Bug 1765430 - P3: Refactor Android Pivot methods. r=Jamie

This creates a clearer distinction between local pivots and remote
pivots. The former happens in the parent process and the latter happens
in the remote content process.

Differential Revision: https://phabricator.services.mozilla.com/D144482

accessible/android/AccessibleWrap.cpp

@@ -283,38 +283,37 @@ bool AccessibleWrap::GetSelectionBounds(int32_t* aStartOffset,
   return false;
 }
 
+Accessible* AccessibleWrap::DoPivot(Accessible* aAccessible,
+                                    int32_t aGranularity, bool aForward,
+                                    bool aInclusive) {
+  a11y::Pivot pivot(nullptr);
+  // Depending on the start accessible, the pivot rule will either traverse
+  // local or remote accessibles exclusively.
+  TraversalRule rule(aGranularity, aAccessible->IsLocal());
+  Accessible* result = aForward ? pivot.Next(aAccessible, rule, aInclusive)
+                                : pivot.Prev(aAccessible, rule, aInclusive);
+
+  if (result && (result != aAccessible || aInclusive)) {
+    return result;
+  }
+
+  return nullptr;
+}
+
 bool AccessibleWrap::PivotTo(int32_t aGranularity, bool aForward,
                              bool aInclusive) {
-  a11y::Pivot pivot(RootAccessible());
-  TraversalRule rule(aGranularity);
-  Accessible* current = IsProxy() ? Proxy() : static_cast<Accessible*>(this);
-  Accessible* result = aForward ? pivot.Next(current, rule, aInclusive)
-                                : pivot.Prev(current, rule, aInclusive);
-
-  if (result && (result != current || aInclusive)) {
-    RefPtr<AccessibleWrap> newPosition =
-        result->IsRemote() ? WrapperFor(result->AsRemote())
-                           : static_cast<AccessibleWrap*>(result->AsLocal());
-
-    if (IPCAccessibilityActive()) {
-      // We are in the child process. Dispatch a virtual cursor
-      // change event that will be turned into an android
-      // accessibility focused changed event in the parent.
-      PivotMoveReason reason = aForward ? nsIAccessiblePivot::REASON_NEXT
-                                        : nsIAccessiblePivot::REASON_PREV;
-      LocalAccessible* localResult = result->AsLocal();
-      MOZ_ASSERT(localResult);
-      RefPtr<AccEvent> event = new AccVCChangeEvent(
-          localResult->Document(), this, -1, -1, localResult, -1, -1, reason,
-          nsIAccessiblePivot::NO_BOUNDARY, eFromUserInput);
-      nsEventShell::FireEvent(event);
-    } else {
-      // We are in the parent process. Dispatch an accessibility focused
-      // event directly.
-      RefPtr<SessionAccessibility> sessionAcc =
-          SessionAccessibility::GetInstanceFor(result);
-      sessionAcc->SendAccessibilityFocusedEvent(newPosition);
-    }
+  Accessible* result = DoPivot(this, aGranularity, aForward, aInclusive);
+  if (result) {
+    MOZ_ASSERT(result->IsLocal());
+    // Dispatch a virtual cursor change event that will be turned into an
+    // android accessibility focused changed event in the parent.
+    PivotMoveReason reason = aForward ? nsIAccessiblePivot::REASON_NEXT
+                                      : nsIAccessiblePivot::REASON_PREV;
+    LocalAccessible* localResult = result->AsLocal();
+    RefPtr<AccEvent> event = new AccVCChangeEvent(
+        localResult->Document(), this, -1, -1, localResult, -1, -1, reason,
+        nsIAccessiblePivot::NO_BOUNDARY, eFromUserInput);
+    nsEventShell::FireEvent(event);
 
     return true;
   }
@@ -324,7 +323,7 @@ bool AccessibleWrap::PivotTo(int32_t aGranularity, bool aForward,
 
 void AccessibleWrap::ExploreByTouch(float aX, float aY) {
   a11y::Pivot pivot(RootAccessible());
-  ExploreByTouchRule rule;
+  TraversalRule rule;
 
   Accessible* maybeResult = pivot.AtPoint(aX, aY, rule);
   LocalAccessible* result = maybeResult ? maybeResult->AsLocal() : nullptr;

accessible/android/AccessibleWrap.h

@@ -83,6 +83,9 @@ class AccessibleWrap : public LocalAccessible {
 
   static void SetVirtualViewID(Accessible* aAccessible, int32_t aVirtualViewID);
 
+  static Accessible* DoPivot(Accessible* aAccessible, int32_t aGranularity,
+                             bool aForward, bool aInclusive);
+
  protected:
   int32_t mID;
 

accessible/android/DocAccessibleWrap.cpp

@@ -157,7 +157,8 @@ void DocAccessibleWrap::CacheViewportCallback(nsITimer* aTimer,
 
   if (docAcc->mCachePivotBoundaries) {
     a11y::Pivot pivot(docAcc);
-    TraversalRule rule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT);
+    TraversalRule rule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT,
+                       true);
     Accessible* maybeFirst = pivot.First(rule);
     Accessible* maybeLast = pivot.Last(rule);
     LocalAccessible* first = maybeFirst ? maybeFirst->AsLocal() : nullptr;

accessible/android/RemoteAccessibleWrap.cpp

@@ -109,7 +109,7 @@ bool RemoteAccessibleWrap::PivotTo(int32_t aGranularity, bool aForward,
     return AccessibleWrap::PivotTo(aGranularity, aForward, aInclusive);
   }
 
-  Unused << Proxy()->Document()->GetPlatformExtension()->SendPivot(
+  Unused << Proxy()->Document()->GetPlatformExtension()->SendPivotTo(
       Proxy()->ID(), aGranularity, aForward, aInclusive);
 
   return true;

accessible/android/SessionAccessibility.cpp

@@ -126,11 +126,24 @@ bool SessionAccessibility::CachedPivot(int32_t aID, int32_t aGranularity,
   bool ret = false;
   nsAppShell::SyncRunEvent(
       [this, self, aID, aGranularity, aForward, aInclusive, &ret] {
-        if (AccessibleWrap* acc = GetAccessibleByID(aID)) {
-          ret = acc->PivotTo(aGranularity, aForward, aInclusive);
+        if (Accessible* acc = GetAccessibleByID(aID)) {
+          if (acc->AsLocal()->IsProxy()) {
+            // XXX: Will be removed with RemoteAccessibleWrap
+            acc = acc->AsLocal()->Proxy();
+          }
+          Accessible* result =
+              AccessibleWrap::DoPivot(acc, aGranularity, aForward, aInclusive);
+          if (result) {
+            ret = true;
+            int32_t virtualViewID = AccessibleWrap::GetVirtualViewID(result);
+            nsAppShell::PostEvent([this, self, virtualViewID] {
+              if (AccessibleWrap* acc = GetAccessibleByID(virtualViewID)) {
+                SendAccessibilityFocusedEvent(acc);
+              }
+            });
+          }
         }
       });
-
   return ret;
 }
 
@@ -236,7 +249,8 @@ void SessionAccessibility::SendAccessibilityFocusedEvent(
   mSessionAccessibility->SendEvent(
       java::sdk::AccessibilityEvent::TYPE_VIEW_ACCESSIBILITY_FOCUSED,
       aAccessible->VirtualViewID(), aAccessible->AndroidClass(), nullptr);
-  aAccessible->ScrollTo(nsIAccessibleScrollType::SCROLL_TYPE_ANYWHERE);
+  RefPtr<AccessibleWrap> acc = aAccessible;
+  acc->ScrollTo(nsIAccessibleScrollType::SCROLL_TYPE_ANYWHERE);
 }
 
 void SessionAccessibility::SendHoverEnterEvent(AccessibleWrap* aAccessible) {

accessible/android/SessionAccessibility.h

@@ -70,7 +70,7 @@ class SessionAccessibility final
   void SendScrollingEvent(AccessibleWrap* aAccessible, int32_t aScrollX,
                           int32_t aScrollY, int32_t aMaxScrollX,
                           int32_t aMaxScrollY);
-  MOZ_CAN_RUN_SCRIPT
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
   void SendAccessibilityFocusedEvent(AccessibleWrap* aAccessible);
   void SendHoverEnterEvent(AccessibleWrap* aAccessible);
   void SendTextSelectionChangedEvent(AccessibleWrap* aAccessible,

accessible/android/TraversalRule.cpp

@@ -19,14 +19,28 @@ using namespace mozilla;
 using namespace mozilla::a11y;
 
 TraversalRule::TraversalRule()
-    : TraversalRule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT) {}
+    : TraversalRule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT,
+                    true) {}
 
-TraversalRule::TraversalRule(int32_t aGranularity)
-    : mGranularity(aGranularity) {}
+TraversalRule::TraversalRule(int32_t aGranularity, bool aIsLocal)
+    : mGranularity(aGranularity), mIsLocal(aIsLocal) {}
 
 uint16_t TraversalRule::Match(Accessible* aAcc) {
   MOZ_ASSERT(aAcc);
 
+  if (mIsLocal && aAcc->IsRemote()) {
+    // If we encounter a remote accessible in a local rule, we should
+    // ignore the subtree because we won't encounter anymore local accessibles
+    // in it.
+    return nsIAccessibleTraversalRule::FILTER_IGNORE |
+           nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
+  } else if (!mIsLocal && aAcc->IsLocal()) {
+    // If we encounter a local accessible in a remote rule we are likely
+    // traversing backwards/upwards, we don't ignore its subtree because it is
+    // likely the outer doc root of the remote tree.
+    return nsIAccessibleTraversalRule::FILTER_IGNORE;
+  }
+
   uint16_t result = nsIAccessibleTraversalRule::FILTER_IGNORE;
 
   if (nsAccUtils::MustPrune(aAcc)) {
@@ -281,14 +295,3 @@ uint16_t TraversalRule::DefaultMatch(Accessible* aAccessible) {
 
   return nsIAccessibleTraversalRule::FILTER_IGNORE;
 }
-
-uint16_t ExploreByTouchRule::Match(Accessible* aAcc) {
-  if (aAcc->IsRemote()) {
-    // Explore by touch happens in the local process and should
-    // not drill down into remote frames.
-    return nsIAccessibleTraversalRule::FILTER_IGNORE |
-           nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
-  }
-
-  return TraversalRule::Match(aAcc);
-}

accessible/android/TraversalRule.h

@@ -20,7 +20,7 @@ class Accessible;
 class TraversalRule : public PivotRule {
  public:
   TraversalRule();
-  explicit TraversalRule(int32_t aGranularity);
+  explicit TraversalRule(int32_t aGranularity, bool aIsLocal);
 
   ~TraversalRule() = default;
 
@@ -48,10 +48,8 @@ class TraversalRule : public PivotRule {
   uint16_t LandmarkMatch(Accessible* aAccessible);
 
   int32_t mGranularity;
-};
 
-class ExploreByTouchRule final : public TraversalRule {
-  virtual uint16_t Match(Accessible* aAcc) override;
+  bool mIsLocal;
 };
 
 }  // namespace a11y

accessible/base/Platform.h

@@ -119,7 +119,6 @@ void ProxySelectionEvent(RemoteAccessible* aTarget, RemoteAccessible* aWidget,
                          uint32_t aType);
 
 #if defined(ANDROID)
-MOZ_CAN_RUN_SCRIPT
 void ProxyVirtualCursorChangeEvent(RemoteAccessible* aTarget,
                                    RemoteAccessible* aOldPosition,
                                    int32_t aOldStartOffset,

accessible/ipc/DocAccessibleParent.h

@@ -129,7 +129,6 @@ class DocAccessibleParent : public RemoteAccessible,
       const uint64_t& aID, const uint64_t& aWidgetID,
       const uint32_t& aType) override;
 
-  MOZ_CAN_RUN_SCRIPT_BOUNDARY
   virtual mozilla::ipc::IPCResult RecvVirtualCursorChangeEvent(
       const uint64_t& aID, const uint64_t& aOldPositionID,
       const int32_t& aOldStartOffset, const int32_t& aOldEndOffset,

accessible/ipc/extension/android/DocAccessiblePlatformExtChild.cpp

@@ -12,7 +12,7 @@
 namespace mozilla {
 namespace a11y {
 
-mozilla::ipc::IPCResult DocAccessiblePlatformExtChild::RecvPivot(
+mozilla::ipc::IPCResult DocAccessiblePlatformExtChild::RecvPivotTo(
     uint64_t aID, int32_t aGranularity, bool aForward, bool aInclusive) {
   if (auto acc = IdToAccessibleWrap(aID)) {
     acc->PivotTo(aGranularity, aForward, aInclusive);

accessible/ipc/extension/android/DocAccessiblePlatformExtChild.h

@@ -16,8 +16,8 @@ class DocAccessibleChild;
 
 class DocAccessiblePlatformExtChild : public PDocAccessiblePlatformExtChild {
  public:
-  mozilla::ipc::IPCResult RecvPivot(uint64_t aID, int32_t aGranularity,
-                                    bool aForward, bool aInclusive);
+  mozilla::ipc::IPCResult RecvPivotTo(uint64_t aID, int32_t aGranularity,
+                                      bool aForward, bool aInclusive);
 
   mozilla::ipc::IPCResult RecvNavigateText(uint64_t aID, int32_t aGranularity,
                                            int32_t aStartOffset,

accessible/ipc/extension/android/PDocAccessiblePlatformExt.ipdl

@@ -16,7 +16,7 @@ protocol PDocAccessiblePlatformExt {
 child:
   async __delete__();
 
-  async Pivot(uint64_t aID, int32_t aGranularity, bool aForward, bool aInclusive);
+  async PivotTo(uint64_t aID, int32_t aGranularity, bool aForward, bool aInclusive);
 
   async NavigateText(uint64_t aID, int32_t aGranularity, int32_t aStartOffset, int32_t aEndOffset, bool aForward, bool aSelect);