LibWeb: Add StereoPannerNode interface

Author: https://github.com/tcl3
Commit: 56907e2de6
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3291

Libraries/LibWeb/WebAudio/StereoPannerNode.cpp

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/WebAudio/AudioNode.h>
+#include <LibWeb/WebAudio/AudioParam.h>
+#include <LibWeb/WebAudio/BaseAudioContext.h>
+#include <LibWeb/WebAudio/StereoPannerNode.h>
+
+namespace Web::WebAudio {
+
+GC_DEFINE_ALLOCATOR(StereoPannerNode);
+
+StereoPannerNode::~StereoPannerNode() = default;
+
+WebIDL::ExceptionOr<GC::Ref<StereoPannerNode>> StereoPannerNode::create(JS::Realm& realm, GC::Ref<BaseAudioContext> context, StereoPannerOptions const& options)
+{
+    return construct_impl(realm, context, options);
+}
+
+// https://webaudio.github.io/web-audio-api/#dom-stereopannernode-stereopannernode
+WebIDL::ExceptionOr<GC::Ref<StereoPannerNode>> StereoPannerNode::construct_impl(JS::Realm& realm, GC::Ref<BaseAudioContext> context, StereoPannerOptions const& options)
+{
+    // Create the node and allocate memory
+    auto node = realm.create<StereoPannerNode>(realm, context, options);
+
+    // Default options for channel count and interpretation
+    // https://webaudio.github.io/web-audio-api/#stereopannernode
+    AudioNodeDefaultOptions default_options;
+    default_options.channel_count_mode = Bindings::ChannelCountMode::ClampedMax;
+    default_options.channel_interpretation = Bindings::ChannelInterpretation::Speakers;
+    default_options.channel_count = 2;
+    // FIXME: Set tail-time to no
+
+    TRY(node->initialize_audio_node_options(options, default_options));
+    return node;
+}
+
+// https://webaudio.github.io/web-audio-api/#dom-audionode-channelcountmode
+WebIDL::ExceptionOr<void> StereoPannerNode::set_channel_count_mode(Bindings::ChannelCountMode mode)
+{
+    // https://webaudio.github.io/web-audio-api/#audionode-channelcountmode-constraints
+    // The channel count mode cannot be set to "max", and a NotSupportedError exception MUST be thrown for any attempt to set it to "max".
+    if (mode == Bindings::ChannelCountMode::Max) {
+        return WebIDL::NotSupportedError::create(realm(), "StereoPannerNode does not support 'max' as channelCountMode."_string);
+    }
+
+    // If the mode is valid, call the base class implementation
+    return AudioNode::set_channel_count_mode(mode);
+}
+
+// https://webaudio.github.io/web-audio-api/#dom-audionode-channelcount
+WebIDL::ExceptionOr<void> StereoPannerNode::set_channel_count(WebIDL::UnsignedLong channel_count)
+{
+    // https://webaudio.github.io/web-audio-api/#audionode-channelcount-constraints
+    // The channel count cannot be greater than two, and a NotSupportedError exception MUST be thrown for any attempt to change it to a value greater than two.
+    if (channel_count > 2) {
+        return WebIDL::NotSupportedError::create(realm(), "StereoPannerNode does not support channel count greater than 2"_string);
+    }
+
+    return AudioNode::set_channel_count(channel_count);
+}
+
+StereoPannerNode::StereoPannerNode(JS::Realm& realm, GC::Ref<BaseAudioContext> context, StereoPannerOptions const& options)
+    : AudioNode(realm, context)
+    , m_pan(AudioParam::create(realm, context, options.pan, -1, 1, Bindings::AutomationRate::ARate))
+{
+}
+
+void StereoPannerNode::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(StereoPannerNode);
+}
+
+void StereoPannerNode::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_pan);
+}
+
+}

Libraries/LibWeb/WebAudio/StereoPannerNode.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/StereoPannerNodePrototype.h>
+#include <LibWeb/WebAudio/AudioNode.h>
+
+namespace Web::WebAudio {
+
+// https://webaudio.github.io/web-audio-api/#StereoPannerOptions
+struct StereoPannerOptions : AudioNodeOptions {
+    float pan { 0 };
+};
+
+// https://webaudio.github.io/web-audio-api/#stereopannernode
+class StereoPannerNode : public AudioNode {
+    WEB_PLATFORM_OBJECT(StereoPannerNode, AudioNode);
+    GC_DECLARE_ALLOCATOR(StereoPannerNode);
+
+public:
+    virtual ~StereoPannerNode() override;
+
+    static WebIDL::ExceptionOr<GC::Ref<StereoPannerNode>> create(JS::Realm&, GC::Ref<BaseAudioContext>, StereoPannerOptions const& = {});
+    static WebIDL::ExceptionOr<GC::Ref<StereoPannerNode>> construct_impl(JS::Realm&, GC::Ref<BaseAudioContext>, StereoPannerOptions const& = {});
+
+    WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
+    WebIDL::ExceptionOr<void> set_channel_count_mode(Bindings::ChannelCountMode) override;
+    WebIDL::ExceptionOr<void> set_channel_count(WebIDL::UnsignedLong) override;
+
+    GC::Ref<AudioParam const> pan() const { return m_pan; }
+
+protected:
+    StereoPannerNode(JS::Realm&, GC::Ref<BaseAudioContext>, StereoPannerOptions const& = {});
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+
+private:
+    // https://webaudio.github.io/web-audio-api/#dom-stereopannernode-pan
+    GC::Ref<AudioParam> m_pan;
+};
+
+}

Libraries/LibWeb/WebAudio/StereoPannerNode.idl

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+#import <WebAudio/AudioNode.idl>
+#import <WebAudio/AudioParam.idl>
+#import <WebAudio/BaseAudioContext.idl>
+
+// https://webaudio.github.io/web-audio-api/#StereoPannerOptions
+dictionary StereoPannerOptions : AudioNodeOptions {
+    float pan = 0;
+};
+
+// https://webaudio.github.io/web-audio-api/#stereopannernode
+[Exposed=Window]
+interface StereoPannerNode : AudioNode {
+    constructor (BaseAudioContext context, optional StereoPannerOptions options = {});
+    readonly attribute AudioParam pan;
+};