;;; button.el --- clickable buttons
;;
;; Copyright (C) 2001, 2002, 2003, 2004, 2005,
-;; 2006 Free Software Foundation, Inc.
+;; 2006, 2007 Free Software Foundation, Inc.
;;
;; Author: Miles Bader <miles@gnu.org>
;; Keywords: extensions
;;
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
+;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.
;;
;; GNU Emacs is distributed in the hope that it will be useful,
;; Globals
;; 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"))
- (t :underline t))
+ (((supports :underline t)) :underline t)
+ (t (:foreground "lightblue")))
"Default face used for buttons."
:group 'basic-faces)
;; Prevent insertions adjacent to the text-property buttons from
;; inheriting its properties.
(put 'default-button 'rear-nonsticky t)
-;; Text property buttons don't have a `button' property of their own, so
-;; they inherit this.
-(put 'default-button 'button t)
;; A `category-symbol' property for the default button type
(put 'button 'button-category-symbol 'default-button)
(setcar (cdr type-entry)
(button-category-symbol (car (cdr type-entry))))))
;; Now add all the text properties at once
- (add-text-properties beg end properties)
+ (add-text-properties beg end
+ ;; Each button should have a non-eq `button'
+ ;; property so that next-single-property-change can
+ ;; detect boundaries reliably.
+ (cons 'button (cons (list t) properties)))
;; Return something that can be used to get at the button.
beg)
(next-button pos))))
(defun previous-button (pos &optional count-current)
- "Return the Nth button before position POS in the current buffer.
+ "Return the previous button before position POS in the current buffer.
If COUNT-CURRENT is non-nil, count any button at POS in the search,
instead of starting at the next button."
- (unless count-current
- (setq pos (previous-single-char-property-change pos 'button)))
- (and (> pos (point-min))
- (or (button-at (1- pos))
- ;; We must have originally been on a button, and are now in
- ;; the inter-button space. Recurse to find a button.
- (previous-button pos))))
+ (let ((button (button-at pos)))
+ (if button
+ (if count-current
+ button
+ ;; We started out on a button, so move to its start and look
+ ;; for the previous button boundary.
+ (setq pos (previous-single-char-property-change
+ (button-start button) 'button))
+ (let ((new-button (button-at pos)))
+ (if new-button
+ ;; We are in a button again; this can happen if there
+ ;; are adjacent buttons (or at bob).
+ (unless (= pos (button-start button)) new-button)
+ ;; We are now in the space between buttons.
+ (previous-button pos))))
+ ;; We started out in the space between buttons.
+ (setq pos (previous-single-char-property-change pos 'button))
+ (or (button-at pos)
+ (and (> pos (point-min))
+ (button-at (1- pos)))))))
\f
;; User commands
(provide 'button)
-;;; arch-tag: 5f2c7627-413b-4097-b282-630f89d9c5e9
+;; arch-tag: 5f2c7627-413b-4097-b282-630f89d9c5e9
;;; button.el ends here