(mouse-drag-vertical-line): Handle left-side scroll bars.

diff --git a/lisp/mouse.el b/lisp/mouse.el
index d760c437bf74f1da6d72d6894b26a9ae8d252260..6f4a60a86ec8175e82943f6995fdab20567352f7 100644 (file)
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -306,12 +306,18 @@ This command must be bound to a mouse click."
        (start-event-window (car (car (cdr start-event))))
        (start-nwindows (count-windows t))
        (old-selected-window (selected-window))
-       event mouse x left right edges wconfig growth)
+       event mouse x left right edges wconfig growth
+       (which-side
+        (or (cdr (assq 'vertical-scroll-bars default-frame-alist))
+            'left)))
     (if (one-window-p t)
        (error "Attempt to resize sole ordinary window"))
-    (if (= (nth 2 (window-edges start-event-window))
-          (frame-width start-event-frame))
-       (error "Attempt to drag rightmost scrollbar"))
+    (if (eq which-side 'left)
+       (if (= (nth 0 (window-edges start-event-window)) 0)
+           (error "Attempt to drag leftmost scrollbar"))
+      (if (= (nth 2 (window-edges start-event-window))
+            (frame-width start-event-frame))
+         (error "Attempt to drag rightmost scrollbar")))
     (track-mouse
       (progn
        ;; enlarge-window only works on the selected window, so
@@ -349,28 +355,34 @@ This command must be bound to a mouse click."
                ((null (car (cdr mouse)))
                 nil)
                (t
-                (setq x (car (cdr mouse))
-                      edges (window-edges)
-                      left (nth 0 edges)
-                      right (nth 2 edges))
-                ;; scale back a move that would make the
-                ;; window too thin.
-                (cond ((< (- x left -1) window-min-width)
-                       (setq x (+ left window-min-width -1))))
-                ;; compute size change needed
-                (setq growth (- x right -1)
-                      wconfig (current-window-configuration))
-                (enlarge-window growth t)
-                ;; if this window's growth caused another
-                ;; window to be deleted because it was too
-                ;; thin, rescind the change.
-                ;;
-                ;; if size change caused space to be stolen
-                ;; from a window to the left of this one,
-                ;; rescind the change.
-                (if (or (/= start-nwindows (count-windows t))
-                        (/= left (nth 0 (window-edges))))
-                    (set-window-configuration wconfig)))))))))
+                (save-selected-window
+                  ;; If the scroll bar is on the window's left,
+                  ;; adjust the window on the left.
+                  (if (eq which-side 'left)
+                      (select-window (previous-window)))
+                  (setq x (- (car (cdr mouse))
+                             (if (eq which-side 'left) 2 0))
+                        edges (window-edges)
+                        left (nth 0 edges)
+                        right (nth 2 edges))
+                  ;; scale back a move that would make the
+                  ;; window too thin.
+                  (if (< (- x left -1) window-min-width)
+                      (setq x (+ left window-min-width -1)))
+                  ;; compute size change needed
+                  (setq growth (- x right -1)
+                        wconfig (current-window-configuration))
+                  (enlarge-window growth t)
+                  ;; if this window's growth caused another
+                  ;; window to be deleted because it was too
+                  ;; thin, rescind the change.
+                  ;;
+                  ;; if size change caused space to be stolen
+                  ;; from a window to the left of this one,
+                  ;; rescind the change.
+                  (if (or (/= start-nwindows (count-windows t))
+                          (/= left (nth 0 (window-edges))))
+                      (set-window-configuration wconfig))))))))))
 \f
 (defun mouse-set-point (event)
   "Move point to the position clicked on with the mouse.