(next-button, previous-button): Remove N and WRAP parameters.

Don't pay attention to `skip' properties.
(forward-button): Implement wrapping, iterating, and skipping here instead.

1 files changed, 37 insertions, 59 deletions

diff --git a/lisp/button.el b/lisp/button.el
index ed2ea106366..f1ce1fff413 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -303,72 +303,30 @@ Also see `make-text-button'."
       ;; Must be a text-property button; return a marker pointing to it.
       (copy-marker pos t))))
 
-(defun next-button (pos &optional n wrap count-current)
-  "Return the Nth button after position POS in the current buffer.
-If N is negative, return the Nth button before POS.
-If no Nth button is found, return nil.
-If WRAP is non-nil, the search wraps around at the end of the buffer.
+(defun next-button (pos &optional count-current)
+  "Return the next button after 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."
-  (when (null n)
-    (setq n 1))
-  (if (< n 0)
-      ;; reverse direction
-      (previous-button pos (- n) wrap)
+instead of starting at the next button."
     (unless count-current
       ;; Search for the next button boundary.
       (setq pos (next-single-char-property-change pos 'button)))
-    (let ((button (button-at pos)))
-      (cond ((and button (button-get button 'skip))
-             ;; Found a button, but the button declines to be found; recurse.
-             (next-button (button-start button) n wrap))
-            ((and button (>= n 2))
-             ;; Found a button, but we want a different one; recurse.
-             (next-button (button-start button) (1- n) wrap))
-            (button
-             ;; This is the button we want.
-             button)
-            ((= pos (point-max))
-             ;; Failed to find a button going forwards, either wrap or
-             ;; return failure.
-             (and wrap (next-button (point-min) n nil t)))
-            (t
+    (and (< pos (point-max))
+         (or (button-at pos)
              ;; We must have originally been on a button, and are now in
              ;; the inter-button space.  Recurse to find a button.
-             (next-button pos n wrap))))))
+             (next-button pos))))
 
-(defun previous-button (pos &optional n wrap count-current)
+(defun previous-button (pos &optional count-current)
   "Return the Nth button before position POS in the current buffer.
-If N is negative, return the Nth button after POS.
-If no Nth button is found, return nil.
-If WRAP is non-nil, the search wraps around at the beginning of the buffer.
 If COUNT-CURRENT is non-nil, count any button at POS in the search,
- instead of starting at the next button."
-  (when (null n)
-    (setq n 1))
-  (if (< n 0)
-      ;; reverse direction
-      (next-button pos (- n) wrap)
-    (unless count-current
-      (setq pos (previous-single-char-property-change pos 'button)))
-    (let ((button (and (> pos (point-min)) (button-at (1- pos)))))
-      (cond ((and button (button-get button 'skip))
-             ;; Found a button, but the button declines to be found; recurse.
-             (previous-button (button-start button) n wrap))
-            ((and button (>= n 2))
-             ;; Found a button, but we want a different one; recurse.
-             (previous-button (button-start button) (1- n) wrap))
-            (button
-             ;; This is the button we want.
-             button)
-            ((= pos (point-min))
-             ;; Failed to find a button going backwards, either wrap
-             ;; or return failure.
-             (and wrap (previous-button (point-max) n nil t)))
-            (t
-             ;; We must have originally been on a button, and are now in
-             ;; the inter-button space.  Recurse to find a button.
-             (previous-button pos (max n 1) wrap))))))
+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))))
 
 
 ;; User commands
@@ -400,15 +358,33 @@ return t."
 
 (defun forward-button (n &optional wrap display-message)
   "Move to the Nth next button, or Nth previous button if N is negative.
+If N is 0, move to the start of any button at point.
 If WRAP is non-nil, moving past either end of the buffer continues from the
 other end.
 If DISPLAY-MESSAGE is non-nil, the button's help-echo string is displayed.
+Any button with a non-nil `skip' property is skipped over.
 Returns the button found."
   (interactive "p\nd\nd")
-  (let ((button (next-button (point) n wrap)))
+  (let (button)
+    (if (zerop n)
+        ;; Move to start of current button
+        (if (setq button (button-at (point)))
+            (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))))
+        (setq n (abs n))
+        (setq button t)                 ; just to start the loop
+        (while (and (> 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))
+            (unless (button-get button 'skip)
+              (setq n (1- n)))))))
     (if (null button)
         (error (if wrap "No buttons!" "No more buttons"))
-      (goto-char (button-start button))
       (let ((msg (and display-message (button-get button 'help-echo))))
         (when msg
           (message "%s" msg)))
@@ -416,9 +392,11 @@ Returns the button found."
 
 (defun backward-button (n &optional wrap display-message)
   "Move to the Nth previous button, or Nth next button if N is negative.
+If N is 0, move to the start of any button at point.
 If WRAP is non-nil, moving past either end of the buffer continues from the
 other end.
 If DISPLAY-MESSAGE is non-nil, the button's help-echo string is displayed.
+Any button with a non-nil `skip' property is skipped over.
 Returns the button found."
   (interactive "p\nd\nd")
   (forward-button (- n) wrap display-message))