LibWeb/WebAudio: Add DelayNode interface

Author: https://github.com/tcl3
Commit: https://github.com/LadybirdBrowser/ladybird/commit/6c4c925f026
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3125

Libraries/LibWeb/CMakeLists.txt

@@ -797,6 +797,7 @@ set(SOURCES
     WebAudio/ChannelMergerNode.cpp
     WebAudio/ChannelSplitterNode.cpp
     WebAudio/ConstantSourceNode.cpp
+    WebAudio/DelayNode.cpp
     WebAudio/DynamicsCompressorNode.cpp
     WebAudio/GainNode.cpp
     WebAudio/OfflineAudioContext.cpp

Libraries/LibWeb/WebAudio/DelayNode.cpp

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/DelayNodePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/WebAudio/BaseAudioContext.h>
+#include <LibWeb/WebAudio/DelayNode.h>
+
+namespace Web::WebAudio {
+
+GC_DEFINE_ALLOCATOR(DelayNode);
+
+DelayNode::DelayNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, DelayOptions const& options)
+    : AudioNode(realm, context)
+    , m_delay_time(AudioParam::create(realm, options.delay_time, 0, options.max_delay_time, Bindings::AutomationRate::ARate))
+{
+}
+
+DelayNode::~DelayNode() = default;
+
+WebIDL::ExceptionOr<GC::Ref<DelayNode>> DelayNode::create(JS::Realm& realm, GC::Ref<BaseAudioContext> context, DelayOptions const& options)
+{
+    return construct_impl(realm, context, options);
+}
+
+WebIDL::ExceptionOr<GC::Ref<DelayNode>> DelayNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, DelayOptions const& options)
+{
+    // https://webaudio.github.io/web-audio-api/#dom-delayoptions-maxdelaytime
+    // If specified, this value MUST be greater than zero and less than three minutes or a NotSupportedError exception MUST be thrown.
+    static constexpr double maximum_delay_time_seconds = 180;
+    if (options.max_delay_time <= 0 || options.max_delay_time >= maximum_delay_time_seconds || isnan(options.max_delay_time))
+        return WebIDL::NotSupportedError::create(realm, "Max delay time must be between 0 and 180 seconds exclusive"_string);
+
+    auto node = realm.create<DelayNode>(realm, context, options);
+
+    // Default options for channel count and interpretation
+    // https://webaudio.github.io/web-audio-api/#DelayNode
+    AudioNodeDefaultOptions default_options;
+    default_options.channel_count = 2;
+    default_options.channel_count_mode = Bindings::ChannelCountMode::Max;
+    default_options.channel_interpretation = Bindings::ChannelInterpretation::Speakers;
+    // FIXME: Set tail-time to yes
+
+    TRY(node->initialize_audio_node_options(options, default_options));
+
+    return node;
+}
+
+void DelayNode::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(DelayNode);
+}
+
+void DelayNode::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_delay_time);
+}
+
+}

Libraries/LibWeb/WebAudio/DelayNode.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/WebAudio/AudioNode.h>
+
+namespace Web::WebAudio {
+
+// https://webaudio.github.io/web-audio-api/#DelayOptions
+struct DelayOptions : AudioNodeOptions {
+    double max_delay_time { 1 };
+    double delay_time { 0 };
+};
+
+// https://webaudio.github.io/web-audio-api/#DelayNode
+class DelayNode final : public AudioNode {
+    WEB_PLATFORM_OBJECT(DelayNode, AudioNode);
+    GC_DECLARE_ALLOCATOR(DelayNode);
+
+public:
+    virtual ~DelayNode() override;
+
+    static WebIDL::ExceptionOr<GC::Ref<DelayNode>> create(JS::Realm&, GC::Ref<BaseAudioContext>, DelayOptions const& = {});
+    static WebIDL::ExceptionOr<GC::Ref<DelayNode>> construct_impl(JS::Realm&, GC::Ref<BaseAudioContext>, DelayOptions const& = {});
+
+    virtual WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    virtual WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
+    GC::Ref<AudioParam const> delay_time() const { return m_delay_time; }
+
+private:
+    DelayNode(JS::Realm&, GC::Ref<BaseAudioContext>, DelayOptions const&);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+
+    // https://webaudio.github.io/web-audio-api/#dom-delaynode-delaytime
+    GC::Ref<AudioParam> m_delay_time;
+};
+
+}

Libraries/LibWeb/WebAudio/DelayNode.idl

@@ -0,0 +1,16 @@
+#import <WebAudio/AudioNode.idl>
+#import <WebAudio/AudioParam.idl>
+#import <WebAudio/BaseAudioContext.idl>
+
+// https://webaudio.github.io/web-audio-api/#DelayOptions
+dictionary DelayOptions : AudioNodeOptions {
+    double maxDelayTime = 1;
+    double delayTime = 0;
+};
+
+// https://webaudio.github.io/web-audio-api/#DelayNode
+[Exposed=Window]
+interface DelayNode : AudioNode {
+    constructor (BaseAudioContext context, optional DelayOptions options = {});
+    readonly attribute AudioParam delayTime;
+};

Libraries/LibWeb/idl_files.cmake

@@ -372,6 +372,7 @@ libweb_js_bindings(WebAudio/GainNode)
 libweb_js_bindings(WebAudio/ChannelMergerNode)
 libweb_js_bindings(WebAudio/ChannelSplitterNode)
 libweb_js_bindings(WebAudio/ConstantSourceNode)
+libweb_js_bindings(WebAudio/DelayNode)
 libweb_js_bindings(WebAudio/OfflineAudioContext)
 libweb_js_bindings(WebAudio/OscillatorNode)
 libweb_js_bindings(WebAudio/PannerNode)

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -93,6 +93,7 @@ DataTransferItemList
 DataView
 Date
 DecompressionStream
+DelayNode
 DisposableStack
 Document
 DocumentFragment

Tests/LibWeb/Text/expected/wpt-import/webaudio/the-audio-api/the-delaynode-interface/ctor-delay.txt

@@ -0,0 +1,58 @@
+Harness status: OK
+
+Found 53 tests
+
+53 Pass
+Pass	# AUDIT TASK RUNNER STARTED.
+Pass	Executing "initialize"
+Pass	Executing "invalid constructor"
+Pass	Executing "default constructor"
+Pass	Executing "test AudioNodeOptions"
+Pass	Executing "constructor options"
+Pass	Audit report
+Pass	> [initialize] 
+Pass	  context = new OfflineAudioContext(...) did not throw an exception.
+Pass	< [initialize] All assertions passed. (total 1 assertions)
+Pass	> [invalid constructor] 
+Pass	  new DelayNode() threw TypeError: "DelayNode() needs one argument".
+Pass	  new DelayNode(1) threw TypeError: "Not an object of type BaseAudioContext".
+Pass	  new DelayNode(context, 42) threw TypeError: "Not an object of type DelayOptions".
+Pass	< [invalid constructor] All assertions passed. (total 3 assertions)
+Pass	> [default constructor] 
+Pass	  node0 = new DelayNode(context) did not throw an exception.
+Pass	  node0 instanceof DelayNode is equal to true.
+Pass	  node0.numberOfInputs is equal to 1.
+Pass	  node0.numberOfOutputs is equal to 1.
+Pass	  node0.channelCount is equal to 2.
+Pass	  node0.channelCountMode is equal to max.
+Pass	  node0.channelInterpretation is equal to speakers.
+Pass	  node0.delayTime.value is equal to 0.
+Pass	< [default constructor] All assertions passed. (total 8 assertions)
+Pass	> [test AudioNodeOptions] 
+Pass	  new DelayNode(c, {channelCount: 17}) did not throw an exception.
+Pass	  node.channelCount is equal to 17.
+Pass	  new DelayNode(c, {channelCount: 0}) threw NotSupportedError: "Invalid channel count".
+Pass	  new DelayNode(c, {channelCount: 99}) threw NotSupportedError: "Invalid channel count".
+Pass	  new DelayNode(c, {channelCountMode: "max"} did not throw an exception.
+Pass	  node.channelCountMode is equal to max.
+Pass	  new DelayNode(c, {channelCountMode: "max"}) did not throw an exception.
+Pass	  node.channelCountMode after valid setter is equal to max.
+Pass	  new DelayNode(c, {channelCountMode: "clamped-max"}) did not throw an exception.
+Pass	  node.channelCountMode after valid setter is equal to clamped-max.
+Pass	  new DelayNode(c, {channelCountMode: "explicit"}) did not throw an exception.
+Pass	  node.channelCountMode after valid setter is equal to explicit.
+Pass	  new DelayNode(c, {channelCountMode: "foobar"} threw TypeError: "Invalid value 'foobar' for enumeration type 'ChannelCountMode'".
+Pass	  node.channelCountMode after invalid setter is equal to explicit.
+Pass	  new DelayNode(c, {channelInterpretation: "speakers"}) did not throw an exception.
+Pass	  node.channelInterpretation is equal to speakers.
+Pass	  new DelayNode(c, {channelInterpretation: "discrete"}) did not throw an exception.
+Pass	  node.channelInterpretation is equal to discrete.
+Pass	  new DelayNode(c, {channelInterpretation: "foobar"}) threw TypeError: "Invalid value 'foobar' for enumeration type 'ChannelInterpretation'".
+Pass	  node.channelInterpretation after invalid setter is equal to discrete.
+Pass	< [test AudioNodeOptions] All assertions passed. (total 20 assertions)
+Pass	> [constructor options] 
+Pass	  node1 = new DelayNode(c, {"delayTime":0.5,"maxDelayTime":1.5}) did not throw an exception.
+Pass	  node1.delayTime.value is equal to 0.5.
+Pass	  node1.delayTime.maxValue is equal to 1.5.
+Pass	< [constructor options] All assertions passed. (total 3 assertions)
+Pass	# AUDIT TASK RUNNER FINISHED: 5 tasks ran successfully.

Tests/LibWeb/Text/input/wpt-import/webaudio/the-audio-api/the-delaynode-interface/ctor-delay.html

@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>
+      Test Constructor: Delay
+    </title>
+    <script src="../../../resources/testharness.js"></script>
+    <script src="../../../resources/testharnessreport.js"></script>
+    <script src="../../../webaudio/resources/audit-util.js"></script>
+    <script src="../../../webaudio/resources/audit.js"></script>
+    <script src="../../../webaudio/resources/audionodeoptions.js"></script>
+  </head>
+  <body>
+    <script id="layout-test-code">
+      let context;
+
+      let audit = Audit.createTaskRunner();
+
+      audit.define('initialize', (task, should) => {
+        context = initializeContext(should);
+        task.done();
+      });
+
+      audit.define('invalid constructor', (task, should) => {
+        testInvalidConstructor(should, 'DelayNode', context);
+        task.done();
+      });
+
+      audit.define('default constructor', (task, should) => {
+        let prefix = 'node0';
+        let node = testDefaultConstructor(should, 'DelayNode', context, {
+          prefix: prefix,
+          numberOfInputs: 1,
+          numberOfOutputs: 1,
+          channelCount: 2,
+          channelCountMode: 'max',
+          channelInterpretation: 'speakers'
+        });
+
+        testDefaultAttributes(
+            should, node, prefix, [{name: 'delayTime', value: 0}]);
+
+        task.done();
+      });
+
+      audit.define('test AudioNodeOptions', (task, should) => {
+        testAudioNodeOptions(should, context, 'DelayNode');
+        task.done();
+      });
+
+      audit.define('constructor options', (task, should) => {
+        let node;
+        let options = {
+          delayTime: 0.5,
+          maxDelayTime: 1.5,
+        };
+
+        should(
+            () => {
+              node = new DelayNode(context, options);
+            },
+            'node1 = new DelayNode(c, ' + JSON.stringify(options) + ')')
+            .notThrow();
+
+        should(node.delayTime.value, 'node1.delayTime.value')
+            .beEqualTo(options.delayTime);
+        should(node.delayTime.maxValue, 'node1.delayTime.maxValue')
+            .beEqualTo(options.maxDelayTime);
+
+        task.done();
+      });
+
+      audit.run();
+    </script>
+  </body>
+</html>