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Add examples to the Widget manual

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* doc/misc/widget.texi (Widget Gallery, Defining New Widgets): Add
examples.  (Bug#66229)
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Mauro Aranda 2023-09-22 20:45:00 -03:00 committed by Stefan Kangas
parent 1bbb610821
commit 4fadbfe300
1 changed files with 206 additions and 0 deletions
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doc/misc/widget.texi
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@ -1384,6 +1384,15 @@ a specific way. If present, @var{value} is used to initialize the
@code{:value} property. When created, it inserts the value as a
string in the buffer.
@noindent
Example:
@lisp
(widget-create 'item :tag "Today is" :format "%t: %v\n"
(format-time-string "%d-%m-%Y"))
@end lisp
By default, it has the following properties:
@table @code
@ -1428,6 +1437,20 @@ The @var{value}, if present, is used to initialize the @code{:value}
property. The value should be a string, which will be inserted in the
buffer.
@noindent
Example:
@lisp
(widget-create 'link
:button-prefix ""
:button-suffix ""
:tag "Mail yourself"
:action #'(lambda (widget &optional _event)
(compose-mail-other-window (widget-value widget)))
user-mail-address)
@end lisp
By default, it has the following properties:
@table @code
@ -1471,6 +1494,29 @@ A widget to represent a link to a web page. Its super is the
It overrides the @code{:action} property to open up the @var{url}
specified.
@noindent
Example:
@lisp
(widget-create 'url-link
:button-prefix ""
:button-suffix ""
;; Return appropriate face.
:button-face-get (lambda (widget)
(if (widget-get widget :visited)
'link-visited
'link))
:format "%[%t%]"
:tag "Browse this manual"
:action (lambda (widget &optional _event)
(widget-put widget :visited t)
;; Takes care of redrawing the widget.
(widget-value-set widget (widget-value widget))
;; And then call the original function.
(widget-url-link-action widget))
"https://www.gnu.org/software/emacs/manual/html_mono/widget.html")
@end lisp
@node info-link
@subsection The @code{info-link} Widget
@findex info-link@r{ widget}
@ -1487,6 +1533,17 @@ A widget to represent a link to an info file. Its super is the
It overrides the @code{:action} property, to a function to start the
built-in Info reader on @var{address}, when invoked.
@noindent
Example:
@lisp
(widget-create 'info-link
:button-prefix ""
:button-suffix ""
:tag "Browse this manual"
"(widget) info-link")))
@end lisp
@node function-link
@subsection The @code{function-link} Widget
@findex function-link@r{ widget}
@ -1502,6 +1559,17 @@ A widget to represent a link to an Emacs function. Its super is the
It overrides the @code{:action} property, to a function to describe
@var{function}.
@noindent
Example:
@lisp
(widget-create 'function-link
:button-prefix ""
:button-suffix ""
:tag "Describe the function that gets called"
#'widget-function-link-action)
@end lisp
@node variable-link
@subsection The @code{variable-link} Widget
@findex variable-link@r{ widget}
@ -1517,6 +1585,17 @@ A widget to represent a link to an Emacs variable. Its super is the
It overrides the @code{:action} property, to a function to describe
@var{var}.
@noindent
Example:
@lisp
(widget-create 'variable-link
:button-prefix ""
:button-suffix ""
:tag "What setting controlls button-prefix?"
'widget-button-prefix)
@end lisp
@node face-link
@subsection The @code{face-link} Widget
@findex face-link@r{ widget}
@ -1532,6 +1611,17 @@ A widget to represent a link to an Emacs face. Its super is the
It overrides the @code{:action} property, to a function to describe
@var{face}.
@noindent
Example:
@lisp
(widget-create 'face-link
:button-prefix ""
:button-suffix ""
:tag "Which face is this one?"
'widget-button)
@end lisp
@node file-link
@subsection The @code{file-link} Widget
@findex file-link@r{ widget}
@ -1547,6 +1637,19 @@ A widget to represent a link to a file. Its super is the
It overrides the @code{:action} property, to a function to find the file
@var{file}.
@noindent
Example:
@lisp
(let ((elisp-files (directory-files user-emacs-directory t ".el$")))
(dolist (file elisp-files)
(widget-create 'file-link
:button-prefix ""
:button-suffix ""
file)
(widget-insert "\n")))
@end lisp
@node emacs-library-link
@subsection The @code{emacs-library-link} Widget
@findex emacs-library-link@r{ widget}
@ -1562,6 +1665,17 @@ A widget to represent a link to an Emacs Lisp file. Its super is the
It overrides the @code{:action} property, to a function to find the file
@var{file}.
@noindent
Example:
@lisp
(widget-create 'emacs-library-link
:button-prefix ""
:button-suffix ""
:tag "Show yourself, Widget Library!"
"wid-edit.el")
@end lisp
@node emacs-commentary-link
@subsection The @code{emacs-commentary-link} Widget
@findex emacs-commentary-link@r{ widget}
@ -1577,6 +1691,17 @@ file. Its super is the @code{link} widget.
It overrides the @code{:action} property, to a function to find the file
@var{file} and put point in the Comment section.
@noindent
Example:
@lisp
(widget-create 'emacs-commentary-link
:button-prefix ""
:button-suffix ""
:tag "Check our good friend Customize"
"cus-edit.el")
@end lisp
@node push-button
@subsection The @code{push-button} Widget
@findex push-button@r{ widget}
@ -2009,6 +2134,29 @@ A widget that can toggle between two states. Its super is the
The widget has two possible states, @samp{on} and @samp{off}, which
correspond to a @code{t} or @code{nil} value, respectively.
@noindent
Example:
@lisp
(widget-insert "Press the button to activate/deactivate the field: ")
(widget-create 'toggle
:notify (lambda (widget &rest _ignored)
(widget-apply widget-example-field
(if (widget-value widget)
:activate
:deactivate))))
(widget-insert "\n")
(setq widget-example-field
(widget-create 'editable-field
:deactivate (lambda (widget)
(widget-specify-inactive
widget
(widget-field-start widget)
(widget-get widget :to)))))
(widget-apply widget-example-field :deactivate)))
@end lisp
It either overrides or adds the following properties:
@table @code
@ -2148,6 +2296,21 @@ The @var{type} arguments represent each checklist item. The widget's
value will be a list containing the values of all checked @var{type}
arguments.
@noindent
Example:
@lisp
(widget-create 'checklist
:notify (lambda (widget child &optional _event)
(funcall
(widget-value (widget-get-sibling child))
'toggle))
:value (list 'tool-bar-mode 'menu-bar-mode)
'(item :tag "Tool-bar" tool-bar-mode)
'(item :tag "Menu-bar" menu-bar-mode))))
@end lisp
It either overrides or adds the following properties:
@table @code
@ -2899,6 +3062,49 @@ The predefined functions @code{widget-types-convert-widget} and
@code{widget-value-convert-widget} can be used here.
@end table
@noindent
Example:
@lisp
(defvar widget-ranged-integer-map
(let ((map (copy-keymap widget-keymap)))
(define-key map [up] #'widget-ranged-integer-increase)
(define-key map [down] #'widget-ranged-integer-decrease)
map))
(define-widget 'ranged-integer 'integer
"A ranged integer widget."
:min-value most-negative-fixnum
:max-value most-positive-fixnum
:keymap widget-ranged-integer-map)
(defun widget-ranged-integer-change (widget how)
"Change the value of the ranged-integer WIDGET, according to HOW."
(let* ((value (widget-value widget))
(newval (cond
((eq how 'up)
(if (< (1+ value) (widget-get widget :max-value))
(1+ value)
(widget-get widget :max-value)))
((eq how 'down)
(if (> (1- value) (widget-get widget :min-value))
(1- value)
(widget-get widget :min-value)))
(t (error "HOW has a bad value"))))
(inhibit-read-only t))
(widget-value-set widget newval)))
(defun widget-ranged-integer-increase (widget)
"Increase the value of the ranged-integer WIDGET."
(interactive (list (widget-at)))
(widget-ranged-integer-change widget 'up))
(defun widget-ranged-integer-decrease (widget)
"Decrease the value of the ranged-integer WIDGET."
(interactive (list (widget-at)))
(widget-ranged-integer-change widget 'down))
@end lisp
@node Inspecting Widgets
@chapter Inspecting Widgets
@cindex widget browser