Fuchsia a11y actions (flutter/engine#16321)

engine/src/flutter/shell/platform/fuchsia/flutter/accessibility_bridge.cc

@@ -281,12 +281,65 @@ void AccessibilityBridge::UpdateScreenRects(
   }
 }
 
+std::optional<flutter::SemanticsAction>
+AccessibilityBridge::GetFlutterSemanticsAction(
+    fuchsia::accessibility::semantics::Action fuchsia_action,
+    uint32_t node_id) {
+  switch (fuchsia_action) {
+    // The default action associated with the element.
+    case fuchsia::accessibility::semantics::Action::DEFAULT:
+      return flutter::SemanticsAction::kTap;
+    // The secondary action associated with the element. This may correspond to
+    // a long press (touchscreens) or right click (mouse).
+    case fuchsia::accessibility::semantics::Action::SECONDARY:
+      return flutter::SemanticsAction::kLongPress;
+    // Set (input/non-accessibility) focus on this element.
+    case fuchsia::accessibility::semantics::Action::SET_FOCUS:
+      FML_DLOG(WARNING)
+          << "Unsupported action SET_FOCUS sent for accessibility node "
+          << node_id;
+      return {};
+    // Set the element's value.
+    case fuchsia::accessibility::semantics::Action::SET_VALUE:
+      FML_DLOG(WARNING)
+          << "Unsupported action SET_VALUE sent for accessibility node "
+          << node_id;
+      return {};
+    // Scroll node to make it visible.
+    case fuchsia::accessibility::semantics::Action::SHOW_ON_SCREEN:
+      return flutter::SemanticsAction::kShowOnScreen;
+    default:
+      FML_DLOG(WARNING) << "Unexpected action "
+                        << static_cast<int32_t>(fuchsia_action)
+                        << " sent for accessibility node " << node_id;
+      return {};
+  }
+}
+
 // |fuchsia::accessibility::semantics::SemanticListener|
 void AccessibilityBridge::OnAccessibilityActionRequested(
     uint32_t node_id,
     fuchsia::accessibility::semantics::Action action,
     fuchsia::accessibility::semantics::SemanticListener::
-        OnAccessibilityActionRequestedCallback callback) {}
+        OnAccessibilityActionRequestedCallback callback) {
+  if (nodes_.find(node_id) == nodes_.end()) {
+    FML_LOG(ERROR) << "Attempted to send accessibility action "
+                   << static_cast<int32_t>(action)
+                   << " to unkonwn node id: " << node_id;
+    callback(false);
+    return;
+  }
+
+  std::optional<flutter::SemanticsAction> flutter_action =
+      GetFlutterSemanticsAction(action, node_id);
+  if (!flutter_action.has_value()) {
+    callback(false);
+    return;
+  }
+  delegate_.DispatchSemanticsAction(static_cast<int32_t>(node_id),
+                                    flutter_action.value());
+  callback(true);
+}
 
 // |fuchsia::accessibility::semantics::SemanticListener|
 void AccessibilityBridge::HitTest(

engine/src/flutter/shell/platform/fuchsia/flutter/accessibility_bridge.h

@@ -44,6 +44,8 @@ class AccessibilityBridge
   class Delegate {
    public:
     virtual void SetSemanticsEnabled(bool enabled) = 0;
+    virtual void DispatchSemanticsAction(int32_t node_id,
+                                         flutter::SemanticsAction action) = 0;
   };
 
   // TODO(MI4-2531, FIDL-718): Remove this. We shouldn't be worried about
@@ -91,6 +93,13 @@ class AccessibilityBridge
       fuchsia::accessibility::semantics::SemanticListener::HitTestCallback
           callback) override;
 
+  // |fuchsia::accessibility::semantics::SemanticListener|
+  void OnAccessibilityActionRequested(
+      uint32_t node_id,
+      fuchsia::accessibility::semantics::Action action,
+      fuchsia::accessibility::semantics::SemanticListener::
+          OnAccessibilityActionRequestedCallback callback) override;
+
  private:
   // Holds only the fields we need for hit testing.
   // In particular, it adds a screen_rect field to flutter::SemanticsNode.
@@ -164,12 +173,14 @@ class AccessibilityBridge
   // Assumes that SemanticsNode::screen_rect is up to date.
   std::optional<int32_t> GetHitNode(int32_t node_id, float x, float y);
 
-  // |fuchsia::accessibility::semantics::SemanticListener|
-  void OnAccessibilityActionRequested(
-      uint32_t node_id,
-      fuchsia::accessibility::semantics::Action action,
-      fuchsia::accessibility::semantics::SemanticListener::
-          OnAccessibilityActionRequestedCallback callback) override;
+  // Converts a fuchsia::accessibility::semantics::Action to a
+  // flutter::SemanticsAction.
+  //
+  // The node_id parameter is used for printing warnings about unsupported
+  // action types.
+  std::optional<flutter::SemanticsAction> GetFlutterSemanticsAction(
+      fuchsia::accessibility::semantics::Action fuchsia_action,
+      uint32_t node_id);
 
   // |fuchsia::accessibility::semantics::SemanticListener|
   void OnSemanticsModeChanged(bool enabled,

engine/src/flutter/shell/platform/fuchsia/flutter/accessibility_bridge_unittest.cc

@@ -23,7 +23,13 @@ class AccessibilityBridgeTestDelegate
     : public flutter_runner::AccessibilityBridge::Delegate {
  public:
   void SetSemanticsEnabled(bool enabled) override { enabled_ = enabled; }
+  void DispatchSemanticsAction(int32_t node_id,
+                               flutter::SemanticsAction action) override {
+    actions.push_back(std::make_pair(node_id, action));
+  }
+
   bool enabled() { return enabled_; }
+  std::vector<std::pair<int32_t, flutter::SemanticsAction>> actions;
 
  private:
   bool enabled_;
@@ -50,6 +56,7 @@ class AccessibilityBridgeTest : public testing::Test {
         /*flags*/ 0u, &view_ref_control_.reference, &view_ref_.reference);
     EXPECT_EQ(status, ZX_OK);
 
+    accessibility_delegate_.actions.clear();
     accessibility_bridge_ =
         std::make_unique<flutter_runner::AccessibilityBridge>(
             accessibility_delegate_, services_provider_.service_directory(),
@@ -364,4 +371,59 @@ TEST_F(AccessibilityBridgeTest, HitTest) {
   accessibility_bridge_->HitTest({30, 30}, callback);
   EXPECT_EQ(hit_node_id, 4u);
 }
+
+TEST_F(AccessibilityBridgeTest, Actions) {
+  flutter::SemanticsNode node0;
+  node0.id = 0;
+
+  flutter::SemanticsNode node1;
+  node1.id = 1;
+
+  node0.childrenInTraversalOrder = {1};
+  node0.childrenInHitTestOrder = {1};
+
+  accessibility_bridge_->AddSemanticsNodeUpdate({
+      {0, node0},
+      {1, node1},
+  });
+  RunLoopUntilIdle();
+
+  auto handled_callback = [](bool handled) { EXPECT_TRUE(handled); };
+  auto unhandled_callback = [](bool handled) { EXPECT_FALSE(handled); };
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      0u, fuchsia::accessibility::semantics::Action::DEFAULT, handled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 1u);
+  EXPECT_EQ(accessibility_delegate_.actions.back(),
+            std::make_pair(0, flutter::SemanticsAction::kTap));
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      0u, fuchsia::accessibility::semantics::Action::SECONDARY,
+      handled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 2u);
+  EXPECT_EQ(accessibility_delegate_.actions.back(),
+            std::make_pair(0, flutter::SemanticsAction::kLongPress));
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      0u, fuchsia::accessibility::semantics::Action::SET_FOCUS,
+      unhandled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 2u);
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      0u, fuchsia::accessibility::semantics::Action::SET_VALUE,
+      unhandled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 2u);
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      0u, fuchsia::accessibility::semantics::Action::SHOW_ON_SCREEN,
+      handled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 3u);
+  EXPECT_EQ(accessibility_delegate_.actions.back(),
+            std::make_pair(0, flutter::SemanticsAction::kShowOnScreen));
+
+  accessibility_bridge_->OnAccessibilityActionRequested(
+      2u, fuchsia::accessibility::semantics::Action::DEFAULT,
+      unhandled_callback);
+  EXPECT_EQ(accessibility_delegate_.actions.size(), 3u);
+}
 }  // namespace flutter_runner_test

engine/src/flutter/shell/platform/fuchsia/flutter/platform_view.cc

@@ -602,6 +602,13 @@ void PlatformView::SetSemanticsEnabled(bool enabled) {
   }
 }
 
+// |flutter::PlatformView|
+// |flutter_runner::AccessibilityBridge::Delegate|
+void PlatformView::DispatchSemanticsAction(int32_t node_id,
+                                           flutter::SemanticsAction action) {
+  flutter::PlatformView::DispatchSemanticsAction(node_id, action, {});
+}
+
 // |flutter::PlatformView|
 void PlatformView::UpdateSemantics(
     flutter::SemanticsNodeUpdates update,

engine/src/flutter/shell/platform/fuchsia/flutter/platform_view.h

@@ -69,6 +69,10 @@ class PlatformView final : public flutter::PlatformView,
   // |flutter_runner::AccessibilityBridge::Delegate|
   void SetSemanticsEnabled(bool enabled) override;
 
+  // |flutter_runner::AccessibilityBridge::Delegate|
+  void DispatchSemanticsAction(int32_t node_id,
+                               flutter::SemanticsAction action) override;
+
   // |PlatformView|
   flutter::PointerDataDispatcherMaker GetDispatcherMaker() override;