Update FlutterPlatformNodeDelegate (flutter#38615)

* Update FlutterPlatformNodeDelegate

* Unit test

Author: yaakovschectman

shell/platform/common/flutter_platform_node_delegate.cc

@@ -6,7 +6,9 @@
 
 #include <utility>
 
+#include "flutter/shell/platform/common/accessibility_bridge.h"
 #include "flutter/third_party/accessibility/ax/ax_action_data.h"
+#include "flutter/third_party/accessibility/ax/ax_tree_manager_map.h"
 #include "flutter/third_party/accessibility/gfx/geometry/rect_conversions.h"
 
 namespace flutter {
@@ -118,4 +120,46 @@ ui::AXPlatformNode* FlutterPlatformNodeDelegate::GetPlatformNode() const {
   return nullptr;
 }
 
+gfx::NativeViewAccessible
+FlutterPlatformNodeDelegate::GetLowestPlatformAncestor() const {
+  auto bridge_ptr = bridge_.lock();
+  BASE_DCHECK(bridge_ptr);
+  auto lowest_platform_ancestor = ax_node_->GetLowestPlatformAncestor();
+  if (lowest_platform_ancestor) {
+    return bridge_ptr->GetNativeAccessibleFromId(
+        ax_node_->GetLowestPlatformAncestor()->id());
+  }
+  return nullptr;
+}
+
+ui::AXNodePosition::AXPositionInstance
+FlutterPlatformNodeDelegate::CreateTextPositionAt(int offset) const {
+  return ui::AXNodePosition::CreatePosition(*ax_node_, offset);
+}
+
+ui::AXPlatformNode* FlutterPlatformNodeDelegate::GetFromNodeID(
+    int32_t node_id) {
+  ui::AXTreeManager* tree_manager =
+      ui::AXTreeManagerMap::GetInstance().GetManager(
+          ax_node_->tree()->GetAXTreeID());
+  AccessibilityBridge* platform_manager =
+      static_cast<AccessibilityBridge*>(tree_manager);
+  return platform_manager->GetPlatformNodeFromTree(node_id);
+}
+
+ui::AXPlatformNode* FlutterPlatformNodeDelegate::GetFromTreeIDAndNodeID(
+    const ui::AXTreeID& tree_id,
+    int32_t node_id) {
+  ui::AXTreeManager* tree_manager =
+      ui::AXTreeManagerMap::GetInstance().GetManager(tree_id);
+  AccessibilityBridge* platform_manager =
+      static_cast<AccessibilityBridge*>(tree_manager);
+  return platform_manager->GetPlatformNodeFromTree(node_id);
+}
+
+const ui::AXTree::Selection FlutterPlatformNodeDelegate::GetUnignoredSelection()
+    const {
+  return ax_node_->GetUnignoredSelection();
+}
+
 }  // namespace flutter

shell/platform/common/flutter_platform_node_delegate.h

@@ -125,6 +125,13 @@ class FlutterPlatformNodeDelegate : public ui::AXPlatformNodeDelegateBase {
       const ui::AXClippingBehavior clipping_behavior,
       ui::AXOffscreenResult* offscreen_result) const override;
 
+  // |ui::AXPlatformNodeDelegateBase|
+  gfx::NativeViewAccessible GetLowestPlatformAncestor() const override;
+
+  // |ui::AXPlatformNodeDelegateBase|
+  ui::AXNodePosition::AXPositionInstance CreateTextPositionAt(
+      int offset) const override;
+
   //------------------------------------------------------------------------------
   /// @brief      Called only once, immediately after construction. The
   ///             constructor doesn't take any arguments because in the Windows
@@ -147,6 +154,17 @@ class FlutterPlatformNodeDelegate : public ui::AXPlatformNodeDelegateBase {
   // Get the platform node represented by this delegate.
   virtual ui::AXPlatformNode* GetPlatformNode() const;
 
+  // |ui::AXPlatformNodeDelegateBase|
+  virtual ui::AXPlatformNode* GetFromNodeID(int32_t id) override;
+
+  // |ui::AXPlatformNodeDelegateBase|
+  virtual ui::AXPlatformNode* GetFromTreeIDAndNodeID(
+      const ui::AXTreeID& tree_id,
+      int32_t node_id) override;
+
+  // |ui::AXPlatformNodeDelegateBase|
+  virtual const ui::AXTree::Selection GetUnignoredSelection() const override;
+
  private:
   ui::AXNode* ax_node_;
   std::weak_ptr<OwnerBridge> bridge_;

shell/platform/common/flutter_platform_node_delegate_unittests.cc

@@ -246,5 +246,63 @@ TEST(FlutterPlatformNodeDelegateTest, canUseOwnerBridge) {
   EXPECT_EQ(result, false);
 }
 
+TEST(FlutterPlatformNodeDelegateTest, selfIsLowestPlatformAncestor) {
+  std::shared_ptr<TestAccessibilityBridge> bridge =
+      std::make_shared<TestAccessibilityBridge>();
+  FlutterSemanticsNode root;
+  root.id = 0;
+  root.label = "root";
+  root.hint = "";
+  root.value = "";
+  root.increased_value = "";
+  root.decreased_value = "";
+  root.tooltip = "";
+  root.child_count = 0;
+  root.children_in_traversal_order = nullptr;
+  root.custom_accessibility_actions_count = 0;
+  bridge->AddFlutterSemanticsNodeUpdate(&root);
+
+  bridge->CommitUpdates();
+  auto root_node = bridge->GetFlutterPlatformNodeDelegateFromID(0).lock();
+  auto lowest_platform_ancestor = root_node->GetLowestPlatformAncestor();
+  EXPECT_EQ(root_node->GetNativeViewAccessible(), lowest_platform_ancestor);
+}
+
+TEST(FlutterPlatformNodeDelegateTest, canGetFromNodeID) {
+  std::shared_ptr<TestAccessibilityBridge> bridge =
+      std::make_shared<TestAccessibilityBridge>();
+  FlutterSemanticsNode root;
+  root.id = 0;
+  root.label = "root";
+  root.hint = "";
+  root.value = "";
+  root.increased_value = "";
+  root.decreased_value = "";
+  root.tooltip = "";
+  root.child_count = 1;
+  int32_t children[] = {1};
+  root.children_in_traversal_order = children;
+  root.custom_accessibility_actions_count = 0;
+  bridge->AddFlutterSemanticsNodeUpdate(&root);
+
+  FlutterSemanticsNode child1;
+  child1.id = 1;
+  child1.label = "child 1";
+  child1.hint = "";
+  child1.value = "";
+  child1.increased_value = "";
+  child1.decreased_value = "";
+  child1.tooltip = "";
+  child1.child_count = 0;
+  child1.custom_accessibility_actions_count = 0;
+  bridge->AddFlutterSemanticsNodeUpdate(&child1);
+
+  bridge->CommitUpdates();
+  auto root_node = bridge->GetFlutterPlatformNodeDelegateFromID(0).lock();
+  auto child1_node = bridge->GetFlutterPlatformNodeDelegateFromID(1).lock();
+  auto node_by_id = root_node->GetFromNodeID(1);
+  EXPECT_EQ(child1_node->GetPlatformNode(), node_by_id);
+}
+
 }  // namespace testing
 }  // namespace flutter