LibWeb: Initialize OfflineAudioContext with correct defaults

Author: https://github.com/tcl3
Commit: 27dbe49f00
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3175
Reviewed-by: https://github.com/AtkinsSJ ✅

Libraries/LibWeb/WebAudio/AudioContext.cpp

@@ -11,6 +11,7 @@
 #include <LibWeb/HTML/Scripting/TemporaryExecutionContext.h>
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/WebAudio/AudioContext.h>
+#include <LibWeb/WebAudio/AudioDestinationNode.h>
 #include <LibWeb/WebIDL/Promise.h>
 
 namespace Web::WebAudio {
@@ -20,7 +21,9 @@ GC_DEFINE_ALLOCATOR(AudioContext);
 // https://webaudio.github.io/web-audio-api/#dom-audiocontext-audiocontext
 WebIDL::ExceptionOr<GC::Ref<AudioContext>> AudioContext::construct_impl(JS::Realm& realm, AudioContextOptions const& context_options)
 {
-    return realm.create<AudioContext>(realm, context_options);
+    auto context = realm.create<AudioContext>(realm, context_options);
+    context->m_destination = TRY(AudioDestinationNode::construct_impl(realm, context));
+    return context;
 }
 
 AudioContext::AudioContext(JS::Realm& realm, AudioContextOptions const& context_options)

Libraries/LibWeb/WebAudio/AudioDestinationNode.cpp

@@ -17,8 +17,8 @@ namespace Web::WebAudio {
 
 GC_DEFINE_ALLOCATOR(AudioDestinationNode);
 
-AudioDestinationNode::AudioDestinationNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context)
-    : AudioNode(realm, context)
+AudioDestinationNode::AudioDestinationNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, WebIDL::UnsignedLong channel_count)
+    : AudioNode(realm, context, channel_count)
 {
 }
 
@@ -31,9 +31,21 @@ WebIDL::UnsignedLong AudioDestinationNode::max_channel_count()
     return 2;
 }
 
-GC::Ref<AudioDestinationNode> AudioDestinationNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context)
+WebIDL::ExceptionOr<GC::Ref<AudioDestinationNode>> AudioDestinationNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, WebIDL::UnsignedLong channel_count)
 {
-    return realm.create<AudioDestinationNode>(realm, context);
+    auto node = realm.create<AudioDestinationNode>(realm, context, channel_count);
+
+    // Default options for channel count and interpretation
+    // https://webaudio.github.io/web-audio-api/#AudioDestinationNode
+    AudioNodeDefaultOptions default_options;
+    default_options.channel_count_mode = Bindings::ChannelCountMode::Explicit;
+    default_options.channel_interpretation = Bindings::ChannelInterpretation::Speakers;
+    default_options.channel_count = channel_count;
+    // FIXME: Set tail-time to no
+
+    TRY(node->initialize_audio_node_options({}, default_options));
+
+    return node;
 }
 
 void AudioDestinationNode::initialize(JS::Realm& realm)
@@ -50,6 +62,9 @@ void AudioDestinationNode::visit_edges(Cell::Visitor& visitor)
 // https://webaudio.github.io/web-audio-api/#dom-audionode-channelcount
 WebIDL::ExceptionOr<void> AudioDestinationNode::set_channel_count(WebIDL::UnsignedLong channel_count)
 {
+    if (channel_count == this->channel_count())
+        return {};
+
     // The behavior depends on whether the destination node is the destination of an AudioContext
     // or OfflineAudioContext:
 

Libraries/LibWeb/WebAudio/AudioDestinationNode.h

@@ -27,10 +27,10 @@ public:
     WebIDL::UnsignedLong number_of_outputs() override { return 1; }
     WebIDL::ExceptionOr<void> set_channel_count(WebIDL::UnsignedLong) override;
 
-    static GC::Ref<AudioDestinationNode> construct_impl(JS::Realm&, GC::Ref<BaseAudioContext>);
+    static WebIDL::ExceptionOr<GC::Ref<AudioDestinationNode>> construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, WebIDL::UnsignedLong channel_count = 2);
 
 protected:
-    AudioDestinationNode(JS::Realm&, GC::Ref<BaseAudioContext>);
+    AudioDestinationNode(JS::Realm&, GC::Ref<BaseAudioContext>, WebIDL::UnsignedLong channel_count);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;

Libraries/LibWeb/WebAudio/AudioNode.cpp

@@ -12,9 +12,10 @@ namespace Web::WebAudio {
 
 GC_DEFINE_ALLOCATOR(AudioNode);
 
-AudioNode::AudioNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context)
+AudioNode::AudioNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, WebIDL::UnsignedLong channel_count)
     : DOM::EventTarget(realm)
     , m_context(context)
+    , m_channel_count(channel_count)
 
 {
 }

Libraries/LibWeb/WebAudio/AudioNode.h

@@ -71,7 +71,7 @@ public:
     WebIDL::ExceptionOr<void> initialize_audio_node_options(AudioNodeOptions const& given_options, AudioNodeDefaultOptions const& default_options);
 
 protected:
-    AudioNode(JS::Realm&, GC::Ref<BaseAudioContext>);
+    AudioNode(JS::Realm&, GC::Ref<BaseAudioContext>, WebIDL::UnsignedLong channel_count = 2);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;

Libraries/LibWeb/WebAudio/BaseAudioContext.cpp

@@ -28,7 +28,6 @@ namespace Web::WebAudio {
 
 BaseAudioContext::BaseAudioContext(JS::Realm& realm, float sample_rate)
     : DOM::EventTarget(realm)
-    , m_destination(AudioDestinationNode::construct_impl(realm, *this))
     , m_sample_rate(sample_rate)
     , m_listener(AudioListener::create(realm))
 {

Libraries/LibWeb/WebAudio/BaseAudioContext.h

@@ -40,7 +40,7 @@ public:
     static constexpr float MIN_SAMPLE_RATE { 8000 };
     static constexpr float MAX_SAMPLE_RATE { 192000 };
 
-    GC::Ref<AudioDestinationNode> destination() const { return m_destination; }
+    GC::Ref<AudioDestinationNode> destination() const { return *m_destination; }
     float sample_rate() const { return m_sample_rate; }
     double current_time() const { return m_current_time; }
     GC::Ref<AudioListener> listener() const { return m_listener; }
@@ -80,7 +80,7 @@ protected:
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
-    GC::Ref<AudioDestinationNode> m_destination;
+    GC::Ptr<AudioDestinationNode> m_destination;
     Vector<GC::Ref<WebIDL::Promise>> m_pending_promises;
 
 private:

Libraries/LibWeb/WebAudio/OfflineAudioContext.cpp

@@ -7,6 +7,7 @@
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/HTML/EventNames.h>
 #include <LibWeb/HTML/Window.h>
+#include <LibWeb/WebAudio/AudioDestinationNode.h>
 #include <LibWeb/WebAudio/OfflineAudioContext.h>
 
 namespace Web::WebAudio {
@@ -26,7 +27,9 @@ WebIDL::ExceptionOr<GC::Ref<OfflineAudioContext>> OfflineAudioContext::construct
     // A NotSupportedError exception MUST be thrown if any of the arguments is negative, zero, or outside its nominal range.
     TRY(verify_audio_options_inside_nominal_range(realm, number_of_channels, length, sample_rate));
 
-    return realm.create<OfflineAudioContext>(realm, number_of_channels, length, sample_rate);
+    auto context = realm.create<OfflineAudioContext>(realm, length, sample_rate);
+    context->m_destination = TRY(AudioDestinationNode::construct_impl(realm, context, number_of_channels));
+    return context;
 }
 
 OfflineAudioContext::~OfflineAudioContext() = default;
@@ -67,16 +70,10 @@ void OfflineAudioContext::set_oncomplete(GC::Ptr<WebIDL::CallbackType> value)
     set_event_handler_attribute(HTML::EventNames::complete, value);
 }
 
-OfflineAudioContext::OfflineAudioContext(JS::Realm& realm, OfflineAudioContextOptions const&)
-    : BaseAudioContext(realm)
-{
-}
-
-OfflineAudioContext::OfflineAudioContext(JS::Realm& realm, WebIDL::UnsignedLong number_of_channels, WebIDL::UnsignedLong length, float sample_rate)
+OfflineAudioContext::OfflineAudioContext(JS::Realm& realm, WebIDL::UnsignedLong length, float sample_rate)
     : BaseAudioContext(realm, sample_rate)
     , m_length(length)
 {
-    (void)number_of_channels;
 }
 
 void OfflineAudioContext::initialize(JS::Realm& realm)

Libraries/LibWeb/WebAudio/OfflineAudioContext.h

@@ -42,8 +42,7 @@ public:
     void set_oncomplete(GC::Ptr<WebIDL::CallbackType>);
 
 private:
-    OfflineAudioContext(JS::Realm&, OfflineAudioContextOptions const&);
-    OfflineAudioContext(JS::Realm&, WebIDL::UnsignedLong number_of_channels, WebIDL::UnsignedLong length, float sample_rate);
+    OfflineAudioContext(JS::Realm&, WebIDL::UnsignedLong length, float sample_rate);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;