From 49e66fee68a4ad69418dae329e24e5611ea8de6e Mon Sep 17 00:00:00 2001 From: "F. Jason Park" Date: Sat, 22 Jul 2023 00:46:44 -0700 Subject: [PATCH 1/1] [5.6] Consider all windows in erc-scrolltobottom-mode * lisp/erc/erc-goodies.el (erc-scrolltobottom-mode, erc-scrolltobottom-enable, erc-scrolltobottom-disable): Use `erc--scroll-to-bottom-all' instead of `erc-possibly-scroll-to-bottom' for `erc-insert-done-hook' and now also `erc-send-completed-hook'. Add `erc--scroll-to-bottom-on-pre-insert' to `erc-insert-pre-hook' and `erc-send-pre-functions'. Call `erc-add-scroll-to-bottom' for teardown as well. (erc--scroll-to-bottom-debounce-expire): New variable to help ERC refrain from calling `recenter' when the user is typing at the prompt. (erc--scroll-to-bottom-last-window-start): New variable used by `erc--scroll-to-bottom-on-pre-insert' and `erc--scroll-to-bottom' for stashing and restoring the `window-start' of all windows displaying the buffer. (erc--possibly-scroll-to-bottom): New function resembling `erc-possibly-scroll-to-bottom' that tries to avoid scrolling again when user has done so recently. (erc--scroll-to-bottom-all): New function to scroll all windows displaying the current buffer. (erc-add-scroll-to-bottom): Perform teardown as well when mode is disabled. Also run on `window-configuration-changed-hook'. (erc-scroll-to-bottom): Use `window-point' instead of `point'. (erc--scroll-to-bottom-on-pre-insert): New generic function that remembers the `window-start' before inserting a message in order to restore it afterward. (erc--scroll-to-bottom): New function, a replacement for `erc-scroll-to-bottom', that takes returns non-nil when it's actually performed a recentering. (Bug#64855) --- lisp/erc/erc-goodies.el | 102 +++++++++++++++++++++++++++++++++++----- 1 file changed, 91 insertions(+), 11 deletions(-) diff --git a/lisp/erc/erc-goodies.el b/lisp/erc/erc-goodies.el index d9ededa8e68..e82dc73f82f 100644 --- a/lisp/erc/erc-goodies.el +++ b/lisp/erc/erc-goodies.el @@ -52,34 +52,114 @@ erc-input-line-position (define-erc-module scrolltobottom nil "This mode causes the prompt to stay at the end of the window." ((add-hook 'erc-mode-hook #'erc-add-scroll-to-bottom) - (add-hook 'erc-insert-done-hook #'erc-possibly-scroll-to-bottom) + (add-hook 'erc-insert-pre-hook #'erc--scroll-to-bottom-on-pre-insert) + (add-hook 'erc-send-pre-functions #'erc--scroll-to-bottom-on-pre-insert) + (add-hook 'erc-insert-done-hook #'erc--scroll-to-bottom-all) + (add-hook 'erc-send-completed-hook #'erc--scroll-to-bottom-all) (unless erc--updating-modules-p (erc-buffer-do #'erc-add-scroll-to-bottom))) ((remove-hook 'erc-mode-hook #'erc-add-scroll-to-bottom) - (remove-hook 'erc-insert-done-hook #'erc-possibly-scroll-to-bottom) - (dolist (buffer (erc-buffer-list)) - (with-current-buffer buffer - (remove-hook 'post-command-hook #'erc-scroll-to-bottom t))))) + (remove-hook 'erc-insert-pre-hook #'erc--scroll-to-bottom-on-pre-insert) + (remove-hook 'erc-send-pre-functions #'erc--scroll-to-bottom-on-pre-insert) + (remove-hook 'erc-insert-done-hook #'erc--scroll-to-bottom-all) + (remove-hook 'erc-send-completed-hook #'erc--scroll-to-bottom-all) + (erc-buffer-do #'erc-add-scroll-to-bottom))) + +(defvar-local erc--scroll-to-bottom-debounce-expire nil + "A cons of some window and the expiration time in seconds. +The CAR is a window in whose buffer this variable is local. The +CDR is a half second after the last attempted refresh of such a +window.") + +(defvar-local erc--scroll-to-bottom-last-window-start nil + "Alist whose members are a cons of a window and a starting position.") (defun erc-possibly-scroll-to-bottom () "Like `erc-add-scroll-to-bottom', but only if window is selected." (when (eq (selected-window) (get-buffer-window)) (erc-scroll-to-bottom))) +(defun erc--possibly-scroll-to-bottom () + "Call `erc-scroll-to-bottom' when buffer occupies selected window. +Expect narrowing not to be in effect. Skip when +`erc--scroll-to-bottom-debounce-expire' has not yet transpired." + (when (eq (selected-window) (get-buffer-window)) + (unless (or (eq this-command 'recenter-top-bottom) (input-pending-p)) + (let ((now (erc-current-time)) + (at-prompt-p (>= (point) erc-input-marker))) + (unless (and at-prompt-p + erc--scroll-to-bottom-debounce-expire + (eq (car erc--scroll-to-bottom-debounce-expire) + (selected-window)) + (< now (cdr erc--scroll-to-bottom-debounce-expire))) + (erc--scroll-to-bottom)) + (setq erc--scroll-to-bottom-debounce-expire + (and at-prompt-p (cons (selected-window) (+ now 0.5)))))))) + +(defun erc--scroll-to-bottom-all (&rest _) + "Maybe put prompt on last line in all windows displaying current buffer. +Expect to run when narrowing is in effect, such as on insertion +or send-related hooks. When recentering has not been performed, +attempt to restore last `window-start', if known." + (dolist (window (get-buffer-window-list nil nil 'visible)) + (with-selected-window window + (when-let + (((not (erc--scroll-to-bottom))) + (erc--scroll-to-bottom-last-window-start) + (found (assq window erc--scroll-to-bottom-last-window-start))) + (setf (window-start window) (cdr found))))) + ;; Necessary unless we're sure `erc--scroll-to-bottom-on-pre-insert' + ;; always runs between calls to this function. + (setq erc--scroll-to-bottom-last-window-start nil)) + (defun erc-add-scroll-to-bottom () - "A hook function for `erc-mode-hook' to recenter output at bottom of window. + "Arrange for `scrolltobottom' to refresh on window configuration changes. +Undo that arrangement when `erc-scrolltobottom-mode' is disabled. If you find that ERC hangs when using this function, try customizing the value of `erc-input-line-position'. -This works whenever scrolling happens, so it's added to -`window-scroll-functions' rather than `erc-insert-post-hook'." - (add-hook 'post-command-hook #'erc-scroll-to-bottom nil t)) +Note that the prior suggestion comes from a time when this +function used `window-scroll-functions', which was replaced by +`post-command-hook' in ERC 5.3." + (if erc-scrolltobottom-mode + (progn + (add-hook 'window-configuration-change-hook + #'erc--possibly-scroll-to-bottom nil t) + (add-hook 'post-command-hook + #'erc--possibly-scroll-to-bottom nil t)) + (remove-hook 'window-configuration-change-hook + #'erc--possibly-scroll-to-bottom t) + (remove-hook 'post-command-hook + #'erc--possibly-scroll-to-bottom t))) + +(cl-defmethod erc--scroll-to-bottom-on-pre-insert (_input-or-string) + "Remember the `window-start' before inserting a message." + (setq erc--scroll-to-bottom-last-window-start + (mapcar (lambda (w) (cons w (window-start w))) + (get-buffer-window-list nil nil 'visible)))) + +(cl-defmethod erc--scroll-to-bottom-on-pre-insert ((input erc-input)) + "Remember the `window-start' before inserting a message." + (when (erc-input-insertp input) + (cl-call-next-method))) + +(defun erc--scroll-to-bottom () + "Like `erc-scroll-to-bottom', but use `window-point'. +Expect to run in some window, not necessarily the user-selected +one. Return non-nil when recentering has occurred." + (when erc-insert-marker + (let ((resize-mini-windows nil)) + (save-restriction + (widen) + (when (>= (window-point) erc-input-marker) + (save-excursion + (goto-char (point-max)) + (recenter (or erc-input-line-position -1)) + t)))))) (defun erc-scroll-to-bottom () "Recenter WINDOW so that `point' is on the last line. -This is added to `window-scroll-functions' by `erc-add-scroll-to-bottom'. - You can control which line is recentered to by customizing the variable `erc-input-line-position'." ;; Temporarily bind resize-mini-windows to nil so that users who have it -- 2.41.0