Add level attribute to AtkObjects

The level attributes specifies the hierarchical level of the element.
This is used for HTML heading elements.

TEST=accessibility_unittests --gtest_filter=AXPlatformNodeAuraLinuxTest.*

Bug: 866612
Change-Id: If3e1d5192dc6d0749bdaffda203d4539ea02bf63
Reviewed-on: https://chromium-review.googlesource.com/1150144Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577917}

ui/accessibility/platform/ax_platform_node_auralinux.cc

@@ -7,6 +7,7 @@
 #include <stdint.h>
 
 #include "base/command_line.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_action_data.h"
@@ -306,7 +307,13 @@ static AtkRelationSet* ax_platform_node_auralinux_ref_relation_set(
 
 static AtkAttributeSet* ax_platform_node_auralinux_get_attributes(
     AtkObject* atk_object) {
-  return NULL;
+
+  ui::AXPlatformNodeAuraLinux* obj =
+      AtkObjectToAXPlatformNodeAuraLinux(atk_object);
+  if (!obj)
+    return nullptr;
+
+  return obj->GetAtkAttributes();
 }
 
 static AtkRole ax_platform_node_auralinux_get_role(AtkObject* atk_object) {
@@ -1533,6 +1540,15 @@ const gchar* AXPlatformNodeAuraLinux::GetDefaultActionName() {
   ATK_AURALINUX_RETURN_STRING(base::UTF16ToUTF8(action_verb));
 }
 
+AtkAttributeSet* AXPlatformNodeAuraLinux::GetAtkAttributes() const {
+  AtkAttributeSet* atk_attributes = nullptr;
+
+  atk_attributes = AddIntAttributeToAtkAttributeSet(
+      atk_attributes, ax::mojom::IntAttribute::kHierarchicalLevel, "level");
+
+  return atk_attributes;
+}
+
 // AtkDocumentHelpers
 
 const gchar* AXPlatformNodeAuraLinux::GetDocumentAttributeValue(
@@ -1549,6 +1565,17 @@ const gchar* AXPlatformNodeAuraLinux::GetDocumentAttributeValue(
   return nullptr;
 }
 
+static AtkAttributeSet* PrependAtkAttributeToAtkAttributeSet(
+    AtkAttributeSet* attribute_set,
+    const char* name,
+    const char* value) {
+  AtkAttribute* attribute =
+      static_cast<AtkAttribute*>(g_malloc(sizeof(AtkAttribute)));
+  attribute->name = g_strdup(name);
+  attribute->value = g_strdup(value);
+  return g_slist_prepend(attribute_set, attribute);
+}
+
 AtkAttributeSet* AXPlatformNodeAuraLinux::GetDocumentAttributes() const {
   AtkAttributeSet* attribute_set = nullptr;
   const gchar* doc_attributes[] = {"DocType", "MimeType", "Title", "URI"};
@@ -1557,11 +1584,8 @@ AtkAttributeSet* AXPlatformNodeAuraLinux::GetDocumentAttributes() const {
   for (unsigned i = 0; i < G_N_ELEMENTS(doc_attributes); i++) {
     value = GetDocumentAttributeValue(doc_attributes[i]);
     if (value) {
-      AtkAttribute* attribute =
-          static_cast<AtkAttribute*>(g_malloc(sizeof(AtkAttribute)));
-      attribute->name = g_strdup(doc_attributes[i]);
-      attribute->value = g_strdup(value);
-      attribute_set = g_slist_prepend(attribute_set, attribute);
+      attribute_set = PrependAtkAttributeToAtkAttributeSet(
+          attribute_set, doc_attributes[i], value);
     }
   }
 
@@ -1601,4 +1625,17 @@ void AXPlatformNodeAuraLinux::GetFloatAttributeInGValue(
   }
 }
 
+AtkAttributeSet* AXPlatformNodeAuraLinux::AddIntAttributeToAtkAttributeSet(
+    AtkAttributeSet* attributes,
+    ax::mojom::IntAttribute attribute,
+    const char* atk_attribute) const {
+  int value;
+  if (GetIntAttribute(attribute, &value)) {
+    attributes = PrependAtkAttributeToAtkAttributeSet(
+        attributes, atk_attribute, base::IntToString(value).c_str());
+  }
+
+  return attributes;
+}
+
 }  // namespace ui

ui/accessibility/platform/ax_platform_node_auralinux.h

@@ -57,6 +57,7 @@ class AXPlatformNodeAuraLinux : public AXPlatformNodeBase {
   bool GrabFocus();
   bool DoDefaultAction();
   const gchar* GetDefaultActionName();
+  AtkAttributeSet* GetAtkAttributes() const;
 
   void SetExtentsRelativeToAtkCoordinateType(
       gint* x, gint* y, gint* width, gint* height,
@@ -71,6 +72,10 @@ class AXPlatformNodeAuraLinux : public AXPlatformNodeBase {
 
   // Misc helpers
   void GetFloatAttributeInGValue(ax::mojom::FloatAttribute attr, GValue* value);
+  AtkAttributeSet* AddIntAttributeToAtkAttributeSet(
+      AtkAttributeSet* attributes,
+      ax::mojom::IntAttribute attribute,
+      const char* atk_attribute) const;
 
   // Event helpers
   void OnFocused();

ui/accessibility/platform/ax_platform_node_auralinux_unittest.cc

@@ -35,6 +35,44 @@ class AXPlatformNodeAuraLinuxTest : public AXPlatformNodeTest {
   AtkObject* GetRootAtkObject() { return AtkObjectFromNode(GetRootNode()); }
 };
 
+static void EnsureAtkObjectHasAttributeWithValue(
+    AtkObject* atk_object,
+    const gchar* attribute_name,
+    const gchar* attribute_value) {
+  AtkAttributeSet* attributes = atk_object_get_attributes(atk_object);
+  bool saw_attribute = false;
+
+  AtkAttributeSet* current = attributes;
+  while (current) {
+    AtkAttribute* attribute = static_cast<AtkAttribute*>(current->data);
+
+    if (0 == strcmp(attribute_name, attribute->name)) {
+      // Ensure that we only see this attribute once.
+      ASSERT_FALSE(saw_attribute);
+
+      EXPECT_STREQ(attribute_value, attribute->value);
+      saw_attribute = true;
+    }
+
+    current = current->next;
+  }
+
+  ASSERT_TRUE(saw_attribute);
+  atk_attribute_set_free(attributes);
+}
+
+static void EnsureAtkObjectDoesNotHaveAttribute(
+    AtkObject* atk_object,
+    const gchar* attribute_name) {
+  AtkAttributeSet* attributes = atk_object_get_attributes(atk_object);
+  AtkAttributeSet* current = attributes;
+  while (current) {
+    AtkAttribute* attribute = static_cast<AtkAttribute*>(current->data);
+    ASSERT_NE(0, strcmp(attribute_name, attribute->name));
+  }
+  atk_attribute_set_free(attributes);
+}
+
 //
 // AtkObject tests
 //
@@ -244,6 +282,39 @@ TEST_F(AXPlatformNodeAuraLinuxTest, TestAtkObjectIndexInParent) {
   g_object_unref(root_obj);
 }
 
+TEST_F(AXPlatformNodeAuraLinuxTest, TestAtkObjectAttributes) {
+  AXNodeData root_data;
+  root_data.id = 1;
+
+  Init(root_data);
+
+  AXNode* root_node = GetRootNode();
+  AtkObject* root_atk_object(AtkObjectFromNode(root_node));
+  ASSERT_TRUE(ATK_IS_OBJECT(root_atk_object));
+  g_object_ref(root_atk_object);
+  EnsureAtkObjectDoesNotHaveAttribute(root_atk_object, "level");
+
+  root_data = AXNodeData();
+  root_data.id = 1;
+  root_data.AddIntAttribute(ax::mojom::IntAttribute::kHierarchicalLevel, 1);
+  root_node->SetData(root_data);
+  EnsureAtkObjectHasAttributeWithValue(root_atk_object, "level", "1");
+
+  root_data = AXNodeData();
+  root_data.id = 1;
+  root_data.AddIntAttribute(ax::mojom::IntAttribute::kHierarchicalLevel, 2);
+  root_node->SetData(root_data);
+  EnsureAtkObjectHasAttributeWithValue(root_atk_object, "level", "2");
+
+  root_data = AXNodeData();
+  root_data.id = 1;
+  root_data.AddIntAttribute(ax::mojom::IntAttribute::kHierarchicalLevel, 34);
+  root_node->SetData(root_data);
+  EnsureAtkObjectHasAttributeWithValue(root_atk_object, "level", "34");
+
+  g_object_unref(root_atk_object);
+}
+
 //
 // AtkComponent tests
 //