actually scroll to playhead

tl/src/tl/views.cljs

@@ -66,6 +66,11 @@
   (when (and @video-el source-frame)
     (set! (.-currentTime @video-el) (/ source-frame fps))))
 
+(defn- follow! [fps zoom playhead]
+  (when-let [el @scroll-el]
+    (let [x (px playhead fps zoom)]
+      (set! (.-scrollLeft el) (max 0 (- x (/ (.-clientWidth el) 2)))))))
+
 (defn- seg-at
   "Index of the segment whose LOCAL range contains `local` (0 if none)."
   [segs local]
@@ -151,14 +156,19 @@
 (rf/reg-fx :player/pause (fn [_]    (when-let [v @video-el] (.pause v))))
 (rf/reg-fx :player/seek  (fn [secs] (when (and @video-el secs) (set! (.-currentTime @video-el) secs))))
 
-(defn- goto! [local]
+(defn- goto!
   "Move the playhead to local frame `local` and seek the video to match."
+  ([local] (goto! local false))
+  ([local follow?]
    (let [ctx  @(rf/subscribe [::subs/context])
          segs @(rf/subscribe [::subs/segments])
-        fps  @(rf/subscribe [::subs/fps])]
+         fps  @(rf/subscribe [::subs/fps])
+         zoom @(rf/subscribe [::subs/zoom])]
      (rf/dispatch [::events/set-playhead ctx local])
      (seek-video! fps (scene/local->source segs local))
-    (when @play (swap! play assoc :idx (seg-at segs local)))))   ; keep playback in sync
+     (when @play (swap! play assoc :idx (seg-at segs local)))   ; keep playback in sync
+     (when follow?
+       (r/after-render #(follow! fps zoom local))))))
 
 (defn video-monitor []
   [:video {:src @(rf/subscribe [::subs/clip-url]) :controls true :preload "auto"
@@ -238,11 +248,6 @@
     (.addEventListener js/document "mousemove" move)
     (.addEventListener js/document "mouseup" up)))
 
-(defn- follow! [fps zoom playhead]
-  (when-let [el @scroll-el]
-    (let [x (px playhead fps zoom)]
-      (set! (.-scrollLeft el) (max 0 (- x (/ (.-clientWidth el) 2)))))))
-
 (defn timeline []
   (let [content (atom nil)
         lanes-scroll (atom nil)
@@ -343,6 +348,10 @@
   (scene/link-local @(rf/subscribe [::subs/scene]) @(rf/subscribe [::subs/context])
                     {:ref (keyword ref) :at (js/parseInt at 10)}))
 
+(defn- goto-link! [local]
+  (when local
+    (goto! local true)))
+
 (defn content-display
   "Read-only render of annotation `content`: markdown blocks (headings, lists,
    paragraphs) with inline formatting plus clickable link chips."
@@ -358,7 +367,7 @@
                  (let [lf (scene/link-local scene ctx {:ref ref :at at})]
                    [:span.link-chip {:class (when-not lf "broken")
                                      :title (when-not lf "linked clip no longer in this timeline")
-                                     :on-click #(when lf (goto! lf))}
+                                     :on-click #(goto-link! lf)}
                     (when-not lf "△ ") label
                     (when lf [:span.link-f (str " " (js/Math.round lf) "f")])])))))
 
@@ -431,7 +440,7 @@
       :on-input emit :on-key-up save! :on-mouse-up save! :on-blur save!
       :on-click (fn [e] (when-let [chip (.closest (.-target e) ".link-chip")]
                           (when-let [lf (link-frame (.. chip -dataset -ref) (.. chip -dataset -at))]
-                            (goto! lf))))}]))
+                            (goto-link! lf))))}]))
 
 (defn- point-candidates [scene ctx q timelines?]
   (let [needle (str/lower-case q)
@@ -599,7 +608,7 @@
   [open a scene segs]
   (let [bars (:bars a)]
     (if (< (count bars) 2)
-      [:button.jump-btn {:on-click #(goto! (:start a))} "↪ jump"]
+      [:button.jump-btn {:on-click #(goto! (:start a) true)} "↪ jump"]
       [:span {:style {:position "relative"}}
        [:button.jump-btn {:on-click #(swap! open (fn [x] (when (not= x (:id a)) (:id a))))}
         (str "↪ jump (" (count bars) ") ▾")]
@@ -607,7 +616,7 @@
          [:div.jump-pop
           (for [[i [lo _]] (map-indexed vector bars)]
             ^{:key i}
-            [:button {:on-click #(do (goto! lo) (reset! open nil))}
+            [:button {:on-click #(do (goto! lo true) (reset! open nil))}
              (str "▸ " (clip-at scene segs lo))])])])))
 
 (defn commentary []
@@ -853,7 +862,7 @@
      (let [[x0 y0 x1 y1] rect]
        [:div.script-hl {:title (:name a) :data-ann (name (:id a))
                         :on-mouse-down #(.stopPropagation %)
-                        :on-click #(goto! (:start a))    ; jump the timeline to this annotation
+                        :on-click #(goto! (:start a) true) ; jump the timeline to this annotation
                         :style {:left (* x0 w) :top (* y0 h)
                                 :width (* (- x1 x0) w) :height (* (- y1 y0) h)
                                 :background (str (:color a) "44") :border (str "1.5px solid " (:color a))}}]))