;;; button.el --- clickable buttons
;;
-;; Copyright (C) 2001, 2002, 2003, 2004, 2005,
-;; 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+;; Copyright (C) 2001-2014 Free Software Foundation, Inc.
;;
;; Author: Miles Bader <miles@gnu.org>
;; Keywords: extensions
;; the button is represented by a marker or buffer-position pointing
;; somewhere in the button. In the latter case, no markers into the
;; buffer are retained, which is important for speed if there are are
-;; extremely large numbers of buttons.
+;; extremely large numbers of buttons. Note however that if there is
+;; an existing face text-property at the site of the button, the
+;; button face may not be visible. Using overlays avoids this.
;;
;; Using `define-button-type' to define default properties for buttons
-;; is not necessary, but it is is encouraged, since doing so makes the
+;; is not necessary, but it is encouraged, since doing so makes the
;; resulting code clearer and more efficient.
;;
;; Use color for the MS-DOS port because it doesn't support underline.
;; FIXME if MS-DOS correctly answers the (supports) question, it need
;; no longer be a special case.
-(defface button '((((type pc) (class color))
- (:foreground "lightblue"))
- (((supports :underline t)) :underline t)
- (t (:foreground "lightblue")))
+(defface button '((t :inherit link))
"Default face used for buttons."
:group 'basic-faces)
;; might get converted to ^M when building loaddefs.el
(define-key map [(control ?m)] 'push-button)
(define-key map [mouse-2] 'push-button)
+ ;; FIXME: You'd think that for keymaps coming from text-properties on the
+ ;; mode-line or header-line, the `mode-line' or `header-line' prefix
+ ;; shouldn't be necessary!
+ (define-key map [mode-line mouse-2] 'push-button)
+ (define-key map [header-line mouse-2] 'push-button)
map)
"Keymap used by buttons.")
(defun button-get (button prop)
"Get the property of button BUTTON named PROP."
- (if (overlayp button)
- (overlay-get button prop)
- ;; Must be a text-property button.
- (get-text-property button prop)))
+ (cond ((overlayp button)
+ (overlay-get button prop))
+ ((button--area-button-p button)
+ (get-text-property (cdr button)
+ prop (button--area-button-string button)))
+ (t ; Must be a text-property button.
+ (get-text-property button prop))))
(defun button-put (button prop val)
"Set BUTTON's PROP property to VAL."
;; Disallow updating the `category' property directly.
(error "Button `category' property may not be set directly")))
;; Add the property.
- (if (overlayp button)
- (overlay-put button prop val)
- ;; Must be a text-property button.
- (put-text-property
- (or (previous-single-property-change (1+ button) 'button)
- (point-min))
- (or (next-single-property-change button 'button)
- (point-max))
- prop val)))
-
-(defsubst button-activate (button &optional use-mouse-action)
+ (cond ((overlayp button)
+ (overlay-put button prop val))
+ ((button--area-button-p button)
+ (setq button (button--area-button-string button))
+ (put-text-property 0 (length button) prop val button))
+ (t ; Must be a text-property button.
+ (put-text-property
+ (or (previous-single-property-change (1+ button) 'button)
+ (point-min))
+ (or (next-single-property-change button 'button)
+ (point-max))
+ prop val))))
+
+(defun button-activate (button &optional use-mouse-action)
"Call BUTTON's action property.
If USE-MOUSE-ACTION is non-nil, invoke the button's mouse-action
instead of its normal action; if the button has no mouse-action,
-the normal action is used instead."
+the normal action is used instead.
+
+The action can either be a marker or a function. If it's a
+marker then goto it. Otherwise it it is a function then it is
+called with BUTTON as only argument. BUTTON is either an
+overlay, a buffer position, or (for buttons in the mode-line or
+header-line) a string."
(let ((action (or (and use-mouse-action (button-get button 'mouse-action))
(button-get button 'action))))
(if (markerp action)
(defun button-label (button)
"Return BUTTON's text label."
- (buffer-substring-no-properties (button-start button) (button-end button)))
+ (if (button--area-button-p button)
+ (substring-no-properties (button--area-button-string button))
+ (buffer-substring-no-properties (button-start button)
+ (button-end button))))
(defsubst button-type (button)
"Return BUTTON's 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))
+(defun button--area-button-p (b)
+ "Return non-nil if BUTTON is an area button.
+Such area buttons are used for buttons in the mode-line and header-line."
+ (stringp (car-safe b)))
+
+(defalias 'button--area-button-string #'car
+ "Return area button BUTTON's button-string.")
\f
;; Creating overlay buttons
`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
-large numbers of buttons can also be somewhat faster using
-`make-text-button'.
+part of the text instead of being a property of the buffer. That is,
+this function uses text properties, the other uses overlays.
+Creating large numbers of buttons can also be somewhat faster
+using `make-text-button'. Note, however, that if there is an existing
+face property at the site of the button, the button face may not be visible.
+You may want to use `make-button' in that case.
BEG can also be a string, in which case it is made into a button.
(cons 'button (cons (list t) properties))
object)
;; Return something that can be used to get at the button.
- beg))
+ (or object beg)))
(defun insert-text-button (label &rest properties)
"Insert a button with the label LABEL.
;; Finding buttons in a buffer
(defun button-at (pos)
- "Return the button at position POS in the current buffer, or nil."
+ "Return the button at position POS in the current buffer, or nil.
+If the button at POS is a text property button, the return value
+is a marker pointing to POS."
(let ((button (get-char-property pos 'button)))
(if (or (overlayp button) (null button))
button
USE-MOUSE-ACTION is non-nil, invoke the button's mouse-action
instead of its normal action; if the button has no mouse-action,
the normal action is used instead. The action may be either a
-function to call or a marker to display.
+function to call or a marker to display and is invoked using
+`button-activate' (which see).
+
POS defaults to point, except when `push-button' is invoked
interactively as the result of a mouse-event, in which case, the
mouse event is used.
;; POS is a mouse event; switch to the proper window/buffer
(let ((posn (event-start pos)))
(with-current-buffer (window-buffer (posn-window posn))
- (push-button (posn-point posn) t)))
+ (if (posn-string posn)
+ ;; mode-line, header-line, or display string event.
+ (button-activate (posn-string posn) t)
+ (push-button (posn-point posn)) t)))
;; POS is just normal position
(let ((button (button-at (or pos (point)))))
- (if (not button)
- nil
+ (when button
(button-activate button use-mouse-action)
t))))
(provide 'button)
-;; arch-tag: 5f2c7627-413b-4097-b282-630f89d9c5e9
;;; button.el ends here