Fix follow-scroll-up/down, making them replacements for scroll-up/down.
1. Allow point to move between follow windows in scroll operations. 2. Fix bug where `right-char' just before EOB caused spurious scrolling, when EOB was isolated in the last follow window. lisp/follow.el (follow-fixed-window): New variable. (follow-get-scrolled-point): New function. (follow-scrol-up, follow-scroll-down): Add autoload cookies. Reformulate the code. Put `scroll-command' properties on the functions. Correct minor errors in ...-down's doc string and code. (follow-calc-win-end): Amend incomplete doc string. Use `pos-visible-in-window-p' to check whether EOB is in the window. (follow-estimate-first-window-start): Correct an off-by-1 error. (follow-adjust-window): Add handling for explicit scrolling operations.
This commit is contained in:
Alan Mackenzie
parent
2e775b43e0
commit
3d16ffb304
1 changed files with 217 additions and 161 deletions
378
lisp/follow.el
378
lisp/follow.el
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@ -347,6 +347,9 @@ Used by `follow-window-size-change'.")
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(defvar follow-windows-start-end-cache nil
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"Cache used by `follow-window-start-end'.")
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(defvar follow-fixed-window nil
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"If non-nil, the current window must not be scrolled.
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This is typically set by explicit scrolling commands.")
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;;; Debug messages
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;; This inline function must be as small as possible!
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@ -439,6 +442,54 @@ Keys specific to Follow mode:
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;;; Scroll
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(defun follow-get-scrolled-point (dest windows)
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"Calculate the correct value for point after a scrolling operation.
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DEST is our default position, typically where point was before the scroll.
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If `scroll-preserve-screen-position' is non-nil and active, DEST will be
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in the same screen position as before the scroll. WINDOWS is the list of
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windows in the follow chain.
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This function attempts to duplicate the point placing from
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`window_scroll_line_based' in the Emacs core source window.c.
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Return the new position."
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(if (and scroll-preserve-screen-position
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(get this-command 'scroll-command))
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dest
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(let ((dest-column
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(save-excursion
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(goto-char dest)
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(- (current-column)
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(progn (vertical-motion 0) (current-column)))))
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(limit0
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(with-selected-window (car windows)
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(save-excursion
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(goto-char (window-start))
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(vertical-motion 0)
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(point))))
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(limitn
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(with-selected-window (car (reverse windows))
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(save-excursion
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(goto-char (window-end nil t))
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(if (pos-visible-in-window-p)
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(point) ; i.e. (point-max)
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(1- (point)))))))
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(cond
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((< dest limit0)
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(with-selected-window (car windows)
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(save-excursion
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(goto-char limit0)
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(vertical-motion (cons dest-column 0))
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(point))))
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((> dest limitn)
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(with-selected-window (car (reverse windows))
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(save-excursion
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(goto-char limitn)
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(vertical-motion (cons dest-column 0))
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(point))))
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(t dest)))))
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;; `scroll-up' and `-down', but for windows in Follow mode.
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;;
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;; Almost like the real thing, except when the cursor ends up outside
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@ -454,6 +505,7 @@ Keys specific to Follow mode:
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;; position... (This would also be corrected if we would have had a
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;; good redisplay abstraction.)
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;;;###autoload
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(defun follow-scroll-up (&optional arg)
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"Scroll text in a Follow mode window chain up.
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@ -467,22 +519,26 @@ Works like `scroll-up' when not in Follow mode."
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(interactive "P")
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(cond ((not follow-mode)
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(scroll-up arg))
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(arg
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(save-excursion (scroll-up arg))
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(setq follow-internal-force-redisplay t))
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((eq arg '-)
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(follow-scroll-down))
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(t
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(let* ((windows (follow-all-followers))
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(end (window-end (car (reverse windows)))))
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(if (eq end (point-max))
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(signal 'end-of-buffer nil)
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(select-window (car windows))
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;; `window-end' might return nil.
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(if end
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(goto-char end))
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(vertical-motion (- next-screen-context-lines))
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(set-window-start (car windows) (point)))))))
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(let ((opoint (point)) (owin (selected-window)))
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(while
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;; If we are too near EOB, try scrolling the previous window.
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(condition-case nil (progn (scroll-up arg) nil)
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(end-of-buffer
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(condition-case nil (progn (follow-previous-window) t)
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(error
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(select-window owin)
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(goto-char opoint)
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(signal 'end-of-buffer nil))))))
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(unless (and scroll-preserve-screen-position
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(get this-command 'scroll-command))
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(goto-char opoint))
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(setq follow-fixed-window t)))))
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(put 'follow-scroll-up 'scroll-command t)
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;;;###autoload
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(defun follow-scroll-down (&optional arg)
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"Scroll text in a Follow mode window chain down.
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@ -492,27 +548,20 @@ the top window in the chain will be visible in the bottom window.
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If called with an argument, scroll ARG lines down.
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Negative ARG means scroll upward.
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Works like `scroll-up' when not in Follow mode."
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Works like `scroll-down' when not in Follow mode."
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(interactive "P")
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(cond ((not follow-mode)
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(scroll-up arg))
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(arg
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(save-excursion (scroll-down arg)))
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(scroll-down arg))
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((eq arg '-)
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(follow-scroll-up))
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(t
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(let* ((windows (follow-all-followers))
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(win (car (reverse windows)))
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(start (window-start (car windows))))
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(if (eq start (point-min))
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(signal 'beginning-of-buffer nil)
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(select-window win)
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(goto-char start)
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(vertical-motion (- (- (window-height win)
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(if header-line-format 2 1)
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next-screen-context-lines)))
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(set-window-start win (point))
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(goto-char start)
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(vertical-motion (- next-screen-context-lines 1))
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(setq follow-internal-force-redisplay t))))))
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(let ((opoint (point)))
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(scroll-down arg)
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(unless (and scroll-preserve-screen-position
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(get this-command 'scroll-command))
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(goto-char opoint))
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(setq follow-fixed-window t)))))
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(put 'follow-scroll-down 'scroll-command t)
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(declare-function comint-adjust-point "comint" (window))
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(defvar comint-scroll-show-maximum-output)
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@ -766,15 +815,16 @@ from the selected window."
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Return (END-POS END-OF-BUFFER).
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Actually, the position returned is the start of the line after
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the last fully-visible line in WIN. If WIN is nil, the selected
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window is used."
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the last fully-visible line in WIN. END-OF-BUFFER is t when EOB
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is fully-visible in WIN. If WIN is nil, the selected window is
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used."
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(let* ((win (or win (selected-window)))
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(edges (window-inside-pixel-edges win))
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(ht (- (nth 3 edges) (nth 1 edges)))
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(last-line-pos (posn-point (posn-at-x-y 0 (1- ht) win))))
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(if (pos-visible-in-window-p last-line-pos win)
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(let ((end (window-end win t)))
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(list end (= end (point-max))))
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(list end (pos-visible-in-window-p (point-max) win)))
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(list last-line-pos nil))))
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(defun follow-calc-win-start (windows pos win)
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@ -1008,7 +1058,7 @@ should be a member of WINDOWS, starts at position START."
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(goto-char start)
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(vertical-motion 0 win)
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(dolist (w windows-before)
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(vertical-motion (- 1 (window-text-height w)) w))
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(vertical-motion (- (window-text-height w)) w))
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(point))))
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@ -1130,138 +1180,144 @@ non-first windows in Follow mode."
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(cl-assert (eq (window-buffer win) (current-buffer)))
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(when (and follow-mode
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(not (window-minibuffer-p win)))
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(let* ((dest (point))
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(windows (follow-all-followers win))
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(win-start-end (progn
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(follow-update-window-start (car windows))
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(follow-windows-start-end windows)))
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(aligned (follow-windows-aligned-p win-start-end))
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(visible (follow-pos-visible dest win win-start-end))
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selected-window-up-to-date)
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(unless (and aligned visible)
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(setq follow-windows-start-end-cache nil))
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(let ((windows (follow-all-followers win)))
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;; If we've explicitly scrolled, align the windows first.
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(when follow-fixed-window
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(follow-debug-message "fixed")
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(follow-redisplay windows win)
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(goto-char (follow-get-scrolled-point (point) windows))
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(setq follow-fixed-window nil))
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(let* ((dest (point))
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(win-start-end (progn
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(follow-update-window-start (car windows))
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(follow-windows-start-end windows)))
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(aligned (follow-windows-aligned-p win-start-end))
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(visible (follow-pos-visible dest win win-start-end))
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selected-window-up-to-date)
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(unless (and aligned visible)
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(setq follow-windows-start-end-cache nil))
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;; Select a window to display point.
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(unless follow-internal-force-redisplay
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(if (eq dest (point-max))
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;; Be careful at point-max: the display can be aligned
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;; while DEST can be visible in several windows.
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(cond
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;; Select the current window, but only when the display
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;; is correct. (When inserting characters in a tail
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;; window, the display is not correct, as they are
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;; shown twice.)
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;;
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;; Never stick to the current window after a deletion.
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;; Otherwise, when typing `DEL' in a window showing
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;; only the end of the file, a character would be
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;; removed from the window above, which is very
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;; unintuitive.
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((and visible
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aligned
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(not (memq this-command
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'(backward-delete-char
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delete-backward-char
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backward-delete-char-untabify
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kill-region))))
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(follow-debug-message "Max: same"))
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;; If the end is visible, and the window doesn't
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;; seems like it just has been moved, select it.
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((follow-select-if-end-visible win-start-end)
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(follow-debug-message "Max: end visible")
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(setq visible t aligned nil)
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(goto-char dest))
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;; Just show the end...
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(t
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(follow-debug-message "Max: default")
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(select-window (car (last windows)))
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(goto-char dest)
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(setq visible nil aligned nil)))
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;; Select a window to display point.
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(unless follow-internal-force-redisplay
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(if (eq dest (point-max))
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;; Be careful at point-max: the display can be aligned
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;; while DEST can be visible in several windows.
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(cond
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;; Select the current window, but only when the display
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;; is correct. (When inserting characters in a tail
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;; window, the display is not correct, as they are
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;; shown twice.)
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;;
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;; Never stick to the current window after a deletion.
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;; Otherwise, when typing `DEL' in a window showing
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;; only the end of the file, a character would be
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;; removed from the window above, which is very
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;; unintuitive.
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((and visible
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aligned
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(not (memq this-command
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'(backward-delete-char
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delete-backward-char
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backward-delete-char-untabify
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kill-region))))
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(follow-debug-message "Max: same"))
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;; If the end is visible, and the window doesn't
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;; seems like it just has been moved, select it.
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((follow-select-if-end-visible win-start-end)
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(follow-debug-message "Max: end visible")
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(setq visible t aligned nil)
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(goto-char dest))
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;; Just show the end...
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(t
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(follow-debug-message "Max: default")
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(select-window (car (last windows)))
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(goto-char dest)
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(setq visible nil aligned nil)))
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;; We're not at the end, here life is much simpler.
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(cond
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;; This is the normal case!
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;; It should be optimized for speed.
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((and visible aligned)
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(follow-debug-message "same"))
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;; Pick a position in any window. If the display is ok,
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;; this picks the `correct' window.
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((follow-select-if-visible dest win-start-end)
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(follow-debug-message "visible")
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(goto-char dest)
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;; Perform redisplay, in case line is partially visible.
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(setq visible nil))
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;; Not visible anywhere else, lets pick this one.
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(visible
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(follow-debug-message "visible in selected."))
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;; If DEST is before the first window start, select the
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;; first window.
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((< dest (nth 1 (car win-start-end)))
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(follow-debug-message "before first")
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(select-window (car windows))
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(goto-char dest)
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(setq visible nil aligned nil))
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;; If we can position the cursor without moving the first
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;; window, do it. This is the case that catches `RET' at
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;; the bottom of a window.
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((follow-select-if-visible-from-first dest windows)
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(follow-debug-message "Below first")
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(setq visible t aligned t))
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;; None of the above. Stick to the selected window.
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(t
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(follow-debug-message "None")
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(setq visible nil aligned nil))))
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;; We're not at the end, here life is much simpler.
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(cond
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;; This is the normal case!
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;; It should be optimized for speed.
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((and visible aligned)
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(follow-debug-message "same"))
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;; Pick a position in any window. If the display is ok,
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;; this picks the `correct' window.
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((follow-select-if-visible dest win-start-end)
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(follow-debug-message "visible")
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(goto-char dest)
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;; Perform redisplay, in case line is partially visible.
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(setq visible nil))
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;; Not visible anywhere else, lets pick this one.
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(visible
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(follow-debug-message "visible in selected."))
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;; If DEST is before the first window start, select the
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;; first window.
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((< dest (nth 1 (car win-start-end)))
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(follow-debug-message "before first")
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(select-window (car windows))
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(goto-char dest)
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(setq visible nil aligned nil))
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;; If we can position the cursor without moving the first
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;; window, do it. This is the case that catches `RET' at
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;; the bottom of a window.
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((follow-select-if-visible-from-first dest windows)
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(follow-debug-message "Below first")
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(setq visible t aligned t))
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;; None of the above. Stick to the selected window.
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(t
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(follow-debug-message "None")
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(setq visible nil aligned nil))))
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;; If a new window was selected, make sure that the old is
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;; not scrolled when point is outside the window.
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(unless (eq win (selected-window))
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(let ((p (window-point win)))
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(set-window-start win (window-start win) nil)
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(set-window-point win p))))
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;; If a new window was selected, make sure that the old is
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;; not scrolled when point is outside the window.
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(unless (eq win (selected-window))
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(let ((p (window-point win)))
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(set-window-start win (window-start win) nil)
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(set-window-point win p))))
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(unless visible
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;; If point may not be visible in the selected window,
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;; perform a redisplay; this ensures scrolling.
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(let ((opoint (point)))
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(redisplay)
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;; If this `redisplay' moved point, we got clobbered by a
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;; previous call to `set-window-start'. Try again.
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(when (/= (point) opoint)
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(goto-char opoint)
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(redisplay)))
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(unless visible
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;; If point may not be visible in the selected window,
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;; perform a redisplay; this ensures scrolling.
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(let ((opoint (point)))
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(redisplay)
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;; If this `redisplay' moved point, we got clobbered by a
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;; previous call to `set-window-start'. Try again.
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(when (/= (point) opoint)
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(goto-char opoint)
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(redisplay)))
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(setq selected-window-up-to-date t)
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(follow-avoid-tail-recenter)
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(setq win-start-end (follow-windows-start-end windows)
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follow-windows-start-end-cache nil
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aligned nil))
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(setq selected-window-up-to-date t)
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(follow-avoid-tail-recenter)
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(setq win-start-end (follow-windows-start-end windows)
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follow-windows-start-end-cache nil
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aligned nil))
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;; Now redraw the windows around the selected window.
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(unless (and (not follow-internal-force-redisplay)
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(or aligned
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(follow-windows-aligned-p win-start-end))
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(follow-point-visible-all-windows-p win-start-end))
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(setq follow-internal-force-redisplay nil)
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(follow-redisplay windows (selected-window)
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selected-window-up-to-date)
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(setq win-start-end (follow-windows-start-end windows)
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follow-windows-start-end-cache nil)
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;; Point can end up in another window when DEST is at
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;; the beginning of the buffer and the selected window is
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;; not the first. It can also happen when long lines are
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;; used and there is a big difference between the width of
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;; the windows. (When scrolling one line in a wide window
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;; which will cause a move larger that an entire small
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;; window.)
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(unless (follow-pos-visible dest win win-start-end)
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(follow-select-if-visible dest win-start-end)
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(goto-char dest)))
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;; Now redraw the windows around the selected window.
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(unless (and (not follow-internal-force-redisplay)
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(or aligned
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(follow-windows-aligned-p win-start-end))
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(follow-point-visible-all-windows-p win-start-end))
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(setq follow-internal-force-redisplay nil)
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(follow-redisplay windows (selected-window)
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selected-window-up-to-date)
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(setq win-start-end (follow-windows-start-end windows)
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follow-windows-start-end-cache nil)
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;; Point can end up in another window when DEST is at
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;; the beginning of the buffer and the selected window is
|
||||
;; not the first. It can also happen when long lines are
|
||||
;; used and there is a big difference between the width of
|
||||
;; the windows. (When scrolling one line in a wide window
|
||||
;; which will cause a move larger that an entire small
|
||||
;; window.)
|
||||
(unless (follow-pos-visible dest win win-start-end)
|
||||
(follow-select-if-visible dest win-start-end)
|
||||
(goto-char dest)))
|
||||
|
||||
;; If the region is visible, make it look good when spanning
|
||||
;; multiple windows.
|
||||
(when (region-active-p)
|
||||
(follow-maximize-region
|
||||
(selected-window) windows win-start-end)))
|
||||
;; If the region is visible, make it look good when spanning
|
||||
;; multiple windows.
|
||||
(when (region-active-p)
|
||||
(follow-maximize-region
|
||||
(selected-window) windows win-start-end))))
|
||||
|
||||
;; Whether or not the buffer was in follow mode, update windows
|
||||
;; displaying the tail so that Emacs won't recenter them.
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue