Fix typos.

[bpt/emacs.git] / lisp / button.el

diff --git a/lisp/button.el b/lisp/button.el
index 1be68ac..262a19c 100644 (file)
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -1,10 +1,10 @@
 ;;; button.el --- clickable buttons
 ;;
-;; Copyright (C) 2001, 2002, 2003, 2004, 2005,
-;;   2006, 2007, 2008 Free Software Foundation, Inc.
+;; Copyright (C) 2001-2011  Free Software Foundation, Inc.
 ;;
 ;; Author: Miles Bader <miles@gnu.org>
 ;; Keywords: extensions
+;; Package: emacs
 ;;
 ;; This file is part of GNU Emacs.
 ;;
@@ -37,10 +37,12 @@
 ;; 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.
 ;;
 
@@ -52,10 +54,7 @@
 ;; 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)
 
@@ -84,7 +83,7 @@ Mode-specific keymaps may want to use this as their parent keymap.")
 (put 'default-button 'type 'button)
 ;; action may be either a function to call, or a marker to go to
 (put 'default-button 'action 'ignore)
-(put 'default-button 'help-echo "mouse-2, RET: Push this button")
+(put 'default-button 'help-echo (purecopy "mouse-2, RET: Push this button"))
 ;; Make overlay buttons go away if their underlying text is deleted.
 (put 'default-button 'evaporate t)
 ;; Prevent insertions adjacent to the text-property buttons from
@@ -289,14 +288,22 @@ 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
-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.
 
 Also see `insert-text-button'."
-  (let ((type-entry
+  (let ((object nil)
+        (type-entry
         (or (plist-member properties 'type)
             (plist-member properties :type))))
+    (when (stringp beg)
+      (setq object beg beg 0 end (length object)))
     ;; Disallow setting the `category' property directly.
     (when (plist-get properties 'category)
       (error "Button `category' property may not be set directly"))
@@ -308,15 +315,16 @@ Also see `insert-text-button'."
       ;; text-properties for inheritance.
       (setcar type-entry 'category)
       (setcar (cdr type-entry)
-             (button-category-symbol (car (cdr type-entry))))))
-  ;; Now add all the text properties at once
-  (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)
+             (button-category-symbol (car (cdr type-entry)))))
+    ;; Now add all the text properties at once
+    (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))
+                         object)
+    ;; Return something that can be used to get at the button.
+    beg))
 
 (defun insert-text-button (label &rest properties)
   "Insert a button with the label LABEL.
@@ -431,15 +439,22 @@ Returns the button found."
            (goto-char (button-start button)))
       ;; Move to Nth next button
       (let ((iterator (if (> n 0) #'next-button #'previous-button))
-           (wrap-start (if (> n 0) (point-min) (point-max))))
+           (wrap-start (if (> n 0) (point-min) (point-max)))
+           opoint fail)
        (setq n (abs n))
        (setq button t)                 ; just to start the loop
-       (while (and (> n 0) button)
+       (while (and (null fail) (> n 0) button)
          (setq button (funcall iterator (point)))
          (when (and (not button) wrap)
            (setq button (funcall iterator wrap-start t)))
          (when button
            (goto-char (button-start button))
+           ;; Avoid looping forever (e.g., if all the buttons have
+           ;; the `skip' property).
+           (cond ((null opoint)
+                  (setq opoint (point)))
+                 ((= opoint (point))
+                  (setq fail t)))
            (unless (button-get button 'skip)
              (setq n (1- n)))))))
     (if (null button)
@@ -463,5 +478,4 @@ Returns the button found."
 
 (provide 'button)
 
-;; arch-tag: 5f2c7627-413b-4097-b282-630f89d9c5e9
 ;;; button.el ends here