;;; wid-edit.el --- Functions for creating and using widgets -*-byte-compile-dynamic: t;-*-
;;
-;; Copyright (C) 1996, 1997, 1999, 2000, 2001 Free Software Foundation, Inc.
+;; Copyright (C) 1996,97,1999,2000,01,02,2003, 2004 Free Software Foundation, Inc.
;;
;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
;; Maintainer: FSF
"Character position of the end of event if that exists, or nil."
(posn-point (event-end event)))
-(autoload 'pp-to-string "pp")
-(autoload 'Info-goto-node "info")
-
(defun widget-button-release-event-p (event)
"Non-nil if EVENT is a mouse-button-release event object."
(and (eventp event)
"Face used for buttons in widgets.
This exists as a variable so it can be set locally in certain buffers.")
-(defface widget-button-face '((t (:bold t)))
+(defface widget-button-face '((t (:weight bold)))
"Face used for widget buttons."
:group 'widget-faces)
;; the gray colors defined for other displays cause black text on a black
;; background, at least on light-background TTYs.
(defface widget-field-face '((((type tty))
- (:background "yellow3"))
+ :background "yellow3"
+ :foreground "black")
(((class grayscale color)
(background light))
- (:background "gray85"))
+ :background "gray85")
(((class grayscale color)
(background dark))
- (:background "dim gray"))
+ :background "dim gray")
(t
- (:italic t)))
+ :slant italic))
"Face used for editable fields."
:group 'widget-faces)
(defface widget-single-line-field-face '((((type tty))
- (:background "green3"))
+ :background "green3"
+ :foreground "black")
(((class grayscale color)
(background light))
- (:background "gray85"))
+ :background "gray85")
(((class grayscale color)
(background dark))
- (:background "dim gray"))
+ :background "dim gray")
(t
- (:italic t)))
+ :slant italic))
"Face used for editable fields spanning only a single line."
:group 'widget-faces)
"Choose an item from a list.
First argument TITLE is the name of the list.
-Second argument ITEMS is an list whose members are either
+Second argument ITEMS is a list whose members are either
(NAME . VALUE), to indicate selectable items, or just strings to
indicate unselectable items.
Optional third argument EVENT is an input event.
;; Define SPC as a prefix char to get to this menu.
(define-key overriding-terminal-local-map " "
(setq map (make-sparse-keymap title)))
- (save-excursion
- (set-buffer (get-buffer-create " widget-choose"))
+ (with-current-buffer (get-buffer-create " widget-choose")
(erase-buffer)
(insert "Available choices:\n\n")
(while items
(while (not (or (and (>= char ?0) (< char next-digit))
(eq value 'keyboard-quit)))
;; Unread a SPC to lead to our new menu.
- (setq unread-command-events (cons ?\ unread-command-events))
+ (setq unread-command-events (cons ?\ unread-command-events))
(setq keys (read-key-sequence title))
(setq value
(lookup-key overriding-terminal-local-map keys t)
(nreverse result)))
;;; Widget text specifications.
-;;
+;;
;; These functions are for specifying text properties.
-(defvar widget-field-add-space t
+;; We can set it to nil now that get_local_map uses get_pos_property.
+(defconst widget-field-add-space nil
"Non-nil means add extra space at the end of editable text fields.
If you don't add the space, it will become impossible to edit a zero
size field.")
(rear-sticky
(or (not widget-field-add-space) (widget-get widget :size))))
(if (functionp help-echo)
- (setq help-echo 'widget-mouse-help))
+ (setq help-echo 'widget-mouse-help))
(when (= (char-before to) ?\n)
;; When the last character in the field is a newline, we want to
;; give it a `field' char-property of `boundary', which helps the
(setq help-echo 'widget-mouse-help))
(overlay-put overlay 'button widget)
(overlay-put overlay 'keymap (widget-get widget :keymap))
+ (overlay-put overlay 'evaporate t)
;; We want to avoid the face with image buttons.
(unless (widget-get widget :suppress-face)
- (overlay-put overlay 'face (widget-apply widget :button-face-get))
- (overlay-put overlay 'mouse-face widget-mouse-face))
+ (overlay-put overlay 'face (widget-apply widget :button-face-get)))
+ (overlay-put overlay 'pointer 'hand)
(overlay-put overlay 'help-echo help-echo)))
(defun widget-mouse-help (window overlay point)
"Specify sample for WIDGET between FROM and TO."
(let ((overlay (make-overlay from to nil t nil)))
(overlay-put overlay 'face (widget-apply widget :sample-face-get))
+ (overlay-put overlay 'evaporate t)
(widget-put widget :sample-overlay overlay)))
(defun widget-specify-doc (widget from to)
(let ((overlay (make-overlay from to nil t nil)))
(overlay-put overlay 'widget-doc widget)
(overlay-put overlay 'face widget-documentation-face)
+ (overlay-put overlay 'evaporate t)
(widget-put widget :doc-overlay overlay)))
(defmacro widget-specify-insert (&rest form)
"Execute FORM without inheriting any text properties."
`(save-restriction
(let ((inhibit-read-only t)
- (inhibit-modification-hooks t)
- result)
- (insert "<>")
- (narrow-to-region (- (point) 2) (point))
- (goto-char (1+ (point-min)))
- (setq result (progn ,@form))
- (delete-region (point-min) (1+ (point-min)))
- (delete-region (1- (point-max)) (point-max))
- (goto-char (point-max))
- result)))
+ (inhibit-modification-hooks t))
+ (narrow-to-region (point) (point))
+ (prog1 (progn ,@form)
+ (goto-char (point-max))))))
(defface widget-inactive-face '((((class grayscale color)
(background dark))
(background light))
(:foreground "dim gray"))
(t
- (:italic t)))
+ (:slant italic)))
"Face used for inactive widgets."
:group 'widget-faces)
"Return the type of WIDGET, a symbol."
(car widget))
+;;;###autoload
+(defun widgetp (widget)
+ "Return non-nil iff WIDGET is a widget."
+ (if (symbolp widget)
+ (get widget 'widget-type)
+ (and (consp widget)
+ (symbolp (car widget))
+ (get (car widget) 'widget-type))))
+
(defun widget-get-indirect (widget property)
"In WIDGET, get the value of PROPERTY.
If the value is a symbol, return its binding.
:value-to-internal value)))
(defun widget-default-get (widget)
- "Extract the default value of WIDGET."
- (or (widget-get widget :value)
- (widget-apply widget :default-get)))
+ "Extract the default external value of WIDGET."
+ (widget-apply widget :value-to-external
+ (or (widget-get widget :value)
+ (widget-apply widget :default-get))))
(defun widget-match-inline (widget vals)
"In WIDGET, match the start of VALS."
respectively."
(let ((cur (point-min))
(widget nil)
- (parent nil)
(overlays (if buffer
- (save-excursion (set-buffer buffer) (overlay-lists))
+ (with-current-buffer buffer (overlay-lists))
(overlay-lists))))
(setq overlays (append (car overlays) (cdr overlays)))
(while (setq cur (pop overlays))
(defun widget-create-child (parent type)
"Create widget of TYPE."
- (let ((widget (copy-sequence type)))
+ (let ((widget (widget-copy type)))
(widget-put widget :parent parent)
(unless (widget-get widget :indent)
(widget-put widget :indent (+ (or (widget-get parent :indent) 0)
(defun widget-create-child-value (parent type value)
"Create widget of TYPE with value VALUE."
- (let ((widget (copy-sequence type)))
+ (let ((widget (widget-copy type)))
(widget-put widget :value (widget-apply widget :value-to-internal value))
(widget-put widget :parent parent)
(unless (widget-get widget :indent)
"Delete WIDGET."
(widget-apply widget :delete))
+(defun widget-copy (widget)
+ "Make a deep copy of WIDGET."
+ (widget-apply (copy-sequence widget) :copy))
+
(defun widget-convert (type &rest args)
"Convert TYPE to a widget without inserting it in the buffer.
The optional ARGS are additional keyword arguments."
(list type)
(copy-sequence type)))
(current widget)
+ done
(keys args))
;; First set the :args keyword.
(while (cdr current) ;Look in the type.
- (if (keywordp (car (cdr current)))
- (setq current (cdr (cdr current)))
+ (if (and (keywordp (cadr current))
+ ;; If the last element is a keyword,
+ ;; it is still the :args element,
+ ;; even though it is a keyword.
+ (cddr current))
+ (if (eq (cadr current) :args)
+ ;; If :args is explicitly specified, obey it.
+ (setq current nil)
+ ;; Some other irrelevant keyword.
+ (setq current (cdr (cdr current))))
(setcdr current (list :args (cdr current)))
(setq current nil)))
- (while args ;Look in the args.
- (if (keywordp (nth 0 args))
- (setq args (nthcdr 2 args))
- (widget-put widget :args args)
- (setq args nil)))
+ (while (and args (not done)) ;Look in ARGS.
+ (cond ((eq (car args) :args)
+ ;; Handle explicit specification of :args.
+ (setq args (cadr args)
+ done t))
+ ((keywordp (car args))
+ (setq args (cddr args)))
+ (t (setq done t))))
+ (when done
+ (widget-put widget :args args))
;; Then Convert the widget.
(setq type widget)
(while type
;; Return the newly create widget.
widget))
+;;;###autoload
(defun widget-insert (&rest args)
"Call `insert' with ARGS even if surrounding text is read only."
(let ((inhibit-read-only t)
;;; Keymap and Commands.
+;;;###autoload
(defvar widget-keymap
(let ((map (make-sparse-keymap)))
(define-key map "\t" 'widget-forward)
'((((class color))
(:foreground "red"))
(t
- (:bold t :underline t)))
+ (:weight bold :underline t)))
"Face used for pressed buttons."
:group 'widget-faces)
(if (widget-event-point event)
(let* ((pos (widget-event-point event))
(start (event-start event))
- (button (get-char-property
+ (button (get-char-property
pos 'button (and (windowp (posn-window start))
(window-buffer (posn-window start))))))
(if button
"Move point to the ARG next field or button.
ARG may be negative to move backward."
(or (bobp) (> arg 0) (backward-char))
- (let ((pos (point))
+ (let ((wrapped 0)
(number arg)
- (old (widget-tabable-at))
- new)
+ (old (widget-tabable-at)))
;; Forward.
(while (> arg 0)
(cond ((eobp)
- (goto-char (point-min)))
+ (goto-char (point-min))
+ (setq wrapped (1+ wrapped)))
(widget-use-overlay-change
(goto-char (next-overlay-change (point))))
(t
(forward-char 1)))
- (and (eq pos (point))
+ (and (= wrapped 2)
(eq arg number)
(error "No buttons or fields found"))
(let ((new (widget-tabable-at)))
;; Backward.
(while (< arg 0)
(cond ((bobp)
- (goto-char (point-max)))
+ (goto-char (point-max))
+ (setq wrapped (1+ wrapped)))
(widget-use-overlay-change
(goto-char (previous-overlay-change (point))))
(t
(backward-char 1)))
- (and (eq pos (point))
+ (and (= wrapped 2)
(eq arg number)
(error "No buttons or fields found"))
(let ((new (widget-tabable-at)))
;;; Setting up the buffer.
-(defvar widget-field-new nil)
-;; List of all newly created editable fields in the buffer.
+(defvar widget-field-new nil
+ "List of all newly created editable fields in the buffer.")
(make-variable-buffer-local 'widget-field-new)
-(defvar widget-field-list nil)
-;; List of all editable fields in the buffer.
+(defvar widget-field-list nil
+ "List of all editable fields in the buffer.")
(make-variable-buffer-local 'widget-field-list)
(defun widget-at (&optional pos)
(or (get-char-property (or pos (point)) 'button)
(widget-field-at pos)))
+;;;###autoload
(defun widget-setup ()
"Setup current buffer so editing string widgets works."
(let ((inhibit-read-only t)
found (widget-apply child :validate)))
found))
+(defun widget-child-value-get (widget)
+ "Get the value of the first member of :children in WIDGET."
+ (widget-value (car (widget-get widget :children))))
+
+(defun widget-child-value-inline (widget)
+ "Get the inline value of the first member of :children in WIDGET."
+ (widget-apply (car (widget-get widget :children)) :value-inline))
+
+(defun widget-child-validate (widget)
+ "The result of validating the first member of :children in WIDGET."
+ (widget-apply (car (widget-get widget :children)) :validate))
+
+(defun widget-type-value-create (widget)
+ "Convert and instantiate the value of the :type attribute of WIDGET.
+Store the newly created widget in the :children attribute.
+
+The value of the :type attribute should be an unconverted widget type."
+ (let ((value (widget-get widget :value))
+ (type (widget-get widget :type)))
+ (widget-put widget :children
+ (list (widget-create-child-value widget
+ (widget-convert type)
+ value)))))
+
+(defun widget-type-default-get (widget)
+ "Get default value from the :type attribute of WIDGET.
+
+The value of the :type attribute should be an unconverted widget type."
+ (widget-default-get (widget-convert (widget-get widget :type))))
+
+(defun widget-type-match (widget value)
+ "Non-nil if the :type value of WIDGET matches VALUE.
+
+The value of the :type attribute should be an unconverted widget type."
+ (widget-apply (widget-convert (widget-get widget :type)) :match value))
+
+(defun widget-types-copy (widget)
+ "Copy :args as widget types in WIDGET."
+ (widget-put widget :args (mapcar 'widget-copy (widget-get widget :args)))
+ widget)
+
;; Made defsubst to speed up face editor creation.
(defsubst widget-types-convert-widget (widget)
"Convert :args as widget types in WIDGET."
:indent nil
:offset 0
:format-handler 'widget-default-format-handler
- :button-face-get 'widget-default-button-face-get
- :sample-face-get 'widget-default-sample-face-get
+ :button-face-get 'widget-default-button-face-get
+ :sample-face-get 'widget-default-sample-face-get
:delete 'widget-default-delete
+ :copy 'identity
:value-set 'widget-default-value-set
:value-inline 'widget-default-value-inline
+ :value-delete 'ignore
:default-get 'widget-default-default-get
:menu-tag-get 'widget-default-menu-tag-get
:validate #'ignore
(inhibit-modification-hooks t)
(inhibit-read-only t))
(widget-apply widget :value-delete)
+ (widget-children-value-delete widget)
(when inactive-overlay
(delete-overlay inactive-overlay))
(when button-overlay
(or (widget-get widget :always-active)
(and (not (widget-get widget :inactive))
(let ((parent (widget-get widget :parent)))
- (or (null parent)
+ (or (null parent)
(widget-apply parent :active))))))
(defun widget-default-deactivate (widget)
(defun widget-info-link-action (widget &optional event)
"Open the info node specified by WIDGET."
- (Info-goto-node (widget-value widget)))
+ (info (widget-value widget)))
;;; The `url-link' Widget.
(find-file (locate-library (widget-value widget))))
;;; The `emacs-commentary-link' Widget.
-
+
(define-widget 'emacs-commentary-link 'link
"A link to Commentary in an Emacs Lisp library file."
:action 'widget-emacs-commentary-link-action)
-
+
(defun widget-emacs-commentary-link-action (widget &optional event)
"Find the Commentary section of the Emacs file specified by WIDGET."
(finder-commentary (widget-value widget)))
(define-widget 'menu-choice 'default
"A menu of options."
:convert-widget 'widget-types-convert-widget
+ :copy 'widget-types-copy
:format "%[%t%]: %v"
:case-fold t
:tag "choice"
:void '(item :format "invalid (%t)\n")
:value-create 'widget-choice-value-create
- :value-delete 'widget-children-value-delete
- :value-get 'widget-choice-value-get
- :value-inline 'widget-choice-value-inline
+ :value-get 'widget-child-value-get
+ :value-inline 'widget-child-value-inline
:default-get 'widget-choice-default-get
:mouse-down-action 'widget-choice-mouse-down-action
:action 'widget-choice-action
widget void :value value)))
(widget-put widget :choice void))))))
-(defun widget-choice-value-get (widget)
- ;; Get value of the child widget.
- (widget-value (car (widget-get widget :children))))
-
-(defun widget-choice-value-inline (widget)
- ;; Get value of the child widget.
- (widget-apply (car (widget-get widget :children)) :value-inline))
-
(defun widget-choice-default-get (widget)
;; Get default for the first choice.
(widget-default-get (car (widget-get widget :args))))
(when this-explicit
(widget-put widget :explicit-choice current)
(widget-put widget :explicit-choice-value (widget-get widget :value)))
- (widget-value-set
- widget (widget-apply current
- :value-to-external (widget-default-get current)))
+ (widget-value-set widget (widget-default-get current))
(widget-setup)
(widget-apply widget :notify widget event)))
(run-hook-with-args 'widget-edit-functions widget))
;; We could probably do the same job as the images using single
;; space characters in a boxed face with a stretch specification to
;; make them square.
- :on-glyph '(create-image "\000\066\076\034\076\066\000"
- 'xbm t :width 7 :height 7
+ :on-glyph '(create-image "\300\300\141\143\067\076\034\030"
+ 'xbm t :width 8 :height 8
:background "grey75" ; like default mode line
:foreground "black"
- :relief -3
+ :relief -2
:ascent 'center)
:off "[ ]"
- :off-glyph '(create-image (make-string 7 0)
- 'xbm t :width 7 :height 7
+ :off-glyph '(create-image (make-string 8 0)
+ 'xbm t :width 8 :height 8
:background "grey75"
:foreground "black"
- :relief 3
+ :relief -2
:ascent 'center)
:help-echo "Toggle this item."
:action 'widget-checkbox-action)
(define-widget 'checklist 'default
"A multiple choice widget."
:convert-widget 'widget-types-convert-widget
+ :copy 'widget-types-copy
:format "%v"
:offset 4
:entry-format "%b %v"
:greedy nil
:value-create 'widget-checklist-value-create
- :value-delete 'widget-children-value-delete
:value-get 'widget-checklist-value-get
:validate 'widget-checklist-validate
:match 'widget-checklist-match
(define-widget 'radio-button-choice 'default
"Select one of multiple options."
:convert-widget 'widget-types-convert-widget
+ :copy 'widget-types-copy
:offset 4
:format "%v"
:entry-format "%b %v"
:value-create 'widget-radio-value-create
- :value-delete 'widget-children-value-delete
:value-get 'widget-radio-value-get
:value-inline 'widget-radio-value-inline
:value-set 'widget-radio-value-set
(define-widget 'editable-list 'default
"A variable list of widgets of the same type."
:convert-widget 'widget-types-convert-widget
+ :copy 'widget-types-copy
:offset 12
:format "%v%i\n"
:format-handler 'widget-editable-list-format-handler
:entry-format "%i %d %v"
:value-create 'widget-editable-list-value-create
- :value-delete 'widget-children-value-delete
:value-get 'widget-editable-list-value-get
:validate 'widget-children-validate
:match 'widget-editable-list-match
(defun widget-editable-list-format-handler (widget escape)
;; We recognize the insert button.
-;;; (let ((widget-push-button-gui widget-editable-list-gui))
+ ;; (let ((widget-push-button-gui widget-editable-list-gui))
(cond ((eq escape ?i)
(and (widget-get widget :indent)
(insert-char ?\ (widget-get widget :indent)))
(widget-get widget :append-button-args)))
(t
(widget-default-format-handler widget escape)))
-;;; )
+ ;; )
)
(defun widget-editable-list-value-create (widget)
(defun widget-editable-list-entry-create (widget value conv)
;; Create a new entry to the list.
(let ((type (nth 0 (widget-get widget :args)))
-;;; (widget-push-button-gui widget-editable-list-gui)
+ ;; (widget-push-button-gui widget-editable-list-gui)
child delete insert)
(widget-specify-insert
(save-excursion
(setq child (widget-create-child-value
widget type value))
(setq child (widget-create-child-value
- widget type
- (widget-apply type :value-to-external
- (widget-default-get type))))))
+ widget type (widget-default-get type)))))
(t
(error "Unknown escape `%c'" escape)))))
- (widget-put widget
- :buttons (cons delete
- (cons insert
- (widget-get widget :buttons))))
+ (let ((buttons (widget-get widget :buttons)))
+ (if insert (push insert buttons))
+ (if delete (push delete buttons))
+ (widget-put widget :buttons buttons))
(let ((entry-from (point-min-marker))
(entry-to (point-max-marker)))
(set-marker-insertion-type entry-from t)
(set-marker-insertion-type entry-to nil)
(widget-put child :entry-from entry-from)
(widget-put child :entry-to entry-to)))
- (widget-put insert :widget child)
- (widget-put delete :widget child)
+ (if insert (widget-put insert :widget child))
+ (if delete (widget-put delete :widget child))
child))
;;; The `group' Widget.
(define-widget 'group 'default
"A widget which groups other widgets inside."
:convert-widget 'widget-types-convert-widget
+ :copy 'widget-types-copy
:format "%v"
:value-create 'widget-group-value-create
- :value-delete 'widget-children-value-delete
:value-get 'widget-editable-list-value-get
:default-get 'widget-group-default-get
:validate 'widget-children-validate
"A documentation string."
:format "%v"
:action 'widget-documentation-string-action
- :value-delete 'widget-children-value-delete
:value-create 'widget-documentation-string-value-create)
(defun widget-documentation-string-value-create (widget)
(widget-create-child-and-convert
widget 'visibility
:help-echo "Show or hide rest of the documentation."
+ :on "Hide Rest"
:off "More"
:always-active t
:action 'widget-parent-action
:complete-function 'ispell-complete-word
:prompt-history 'widget-string-prompt-value-history)
+(eval-when-compile (defvar widget))
+
+(defun widget-string-complete ()
+ "Complete contents of string field.
+Completions are taken from the :completion-alist property of the
+widget. If that isn't a list, it's evalled and expected to yield a list."
+ (interactive)
+ (let* ((prefix (buffer-substring-no-properties (widget-field-start widget)
+ (point)))
+ (completion-ignore-case (widget-get widget :completion-ignore-case))
+ (alist (widget-get widget :completion-alist))
+ (_ (unless (listp alist)
+ (setq alist (eval alist))))
+ (completion (try-completion prefix alist)))
+ (cond ((eq completion t)
+ (when completion-ignore-case
+ ;; Replace field with completion in case its case is different.
+ (delete-region (widget-field-start widget)
+ (widget-field-end widget))
+ (insert-and-inherit (car (assoc-ignore-case prefix alist))))
+ (message "Only match"))
+ ((null completion)
+ (error "No match"))
+ ((not (eq t (compare-strings prefix nil nil completion nil nil
+ completion-ignore-case)))
+ (when completion-ignore-case
+ ;; Replace field with completion in case its case is different.
+ (delete-region (widget-field-start widget)
+ (widget-field-end widget))
+ (insert-and-inherit completion)))
+ (t
+ (message "Making completion list...")
+ (with-output-to-temp-buffer "*Completions*"
+ (display-completion-list
+ (all-completions prefix alist nil)))
+ (message "Making completion list...done")))))
+
(define-widget 'regexp 'string
"A regular expression."
:match 'widget-regexp-match
(lisp-complete-symbol 'boundp))
:tag "Variable")
-(defvar widget-coding-system-prompt-value-history nil
- "History of input to `widget-coding-system-prompt-value'.")
-
(define-widget 'coding-system 'symbol
"A MULE coding-system."
:format "%{%t%}: %v"
:tag "Coding system"
:base-only nil
- :prompt-history 'widget-coding-system-prompt-value-history
+ :prompt-history 'coding-system-value-history
:prompt-value 'widget-coding-system-prompt-value
:action 'widget-coding-system-action
:complete-function (lambda ()
:match-alternatives '(integerp))
(define-widget 'number 'restricted-sexp
- "A floating point number."
+ "A number (floating point or integer)."
:tag "Number"
:value 0.0
- :type-error "This field should contain a number"
+ :type-error "This field should contain a number (floating point or integer)"
:match-alternatives '(numberp))
+(define-widget 'float 'restricted-sexp
+ "A floating point number."
+ :tag "Floating point number"
+ :value 0.0
+ :type-error "This field should contain a floating point number"
+ :match-alternatives '(floatp))
+
(define-widget 'character 'editable-field
"A character."
:tag "Character"
(aref value 0)
value))
:match (lambda (widget value)
- (char-valid-p value)))
+ (characterp value)))
(define-widget 'list 'group
"A Lisp list."
:value-to-internal (lambda (widget value)
(list (car value) (cdr value)))
:value-to-external (lambda (widget value)
- (cons (nth 0 value) (nth 1 value))))
+ (apply 'cons value)))
(defun widget-cons-match (widget value)
(and (consp value)
(widget-group-match widget
(widget-apply widget :value-to-internal value))))
\f
+;;; The `lazy' Widget.
+;;
+;; Recursive datatypes.
+
+(define-widget 'lazy 'default
+ "Base widget for recursive datastructures.
+
+The `lazy' widget will, when instantiated, contain a single inferior
+widget, of the widget type specified by the :type parameter. The
+value of the `lazy' widget is the same as the value of the inferior
+widget. When deriving a new widget from the 'lazy' widget, the :type
+parameter is allowed to refer to the widget currently being defined,
+thus allowing recursive datastructures to be described.
+
+The :type parameter takes the same arguments as the defcustom
+parameter with the same name.
+
+Most composite widgets, i.e. widgets containing other widgets, does
+not allow recursion. That is, when you define a new widget type, none
+of the inferior widgets may be of the same type you are currently
+defining.
+
+In Lisp, however, it is custom to define datastructures in terms of
+themselves. A list, for example, is defined as either nil, or a cons
+cell whose cdr itself is a list. The obvious way to translate this
+into a widget type would be
+
+ (define-widget 'my-list 'choice
+ \"A list of sexps.\"
+ :tag \"Sexp list\"
+ :args '((const nil) (cons :value (nil) sexp my-list)))
+
+Here we attempt to define my-list as a choice of either the constant
+nil, or a cons-cell containing a sexp and my-lisp. This will not work
+because the `choice' widget does not allow recursion.
+
+Using the `lazy' widget you can overcome this problem, as in this
+example:
+
+ (define-widget 'sexp-list 'lazy
+ \"A list of sexps.\"
+ :tag \"Sexp list\"
+ :type '(choice (const nil) (cons :value (nil) sexp sexp-list)))"
+ :format "%{%t%}: %v"
+ ;; We don't convert :type because we want to allow recursive
+ ;; datastructures. This is slow, so we should not create speed
+ ;; critical widgets by deriving from this.
+ :convert-widget 'widget-value-convert-widget
+ :value-create 'widget-type-value-create
+ :value-get 'widget-child-value-get
+ :value-inline 'widget-child-value-inline
+ :default-get 'widget-type-default-get
+ :match 'widget-type-match
+ :validate 'widget-child-validate)
+
+\f
;;; The `plist' Widget.
;;
;; Property lists.
\f
;;; The `color' Widget.
-;; Fixme: match
+;; Fixme: match
(define-widget 'color 'editable-field
"Choose a color name (with sample)."
:format "%t: %v (%{sample%})\n"
(require 'facemenu) ; for facemenu-color-alist
(let* ((prefix (buffer-substring-no-properties (widget-field-start widget)
(point)))
- (list (or facemenu-color-alist
- (mapcar 'list (defined-colors))))
+ (list (or facemenu-color-alist (defined-colors)))
(completion (try-completion prefix list)))
(cond ((eq completion t)
(message "Exact match."))
(prompt (concat tag ": "))
(value (widget-value widget))
(start (widget-field-start widget))
- (pos (cond ((< (point) start)
- 0)
- ((> (point) (+ start (length value)))
- (length value))
- (t
- (- (point) start))))
(answer (facemenu-read-color prompt)))
(unless (zerop (length answer))
(widget-value-set widget answer)
(help-echo (and widget (widget-get widget :help-echo))))
(if (functionp help-echo)
(setq help-echo (funcall help-echo widget)))
- (if (stringp help-echo)
- (message "%s" help-echo))))
+ (if help-echo (message "%s" (eval help-echo)))))
;;; The End:
(provide 'wid-edit)
+;;; arch-tag: a076e75e-18a1-4b46-8be5-3f317bcbc707
;;; wid-edit.el ends here