diff options
| -rw-r--r-- | modules/music-config.el | 40 | ||||
| -rw-r--r-- | tests/test-music-config--renumber-rows.el | 50 |
2 files changed, 87 insertions, 3 deletions
diff --git a/modules/music-config.el b/modules/music-config.el index 10aa1019..e9095838 100644 --- a/modules/music-config.el +++ b/modules/music-config.el @@ -471,7 +471,10 @@ inserts or kills into one renumber pass." ;; motion walks the header's screen lines, which all map back to the ;; same buffer position, so arrows look dead). Rows are one logical ;; line each; visual movement buys nothing here. - (setq-local line-move-visual nil)) + (setq-local line-move-visual nil) + ;; Sticky header: re-anchor the header block at the window start on + ;; every scroll, so it stays frozen while the list scrolls under it. + (add-hook 'window-scroll-functions #'cj/music--stick-header nil t)) (cj/music--renumber-rows buffer) ;; Set this as the current EMMS playlist buffer (setq emms-playlist-buffer buffer) @@ -1392,14 +1395,45 @@ the controls." (cj/music--fancy-header) (cj/music--text-header))) +(defun cj/music--header-anchor-position () + "Return the position the header overlay should anchor at right now. +The start of the displaying window when the playlist is shown (so the +header stays at the top of the window while the list scrolls under it), +else the top of the buffer. Searches all frames -- the refresh timer can +run with any frame selected, and missing a window on another frame would +anchor at the buffer top and yank a scrolled header back." + (if-let ((win (get-buffer-window (current-buffer) t))) + (max (point-min) (min (window-start win) (point-max))) + (point-min))) + +(defun cj/music--stick-header (win start) + "Re-anchor the header overlay at START, WIN's new display start. +Runs on the buffer-local `window-scroll-functions', so every scroll pins +the header block to the top of the window and the track list scrolls +beneath it. Converges: an already-anchored header is a no-op, so the +redisplay this move triggers doesn't loop. Always returns nil." + (with-current-buffer (window-buffer win) + (when (and (overlayp cj/music--header-overlay) + (overlay-buffer cj/music--header-overlay) + (integer-or-marker-p start)) + (let ((pos (max (point-min) (min start (point-max))))) + (unless (= (overlay-start cj/music--header-overlay) pos) + (move-overlay cj/music--header-overlay pos pos)))) + nil)) + (defun cj/music--update-header () - "Insert or update the multi-line header overlay in the playlist buffer." + "Insert or update the multi-line header overlay in the playlist buffer. +Anchors at the displaying window's start (see +`cj/music--header-anchor-position') -- the refresh timer calls this every +second, and re-anchoring at the buffer top would yank the sticky header +away whenever the list is scrolled." (when-let ((buf (get-buffer cj/music-playlist-buffer-name))) (with-current-buffer buf (unless cj/music--header-overlay (setq cj/music--header-overlay (make-overlay (point-min) (point-min))) (overlay-put cj/music--header-overlay 'priority 100)) - (move-overlay cj/music--header-overlay (point-min) (point-min)) + (let ((pos (cj/music--header-anchor-position))) + (move-overlay cj/music--header-overlay pos pos)) (overlay-put cj/music--header-overlay 'before-string (cj/music--header-text))))) diff --git a/tests/test-music-config--renumber-rows.el b/tests/test-music-config--renumber-rows.el index a5304606..d5bc5141 100644 --- a/tests/test-music-config--renumber-rows.el +++ b/tests/test-music-config--renumber-rows.el @@ -165,6 +165,56 @@ selected -- the dock is glanced at from other windows constantly." (should (buffer-local-value 'hl-line-sticky-flag created))) (when (buffer-live-p created) (kill-buffer created)))))) +;;; Sticky header + +(ert-deftest test-music-stick-header-moves-overlay-to-window-start () + "Normal: a scroll re-anchors the header overlay at the new window start, +so the header block stays at the top of the window while the list scrolls." + (with-temp-buffer + (insert "track one\ntrack two\ntrack three\ntrack four\n") + (setq cj/music--header-overlay (make-overlay (point-min) (point-min))) + (save-window-excursion + (set-window-buffer (selected-window) (current-buffer)) + (let ((start (save-excursion (goto-char (point-min)) (forward-line 2) (point)))) + (cj/music--stick-header (selected-window) start) + (should (= (overlay-start cj/music--header-overlay) start)) + ;; Converges: the same start again is a no-op, not a loop. + (cj/music--stick-header (selected-window) start) + (should (= (overlay-start cj/music--header-overlay) start)))))) + +(ert-deftest test-music-stick-header-no-overlay-noop () + "Boundary: no header overlay yet -- the scroll handler is a silent no-op." + (with-temp-buffer + (insert "track one\n") + (setq cj/music--header-overlay nil) + (save-window-excursion + (set-window-buffer (selected-window) (current-buffer)) + (should-not (cj/music--stick-header (selected-window) (point-min)))))) + +(ert-deftest test-music-header-anchor-position-displayed-vs-not () + "Normal: the header anchors at the displaying window's start; an +undisplayed buffer anchors at the top." + (with-temp-buffer + (insert "track one\ntrack two\ntrack three\ntrack four\n") + (save-window-excursion + (set-window-buffer (selected-window) (current-buffer)) + (let ((start (save-excursion (goto-char (point-min)) (forward-line 2) (point)))) + (set-window-start (selected-window) start) + (should (= (cj/music--header-anchor-position) start)))) + ;; Not displayed after the excursion restores the old config. + (should (= (cj/music--header-anchor-position) (point-min))))) + +(ert-deftest test-music-ensure-playlist-buffer-wires-scroll-hook () + "Normal: the playlist buffer re-sticks its header on every window scroll." + (let (created) + (cl-letf (((symbol-function 'emms-playlist-mode) #'ignore)) + (unwind-protect + (progn + (setq created (cj/music--ensure-playlist-buffer)) + (with-current-buffer created + (should (member #'cj/music--stick-header window-scroll-functions)))) + (when (buffer-live-p created) (kill-buffer created)))))) + ;;; Hook wiring (ert-deftest test-music-renumber-ensure-playlist-buffer-wires-hook () |