Added ToString and SubtreeToString methods to AXPlatformNodeDelegate

Also exposed similar functionality in AXPlatformNode and its subclasses.
A << operator was implemented as well.
This will help in debugging and testing.
R=aleventhal@chromium.org, dmazzoni@chromium.org

Change-Id: Ieda0e076826f422743efdb95eb747cfc63b7d81e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1927293
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#717764}

content/browser/accessibility/browser_accessibility.cc

@@ -658,7 +658,7 @@ gfx::Rect BrowserAccessibility::GetRootFrameHypertextRangeBoundsRect(
     const BrowserAccessibility* child = it.get();
     if (child->GetRole() != ax::mojom::Role::kInlineTextBox) {
       DLOG(WARNING) << "BrowserAccessibility objects with role STATIC_TEXT "
-                    << "should have children of role INLINE_TEXT_BOX.";
+                    << "should have children of role INLINE_TEXT_BOX.\n";
       continue;
     }
 
@@ -1366,6 +1366,21 @@ const ui::AXUniqueId& BrowserAccessibility::GetUniqueId() const {
   return unique_id_;
 }
 
+std::string BrowserAccessibility::SubtreeToStringHelper(size_t level) {
+  std::string result(level * 2, '+');
+  result += ToString();
+  result += '\n';
+
+  for (InternalChildIterator it = InternalChildrenBegin();
+       it != InternalChildrenEnd(); ++it) {
+    BrowserAccessibility* child = it.get();
+    DCHECK(child);
+    result += child->SubtreeToStringHelper(level + 1);
+  }
+
+  return result;
+}
+
 base::Optional<int> BrowserAccessibility::FindTextBoundary(
     ui::AXTextBoundary boundary,
     int offset,
@@ -1531,7 +1546,7 @@ BrowserAccessibility::PlatformChildIterator::PlatformChildIterator(
   DCHECK(parent && parent->instance_active());
 }
 
-BrowserAccessibility::PlatformChildIterator::~PlatformChildIterator() {}
+BrowserAccessibility::PlatformChildIterator::~PlatformChildIterator() = default;
 
 bool BrowserAccessibility::PlatformChildIterator::operator==(
     const ChildIterator& rhs) const {
@@ -1580,6 +1595,7 @@ int BrowserAccessibility::PlatformChildIterator::GetIndexInParent() const {
 
   return platform_iterator->GetIndexInParent();
 }
+
 BrowserAccessibility& BrowserAccessibility::PlatformChildIterator::operator*()
     const {
   return *platform_iterator;
@@ -2204,11 +2220,6 @@ bool BrowserAccessibility::HasInvalidAttribute(
                       }) != attributes.end();
 }
 
-std::ostream& operator<<(std::ostream& stream,
-                         const BrowserAccessibility& object) {
-  return stream << object.ToString();
-}
-
 static bool HasListAncestor(const BrowserAccessibility* node) {
   if (node == nullptr)
     return false;

content/browser/accessibility/browser_accessibility.h

@@ -169,9 +169,8 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
     gfx::NativeViewAccessible GetNativeViewAccessible() const override;
     BrowserAccessibility* get() const;
     int GetIndexInParent() const override;
-
-    BrowserAccessibility& operator*() const;
-    BrowserAccessibility* operator->() const;
+    BrowserAccessibility& operator*() const override;
+    BrowserAccessibility* operator->() const override;
 
    private:
     const BrowserAccessibility* parent_;
@@ -588,6 +587,8 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
   // errors are present.
   ui::TextAttributeMap GetSpellingAndGrammarAttributes() const;
 
+  std::string SubtreeToStringHelper(size_t level) override;
+
  private:
   // Return the bounds after converting from this node's coordinate system
   // (which is relative to its nearest scrollable ancestor) to the coordinate
@@ -654,9 +655,6 @@ class CONTENT_EXPORT BrowserAccessibility : public ui::AXPlatformNodeDelegate {
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibility);
 };
 
-CONTENT_EXPORT std::ostream& operator<<(std::ostream& stream,
-                                        const BrowserAccessibility& object);
-
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_H_

ui/accessibility/platform/ax_platform_node.cc

@@ -62,6 +62,18 @@ int32_t AXPlatformNode::GetUniqueId() const {
   return GetDelegate() ? GetDelegate()->GetUniqueId().Get() : -1;
 }
 
+std::string AXPlatformNode::ToString() {
+  return GetDelegate() ? GetDelegate()->ToString() : "No delegate";
+}
+
+std::string AXPlatformNode::SubtreeToString() {
+  return GetDelegate() ? GetDelegate()->SubtreeToString() : "No delegate";
+}
+
+std::ostream& operator<<(std::ostream& stream, AXPlatformNode& node) {
+  return stream << node.ToString();
+}
+
 // static
 void AXPlatformNode::AddAXModeObserver(AXModeObserver* observer) {
   ax_mode_observers_.Get().AddObserver(observer);

ui/accessibility/platform/ax_platform_node.h

@@ -5,6 +5,9 @@
 #ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_
 #define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_
 
+#include <ostream>
+#include <string>
+
 #include "base/callback.h"
 #include "base/lazy_instance.h"
 #include "base/observer_list.h"
@@ -92,6 +95,15 @@ class AX_EXPORT AXPlatformNode {
   // Return the unique ID
   int32_t GetUniqueId() const;
 
+  // Creates a string representation of this node's data.
+  std::string ToString();
+
+  // Returns a string representation of the subtree of nodes rooted at this
+  // node.
+  std::string SubtreeToString();
+
+  friend std::ostream& operator<<(std::ostream& stream, AXPlatformNode& node);
+
  protected:
   AXPlatformNode();
   virtual ~AXPlatformNode();

ui/accessibility/platform/ax_platform_node_delegate.h

@@ -10,6 +10,7 @@
 #include <map>
 #include <memory>
 #include <new>
+#include <ostream>
 #include <set>
 #include <string>
 #include <utility>
@@ -33,7 +34,8 @@
 namespace gfx {
 
 class Rect;
-}
+
+}  // namespace gfx
 
 namespace ui {
 
@@ -120,7 +122,7 @@ class AX_EXPORT AXPlatformNodeDelegate {
 
   class ChildIterator {
    public:
-    virtual ~ChildIterator() {}
+    virtual ~ChildIterator() = default;
     virtual bool operator==(const ChildIterator& rhs) const = 0;
     virtual bool operator!=(const ChildIterator& rhs) const = 0;
     virtual void operator++() = 0;
@@ -129,6 +131,8 @@ class AX_EXPORT AXPlatformNodeDelegate {
     virtual void operator--(int) = 0;
     virtual gfx::NativeViewAccessible GetNativeViewAccessible() const = 0;
     virtual int GetIndexInParent() const = 0;
+    virtual AXPlatformNodeDelegate& operator*() const = 0;
+    virtual AXPlatformNodeDelegate* operator->() const = 0;
   };
   virtual std::unique_ptr<AXPlatformNodeDelegate::ChildIterator>
   ChildrenBegin() = 0;
@@ -376,9 +380,23 @@ class AX_EXPORT AXPlatformNodeDelegate {
   // element. The default value should be false if not in testing mode.
   virtual bool ShouldIgnoreHoveredStateForTesting() = 0;
 
+  // Creates a string representation of this delegate's data.
+  std::string ToString() { return GetData().ToString(); }
+
+  // Returns a string representation of the subtree of delegates rooted at this
+  // delegate.
+  std::string SubtreeToString() { return SubtreeToStringHelper(0u); }
+
+  friend std::ostream& operator<<(std::ostream& stream,
+                                  AXPlatformNodeDelegate& delegate) {
+    return stream << delegate.ToString();
+  }
+
  protected:
   AXPlatformNodeDelegate() = default;
 
+  virtual std::string SubtreeToStringHelper(size_t level) = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(AXPlatformNodeDelegate);
 };

ui/accessibility/platform/ax_platform_node_delegate_base.cc

@@ -147,6 +147,21 @@ int AXPlatformNodeDelegateBase::ChildIteratorBase::GetIndexInParent() const {
   return index_;
 }
 
+AXPlatformNodeDelegate& AXPlatformNodeDelegateBase::ChildIteratorBase::
+operator*() const {
+  AXPlatformNode* platform_node =
+      AXPlatformNode::FromNativeViewAccessible(GetNativeViewAccessible());
+  DCHECK(platform_node && platform_node->GetDelegate());
+  return *(platform_node->GetDelegate());
+}
+
+AXPlatformNodeDelegate* AXPlatformNodeDelegateBase::ChildIteratorBase::
+operator->() const {
+  AXPlatformNode* platform_node =
+      AXPlatformNode::FromNativeViewAccessible(GetNativeViewAccessible());
+  return platform_node ? platform_node->GetDelegate() : nullptr;
+}
+
 std::unique_ptr<AXPlatformNodeDelegate::ChildIterator>
 AXPlatformNodeDelegateBase::ChildrenBegin() {
   return std::make_unique<ChildIteratorBase>(this, 0);
@@ -527,4 +542,25 @@ AXPlatformNodeDelegate* AXPlatformNodeDelegateBase::GetParentDelegate() {
   return nullptr;
 }
 
+std::string AXPlatformNodeDelegateBase::SubtreeToStringHelper(size_t level) {
+  std::string result(level * 2, '+');
+  result += ToString();
+  result += '\n';
+
+  // We can't use ChildrenBegin() and ChildrenEnd() here, because they both
+  // return an std::unique_ptr<ChildIterator> which is an abstract class.
+  //
+  // TODO(accessibility): Refactor ChildIterator into a separate base
+  // (non-abstract) class.
+  auto iter_start = ChildIteratorBase(this, 0);
+  auto iter_end = ChildIteratorBase(this, GetChildCount());
+  for (auto iter = iter_start; iter != iter_end; ++iter) {
+    AXPlatformNodeDelegateBase& child =
+        static_cast<AXPlatformNodeDelegateBase&>(*iter);
+    result += child.SubtreeToStringHelper(level + 1);
+  }
+
+  return result;
+}
+
 }  // namespace ui

ui/accessibility/platform/ax_platform_node_delegate_base.h

@@ -71,7 +71,7 @@ class AX_EXPORT AXPlatformNodeDelegateBase : public AXPlatformNodeDelegate {
    public:
     ChildIteratorBase(AXPlatformNodeDelegateBase* parent, int index);
     ChildIteratorBase(const ChildIteratorBase& it);
-    ~ChildIteratorBase() override {}
+    ~ChildIteratorBase() override = default;
     bool operator==(const ChildIterator& rhs) const override;
     bool operator!=(const ChildIterator& rhs) const override;
     void operator++() override;
@@ -79,9 +79,9 @@ class AX_EXPORT AXPlatformNodeDelegateBase : public AXPlatformNodeDelegate {
     void operator--() override;
     void operator--(int) override;
     gfx::NativeViewAccessible GetNativeViewAccessible() const override;
-
-   protected:
     int GetIndexInParent() const override;
+    AXPlatformNodeDelegate& operator*() const override;
+    AXPlatformNodeDelegate* operator->() const override;
 
    private:
     int index_;
@@ -280,6 +280,8 @@ class AX_EXPORT AXPlatformNodeDelegateBase : public AXPlatformNodeDelegate {
   bool ShouldIgnoreHoveredStateForTesting() override;
 
  protected:
+  std::string SubtreeToStringHelper(size_t level) override;
+
   // Given a list of node ids, return the nodes in this delegate's tree to
   // which they correspond.
   std::set<ui::AXPlatformNode*> GetNodesForNodeIds(