fix horizontal scroll

[Yuriy Pitometsu]

Do it in the window under cursor, not in the currently active window.

[Yuriy Pitometsu]

Take (window-buffer curwin) and edge cases from mwheel-scroll to hscroll-{left,right}.

;; workaround for smooth horizontal scrolling
;; TODO: C-u prefix
(defun hscroll-left ()
  "Scroll left one step."
  (interactive)
  (let ((step
         (if (zerop hscroll-step)
             nil
           hscroll-step)))
    (scroll-left step t)))

(defun hscroll-right ()
  "Scroll right one step."
  (interactive)
  (let ((step
         (if (zerop hscroll-step)
             nil
           hscroll-step)))
    (scroll-right step t)))

(defun mwheel-scroll (event)
  "Scroll up or down according to the EVENT.
This should be bound only to mouse buttons 4 and 5 on non-Windows
systems."
  (interactive (list last-input-event))
  (let* ((curwin (if mouse-wheel-follow-mouse
                     (prog1
                         (selected-window)
                       (select-window (mwheel-event-window event)))))
     (buffer (window-buffer curwin))
     (opoint (with-current-buffer buffer
           (when (eq (car-safe transient-mark-mode) 'only)
             (point))))
         (mods
      (delq 'click (delq 'double (delq 'triple (event-modifiers event)))))
         (amt (assoc mods mouse-wheel-scroll-amount)))
    ;; Extract the actual amount or find the element that has no modifiers.
    (if amt (setq amt (cdr amt))
      (let ((list-elt mouse-wheel-scroll-amount))
    (while (consp (setq amt (pop list-elt))))))
    (if (floatp amt) (setq amt (1+ (truncate (* amt (window-height))))))
    (when (and mouse-wheel-progressive-speed (numberp amt))
      ;; When the double-mouse-N comes in, a mouse-N has been executed already,
      ;; So by adding things up we get a squaring up (1, 3, 6, 10, 15, ...).
      (setq amt (* amt (event-click-count event))))
    (unwind-protect
    (let ((button (mwheel-event-button event)))
      (cond ((eq button mouse-wheel-down-event)
                 (condition-case nil (funcall mwheel-scroll-down-function amt)
                   ;; Make sure we do indeed scroll to the beginning of
                   ;; the buffer.
                   (beginning-of-buffer
                    (unwind-protect
                        (funcall mwheel-scroll-down-function)
                      ;; If the first scroll succeeded, then some scrolling
                      ;; is possible: keep scrolling til the beginning but
                      ;; do not signal an error.  For some reason, we have
                      ;; to do it even if the first scroll signaled an
                      ;; error, because otherwise the window is recentered
                      ;; for a reason that escapes me.  This problem seems
                      ;; to only affect scroll-down.  --Stef
                      (set-window-start (selected-window) (point-min))))))
        ((eq button mouse-wheel-up-event)
                 (condition-case nil (funcall mwheel-scroll-up-function amt)
                   ;; Make sure we do indeed scroll to the end of the buffer.
                   (end-of-buffer (while t (funcall mwheel-scroll-up-function)))))
        (t (error "Bad binding in mwheel-scroll"))))
      (if curwin (select-window curwin)))
    ;; If there is a temporarily active region, deactivate it if
    ;; scrolling moves point.
    (when opoint
      (with-current-buffer buffer
    (when (/= opoint (point))
      ;; Call `deactivate-mark' at the original position, so that
      ;; the original region is saved to the X selection.
      (let ((newpoint (point)))
        (goto-char opoint)
        (deactivate-mark)
        (goto-char newpoint))))))
  (when (and mouse-wheel-click-event mouse-wheel-inhibit-click-time)
    (if mwheel-inhibit-click-event-timer
    (cancel-timer mwheel-inhibit-click-event-timer)
      (add-hook 'pre-command-hook 'mwheel-filter-click-events))
    (setq mwheel-inhibit-click-event-timer
      (run-with-timer mouse-wheel-inhibit-click-time nil
              'mwheel-inhibit-click-timeout))))

[Yuriy Pitometsu]

UPD: C-u and NOT switch to scrolled window.

(defun horizontal-scroll-left ()
  "Scroll left one step."
  (let ((step
         (if (zerop hscroll-step)
             nil
           hscroll-step)))
    (scroll-left step t)))

(defun hscroll-left ()
  "Scroll left one step."
  (interactive)
  (horizontal-scroll-left))


(defun horizontal-mscroll-left (event)
  "Scroll left one step according to the EVENT."
  (interactive (list last-input-event))
  (with-current-buffer (window-buffer
                        (if mouse-wheel-follow-mouse
                            (prog1
                                (selected-window)
                              (select-window (mwheel-event-window event)))))
    (horizontal-scroll-left)))

(defun horizontal-scroll-right ()
  "Scroll right one step."
  (let ((step
         (if (zerop hscroll-step)
             nil
           hscroll-step)))
    (scroll-right step t)))

(defun hscroll-right ()
  "Scroll right one step."
  (interactive)
  (horizontal-scroll-right))

(defun horizontal-mscroll-right (event)
  "Scroll right one step according to the EVENT."
  (interactive (list last-input-event))
  (with-current-buffer (window-buffer
                        (if mouse-wheel-follow-mouse
                            (prog1
                                (selected-window)
                              (select-window (mwheel-event-window event)))))
    (horizontal-scroll-right)))