LibWeb: Add StereoPannerNode interface

Author: https://github.com/tcl3
Commit: https://github.com/LadybirdBrowser/ladybird/commit/56907e2de65
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3291

Libraries/LibWeb/CMakeLists.txt

@@ -805,6 +805,7 @@ set(SOURCES
     WebAudio/OscillatorNode.cpp
     WebAudio/PannerNode.cpp
     WebAudio/PeriodicWave.cpp
+    WebAudio/StereoPannerNode.cpp
     WebDriver/Actions.cpp
     WebDriver/Capabilities.cpp
     WebDriver/Client.cpp

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

@@ -0,0 +1,15 @@
+#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;
+};

Libraries/LibWeb/idl_files.cmake

@@ -379,6 +379,7 @@ libweb_js_bindings(WebAudio/OfflineAudioContext)
 libweb_js_bindings(WebAudio/OscillatorNode)
 libweb_js_bindings(WebAudio/PannerNode)
 libweb_js_bindings(WebAudio/PeriodicWave)
+libweb_js_bindings(WebAudio/StereoPannerNode)
 libweb_js_bindings(WebGL/ANGLEInstancedArrays)
 libweb_js_bindings(WebGL/WebGL2RenderingContext)
 libweb_js_bindings(WebGL/WebGLActiveInfo)

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

@@ -362,6 +362,7 @@ SharedArrayBuffer
 SourceBuffer
 SourceBufferList
 StaticRange
+StereoPannerNode
 Storage
 StorageEvent
 StorageManager

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

@@ -0,0 +1,56 @@
+Harness status: OK
+
+Found 51 tests
+
+51 Pass
+Pass	# AUDIT TASK RUNNER STARTED.
+Pass	Executing "initialize"
+Pass	Executing "invalid constructor"
+Pass	Executing "default constructor"
+Pass	Executing "test AudioNodeOptions"
+Pass	Executing "constructor with 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 StereoPannerNode() threw TypeError: "StereoPannerNode() needs one argument".
+Pass	  new StereoPannerNode(1) threw TypeError: "Not an object of type BaseAudioContext".
+Pass	  new StereoPannerNode(context, 42) threw TypeError: "Not an object of type StereoPannerOptions".
+Pass	< [invalid constructor] All assertions passed. (total 3 assertions)
+Pass	> [default constructor] 
+Pass	  node0 = new StereoPannerNode(context) did not throw an exception.
+Pass	  node0 instanceof StereoPannerNode 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 clamped-max.
+Pass	  node0.channelInterpretation is equal to speakers.
+Pass	  node0.pan.value is equal to 0.
+Pass	< [default constructor] All assertions passed. (total 8 assertions)
+Pass	> [test AudioNodeOptions] 
+Pass	  new StereoPannerNode(c, {"channelCount":1}) did not throw an exception.
+Pass	  node.channelCount is equal to 1.
+Pass	  new StereoPannerNode(c, {"channelCount":2}) did not throw an exception.
+Pass	  node.channelCount is equal to 2.
+Pass	  new StereoPannerNode(c, {"channelCount":0}) threw NotSupportedError: "Invalid channel count".
+Pass	  new StereoPannerNode(c, {"channelCount":3}) threw NotSupportedError: "StereoPannerNode does not support channel count greater than 2".
+Pass	  new StereoPannerNode(c, {"channelCount":99}) threw NotSupportedError: "StereoPannerNode does not support channel count greater than 2".
+Pass	  new StereoPannerNode(c, {"channelCountMode":"clamped-max"}) did not throw an exception.
+Pass	  node.channelCountMode is equal to clamped-max.
+Pass	  new StereoPannerNode(c, {"channelCountMode":"explicit"}) did not throw an exception.
+Pass	  node.channelCountMode is equal to explicit.
+Pass	  new StereoPannerNode(c, {"channelCountMode":"max"}) threw NotSupportedError: "StereoPannerNode does not support 'max' as channelCountMode.".
+Pass	  new StereoPannerNode(c, {"channelCountMode":"foobar"}) threw TypeError: "Invalid value 'foobar' for enumeration type 'ChannelCountMode'".
+Pass	  new StereoPannerNode(c, {"channelInterpretation":"speakers"}) did not throw an exception.
+Pass	  node.channelInterpretation is equal to speakers.
+Pass	  new StereoPannerNode(c, {"channelInterpretation":"discrete"}) did not throw an exception.
+Pass	  node.channelInterpretation is equal to discrete.
+Pass	  new StereoPannerNode(c, {"channelInterpretation":"foobar"}) threw TypeError: "Invalid value 'foobar' for enumeration type 'ChannelInterpretation'".
+Pass	< [test AudioNodeOptions] All assertions passed. (total 18 assertions)
+Pass	> [constructor with options] 
+Pass	  node1 = new StereoPannerNode(, {"pan":0.75}) did not throw an exception.
+Pass	  node1 instanceof StereoPannerNode is equal to true.
+Pass	  node1.pan.value is equal to 0.75.
+Pass	< [constructor with 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-stereopanner-interface/ctor-stereopanner.html

@@ -0,0 +1,131 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>
+      Test Constructor: StereoPanner
+    </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, 'StereoPannerNode', context);
+        task.done();
+      });
+
+      audit.define('default constructor', (task, should) => {
+        let prefix = 'node0';
+        let node = testDefaultConstructor(should, 'StereoPannerNode', context, {
+          prefix: prefix,
+          numberOfInputs: 1,
+          numberOfOutputs: 1,
+          channelCount: 2,
+          channelCountMode: 'clamped-max',
+          channelInterpretation: 'speakers'
+        });
+
+        testDefaultAttributes(should, node, prefix, [{name: 'pan', value: 0}]);
+
+        task.done();
+      });
+
+      audit.define('test AudioNodeOptions', (task, should) => {
+        // Can't use testAudioNodeOptions because the constraints for this node
+        // are not supported there.
+        let node;
+
+        // An array of tests.
+        [{
+          // Test that we can set the channel count to 1 or 2 and that other
+          // channel counts throw an error.
+          attribute: 'channelCount',
+          tests: [
+            {value: 1}, {value: 2}, {value: 0, error: 'NotSupportedError'},
+            {value: 3, error: 'NotSupportedError'},
+            {value: 99, error: 'NotSupportedError'}
+          ]
+        },
+         {
+           // Test channelCountMode.  A mode of "max" is illegal, but others are
+           // ok.  But also throw an error of unknown values.
+           attribute: 'channelCountMode',
+           tests: [
+             {value: 'clamped-max'}, {value: 'explicit'},
+             {value: 'max', error: 'NotSupportedError'},
+             {value: 'foobar', error: TypeError}
+           ]
+         },
+         {
+           // Test channelInterpretation can be set for valid values and an
+           // error is thrown for others.
+           attribute: 'channelInterpretation',
+           tests: [
+             {value: 'speakers'}, {value: 'discrete'},
+             {value: 'foobar', error: TypeError}
+           ]
+         }].forEach(entry => {
+          entry.tests.forEach(testItem => {
+            let options = {};
+            options[entry.attribute] = testItem.value;
+
+            const testFunction = () => {
+              node = new StereoPannerNode(context, options);
+            };
+            const testDescription =
+                `new StereoPannerNode(c, ${JSON.stringify(options)})`;
+
+            if (testItem.error) {
+              testItem.error === TypeError
+              ? should(testFunction, testDescription).throw(TypeError)
+              : should(testFunction, testDescription)
+                  .throw(DOMException, 'NotSupportedError');
+            } else {
+              should(testFunction, testDescription).notThrow();
+              should(node[entry.attribute], `node.${entry.attribute}`)
+                  .beEqualTo(options[entry.attribute]);
+            }
+          });
+        });
+
+        task.done();
+      });
+
+      audit.define('constructor with options', (task, should) => {
+        let node;
+        let options = {
+          pan: 0.75,
+        };
+
+        should(
+            () => {
+              node = new StereoPannerNode(context, options);
+            },
+            'node1 = new StereoPannerNode(, ' + JSON.stringify(options) + ')')
+            .notThrow();
+        should(
+            node instanceof StereoPannerNode,
+            'node1 instanceof StereoPannerNode')
+            .beEqualTo(true);
+
+        should(node.pan.value, 'node1.pan.value').beEqualTo(options.pan);
+
+        task.done();
+      });
+
+      audit.run();
+    </script>
+  </body>
+</html>