Bug 1950362 - Fix transition-in-hidden-page.html. r=view-transitions-reviewers,boris

Reject InvalidStateError for this case as per spec, and run the view
transition page visibility change steps.

Differential Revision: https://phabricator.services.mozilla.com/D239529

dom/base/Document.cpp

@@ -16179,28 +16179,52 @@ bool Document::SetOrientationPendingPromise(Promise* aPromise) {
   return true;
 }
 
+void Document::MaybeSkipTransitionAfterVisibilityChange() {
+  if (Hidden() && mActiveViewTransition) {
+    mActiveViewTransition->SkipTransition(SkipTransitionReason::DocumentHidden);
+  }
+}
+
+// https://html.spec.whatwg.org/#update-the-visibility-state
 void Document::UpdateVisibilityState(DispatchVisibilityChange aDispatchEvent) {
-  dom::VisibilityState oldState = mVisibilityState;
-  mVisibilityState = ComputeVisibilityState();
-  if (oldState != mVisibilityState) {
-    if (aDispatchEvent == DispatchVisibilityChange::Yes) {
-      nsContentUtils::DispatchTrustedEvent(this, this, u"visibilitychange"_ns,
-                                           CanBubble::eYes, Cancelable::eNo);
-    }
-    NotifyActivityChanged();
-    if (mVisibilityState == dom::VisibilityState::Visible) {
-      MaybeActiveMediaComponents();
-    }
+  const dom::VisibilityState visibilityState = ComputeVisibilityState();
+  if (mVisibilityState == visibilityState) {
+    // 1. If document's visibility state equals visibilityState, then return.
+    return;
+  }
+  // 2. Set document's visibility state to visibilityState.
+  mVisibilityState = visibilityState;
+  if (aDispatchEvent == DispatchVisibilityChange::Yes) {
+    // 3. Fire an event named visibilitychange at document, with its bubbles
+    // attribute initialized to true.
+    nsContentUtils::DispatchTrustedEvent(this, this, u"visibilitychange"_ns,
+                                         CanBubble::eYes, Cancelable::eNo);
+  }
+  // TODO 4. Run the screen orientation change steps with document.
 
-    bool visible = !Hidden();
-    for (auto* listener : mWorkerListeners) {
-      listener->OnVisible(visible);
-    }
+  // 5. Run the view transition page visibility change steps with document.
+  // https://drafts.csswg.org/css-view-transitions/#view-transition-page-visibility-change-steps
+  const bool visible = !Hidden();
+  if (mActiveViewTransition && !visible) {
+    // The mActiveViewTransition check is an optimization: We don't allow
+    // creating transitions while the doc is hidden.
+    Dispatch(
+        NewRunnableMethod("MaybeSkipTransitionAfterVisibilityChange", this,
+                          &Document::MaybeSkipTransitionAfterVisibilityChange));
+  }
 
-    // https://w3c.github.io/screen-wake-lock/#handling-document-loss-of-visibility
-    if (!visible) {
-      UnlockAllWakeLocks(WakeLockType::Screen);
-    }
+  NotifyActivityChanged();
+  if (visible) {
+    MaybeActiveMediaComponents();
+  }
+
+  for (auto* listener : mWorkerListeners) {
+    listener->OnVisible(visible);
+  }
+
+  // https://w3c.github.io/screen-wake-lock/#handling-document-loss-of-visibility
+  if (!visible) {
+    UnlockAllWakeLocks(WakeLockType::Screen);
   }
 }
 

dom/base/Document.h

@@ -3868,6 +3868,7 @@ class Document : public nsINode,
   void ClearActiveViewTransition();
   void PerformPendingViewTransitionOperations();
   void EnsureViewTransitionOperationsHappen();
+  void MaybeSkipTransitionAfterVisibilityChange();
 
   // Getter for PermissionDelegateHandler. Performs lazy initialization.
   PermissionDelegateHandler* GetPermissionDelegateHandler();

dom/view-transitions/ViewTransition.cpp

@@ -1205,7 +1205,7 @@ void ViewTransition::SkipTransition(
             "Skipped ViewTransition due to another transition starting");
         break;
       case SkipTransitionReason::DocumentHidden:
-        readyPromise->MaybeRejectWithAbortError(
+        readyPromise->MaybeRejectWithInvalidStateError(
             "Skipped ViewTransition due to document being hidden");
         break;
       case SkipTransitionReason::Timeout:

testing/web-platform/meta/css/css-view-transitions/transition-in-hidden-page.html.ini

@@ -1,8 +1,3 @@
 [transition-in-hidden-page.html]
   expected:
     if (os == "android"): ERROR
-  [A view transition should be immediately skipped if started when document is hidden]
-    expected: FAIL
-
-  [A view transition should be skipped when a document becomes hidden while processing update callback]
-    expected: FAIL