Return non-nil if image support is currently enabled."
243 (and tree-widget-image-enable
244 widget-image-enable
245 (display-images-p)))
246 (defsubst tree-widget-create-image (type file &optional props)
247 "Create an image of type TYPE from FILE, and return it.
248 Give the image the specified properties PROPS."
249 (apply 'create-image `(,file ,type nil ,@props)))
250 (defsubst tree-widget-image-formats ()
251 "Return the alist of image formats/file name extensions.
252 See also the option `widget-image-conversion'."
253 (delq nil
254 (mapcar
255 #'(lambda (fmt)
256 (and (image-type-available-p (car fmt)) fmt))
257 widget-image-conversion)))
261 ;; Buffer local cache of theme data.
262 (defvar tree-widget--theme nil)
264 (defsubst tree-widget-theme-name ()
265 "Return the current theme name, or nil if no theme is active."
266 (and tree-widget--theme (car (aref tree-widget--theme 0))))
268 (defsubst tree-widget-set-parent-theme (name)
269 "Set to NAME the parent theme of the current theme.
270 The default parent theme is the \"default\" theme."
271 (unless (member name (aref tree-widget--theme 0))
272 (aset tree-widget--theme 0
273 (append (aref tree-widget--theme 0) (list name)))
274 ;; Load the theme setup from the first directory where the theme
275 ;; is found.
276 (catch 'found
277 (dolist (dir (tree-widget-themes-path))
278 (setq dir (expand-file-name name dir))
279 (when (file-accessible-directory-p dir)
280 (throw 'found
281 (load (expand-file-name
282 "tree-widget-theme-setup" dir) t)))))))
284 (defun tree-widget-set-theme (&optional name)
285 "In the current buffer, set the theme to use for images.
286 The current buffer must be where the tree widget is drawn.
287 Optional argument NAME is the name of the theme to use. It defaults
288 to the value of the variable `tree-widget-theme'.
289 Does nothing if NAME is already the current theme.
291 If there is a \"tree-widget-theme-setup\" library in the theme
292 directory, load it to setup a parent theme or the images properties.
293 Typically it should contain something like this:
295 (tree-widget-set-parent-theme \"my-parent-theme\")
296 (tree-widget-set-image-properties
297 (if (featurep 'xemacs)
298 '(:ascent center)
299 '(:ascent center :mask (heuristic t))
301 (or name (setq name (or tree-widget-theme "default")))
302 (unless (string-equal name (tree-widget-theme-name))
303 (set (make-local-variable 'tree-widget--theme)
304 (make-vector 4 nil))
305 (tree-widget-set-parent-theme name)
306 (tree-widget-set-parent-theme "default")))
308 (defun tree-widget--locate-sub-directory (name path &optional found)
309 "Locate all occurrences of the sub-directory NAME in PATH.
310 Return a list of absolute directory names in reverse order, or nil if
311 not found."
312 (condition-case err
313 (dolist (elt path)
314 (setq elt (eval elt))
315 (cond
316 ((stringp elt)
317 (and (file-accessible-directory-p
318 (setq elt (expand-file-name name elt)))
319 (push elt found)))
320 (elt
321 (setq found (tree-widget--locate-sub-directory
322 name (if (atom elt) (list elt) elt) found)))))
323 (error
324 (message "In tree-widget--locate-sub-directory: %s"
325 (error-message-string err))))
326 found)
328 (defun tree-widget-themes-path ()
329 "Return the path where to search for a theme.
330 It is specified in variable `tree-widget-themes-directory'.
331 Return a list of absolute directory names, or nil when no directory
332 has been found accessible."
333 (let ((path (aref tree-widget--theme 1)))
334 (cond
335 ;; No directory was found.
336 ((eq path 'void) nil)
337 ;; The list of directories is available in the cache.
338 (path)
339 ;; Use the directory where this library is located.
340 ((null tree-widget-themes-directory)
341 (when (setq path (locate-library "tree-widget"))
342 (setq path (file-name-directory path))
343 (setq path (and (file-accessible-directory-p path)
344 (list path)))
345 ;; Store the result in the cache for later use.
346 (aset tree-widget--theme 1 (or path 'void))
347 path))
348 ;; Check accessibility of absolute directory name.
349 ((file-name-absolute-p tree-widget-themes-directory)
350 (setq path (expand-file-name tree-widget-themes-directory))
351 (setq path (and (file-accessible-directory-p path)
352 (list path)))
353 ;; Store the result in the cache for later use.
354 (aset tree-widget--theme 1 (or path 'void))
355 path)
356 ;; Locate a sub-directory in `tree-widget-themes-load-path'.
358 (setq path (nreverse (tree-widget--locate-sub-directory
359 tree-widget-themes-directory
360 tree-widget-themes-load-path)))
361 ;; Store the result in the cache for later use.
362 (aset tree-widget--theme 1 (or path 'void))
363 path))))
365 (defconst tree-widget--cursors
366 ;; Pointer shapes when the mouse pointer is over inactive
367 ;; tree-widget images. This feature works since Emacs 22, and
368 ;; ignored on older versions, and XEmacs.
370 ("guide" . arrow)
371 ("no-guide" . arrow)
372 ("end-guide" . arrow)
373 ("handle" . arrow)
374 ("no-handle" . arrow)
377 (defsubst tree-widget-set-image-properties (props)
378 "In current theme, set images properties to PROPS.
379 Does nothing if images properties have already been set for that
380 theme."
381 (or (aref tree-widget--theme 2)
382 (aset tree-widget--theme 2 props)))
384 (defsubst tree-widget-image-properties (name)
385 "Return the properties of image NAME in current theme.
386 Default global properties are provided for respectively Emacs and
387 XEmacs in the variables `tree-widget-image-properties-emacs', and
388 `tree-widget-image-properties-xemacs'."
389 ;; Add the pointer shape
390 (cons :pointer
391 (cons (or (cdr (assoc name tree-widget--cursors)) 'hand)
392 (tree-widget-set-image-properties
393 (if (featurep 'xemacs)
394 tree-widget-image-properties-xemacs
395 tree-widget-image-properties-emacs)))))
397 (defun tree-widget-lookup-image (name)
398 "Look up in current theme for an image with NAME.
399 Search first in current theme, then in parent themes (see also the
400 function `tree-widget-set-parent-theme').
401 Return the first image found having a supported format, or nil if not
402 found."
403 (let (file)
404 (catch 'found
405 (dolist (default-directory (tree-widget-themes-path))
406 (dolist (dir (aref tree-widget--theme 0))
407 (dolist (fmt (tree-widget-image-formats))
408 (dolist (ext (cdr fmt))
409 (setq file (expand-file-name (concat name ext) dir))
410 (and (file-readable-p file)
411 (file-regular-p file)
412 (throw 'found
413 (tree-widget-create-image
414 (car fmt) file
415 (tree-widget-image-properties name))))))))
416 nil)))
418 (defun tree-widget-find-image (name)
419 "Find the image with NAME in current theme.
420 NAME is an image file name sans extension.
421 Return the image found, or nil if not found."
422 (when (tree-widget-use-image-p)
423 ;; Ensure there is an active theme.
424 (tree-widget-set-theme (tree-widget-theme-name))
425 (let ((image (assoc name (aref tree-widget--theme 3))))
426 ;; The image NAME is found in the cache.
427 (if image
428 (cdr image)
429 ;; Search the image in current, and default themes.
430 (prog1
431 (setq image (tree-widget-lookup-image name))
432 ;; Store image reference in the cache for later use.
433 (push (cons name image) (aref tree-widget--theme 3))))
436 ;;; Widgets
438 (defun tree-widget-button-click (event)
439 "Move to the position clicked on, and if it is a button, invoke it.
440 EVENT is the mouse event received."
441 (interactive "e")
442 (mouse-set-point event)
443 (let ((pos (widget-event-point event)))
444 (if (get-char-property pos 'button)
445 (widget-button-click event))))
447 (defvar tree-widget-button-keymap
448 (let ((km (make-sparse-keymap)))
449 (if (boundp 'widget-button-keymap)
450 ;; XEmacs
451 (progn
452 (set-keymap-parent km widget-button-keymap)
453 (define-key km [button1] 'tree-widget-button-click))
454 ;; Emacs
455 (set-keymap-parent km widget-keymap)
456 (define-key km [down-mouse-1] 'tree-widget-button-click))
458 "Keymap used inside node buttons.
459 Handle mouse button 1 click on buttons.")
461 (define-widget 'tree-widget-icon 'push-button
462 "Basic widget other tree-widget icons are derived from."
463 :format "%[%t%]"
464 :button-keymap tree-widget-button-keymap ; XEmacs
465 :keymap tree-widget-button-keymap ; Emacs
466 :create 'tree-widget-icon-create
467 :action 'tree-widget-icon-action
468 :help-echo 'tree-widget-icon-help-echo
471 (define-widget 'tree-widget-open-icon 'tree-widget-icon
472 "Icon for an expanded tree-widget node."
473 :tag "[-]"
474 :glyph-name "open"
477 (define-widget 'tree-widget-empty-icon 'tree-widget-icon
478 "Icon for an expanded tree-widget node with no child."
479 :tag "[X]"
480 :glyph-name "empty"
483 (define-widget 'tree-widget-close-icon 'tree-widget-icon
484 "Icon for a collapsed tree-widget node."
485 :tag "[+]"
486 :glyph-name "close"
489 (define-widget 'tree-widget-leaf-icon 'tree-widget-icon
490 "Icon for a tree-widget leaf node."
491 :tag ""
492 :glyph-name "leaf"
493 :button-face 'default
496 (define-widget 'tree-widget-guide 'item
497 "Vertical guide line."
498 :tag " |"
499 ;;:tag-glyph (tree-widget-find-image "guide")
500 :format "%t"
503 (define-widget 'tree-widget-end-guide 'item
504 "End of a vertical guide line."
505 :tag " `"
506 ;;:tag-glyph (tree-widget-find-image "end-guide")
507 :format "%t"
510 (define-widget 'tree-widget-no-guide 'item
511 "Invisible vertical guide line."
512 :tag " "
513 ;;:tag-glyph (tree-widget-find-image "no-guide")
514 :format "%t"
517 (define-widget 'tree-widget-handle 'item
518 "Horizontal guide line that joins a vertical guide line to a node."
519 :tag "-"
520 ;;:tag-glyph (tree-widget-find-image "handle")
521 :format "%t"
524 (define-widget 'tree-widget-no-handle 'item
525 "Invisible handle."
526 :tag " "
527 ;;:tag-glyph (tree-widget-find-image "no-handle")
528 :format "%t"
531 (define-widget 'tree-widget 'default
532 "Tree widget."
533 :format "%v"
534 :convert-widget 'tree-widget-convert-widget
535 :value-get 'widget-value-value-get
536 :value-delete 'widget-children-value-delete
537 :value-create 'tree-widget-value-create
538 :action 'tree-widget-action
539 :help-echo 'tree-widget-help-echo
540 :expander-p 'tree-widget-expander-p
541 :open-icon 'tree-widget-open-icon
542 :close-icon 'tree-widget-close-icon
543 :empty-icon 'tree-widget-empty-icon
544 :leaf-icon 'tree-widget-leaf-icon
545 :guide 'tree-widget-guide
546 :end-guide 'tree-widget-end-guide
547 :no-guide 'tree-widget-no-guide
548 :handle 'tree-widget-handle
549 :no-handle 'tree-widget-no-handle
552 ;;; Widget support functions
554 (defun tree-widget-p (widget)
555 "Return non-nil if WIDGET is a tree-widget."
556 (let ((type (widget-type widget)))
557 (while (and type (not (eq type 'tree-widget)))
558 (setq type (widget-type (get type 'widget-type))))
559 (eq type 'tree-widget)))
561 (defun tree-widget-node (widget)
562 "Return WIDGET's :node child widget.
563 If not found, setup an `item' widget as default.
564 Signal an error if the :node widget is a tree-widget.
565 WIDGET is, or derives from, a tree-widget."
566 (let ((node (widget-get widget :node)))
567 (if node
568 ;; Check that the :node widget is not a tree-widget.
569 (and (tree-widget-p node)
570 (error "Invalid tree-widget :node %S" node))
571 ;; Setup an item widget as default :node.
572 (setq node `(item :tag ,(or (widget-get widget :tag)
573 (widget-princ-to-string
574 (widget-value widget)))))
575 (widget-put widget :node node))
576 node))
578 (defun tree-widget-keep (arg widget)
579 "Save in ARG the WIDGET's properties specified by :keep."
580 (dolist (prop (widget-get widget :keep))
581 (widget-put arg prop (widget-get widget prop))))
583 (defun tree-widget-children-value-save (widget &optional args node)
584 "Save WIDGET children values.
585 WIDGET is, or derives from, a tree-widget.
586 Children properties and values are saved in ARGS if non-nil, else in
587 WIDGET's :args property value. Properties and values of the
588 WIDGET's :node sub-widget are saved in NODE if non-nil, else in
589 WIDGET's :node sub-widget."
590 (let ((args (cons (or node (widget-get widget :node))
591 (or args (widget-get widget :args))))
592 (children (widget-get widget :children))
593 arg child)
594 (while (and args children)
595 (setq arg (car args)
596 args (cdr args)
597 child (car children)
598 children (cdr children))
599 (if (tree-widget-p child)
600 ;;;; The child is a tree node.
601 (progn
602 ;; Backtrack :args and :node properties.
603 (widget-put arg :args (widget-get child :args))
604 (widget-put arg :node (widget-get child :node))
605 ;; Save :open property.
606 (widget-put arg :open (widget-get child :open))
607 ;; The node is open.
608 (when (widget-get child :open)
609 ;; Save the widget value.
610 (widget-put arg :value (widget-value child))
611 ;; Save properties specified in :keep.
612 (tree-widget-keep arg child)
613 ;; Save children.
614 (tree-widget-children-value-save
615 child (widget-get arg :args) (widget-get arg :node))))
616 ;;;; Another non tree node.
617 ;; Save the widget value.
618 (widget-put arg :value (widget-value child))
619 ;; Save properties specified in :keep.
620 (tree-widget-keep arg child)))))
622 ;;; Widget creation
624 (defvar tree-widget-before-create-icon-functions nil
625 "Hooks run before to create a tree-widget icon.
626 Each function is passed the icon widget not yet created.
627 The value of the icon widget :node property is a tree :node widget or
628 a leaf node widget, not yet created.
629 This hook can be used to dynamically change properties of the icon and
630 associated node widgets. For example, to dynamically change the look
631 and feel of the tree-widget by changing the values of the :tag
632 and :glyph-name properties of the icon widget.
633 This hook should be local in the buffer setup to display widgets.")
635 (defun tree-widget-icon-create (icon)
636 "Create the ICON widget."
637 (run-hook-with-args 'tree-widget-before-create-icon-functions icon)
638 (widget-put icon :tag-glyph
639 (tree-widget-find-image (widget-get icon :glyph-name)))
640 ;; Ensure there is at least one char to display the image.
641 (and (widget-get icon :tag-glyph)
642 (equal "" (or (widget-get icon :tag) ""))
643 (widget-put icon :tag " "))
644 (widget-default-create icon)
645 ;; Insert space between the icon and the node widget.
646 (insert-char ? 1)
647 (put-text-property
648 (1- (point)) (point)
649 'display (list 'space :width tree-widget-space-width)))
651 (defun tree-widget-convert-widget (widget)
652 "Convert :args as widget types in WIDGET."
653 (let ((tree (widget-types-convert-widget widget)))
654 ;; Compatibility
655 (widget-put tree :expander (or (widget-get tree :expander)
656 (widget-get tree :dynargs)))
657 tree))
659 (defvar widget-glyph-enable) ; XEmacs
661 (defun tree-widget-value-create (tree)
662 "Create the TREE tree-widget."
663 (let* ((node (tree-widget-node tree))
664 (flags (widget-get tree :tree-widget--guide-flags))
665 (indent (widget-get tree :indent))
666 ;; Setup widget's image support. Looking up for images, and
667 ;; setting widgets' :tag-glyph is done here, to allow to
668 ;; dynamically change the image theme.
669 (widget-image-enable (tree-widget-use-image-p)) ; Emacs
670 (widget-glyph-enable widget-image-enable) ; XEmacs
671 children buttons)
672 (and indent (not (widget-get tree :parent))
673 (insert-char ?\ indent))
674 (if (widget-get tree :open)
675 ;;;; Expanded node.
676 (let ((args (widget-get tree :args))
677 (guide (widget-get tree :guide))
678 (noguide (widget-get tree :no-guide))
679 (endguide (widget-get tree :end-guide))
680 (handle (widget-get tree :handle))
681 (nohandle (widget-get tree :no-handle))
682 (guidi (tree-widget-find-image "guide"))
683 (noguidi (tree-widget-find-image "no-guide"))
684 (endguidi (tree-widget-find-image "end-guide"))
685 (handli (tree-widget-find-image "handle"))
686 (nohandli (tree-widget-find-image "no-handle")))
687 ;; Request children at run time, when requested.
688 (when (and (widget-get tree :expander)
689 (widget-apply tree :expander-p))
690 (setq args (mapcar 'widget-convert
691 (widget-apply tree :expander)))
692 (widget-put tree :args args))
693 ;; Defer the node widget creation after icon creation.
694 (widget-put tree :node (widget-convert node))
695 ;; Create the icon widget for the expanded tree.
696 (push (widget-create-child-and-convert
697 tree (widget-get tree (if args :open-icon :empty-icon))
698 ;; Pass the node widget to child.
699 :node (widget-get tree :node))
700 buttons)
701 ;; Create the tree node widget.
702 (push (widget-create-child tree (widget-get tree :node))
703 children)
704 ;; Update the icon :node with the created node widget.
705 (widget-put (car buttons) :node (car children))
706 ;; Create the tree children.
707 (while args
708 (setq node (car args)
709 args (cdr args))
710 (and indent (insert-char ?\ indent))
711 ;; Insert guide lines elements from previous levels.
712 (dolist (f (reverse flags))
713 (widget-create-child-and-convert
714 tree (if f guide noguide)
715 :tag-glyph (if f guidi noguidi))
716 (widget-create-child-and-convert
717 tree nohandle :tag-glyph nohandli))
718 ;; Insert guide line element for this level.
719 (widget-create-child-and-convert
720 tree (if args guide endguide)
721 :tag-glyph (if args guidi endguidi))
722 ;; Insert the node handle line
723 (widget-create-child-and-convert
724 tree handle :tag-glyph handli)
725 (if (tree-widget-p node)
726 ;; Create a sub-tree node.
727 (push (widget-create-child-and-convert
728 tree node :tree-widget--guide-flags
729 (cons (if args t) flags))
730 children)
731 ;; Create the icon widget for a leaf node.
732 (push (widget-create-child-and-convert
733 tree (widget-get tree :leaf-icon)
734 ;; At this point the node widget isn't yet created.
735 :node (setq node (widget-convert
736 node :tree-widget--guide-flags
737 (cons (if args t) flags)))
738 :tree-widget--leaf-flag t)
739 buttons)
740 ;; Create the leaf node widget.
741 (push (widget-create-child tree node) children)
742 ;; Update the icon :node with the created node widget.
743 (widget-put (car buttons) :node (car children)))))
744 ;;;; Collapsed node.
745 ;; Defer the node widget creation after icon creation.
746 (widget-put tree :node (widget-convert node))
747 ;; Create the icon widget for the collapsed tree.
748 (push (widget-create-child-and-convert
749 tree (widget-get tree :close-icon)
750 ;; Pass the node widget to child.
751 :node (widget-get tree :node))
752 buttons)
753 ;; Create the tree node widget.
754 (push (widget-create-child tree (widget-get tree :node))
755 children)
756 ;; Update the icon :node with the created node widget.
757 (widget-put (car buttons) :node (car children)))
758 ;; Save widget children and buttons. The tree-widget :node child
759 ;; is the first element in :children.
760 (widget-put tree :children (nreverse children))
761 (widget-put tree :buttons buttons)))
763 ;;; Widget callbacks
765 (defsubst tree-widget-leaf-node-icon-p (icon)
766 "Return non-nil if ICON is a leaf node icon.
767 That is, if its :node property value is a leaf node widget."
768 (widget-get icon :tree-widget--leaf-flag))
770 (defun tree-widget-icon-action (icon &optional event)
771 "Handle the ICON widget :action.
772 If ICON :node is a leaf node it handles the :action. The tree-widget
773 parent of ICON handles the :action otherwise.
774 Pass the received EVENT to :action."
775 (let ((node (widget-get icon (if (tree-widget-leaf-node-icon-p icon)
776 :node :parent))))
777 (widget-apply node :action event)))
779 (defun tree-widget-icon-help-echo (icon)
780 "Return the help-echo string of ICON.
781 If ICON :node is a leaf node it handles the :help-echo. The tree-widget
782 parent of ICON handles the :help-echo otherwise."
783 (let* ((node (widget-get icon (if (tree-widget-leaf-node-icon-p icon)
784 :node :parent)))
785 (help-echo (widget-get node :help-echo)))
786 (if (functionp help-echo)
787 (funcall help-echo node)
788 help-echo)))
790 (defvar tree-widget-after-toggle-functions nil
791 "Hooks run after toggling a tree-widget expansion.
792 Each function is passed a tree-widget. If the value of the :open
793 property is non-nil the tree has been expanded, else collapsed.
794 This hook should be local in the buffer setup to display widgets.")
796 (defun tree-widget-action (tree &optional _event)
797 "Handle the :action of the TREE tree-widget.
798 That is, toggle expansion of the TREE tree-widget.
799 Ignore the EVENT argument."
800 (let ((open (not (widget-get tree :open))))
801 (or open
802 ;; Before to collapse the node, save children values so next
803 ;; open can recover them.
804 (tree-widget-children-value-save tree))
805 (widget-put tree :open open)
806 (widget-value-set tree open)
807 (run-hook-with-args 'tree-widget-after-toggle-functions tree)))
809 (defun tree-widget-help-echo (tree)
810 "Return the help-echo string of the TREE tree-widget."
811 (if (widget-get tree :open)
812 "Collapse node"
813 "Expand node"))
815 (defun tree-widget-expander-p (tree)
816 "Return non-nil if the TREE tree-widget :expander has to be called.
817 That is, if TREE :args is nil."
818 (null (widget-get tree :args)))
820 (provide 'tree-widget)
822 ;;; tree-widget.el ends here