-;;; button.el --- Clickable buttons
+;;; button.el --- clickable buttons
;;
;; Copyright (C) 2001 Free Software Foundation, Inc.
;;
\f
;; Globals
-(defface button '((t :underline t))
+(defface button '((((type pc) (class color))
+ (:foreground "lightblue"))
+ (t :underline t))
"Default face used for buttons.")
;;;###autoload
(put 'default-button 'mouse-face 'highlight)
(put 'default-button 'keymap button-map)
(put 'default-button 'type 'button)
-(put 'default-button 'action 'button-nop)
+(put 'default-button 'action 'ignore)
(put 'default-button 'help-echo "mouse-2, RET: Push this button")
;; Make overlay buttons go away if their underlying text is deleted.
(put 'default-button 'evaporate t)
;; they inherit this.
(put 'default-button 'button t)
-;; This is the default button action.
-(defun button-nop (button)
- "Do nothing to BUTTON."
- nil)
+;; A `category-symbol' property for the default button type
+(put 'button 'button-category-symbol 'default-button)
\f
;; Button types (which can be used to hold default properties for buttons)
+;; Because button-type properties are inherited by buttons using the
+;; special `category' property (implemented by both overlays and
+;; text-properties), we need to store them on a symbol to which the
+;; `category' properties can point. Instead of using the symbol that's
+;; the name of each button-type, however, we use a separate symbol (with
+;; `-button' appended, and uninterned) to store the properties. This is
+;; to avoid name clashes.
+
+;; [this is an internal function]
+(defsubst button-category-symbol (type)
+ "Return the symbol used by button-type TYPE to store properties.
+Buttons inherit them by setting their `category' property to that symbol."
+ (or (get type 'button-category-symbol)
+ (error "Unknown button type `%s'" type)))
+
;;;###autoload
(defun define-button-type (name &rest properties)
"Define a `button type' called NAME.
The remaining arguments form a sequence of PROPERTY VALUE pairs,
specifying properties to use as defaults for buttons with this type
\(a button's type may be set by giving it a `type' property when
-creating the button)."
- ;; We use a different symbol than NAME (with `-button' appended, and
- ;; uninterned) to store the properties. This is to avoid name
- ;; clashes, since many very general properties may be include in
- ;; PROPERTIES.
- (let ((catsym (make-symbol (concat (symbol-name name) "-button"))))
+creating the button, using the :type keyword argument).
+
+In addition, the keyword argument :supertype may be used to specify a
+button-type from which NAME inherits its default property values
+\(however, the inheritance happens only when NAME is defined; subsequent
+changes to a supertype are not reflected in its subtypes)."
+ (let ((catsym (make-symbol (concat (symbol-name name) "-button")))
+ (super-catsym
+ (button-category-symbol
+ (or (plist-get properties 'supertype)
+ (plist-get properties :supertype)
+ 'button))))
;; Provide a link so that it's easy to find the real symbol.
(put name 'button-category-symbol catsym)
;; Initialize NAME's properties using the global defaults.
- (let ((default-props (symbol-plist 'default-button)))
+ (let ((default-props (symbol-plist super-catsym)))
(while default-props
(put catsym (pop default-props) (pop default-props))))
;; Add NAME as the `type' property, which will then be returned as
(put catsym 'type name)
;; Add the properties in PROPERTIES to the real symbol.
(while properties
- (put catsym (pop properties) (pop properties)))
+ (let ((prop (pop properties)))
+ (when (eq prop :supertype)
+ (setq prop 'supertype))
+ (put catsym prop (pop properties))))
+ ;; Make sure there's a `supertype' property
+ (unless (get catsym 'supertype)
+ (put catsym 'supertype 'button))
name))
-;; [this is an internal function]
-(defsubst button-category-symbol (type)
- "Return the symbol used by button-type TYPE to store properties.
-Buttons inherit them by setting their `category' property to that symbol."
- (or (get type 'button-category-symbol)
- (error "Unknown button type `%s'" type)))
-
(defun button-type-put (type prop val)
"Set the button-type TYPE's PROP property to VAL."
(put (button-category-symbol type) prop val))
"Get the property of button-type TYPE named PROP."
(get (button-category-symbol type) prop))
+(defun button-type-subtype-p (type supertype)
+ "Return t if button-type TYPE is a subtype of SUPERTYPE."
+ (or (eq type supertype)
+ (and type
+ (button-type-subtype-p (button-type-get type 'supertype)
+ supertype))))
+
\f
;; Button properties and other attributes
(defun button-put (button prop val)
"Set BUTTON's PROP property to VAL."
;; Treat some properties specially.
- (cond ((eq prop 'type)
+ (cond ((memq prop '(type :type))
;; We translate a `type' property a `category' property, since
;; that's what's actually used by overlays/text-properties for
;; inheriting properties.
"Return BUTTON's text label."
(buffer-substring-no-properties (button-start button) (button-end button)))
+(defsubst button-type (button)
+ "Return BUTTON's button-type."
+ (button-get button 'type))
+
+(defun button-has-type-p (button type)
+ "Return t if BUTTON has button-type TYPE, or one of TYPE's subtypes."
+ (button-type-subtype-p (button-get button 'type) type))
+
\f
;; Creating overlay buttons
(defun make-button (beg end &rest properties)
"Make a button from BEG to END in the current buffer.
The remaining arguments form a sequence of PROPERTY VALUE pairs,
-specifying properties to add to the button. In particular, the `type'
-property may be used to specify a button-type from which to inherit
-other properties; see `define-button-type'.
+specifying properties to add to the button.
+In addition, the keyword argument :type may be used to specify a
+button-type from which to inherit other properties; see
+`define-button-type'.
Also see `make-text-button', `insert-button'."
(let ((overlay (make-overlay beg end nil t nil)))
(defun insert-button (label &rest properties)
"Insert a button with the label LABEL.
The remaining arguments form a sequence of PROPERTY VALUE pairs,
-specifying properties to add to the button. In particular, the `type'
-property may be used to specify a button-type from which to inherit
-other properties; see `define-button-type'.
+specifying properties to add to the button.
+In addition, the keyword argument :type may be used to specify a
+button-type from which to inherit other properties; see
+`define-button-type'.
Also see `insert-text-button', `make-button'."
(apply #'make-button
(defun make-text-button (beg end &rest properties)
"Make a button from BEG to END in the current buffer.
The remaining arguments form a sequence of PROPERTY VALUE pairs,
-specifying properties to add to the button. In particular, the `type'
-property may be used to specify a button-type from which to inherit
-other properties; see `define-button-type'.
+specifying properties to add to the button.
+In addition, the keyword argument :type may be used to specify a
+button-type from which to inherit other properties; see
+`define-button-type'.
This function is like `make-button', except that the button is actually
part of the text instead of being a property of the buffer. Creating
;; Note that all the following code is basically equivalent to
;; `button-put', but we can do it much more efficiently since we
;; already have BEG and END.
- (cond ((eq prop 'type)
+ (cond ((memq prop '(type :type))
;; We translate a `type' property into a `category'
;; property, since that's what's actually used by
;; text-properties for inheritance.
(defun insert-text-button (label &rest properties)
"Insert a button with the label LABEL.
The remaining arguments form a sequence of PROPERTY VALUE pairs,
-specifying properties to add to the button. In particular, the `type'
-property may be used to specify a button-type from which to inherit
-other properties; see `define-button-type'.
+specifying properties to add to the button.
+In addition, the keyword argument :type may be used to specify a
+button-type from which to inherit other properties; see
+`define-button-type'.
This function is like `insert-button', except that the button is
actually part of the text instead of being a property of the buffer.
HCoop / bpt / emacs.git / blobdiff