From 2ef4a51c39a79211158a62e2b64d3a2a854cb2e5 Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Mon, 10 Apr 2023 09:52:53 -0400
Subject: [PATCH] LibWeb: Move dispatching timeupdate events to a helper for
 tracking

For some media APIs, we will need to know whether we are currently in an
event handler for the timeupdate event, and the last time we fired the
event.
---
 Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp | 13 ++++++++++++-
 Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h   |  6 ++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
index 26dfe6740f..b3b8d10048 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
@@ -929,7 +929,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::pause_element()
             auto& realm = this->realm();
 
             // 1. Fire an event named timeupdate at the element.
-            dispatch_event(DOM::Event::create(realm, HTML::EventNames::timeupdate).release_value_but_fixme_should_propagate_errors());
+            dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
 
             // 2. Fire an event named pause at the element.
             dispatch_event(DOM::Event::create(realm, HTML::EventNames::pause).release_value_but_fixme_should_propagate_errors());
@@ -973,6 +973,17 @@ void HTMLMediaElement::set_paused(bool paused)
         on_paused();
 }
 
+WebIDL::ExceptionOr<void> HTMLMediaElement::dispatch_time_update_event()
+{
+    ScopeGuard guard { [this] { m_running_time_update_event_handler = false; } };
+    m_running_time_update_event_handler = true;
+
+    m_last_time_update_event_time = Time::now_monotonic();
+
+    dispatch_event(TRY(DOM::Event::create(realm(), HTML::EventNames::timeupdate)));
+    return {};
+}
+
 // https://html.spec.whatwg.org/multipage/media.html#take-pending-play-promises
 JS::MarkedVector<JS::NonnullGCPtr<WebIDL::Promise>> HTMLMediaElement::take_pending_play_promises()
 {
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
index 93c48fe05a..d5e958ef40 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
@@ -8,6 +8,7 @@
 #pragma once
 
 #include <AK/ByteBuffer.h>
+#include <AK/Time.h>
 #include <AK/Variant.h>
 #include <LibJS/Heap/MarkedVector.h>
 #include <LibJS/SafeFunction.h>
@@ -87,6 +88,8 @@ private:
     void set_paused(bool);
     void set_duration(double);
 
+    WebIDL::ExceptionOr<void> dispatch_time_update_event();
+
     JS::MarkedVector<JS::NonnullGCPtr<WebIDL::Promise>> take_pending_play_promises();
     void resolve_pending_play_promises(ReadonlySpan<JS::NonnullGCPtr<WebIDL::Promise>> promises);
     void reject_pending_play_promises(ReadonlySpan<JS::NonnullGCPtr<WebIDL::Promise>> promises, JS::NonnullGCPtr<WebIDL::DOMException> error);
@@ -126,6 +129,9 @@ private:
     // https://html.spec.whatwg.org/multipage/media.html#media-data
     ByteBuffer m_media_data;
 
+    bool m_running_time_update_event_handler { false };
+    Optional<Time> m_last_time_update_event_time;
+
     JS::GCPtr<Fetch::Infrastructure::FetchController> m_fetch_controller;
 };