Support horizontal scrolling of bidirectional text.

 lisp/scroll-bar.el (scroll-bar-toolkit-horizontal-scroll): Add
 rudimentary support for bidirectional text.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 3f97396ca0258aa1a53f80a4f411fe2ded4933e4..dd87a6100575fb6c6b0931102a483f15e943b8f3 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-07-27  Eli Zaretskii  <eliz@gnu.org>
+
+       * scroll-bar.el (scroll-bar-toolkit-horizontal-scroll): Add
+       rudimentary support for bidirectional text.
+
 2014-07-27  Martin Rudalics  <rudalics@gmx.at>
 
        * frame.el (frame-notice-user-settings): Rewrite using

diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 09f30d5d3f0643e26a9ca8ef7ac75a3475c2ec8a..739670cb1c93437acaf193562f828aa3317799de 100644 (file)
--- a/lisp/scroll-bar.el
+++ b/lisp/scroll-bar.el
@@ -451,6 +451,9 @@ EVENT should be a scroll bar click."
   (let* ((end-position (event-end event))
         (window (nth 0 end-position))
         (part (nth 4 end-position))
+        (bidi-factor (if (eq (current-bidi-paragraph-direction) 'left-to-right)
+                         1
+                       -1))
         before-scroll)
     (cond
      ((eq part 'end-scroll))
@@ -462,27 +465,32 @@ EVENT should be a scroll bar click."
        (setq before-scroll (or before-scroll (point)))
        (cond
         ((eq part 'before-handle)
-         (scroll-right 4))
+         (scroll-right (* bidi-factor 4)))
         ((eq part 'after-handle)
-         (scroll-left 4))
+         (scroll-left (* bidi-factor 4)))
         ((eq part 'ratio)
          (let* ((portion-whole (nth 2 end-position))
                 (columns (scroll-bar-scale portion-whole
                                            (1- (window-width)))))
            (scroll-right
-            (cond
-             ((not (zerop columns))
-              columns)
-             ((< (car portion-whole) 0) -1)
-             (t 1)))))
+            (* (cond
+                ((not (zerop columns))
+                 columns)
+                ((< (car portion-whole) 0) -1)
+                (t 1))
+               bidi-factor))))
         ((eq part 'left)
-         (scroll-right 1))
+         (scroll-right (* bidi-factor 1)))
         ((eq part 'right)
-         (scroll-left 1))
+         (scroll-left (* bidi-factor 1)))
         ((eq part 'leftmost)
-         (goto-char (line-beginning-position)))
+         (goto-char (if (eq bidi-factor 1)
+                        (line-beginning-position)
+                      (line-end-position))))
         ((eq part 'rightmost)
-         (goto-char (line-end-position)))
+         (goto-char (if (eq bidi-factor 1)
+                        (line-end-position)
+                      (line-beginning-position))))
         ((eq part 'horizontal-handle)
          (scroll-bar-horizontal-drag-1 event))))
       (sit-for 0)