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Diffstat (limited to 'lisp/window.el')
| -rw-r--r-- | lisp/window.el | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/lisp/window.el b/lisp/window.el index 0f6ae8ab763..94e4b48a3a7 100644 --- a/lisp/window.el +++ b/lisp/window.el @@ -879,6 +879,44 @@ and the buffer that is killed or buried is the one in that window." ;; Maybe get rid of the window. (and window (not window-handled) (not window-solitary) (delete-window window)))) + +(defvar recenter-last-op nil + "Indicates the last recenter operation performed. +Possible values: `top', `middle', `bottom'.") + +(defun recenter-top-bottom (&optional arg) + "Move current line to window center, top, and bottom, successively. +With a prefix argument, this is the same as `recenter': + With numeric prefix ARG, move current line to window-line ARG. + With plain `C-u', move current line to window center. + +Otherwise move current line to window center on first call, and to +top, middle, or bottom on successive calls. + +The starting position of the window determines the cycling order: + If initially in the top or middle third: top -> middle -> bottom. + If initially in the bottom third: bottom -> middle -> top. + +Top and bottom destinations are actually `scroll-conservatively' lines +from true window top and bottom." + (interactive "P") + (cond + (arg (recenter arg)) ; Always respect ARG. + ((not (eq this-command last-command)) + ;; First time - save mode and recenter. + (let ((bottom (1+ (count-lines 1 (window-end)))) + (current (1+ (count-lines 1 (point)))) + (total (window-height))) + (setq recenter-last-op 'middle) + (recenter))) + (t ;; repeat: loop through various options. + (setq recenter-last-op + (ecase recenter-last-op + (middle (recenter scroll-conservatively) 'top) + (top (recenter (1- (- scroll-conservatively))) 'bottom) + (bottom (recenter) 'middle)))))) + +(define-key global-map [?\C-l] 'recenter-top-bottom) (defvar mouse-autoselect-window-timer nil "Timer used by delayed window autoselection.") |