LibWeb: Add ConstantSourceNode interface

Author: https://github.com/tcl3
Commit: 1b160044c4
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3102
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/WebAudio/ConstantSourceNode.cpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/NumericLimits.h>
+#include <LibWeb/Bindings/ConstantSourceNodePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/WebAudio/BaseAudioContext.h>
+#include <LibWeb/WebAudio/ConstantSourceNode.h>
+
+namespace Web::WebAudio {
+
+GC_DEFINE_ALLOCATOR(ConstantSourceNode);
+
+ConstantSourceNode::ConstantSourceNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ConstantSourceOptions const& options)
+    : AudioScheduledSourceNode(realm, context)
+    , m_offset(AudioParam::create(realm, options.offset, NumericLimits<float>::lowest(), NumericLimits<float>::max(), Bindings::AutomationRate::ARate))
+{
+}
+
+ConstantSourceNode::~ConstantSourceNode() = default;
+
+WebIDL::ExceptionOr<GC::Ref<ConstantSourceNode>> ConstantSourceNode::create(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ConstantSourceOptions const& options)
+{
+    return construct_impl(realm, context, options);
+}
+
+WebIDL::ExceptionOr<GC::Ref<ConstantSourceNode>> ConstantSourceNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, ConstantSourceOptions const& options)
+{
+    return realm.create<ConstantSourceNode>(realm, context, options);
+}
+
+void ConstantSourceNode::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(ConstantSourceNode);
+}
+
+void ConstantSourceNode::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_offset);
+}
+
+}

Libraries/LibWeb/WebAudio/ConstantSourceNode.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/WebAudio/AudioScheduledSourceNode.h>
+
+namespace Web::WebAudio {
+
+// https://webaudio.github.io/web-audio-api/#ChannelMergerOptions
+struct ConstantSourceOptions : AudioNodeOptions {
+    float offset { 1.0f };
+};
+
+// https://webaudio.github.io/web-audio-api/#ChannelMergerNode
+class ConstantSourceNode final : public AudioScheduledSourceNode {
+    WEB_PLATFORM_OBJECT(ConstantSourceNode, AudioScheduledSourceNode);
+    GC_DECLARE_ALLOCATOR(ConstantSourceNode);
+
+public:
+    virtual ~ConstantSourceNode() override;
+
+    static WebIDL::ExceptionOr<GC::Ref<ConstantSourceNode>> create(JS::Realm&, GC::Ref<BaseAudioContext>, ConstantSourceOptions const& = {});
+    static WebIDL::ExceptionOr<GC::Ref<ConstantSourceNode>> construct_impl(JS::Realm&, GC::Ref<BaseAudioContext>, ConstantSourceOptions const& = {});
+
+    virtual WebIDL::UnsignedLong number_of_inputs() override { return 0; }
+    virtual WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
+    GC::Ref<AudioParam const> offset() const { return m_offset; }
+
+private:
+    ConstantSourceNode(JS::Realm&, GC::Ref<BaseAudioContext>, ConstantSourceOptions const&);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+
+    // https://webaudio.github.io/web-audio-api/#dom-constantsourcenode-offset
+    GC::Ref<AudioParam> m_offset;
+};
+
+}

Libraries/LibWeb/WebAudio/ConstantSourceNode.idl

@@ -0,0 +1,15 @@
+#import <WebAudio/AudioNode.idl>
+#import <WebAudio/AudioParam.idl>
+#import <WebAudio/BaseAudioContext.idl>
+
+// https://webaudio.github.io/web-audio-api/#ConstantSourceOptions
+dictionary ConstantSourceOptions {
+    float offset = 1;
+};
+
+// https://webaudio.github.io/web-audio-api/#ConstantSourceNode
+[Exposed=Window]
+interface ConstantSourceNode : AudioScheduledSourceNode {
+    constructor (BaseAudioContext context, optional ConstantSourceOptions options = {});
+    readonly attribute AudioParam offset;
+};