From 9648d30aa25cda674aaa860074bab766b5631205 Mon Sep 17 00:00:00 2001
From: Tamius Han <tamius.han@gmail.com>
Date: Fri, 6 May 2022 00:28:13 +0200
Subject: [PATCH] If videoData is destroyed, remove its eventBus from
 pageInfo's downstream buses

---
 src/ext/lib/EventBus.ts             | 15 +++++++++++++++
 src/ext/lib/video-data/VideoData.ts |  1 +
 2 files changed, 16 insertions(+)

diff --git a/src/ext/lib/EventBus.ts b/src/ext/lib/EventBus.ts
index 4c2da13..5b049f7 100644
--- a/src/ext/lib/EventBus.ts
+++ b/src/ext/lib/EventBus.ts
@@ -16,6 +16,14 @@ export default class EventBus {
       this.upstreamBus.addDownstreamBus(this, true);
     }
   }
+
+  unsetUpstreamBus(stopRecursing: boolean = false) {
+    if (!stopRecursing) {
+      this.upstreamBus.removeDownstreamBus(this, false);
+    }
+    this.upstreamBus = undefined;
+  }
+
   addDownstreamBus(eventBus: EventBus, stopRecursing: boolean = false) {
     if (!this.downstreamBuses.includes(eventBus)) {
       this.downstreamBuses.push(eventBus);
@@ -26,6 +34,13 @@ export default class EventBus {
     }
   }
 
+  removeDownstreamBus(eventBus: EventBus, stopRecursing: boolean = false) {
+    this.downstreamBuses = this.downstreamBuses.filter(x => x !== eventBus);
+    if (!stopRecursing) {
+      eventBus.unsetUpstreamBus(true);
+    }
+  }
+
   subscribe(commandString: string, command: EventBusCommand) {
     if (!this.commands[commandString]) {
       this.commands[commandString] = [command];
diff --git a/src/ext/lib/video-data/VideoData.ts b/src/ext/lib/video-data/VideoData.ts
index c99f11a..b060a14 100644
--- a/src/ext/lib/video-data/VideoData.ts
+++ b/src/ext/lib/video-data/VideoData.ts
@@ -332,6 +332,7 @@ class VideoData {
 
     this.disable();
     this.destroyed = true;
+    this.eventBus?.unsetUpstreamBus();
     try {
       this.arDetector.halt();
       this.arDetector.destroy();