From 8cb0cbc033905a8be5be8d0cd88861ef71faa049 Mon Sep 17 00:00:00 2001
From: skaphan <skaphan@gmail.com>
Date: Tue, 7 Apr 2026 19:59:26 -0700
Subject: [PATCH 1/2] Fix pie chart auto-play stopping on no-transfer rounds

Add resumeFrom() to round player so the pie chart can advance the
dropdown during auto-play without stopping playback. When the pie
chart skips a round with no transfers, updateRound() now calls
resumeFrom() instead of setStep() to keep the animation going.

Co-Authored-By: Claude Opus 4.6
---
 static/visualizer/round-player.js  | 12 +++++++++++-
 templates/pie/pie-nonblocking.html | 10 +++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/static/visualizer/round-player.js b/static/visualizer/round-player.js
index 14914706..c10eb070 100644
--- a/static/visualizer/round-player.js
+++ b/static/visualizer/round-player.js
@@ -158,6 +158,16 @@ function RoundPlayer({
       "Play Animation";
   }
 
+  // Resume playback from a specific step without resetting to round 0.
+  // Used when the pie chart skips a no-transfer round during auto-play
+  // and needs the round player to catch up without interrupting playback.
+  function resumeFrom(step) {
+    changeStep(step);
+    if (!isPlaying) return;
+    window.clearTimeout(timer);
+    nextStep(stepTimeMs);
+  }
+
   function playing() {
     return isPlaying;
   }
@@ -168,5 +178,5 @@ function RoundPlayer({
 
   init();
 
-  return { play, stop, setStep, setTimeBetweenStepsMs, playing };
+  return { play, stop, setStep, resumeFrom, setTimeBetweenStepsMs, playing };
 }
diff --git a/templates/pie/pie-nonblocking.html b/templates/pie/pie-nonblocking.html
index e18da237..2b0f54e2 100644
--- a/templates/pie/pie-nonblocking.html
+++ b/templates/pie/pie-nonblocking.html
@@ -50,9 +50,17 @@
     // When the pie chart is animating it knows it is advancing rounds, but to avoid reactive
     // loops it requests to be told the new currentRound rather than using 2-way binding.
     // And we also update the slider state while we're at it.
+    //
+    // During auto-play, use resumeFrom() to update the dropdown and reset
+    // the timer without stopping playback. This matters when the pie chart
+    // skips a no-transfer round and needs to advance immediately.
     function updateRound(roundNum) {
         pieChart.currentRound = roundNum;
-        pieRoundPlayer.setStep(roundNum - 1);
+        if (pieRoundPlayer.playing()) {
+            pieRoundPlayer.resumeFrom(roundNum - 1);
+        } else {
+            pieRoundPlayer.setStep(roundNum - 1);
+        }
     }
 
 </script>

From 5cfd2235e1e5e34ce0950d3d146db17ea617f62a Mon Sep 17 00:00:00 2001
From: skaphan <skaphan@gmail.com>
Date: Tue, 7 Apr 2026 21:21:48 -0700
Subject: [PATCH 2/2] Simplify auto-play fix: just skip setStep during playback

Revert round-player.js changes. The simpler approach is to skip
the setStep() call entirely during auto-play so it does not stop
playback. The round player timer catches up on its next tick.

Co-Authored-By: Claude Opus 4.6
---
 static/visualizer/round-player.js  | 12 +-----------
 templates/pie/pie-nonblocking.html |  9 +++------
 2 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/static/visualizer/round-player.js b/static/visualizer/round-player.js
index c10eb070..14914706 100644
--- a/static/visualizer/round-player.js
+++ b/static/visualizer/round-player.js
@@ -158,16 +158,6 @@ function RoundPlayer({
       "Play Animation";
   }
 
-  // Resume playback from a specific step without resetting to round 0.
-  // Used when the pie chart skips a no-transfer round during auto-play
-  // and needs the round player to catch up without interrupting playback.
-  function resumeFrom(step) {
-    changeStep(step);
-    if (!isPlaying) return;
-    window.clearTimeout(timer);
-    nextStep(stepTimeMs);
-  }
-
   function playing() {
     return isPlaying;
   }
@@ -178,5 +168,5 @@ function RoundPlayer({
 
   init();
 
-  return { play, stop, setStep, resumeFrom, setTimeBetweenStepsMs, playing };
+  return { play, stop, setStep, setTimeBetweenStepsMs, playing };
 }
diff --git a/templates/pie/pie-nonblocking.html b/templates/pie/pie-nonblocking.html
index 2b0f54e2..3f7c7385 100644
--- a/templates/pie/pie-nonblocking.html
+++ b/templates/pie/pie-nonblocking.html
@@ -51,14 +51,11 @@
     // loops it requests to be told the new currentRound rather than using 2-way binding.
     // And we also update the slider state while we're at it.
     //
-    // During auto-play, use resumeFrom() to update the dropdown and reset
-    // the timer without stopping playback. This matters when the pie chart
-    // skips a no-transfer round and needs to advance immediately.
+    // During auto-play, skip the setStep() call — it stops playback.
+    // The round player's timer will catch up on its next tick.
     function updateRound(roundNum) {
         pieChart.currentRound = roundNum;
-        if (pieRoundPlayer.playing()) {
-            pieRoundPlayer.resumeFrom(roundNum - 1);
-        } else {
+        if (!pieRoundPlayer.playing()) {
             pieRoundPlayer.setStep(roundNum - 1);
         }
     }