Only require a "transient" user activation for Web Audio rendering

https://bugs.webkit.org/show_bug.cgi?id=247614 rdar://102364692 Reviewed by Jer Noble. Only require a "transient" user activation for Web Audio rendering instead of having a strict synchronous user gesture requirement. Our behavior was so strict it was confusing Web developers. It was also causing a lot of demo sites to fail in Safari and work in other browsers. For example: - https://googlechromelabs.github.io/web-audio-samples/audio-worklet/basic/hello-audio-worklet/ Such demos require you to click a button but then they use an async function and use `await` before actually starting the audio rendering. * LayoutTests/webaudio/require-transient-activation-expected.txt: Added. * LayoutTests/webaudio/require-transient-activation.html: Added. * Source/WebCore/Modules/webaudio/AudioContext.cpp: (WebCore::shouldDocumentAllowWebAudioToAutoPlay): Canonical link: https://commits.webkit.org/256721@main
WebKit · Nov 16, 2022 · 7cc4b42 · 7cc4b42
1 parent 4e7d68f
commit 7cc4b42
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Showing 3 changed files with 65 additions and 2 deletions.
diff --git a/LayoutTests/webaudio/require-transient-activation-expected.txt b/LayoutTests/webaudio/require-transient-activation-expected.txt
@@ -0,0 +1,16 @@
+Tests that starting Web Audio rendering requires a transient user activation.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS context.state is "suspended"
+node.connect(context.destination)
+PASS context.state is "suspended"
+PASS navigator.userActivation.isActive is true
+PASS resume() promise was resolved
+PASS context.state is "running"
+PASS navigator.userActivation.isActive is true
+PASS successfullyParsed is true
+
+TEST COMPLETE
+
diff --git a/LayoutTests/webaudio/require-transient-activation.html b/LayoutTests/webaudio/require-transient-activation.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+<head>
+<script src="../resources/js-test.js"></script>
+<script type="text/javascript" src="resources/audio-testing.js"></script>
+</head>
+<body>
+<script>
+description("Tests that starting Web Audio rendering requires a transient user activation.");
+jsTestIsAsync = true;
+
+onload = () => {
+    context = new AudioContext();
+
+    if (window.internals)
+        internals.setAudioContextRestrictions(context, 'RequireUserGestureForAudioStart');
+
+    shouldBeEqualToString('context.state', 'suspended');
+
+    node = context.createBufferSource();
+    evalAndLog('node.connect(context.destination)');
+
+    shouldBeEqualToString('context.state', 'suspended');
+
+    runWithKeyDown(function() {
+        setTimeout(() => {
+            // We should have transient activation.
+            shouldBeTrue("navigator.userActivation.isActive");
+            context.resume().then(() => {
+                testPassed("resume() promise was resolved");
+                shouldBeEqualToString('context.state', 'running');
+                // Transient activation should not have been consumed.
+                shouldBeTrue("navigator.userActivation.isActive");
+                finishJSTest();
+            }, () => {
+                testFailed("resume() promise was rejected");
+                finishJSTest();
+            });
+        }, 10);
+    });
+};
+</script>
+</body>
+</html>
diff --git a/Source/WebCore/Modules/webaudio/AudioContext.cpp b/Source/WebCore/Modules/webaudio/AudioContext.cpp
@@ -77,9 +77,12 @@ static std::optional<float>& defaultSampleRateForTesting()
 
 static bool shouldDocumentAllowWebAudioToAutoPlay(const Document& document)
 {
-    if (document.processingUserGestureForMedia() || document.isCapturing())
+    if (document.isCapturing())
         return true;
-    return document.quirks().shouldAutoplayWebAudioForArbitraryUserGesture() && document.topDocument().hasHadUserInteraction();
+    if (document.quirks().shouldAutoplayWebAudioForArbitraryUserGesture() && document.topDocument().hasHadUserInteraction())
+        return true;
+    auto* window = document.domWindow();
+    return window && window->hasTransientActivation();
 }
 
 void AudioContext::setDefaultSampleRateForTesting(std::optional<float> sampleRate)