LibWeb: Implement the AudioTrack and AudioTrackList interfaces

These are used to own and manage the playing of audio data.

Userland/Libraries/LibWeb/HTML/AudioTrackList.cpp

@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Realm.h>
+#include <LibJS/Runtime/VM.h>
+#include <LibWeb/Bindings/AudioTrackListPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/HTML/AudioTrackList.h>
+#include <LibWeb/HTML/EventNames.h>
+
+namespace Web::HTML {
+
+AudioTrackList::AudioTrackList(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+    , m_audio_tracks(realm.heap())
+{
+}
+
+JS::ThrowCompletionOr<void> AudioTrackList::initialize(JS::Realm& realm)
+{
+    MUST_OR_THROW_OOM(Base::initialize(realm));
+    set_prototype(&Bindings::ensure_web_prototype<Bindings::AudioTrackListPrototype>(realm, "AudioTrackList"));
+
+    return {};
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#dom-tracklist-item
+JS::ThrowCompletionOr<Optional<JS::PropertyDescriptor>> AudioTrackList::internal_get_own_property(JS::PropertyKey const& property_name) const
+{
+    // To determine the value of an indexed property for a given index index in an AudioTrackList or VideoTrackList
+    // object list, the user agent must return the AudioTrack or VideoTrack object that represents the indexth track
+    // in list.
+    if (property_name.is_number()) {
+        if (auto index = property_name.as_number(); index < m_audio_tracks.size()) {
+            JS::PropertyDescriptor descriptor;
+            descriptor.value = m_audio_tracks.at(index);
+
+            return descriptor;
+        }
+    }
+
+    return Base::internal_get_own_property(property_name);
+}
+
+ErrorOr<void> AudioTrackList::add_track(Badge<HTMLMediaElement>, JS::NonnullGCPtr<AudioTrack> audio_track)
+{
+    TRY(m_audio_tracks.try_append(audio_track));
+    audio_track->set_audio_track_list({}, this);
+
+    return {};
+}
+
+void AudioTrackList::remove_all_tracks(Badge<HTMLMediaElement>)
+{
+    m_audio_tracks.clear();
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#dom-audiotracklist-gettrackbyid
+JS::GCPtr<AudioTrack> AudioTrackList::get_track_by_id(StringView id) const
+{
+    // The AudioTrackList getTrackById(id) and VideoTrackList getTrackById(id) methods must return the first AudioTrack
+    // or VideoTrack object (respectively) in the AudioTrackList or VideoTrackList object (respectively) whose identifier
+    // is equal to the value of the id argument (in the natural order of the list, as defined above).
+    auto it = m_audio_tracks.find_if([&](auto const& audio_track) {
+        return audio_track->id() == id;
+    });
+
+    // When no tracks match the given argument, the methods must return null.
+    if (it == m_audio_tracks.end())
+        return nullptr;
+
+    return *it;
+}
+
+bool AudioTrackList::has_enabled_track() const
+{
+    auto it = m_audio_tracks.find_if([&](auto const& audio_track) {
+        return audio_track->enabled();
+    });
+
+    return it != m_audio_tracks.end();
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onchange
+void AudioTrackList::set_onchange(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::change, event_handler);
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onchange
+WebIDL::CallbackType* AudioTrackList::onchange()
+{
+    return event_handler_attribute(HTML::EventNames::change);
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onaddtrack
+void AudioTrackList::set_onaddtrack(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::addtrack, event_handler);
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onaddtrack
+WebIDL::CallbackType* AudioTrackList::onaddtrack()
+{
+    return event_handler_attribute(HTML::EventNames::addtrack);
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onremovetrack
+void AudioTrackList::set_onremovetrack(WebIDL::CallbackType* event_handler)
+{
+    set_event_handler_attribute(HTML::EventNames::removetrack, event_handler);
+}
+
+// https://html.spec.whatwg.org/multipage/media.html#handler-tracklist-onremovetrack
+WebIDL::CallbackType* AudioTrackList::onremovetrack()
+{
+    return event_handler_attribute(HTML::EventNames::removetrack);
+}
+
+}