diff options
Diffstat (limited to 'lisp/follow.el')
| -rw-r--r-- | lisp/follow.el | 75 |
1 files changed, 66 insertions, 9 deletions
diff --git a/lisp/follow.el b/lisp/follow.el index 2ab44b21dd5..acc2b26c550 100644 --- a/lisp/follow.el +++ b/lisp/follow.el @@ -187,8 +187,8 @@ ;; Implementation: ;; ;; The main method by which Follow mode aligns windows is via the -;; function `follow-post-command-hook', which is run after each -;; command. This "fixes up" the alignment of other windows which are +;; function `follow-pre-redisplay-function', which is run before each +;; redisplay. This "fixes up" the alignment of other windows which are ;; showing the same Follow mode buffer, on the same frame as the ;; selected window. It does not try to deal with buffers other than ;; the buffer of the selected frame, or windows on other frames. @@ -311,6 +311,17 @@ are \" Fw\", or simply \"\"." (remove-hook 'find-file-hook 'follow-find-file-hook)) (set-default symbol value))) +(defcustom follow-hide-ghost-cursors t ; Maybe this should be nil. + "When non-nil, Follow mode attempts to hide the obtrusive cursors +in the non-selected windows of a window group. + +This variable takes effect when `follow-mode' is initialized. + +Due to limitations in Emacs, this only operates on the followers +of the selected window." + :type 'boolean + :group 'follow) + (defvar follow-cache-command-list '(next-line previous-line forward-char backward-char right-char left-char) "List of commands that don't require recalculation. @@ -383,9 +394,6 @@ This is typically set by explicit scrolling commands.") ;;;###autoload (define-minor-mode follow-mode "Toggle Follow mode. -With a prefix argument ARG, enable Follow mode if ARG is -positive, and disable it otherwise. If called from Lisp, enable -the mode if ARG is omitted or nil. Follow mode is a minor mode that combines windows into one tall virtual window. This is accomplished by two main techniques: @@ -421,7 +429,7 @@ Keys specific to Follow mode: (if follow-mode (progn (add-hook 'compilation-filter-hook 'follow-align-compilation-windows t t) - (add-hook 'post-command-hook 'follow-post-command-hook t) + (add-function :before pre-redisplay-function 'follow-pre-redisplay-function) (add-hook 'window-size-change-functions 'follow-window-size-change t) (add-hook 'after-change-functions 'follow-after-change nil t) (add-hook 'isearch-update-post-hook 'follow-post-command-hook nil t) @@ -430,6 +438,8 @@ Keys specific to Follow mode: (when isearch-lazy-highlight (setq-local isearch-lazy-highlight 'all-windows)) + (when follow-hide-ghost-cursors + (setq-local cursor-in-non-selected-windows nil)) (setq window-group-start-function 'follow-window-start) (setq window-group-end-function 'follow-window-end) @@ -448,7 +458,7 @@ Keys specific to Follow mode: (setq following (buffer-local-value 'follow-mode (car buffers)) buffers (cdr buffers))) (unless following - (remove-hook 'post-command-hook 'follow-post-command-hook) + (remove-function pre-redisplay-function 'follow-pre-redisplay-function) (remove-hook 'window-size-change-functions 'follow-window-size-change))) (kill-local-variable 'move-to-window-group-line-function) @@ -459,6 +469,8 @@ Keys specific to Follow mode: (kill-local-variable 'window-group-end-function) (kill-local-variable 'window-group-start-function) + (kill-local-variable 'cursor-in-non-selected-windows) + (remove-hook 'ispell-update-post-hook 'follow-post-command-hook t) (remove-hook 'replace-update-post-hook 'follow-post-command-hook t) (remove-hook 'isearch-update-post-hook 'follow-post-command-hook t) @@ -1263,10 +1275,31 @@ non-first windows in Follow mode." (not (eq win top)))) ;; Loop while this is true. (set-buffer orig-buffer)))) -;;; Post Command Hook +;;; Pre Display Function + +(defvar follow-prev-buffer nil + "The buffer current at the last call to `follow-adjust-window' or nil. +follow-mode is not necessarily enabled in this buffer.") -;; The magic little box. This function is called after every command. +;; This function is added to `pre-display-function' and is thus called +;; before each redisplay operation. It supersedes (2018-09) the +;; former use of the post command hook, and now does the right thing +;; when a program calls `redisplay' or `sit-for'. +(defun follow-pre-redisplay-function (wins) + (if (or (eq wins t) + (null wins) + (and (listp wins) + (memq (selected-window) wins))) + (follow-post-command-hook))) + +;;; Post Command Hook + +;; The magic little box. This function was formerly called after every +;; command. It is now called before each redisplay operation (see +;; `follow-pre-redisplay-function' above), and at the end of several +;; search/replace commands. It retains its historical name. +;; ;; This is not as complicated as it seems. It is simply a list of common ;; display situations and the actions to take, plus commands for redrawing ;; the screen if it should be unaligned. @@ -1287,9 +1320,33 @@ non-first windows in Follow mode." (setq follow-windows-start-end-cache nil)) (follow-adjust-window win))))) +;; NOTE: to debug follow-mode with edebug, it is helpful to add +;; `follow-post-command-hook' to `post-command-hook' temporarily. Do +;; this locally to the target buffer with, say,: +;; M-: (add-hook 'post-command-hook 'follow-post-command-hook t t) +;; . + (defun follow-adjust-window (win) ;; Adjust the window WIN and its followers. (cl-assert (eq (window-buffer win) (current-buffer))) + + ;; Have we moved out of or into a follow-mode window group? + ;; If so, attend to the visibility of the cursors. + (when (not (eq (current-buffer) follow-prev-buffer)) + ;; Do we need to switch off cursor handling in the previous buffer? + (when (buffer-live-p follow-prev-buffer) + (with-current-buffer follow-prev-buffer + (when (and follow-mode + (local-variable-p 'cursor-in-non-selected-windows)) + (setq cursor-in-non-selected-windows + (default-value 'cursor-in-non-selected-windows))))) + ;; Do we need to switch on cursor handling in the current buffer? + (when (and follow-mode + (local-variable-p 'cursor-in-non-selected-windows)) + (setq cursor-in-non-selected-windows nil)) + (when (buffer-live-p (current-buffer)) + (setq follow-prev-buffer (current-buffer)))) + (when (and follow-mode (not (window-minibuffer-p win))) (let ((windows (follow-all-followers win))) |