root/content/browser/accessibility/browser_accessibility_android.cc

DEFINITIONS

1. Create
2. IsNative
3. PlatformIsLeaf
4. IsCheckable
5. IsChecked
6. IsClickable
7. IsCollection
8. IsCollectionItem
9. IsContentInvalid
10. IsDismissable
11. IsEnabled
12. IsFocusable
13. IsFocused
14. IsHeading
15. IsHierarchical
16. IsLink
17. IsMultiLine
18. IsPassword
19. IsRangeType
20. IsScrollable
21. IsSelected
22. IsVisibleToUser
23. CanOpenPopup
24. GetClassName
25. GetText
26. GetItemIndex
27. GetItemCount
28. GetScrollX
29. GetScrollY
30. GetMaxScrollX
31. GetMaxScrollY
32. GetTextChangeFromIndex
33. GetTextChangeAddedCount
34. GetTextChangeRemovedCount
35. GetTextChangeBeforeText
36. GetSelectionStart
37. GetSelectionEnd
38. GetEditableTextLength
39. AndroidInputType
40. AndroidLiveRegionType
41. AndroidRangeType
42. RowCount
43. ColumnCount
44. RowIndex
45. RowSpan
46. ColumnIndex
47. ColumnSpan
48. RangeMin
49. RangeMax
50. RangeCurrentValue
51. HasFocusableChild
52. HasOnlyStaticTextChildren
53. IsIframe
54. PostInitialize
55. NotifyLiveRegionUpdate
56. CountChildrenWithRole

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/accessibility/browser_accessibility_android.h"

#include "base/strings/utf_string_conversions.h"
#include "content/browser/accessibility/browser_accessibility_manager_android.h"
#include "content/common/accessibility_messages.h"

namespace {

// These are enums from android.text.InputType in Java:
enum {
  ANDROID_TEXT_INPUTTYPE_TYPE_NULL = 0,
  ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME = 0x4,
  ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME_DATE = 0x14,
  ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME_TIME = 0x24,
  ANDROID_TEXT_INPUTTYPE_TYPE_NUMBER = 0x2,
  ANDROID_TEXT_INPUTTYPE_TYPE_PHONE = 0x3,
  ANDROID_TEXT_INPUTTYPE_TYPE_TEXT = 0x1,
  ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_URI = 0x11,
  ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_WEB_EDIT_TEXT = 0xa1,
  ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_WEB_EMAIL = 0xd1,
  ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_WEB_PASSWORD = 0xe1
};

// These are enums from android.view.View in Java:
enum {
  ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_NONE = 0,
  ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_POLITE = 1,
  ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_ASSERTIVE = 2
};

// These are enums from
// android.view.accessibility.AccessibilityNodeInfo.RangeInfo in Java:
enum {
  ANDROID_VIEW_ACCESSIBILITY_RANGE_TYPE_FLOAT = 1
};

}  // namespace

namespace content {

// static
BrowserAccessibility* BrowserAccessibility::Create() {
  return new BrowserAccessibilityAndroid();
}

BrowserAccessibilityAndroid::BrowserAccessibilityAndroid() {
  first_time_ = true;
}

bool BrowserAccessibilityAndroid::IsNative() const {
  return true;
}

bool BrowserAccessibilityAndroid::PlatformIsLeaf() const {
  if (child_count() == 0)
    return true;

  // Iframes are always allowed to contain children.
  if (IsIframe() ||
      role() == ui::AX_ROLE_ROOT_WEB_AREA ||
      role() == ui::AX_ROLE_WEB_AREA) {
    return false;
  }

  // If it has a focusable child, we definitely can't leave out children.
  if (HasFocusableChild())
    return false;

  // Headings with text can drop their children.
  base::string16 name = GetText();
  if (role() == ui::AX_ROLE_HEADING && !name.empty())
    return true;

  // Focusable nodes with text can drop their children.
  if (HasState(ui::AX_STATE_FOCUSABLE) && !name.empty())
    return true;

  // Nodes with only static text as children can drop their children.
  if (HasOnlyStaticTextChildren())
    return true;

  return BrowserAccessibility::PlatformIsLeaf();
}

bool BrowserAccessibilityAndroid::IsCheckable() const {
  bool checkable = false;
  bool is_aria_pressed_defined;
  bool is_mixed;
  GetAriaTristate("aria-pressed", &is_aria_pressed_defined, &is_mixed);
  if (role() == ui::AX_ROLE_CHECK_BOX ||
      role() == ui::AX_ROLE_RADIO_BUTTON ||
      is_aria_pressed_defined) {
    checkable = true;
  }
  if (HasState(ui::AX_STATE_CHECKED))
    checkable = true;
  return checkable;
}

bool BrowserAccessibilityAndroid::IsChecked() const {
  return HasState(ui::AX_STATE_CHECKED);
}

bool BrowserAccessibilityAndroid::IsClickable() const {
  return (PlatformIsLeaf() && !GetText().empty());
}

bool BrowserAccessibilityAndroid::IsCollection() const {
  return (role() == ui::AX_ROLE_GRID ||
          role() == ui::AX_ROLE_LIST ||
          role() == ui::AX_ROLE_LIST_BOX ||
          role() == ui::AX_ROLE_TABLE ||
          role() == ui::AX_ROLE_TREE);
}

bool BrowserAccessibilityAndroid::IsCollectionItem() const {
  return (role() == ui::AX_ROLE_CELL ||
          role() == ui::AX_ROLE_COLUMN_HEADER ||
          role() == ui::AX_ROLE_DESCRIPTION_LIST_TERM ||
          role() == ui::AX_ROLE_LIST_BOX_OPTION ||
          role() == ui::AX_ROLE_LIST_ITEM ||
          role() == ui::AX_ROLE_ROW_HEADER ||
          role() == ui::AX_ROLE_TREE_ITEM);
}

bool BrowserAccessibilityAndroid::IsContentInvalid() const {
  std::string invalid;
  return GetHtmlAttribute("aria-invalid", &invalid);
}

bool BrowserAccessibilityAndroid::IsDismissable() const {
  return false;  // No concept of "dismissable" on the web currently.
}

bool BrowserAccessibilityAndroid::IsEnabled() const {
  return HasState(ui::AX_STATE_ENABLED);
}

bool BrowserAccessibilityAndroid::IsFocusable() const {
  bool focusable = HasState(ui::AX_STATE_FOCUSABLE);
  if (IsIframe() ||
      role() == ui::AX_ROLE_WEB_AREA) {
    focusable = false;
  }
  return focusable;
}

bool BrowserAccessibilityAndroid::IsFocused() const {
  return manager()->GetFocus(manager()->GetRoot()) == this;
}

bool BrowserAccessibilityAndroid::IsHeading() const {
  return (role() == ui::AX_ROLE_COLUMN_HEADER ||
          role() == ui::AX_ROLE_HEADING ||
          role() == ui::AX_ROLE_ROW_HEADER);
}

bool BrowserAccessibilityAndroid::IsHierarchical() const {
  return (role() == ui::AX_ROLE_LIST ||
          role() == ui::AX_ROLE_TREE);
}

bool BrowserAccessibilityAndroid::IsLink() const {
  return role() == ui::AX_ROLE_LINK || role() == ui::AX_ROLE_IMAGE_MAP_LINK;
}

bool BrowserAccessibilityAndroid::IsMultiLine() const {
  return role() == ui::AX_ROLE_TEXT_AREA;
}

bool BrowserAccessibilityAndroid::IsPassword() const {
  return HasState(ui::AX_STATE_PROTECTED);
}

bool BrowserAccessibilityAndroid::IsRangeType() const {
  return (role() == ui::AX_ROLE_PROGRESS_INDICATOR ||
          role() == ui::AX_ROLE_SCROLL_BAR ||
          role() == ui::AX_ROLE_SLIDER);
}

bool BrowserAccessibilityAndroid::IsScrollable() const {
  int dummy;
  return GetIntAttribute(ui::AX_ATTR_SCROLL_X_MAX, &dummy);
}

bool BrowserAccessibilityAndroid::IsSelected() const {
  return HasState(ui::AX_STATE_SELECTED);
}

bool BrowserAccessibilityAndroid::IsVisibleToUser() const {
  return !HasState(ui::AX_STATE_INVISIBLE);
}

bool BrowserAccessibilityAndroid::CanOpenPopup() const {
  return HasState(ui::AX_STATE_HASPOPUP);
}

const char* BrowserAccessibilityAndroid::GetClassName() const {
  const char* class_name = NULL;

  switch(role()) {
    case ui::AX_ROLE_EDITABLE_TEXT:
    case ui::AX_ROLE_SPIN_BUTTON:
    case ui::AX_ROLE_TEXT_AREA:
    case ui::AX_ROLE_TEXT_FIELD:
      class_name = "android.widget.EditText";
      break;
    case ui::AX_ROLE_SLIDER:
      class_name = "android.widget.SeekBar";
      break;
    case ui::AX_ROLE_COMBO_BOX:
      class_name = "android.widget.Spinner";
      break;
    case ui::AX_ROLE_BUTTON:
    case ui::AX_ROLE_MENU_BUTTON:
    case ui::AX_ROLE_POP_UP_BUTTON:
      class_name = "android.widget.Button";
      break;
    case ui::AX_ROLE_CHECK_BOX:
      class_name = "android.widget.CheckBox";
      break;
    case ui::AX_ROLE_RADIO_BUTTON:
      class_name = "android.widget.RadioButton";
      break;
    case ui::AX_ROLE_TOGGLE_BUTTON:
      class_name = "android.widget.ToggleButton";
      break;
    case ui::AX_ROLE_CANVAS:
    case ui::AX_ROLE_IMAGE:
      class_name = "android.widget.Image";
      break;
    case ui::AX_ROLE_PROGRESS_INDICATOR:
      class_name = "android.widget.ProgressBar";
      break;
    case ui::AX_ROLE_TAB_LIST:
      class_name = "android.widget.TabWidget";
      break;
    case ui::AX_ROLE_GRID:
    case ui::AX_ROLE_TABLE:
      class_name = "android.widget.GridView";
      break;
    case ui::AX_ROLE_LIST:
    case ui::AX_ROLE_LIST_BOX:
      class_name = "android.widget.ListView";
      break;
    case ui::AX_ROLE_DIALOG:
      class_name = "android.app.Dialog";
      break;
    case ui::AX_ROLE_ROOT_WEB_AREA:
      class_name = "android.webkit.WebView";
      break;
    default:
      class_name = "android.view.View";
      break;
  }

  return class_name;
}

base::string16 BrowserAccessibilityAndroid::GetText() const {
  if (IsIframe() ||
      role() == ui::AX_ROLE_WEB_AREA) {
    return base::string16();
  }

  base::string16 description = GetString16Attribute(
      ui::AX_ATTR_DESCRIPTION);
  base::string16 text;
  if (!name().empty())
    text = base::UTF8ToUTF16(name());
  else if (!description.empty())
    text = description;
  else if (!value().empty())
    text = base::UTF8ToUTF16(value());

  // This is called from PlatformIsLeaf, so don't call PlatformChildCount
  // from within this!
  if (text.empty() && HasOnlyStaticTextChildren()) {
    for (uint32 i = 0; i < child_count(); i++) {
      BrowserAccessibility* child = children()[i];
      text += static_cast<BrowserAccessibilityAndroid*>(child)->GetText();
    }
  }

  switch(role()) {
    case ui::AX_ROLE_HEADING:
      // Only append "heading" if this node already has text.
      if (!text.empty())
        text += base::ASCIIToUTF16(" Heading");
      break;
  }

  return text;
}

int BrowserAccessibilityAndroid::GetItemIndex() const {
  int index = 0;
  switch(role()) {
    case ui::AX_ROLE_LIST_ITEM:
    case ui::AX_ROLE_LIST_BOX_OPTION:
    case ui::AX_ROLE_TREE_ITEM:
      index = index_in_parent();
      break;
    case ui::AX_ROLE_SLIDER:
    case ui::AX_ROLE_PROGRESS_INDICATOR: {
      float value_for_range;
      if (GetFloatAttribute(
              ui::AX_ATTR_VALUE_FOR_RANGE, &value_for_range)) {
        index = static_cast<int>(value_for_range);
      }
      break;
    }
  }
  return index;
}

int BrowserAccessibilityAndroid::GetItemCount() const {
  int count = 0;
  switch(role()) {
    case ui::AX_ROLE_LIST:
    case ui::AX_ROLE_LIST_BOX:
      count = PlatformChildCount();
      break;
    case ui::AX_ROLE_SLIDER:
    case ui::AX_ROLE_PROGRESS_INDICATOR: {
      float max_value_for_range;
      if (GetFloatAttribute(ui::AX_ATTR_MAX_VALUE_FOR_RANGE,
                            &max_value_for_range)) {
        count = static_cast<int>(max_value_for_range);
      }
      break;
    }
  }
  return count;
}

int BrowserAccessibilityAndroid::GetScrollX() const {
  int value = 0;
  GetIntAttribute(ui::AX_ATTR_SCROLL_X, &value);
  return value;
}

int BrowserAccessibilityAndroid::GetScrollY() const {
  int value = 0;
  GetIntAttribute(ui::AX_ATTR_SCROLL_Y, &value);
  return value;
}

int BrowserAccessibilityAndroid::GetMaxScrollX() const {
  int value = 0;
  GetIntAttribute(ui::AX_ATTR_SCROLL_X_MAX, &value);
  return value;
}

int BrowserAccessibilityAndroid::GetMaxScrollY() const {
  int value = 0;
  GetIntAttribute(ui::AX_ATTR_SCROLL_Y_MAX, &value);
  return value;
}

int BrowserAccessibilityAndroid::GetTextChangeFromIndex() const {
  size_t index = 0;
  while (index < old_value_.length() &&
         index < new_value_.length() &&
         old_value_[index] == new_value_[index]) {
    index++;
  }
  return index;
}

int BrowserAccessibilityAndroid::GetTextChangeAddedCount() const {
  size_t old_len = old_value_.length();
  size_t new_len = new_value_.length();
  size_t left = 0;
  while (left < old_len &&
         left < new_len &&
         old_value_[left] == new_value_[left]) {
    left++;
  }
  size_t right = 0;
  while (right < old_len &&
         right < new_len &&
         old_value_[old_len - right - 1] == new_value_[new_len - right - 1]) {
    right++;
  }
  return (new_len - left - right);
}

int BrowserAccessibilityAndroid::GetTextChangeRemovedCount() const {
  size_t old_len = old_value_.length();
  size_t new_len = new_value_.length();
  size_t left = 0;
  while (left < old_len &&
         left < new_len &&
         old_value_[left] == new_value_[left]) {
    left++;
  }
  size_t right = 0;
  while (right < old_len &&
         right < new_len &&
         old_value_[old_len - right - 1] == new_value_[new_len - right - 1]) {
    right++;
  }
  return (old_len - left - right);
}

base::string16 BrowserAccessibilityAndroid::GetTextChangeBeforeText() const {
  return old_value_;
}

int BrowserAccessibilityAndroid::GetSelectionStart() const {
  int sel_start = 0;
  GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START, &sel_start);
  return sel_start;
}

int BrowserAccessibilityAndroid::GetSelectionEnd() const {
  int sel_end = 0;
  GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END, &sel_end);
  return sel_end;
}

int BrowserAccessibilityAndroid::GetEditableTextLength() const {
  return value().length();
}

int BrowserAccessibilityAndroid::AndroidInputType() const {
  std::string html_tag = GetStringAttribute(
      ui::AX_ATTR_HTML_TAG);
  if (html_tag != "input")
    return ANDROID_TEXT_INPUTTYPE_TYPE_NULL;

  std::string type;
  if (!GetHtmlAttribute("type", &type))
    return ANDROID_TEXT_INPUTTYPE_TYPE_TEXT;

  if (type == "" || type == "text" || type == "search")
    return ANDROID_TEXT_INPUTTYPE_TYPE_TEXT;
  else if (type == "date")
    return ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME_DATE;
  else if (type == "datetime" || type == "datetime-local")
    return ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME;
  else if (type == "email")
    return ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_WEB_EMAIL;
  else if (type == "month")
    return ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME_DATE;
  else if (type == "number")
    return ANDROID_TEXT_INPUTTYPE_TYPE_NUMBER;
  else if (type == "password")
    return ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_WEB_PASSWORD;
  else if (type == "tel")
    return ANDROID_TEXT_INPUTTYPE_TYPE_PHONE;
  else if (type == "time")
    return ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME_TIME;
  else if (type == "url")
    return ANDROID_TEXT_INPUTTYPE_TYPE_TEXT_URI;
  else if (type == "week")
    return ANDROID_TEXT_INPUTTYPE_TYPE_DATETIME;

  return ANDROID_TEXT_INPUTTYPE_TYPE_NULL;
}

int BrowserAccessibilityAndroid::AndroidLiveRegionType() const {
  std::string live = GetStringAttribute(
      ui::AX_ATTR_LIVE_STATUS);
  if (live == "polite")
    return ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_POLITE;
  else if (live == "assertive")
    return ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_ASSERTIVE;
  return ANDROID_VIEW_VIEW_ACCESSIBILITY_LIVE_REGION_NONE;
}

int BrowserAccessibilityAndroid::AndroidRangeType() const {
  return ANDROID_VIEW_ACCESSIBILITY_RANGE_TYPE_FLOAT;
}

int BrowserAccessibilityAndroid::RowCount() const {
  if (role() == ui::AX_ROLE_GRID ||
      role() == ui::AX_ROLE_TABLE) {
    return CountChildrenWithRole(ui::AX_ROLE_ROW);
  }

  if (role() == ui::AX_ROLE_LIST ||
      role() == ui::AX_ROLE_LIST_BOX ||
      role() == ui::AX_ROLE_TREE) {
    return PlatformChildCount();
  }

  return 0;
}

int BrowserAccessibilityAndroid::ColumnCount() const {
  if (role() == ui::AX_ROLE_GRID ||
      role() == ui::AX_ROLE_TABLE) {
    return CountChildrenWithRole(ui::AX_ROLE_COLUMN);
  }
  return 0;
}

int BrowserAccessibilityAndroid::RowIndex() const {
  if (role() == ui::AX_ROLE_LIST_ITEM ||
      role() == ui::AX_ROLE_LIST_BOX_OPTION ||
      role() == ui::AX_ROLE_TREE_ITEM) {
    return index_in_parent();
  }

  return GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_INDEX);
}

int BrowserAccessibilityAndroid::RowSpan() const {
  return GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_SPAN);
}

int BrowserAccessibilityAndroid::ColumnIndex() const {
  return GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_INDEX);
}

int BrowserAccessibilityAndroid::ColumnSpan() const {
  return GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_SPAN);
}

float BrowserAccessibilityAndroid::RangeMin() const {
  return GetFloatAttribute(ui::AX_ATTR_MIN_VALUE_FOR_RANGE);
}

float BrowserAccessibilityAndroid::RangeMax() const {
  return GetFloatAttribute(ui::AX_ATTR_MAX_VALUE_FOR_RANGE);
}

float BrowserAccessibilityAndroid::RangeCurrentValue() const {
  return GetFloatAttribute(ui::AX_ATTR_VALUE_FOR_RANGE);
}

bool BrowserAccessibilityAndroid::HasFocusableChild() const {
  // This is called from PlatformIsLeaf, so don't call PlatformChildCount
  // from within this!
  for (uint32 i = 0; i < child_count(); i++) {
    BrowserAccessibility* child = children()[i];
    if (child->HasState(ui::AX_STATE_FOCUSABLE))
      return true;
    if (static_cast<BrowserAccessibilityAndroid*>(child)->HasFocusableChild())
      return true;
  }
  return false;
}

bool BrowserAccessibilityAndroid::HasOnlyStaticTextChildren() const {
  // This is called from PlatformIsLeaf, so don't call PlatformChildCount
  // from within this!
  for (uint32 i = 0; i < child_count(); i++) {
    BrowserAccessibility* child = children()[i];
    if (child->role() != ui::AX_ROLE_STATIC_TEXT)
      return false;
  }
  return true;
}

bool BrowserAccessibilityAndroid::IsIframe() const {
  base::string16 html_tag = GetString16Attribute(
      ui::AX_ATTR_HTML_TAG);
  return html_tag == base::ASCIIToUTF16("iframe");
}

void BrowserAccessibilityAndroid::PostInitialize() {
  BrowserAccessibility::PostInitialize();

  if (IsEditableText()) {
    if (base::UTF8ToUTF16(value()) != new_value_) {
      old_value_ = new_value_;
      new_value_ = base::UTF8ToUTF16(value());
    }
  }

  if (role() == ui::AX_ROLE_ALERT && first_time_)
    manager()->NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, this);

  base::string16 live;
  if (GetString16Attribute(
      ui::AX_ATTR_CONTAINER_LIVE_STATUS, &live)) {
    NotifyLiveRegionUpdate(live);
  }

  first_time_ = false;
}

void BrowserAccessibilityAndroid::NotifyLiveRegionUpdate(
    base::string16& aria_live) {
  if (!EqualsASCII(aria_live, aria_strings::kAriaLivePolite) &&
      !EqualsASCII(aria_live, aria_strings::kAriaLiveAssertive))
    return;

  base::string16 text = GetText();
  if (cached_text_ != text) {
    if (!text.empty()) {
      manager()->NotifyAccessibilityEvent(ui::AX_EVENT_SHOW,
                                         this);
    }
    cached_text_ = text;
  }
}

int BrowserAccessibilityAndroid::CountChildrenWithRole(ui::AXRole role) const {
  int count = 0;
  for (uint32 i = 0; i < PlatformChildCount(); i++) {
    if (PlatformGetChild(i)->role() == role)
      count++;
  }
  return count;
}

}  // namespace content