path: root/chromium/components/arc/common/accessibility_helper.mojom

// Copyright 2017 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.

// Next MinVersion: 9

module arc.mojom;

import "screen_rect.mojom";

// For future maintainers, each of the below enums were hand picked
// from their equivalents in the Android source. Keep them in the
// order given below and add as needed. The initial order matches the
// order they appear in source files.
//
// If not explicitly called out, the structs and enums below come from:
// https://developer.android.com/reference/android/view/accessibility/AccessibilityNodeInfo.html

// AccessibilityEventType lists the possible accessibility events on Android.
// https://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html
[Extensible]
enum AccessibilityEventType {
  VIEW_FOCUSED,
  VIEW_CLICKED,
  VIEW_LONG_CLICKED,
  VIEW_SELECTED,
  VIEW_TEXT_CHANGED,
  WINDOW_STATE_CHANGED,
  NOTIFICATION_STATE_CHANGED,
  VIEW_HOVER_ENTER,
  VIEW_HOVER_EXIT,
  TOUCH_EXPLORATION_GESTURE_START,
  TOUCH_EXPLORATION_GESTURE_END,
  WINDOW_CONTENT_CHANGED,
  VIEW_SCROLLED,
  VIEW_TEXT_SELECTION_CHANGED,
  ANNOUNCEMENT,
  VIEW_ACCESSIBILITY_FOCUSED,
  VIEW_ACCESSIBILITY_FOCUS_CLEARED,
  VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY,
  GESTURE_DETECTION_START,
  GESTURE_DETECTION_END,
  TOUCH_INTERACTION_START,
  TOUCH_INTERACTION_END,
  WINDOWS_CHANGED,
  VIEW_CONTEXT_CLICKED,
  ASSIST_READING_CONTEXT,
};

// Possible actions that can be performed on an AccessibilityNodeInfo.
[Extensible]
enum AccessibilityActionType {
  FOCUS,
  CLEAR_FOCUS,
  SELECT,
  CLEAR_SELECTION,
  CLICK,
  LONG_CLICK,
  ACCESSIBILITY_FOCUS,
  CLEAR_ACCESSIBILITY_FOCUS,
  NEXT_AT_MOVEMENT_GRANULARITY,  // unused
  PREVIOUS_AT_MOVEMENT_GRANULARITY,  // unused
  NEXT_HTML_ELEMENT,  // unused
  PREVIOUS_HTML_ELEMENT,  // unused
  SCROLL_FORWARD,
  SCROLL_BACKWARD,
  COPY,
  PASTE,
  CUT,
  SET_SELECTION,
  EXPAND,
  COLLAPSE,
  DISMISS,
  SET_TEXT,
  CONTEXT_CLICK,
  SCROLL_DOWN,
  SCROLL_LEFT,
  SCROLL_RIGHT,
  SCROLL_TO_POSITION,
  SCROLL_UP,
  SET_PROGRESS,
  SHOW_ON_SCREEN,
  CUSTOM_ACTION  // Not a standard action.
};

// Possible boolean properties set on an AccessibilityNodeInfo.
// The enum values appear in the same order as they do within
// AccessibilityNodeInfo.java.
[Extensible]
enum AccessibilityBooleanProperty {
  CHECKABLE,
  CHECKED,
  FOCUSABLE,
  FOCUSED,
  SELECTED,
  CLICKABLE,
  LONG_CLICKABLE,
  ENABLED,
  PASSWORD,
  SCROLLABLE,
  ACCESSIBILITY_FOCUSED,
  VISIBLE_TO_USER,
  EDITABLE,
  OPENS_POPUP,
  DISMISSABLE,
  MULTI_LINE,
  CONTENT_INVALID,
  CONTEXT_CLICKABLE,
  IMPORTANCE
};

// These fields are taken from string instance members of
// AccessibilityNodeInfo.
[Extensible]
enum AccessibilityStringProperty {
  PACKAGE_NAME,
  CLASS_NAME,
  TEXT,
  CONTENT_DESCRIPTION,
  VIEW_ID_RESOURCE_NAME,
  CHROME_ROLE,  // Chrome only
  ROLE_DESCRIPTION  // Chrome only
};

// These fields are taken from int instance members of
// AccessibilityNodeInfo.
[Extensible]
enum AccessibilityIntProperty {
  LABEL_FOR,
  LABELED_BY,
  TRAVERSAL_BEFORE,
  TRAVERSAL_AFTER,
  MAX_TEXT_LENGTH,
  TEXT_SELECTION_START,
  TEXT_SELECTION_END,
  INPUT_TYPE,
  LIVE_REGION
};

// These fields are taken from List<int> instance members of
// AccessibilityNodeInfo.
[Extensible]
enum AccessibilityIntListProperty {
  CHILD_NODE_IDS,
  CUSTOM_ACTION_IDS
};

// These fields are taken from List<String> instance members of
// AccessibilityNodeInfo.
[Extensible]
enum AccessibilityStringListProperty {
  CUSTOM_ACTION_DESCRIPTIONS
};

// This type is a subset of spans available under android.text.style.
[Extensible]
enum SpanType {
  URL,
  CLICKABLE
};

// Groups data about a Spannable.
struct SpanEntry {
  int32 start;
  int32 end;
  SpanType span_type;
};

// These fields are taken from AccessibilityNodeInfo.CollectionItemInfo.
[Extensible]
enum AccessibilitySelectionMode {
  NONE,
  SINGLE,
  MULTIPLE
};

// These fields are taken from AccessibilityNodeInfo.CollectionInfo.
struct AccessibilityCollectionInfoData {
  int32 row_count;
  int32 column_count;
  bool is_hierarchical;
  AccessibilitySelectionMode selection_mode;
};

// These fields are taken from AccessibilityNodeInfo.CollectionItemInfo.
struct AccessibilityCollectionItemInfoData {
  int32 row_index;
  int32 column_index;
  int32 row_span;
  int32 column_span;
  bool is_heading;
  bool is_selected;
};

// These fields are taken from AccessibilityNodeInfo.RangeInfo.
[Extensible]
enum AccessibilityRangeType {
  INT,
  FLOAT,
  PERCENT
};

// These fields are taken from AccessibilityNodeInfo.RangeInfo.
struct AccessibilityRangeInfoData {
  AccessibilityRangeType range_type;
  float min;
  float max;
  float current;
};

// AccessibilityNodeInfoData is a struct to contain info of
// AccessibilityNodeInfo in Android.
struct AccessibilityNodeInfoData {
  ScreenRect bounds_in_screen;
  [MinVersion=1]int32 id;
  [MinVersion=1]map<AccessibilityBooleanProperty, bool>? boolean_properties;
  [MinVersion=1]map<AccessibilityStringProperty, string>? string_properties;
  [MinVersion=1]map<AccessibilityIntProperty, int32>? int_properties;
  [MinVersion=1]
      map<AccessibilityIntListProperty, array<int32>>? int_list_properties;
  [MinVersion=3]map<AccessibilityStringListProperty, array<string>>?
      string_list_properties;
  [MinVersion=5]map<AccessibilityStringProperty, array<SpanEntry>>?
      spannable_string_properties;
  [MinVersion=5]AccessibilityCollectionInfoData? collection_info;
  [MinVersion=5]AccessibilityCollectionItemInfoData? collection_item_info;
  [MinVersion=5]AccessibilityRangeInfoData? range_info;
};

// Filters the event type (and implicitly the data) sent by the ARC
// accessibility service.
[Extensible]
enum AccessibilityFilterType {
  // No events will be sent.
  OFF,

  // Only send focus events along with the source focus node.
  FOCUS,

  // Send a complete tree from the event source's root for every event.
  ALL,

  // Send complete subtrees for root nodes with whitelisted package names.
  [MinVersion=2]WHITELISTED_PACKAGE_NAME
};

// AccessibilityEventData is a struct to contain info of
// AccessibilityEvent in Android.
// https://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html
struct AccessibilityEventData {
  AccessibilityEventType event_type;
  int32 source_id;
  array<AccessibilityNodeInfoData> node_data;

  // notification_key is set only for an event on an Android notification.
  [MinVersion=6]string? notification_key;

  // window_id where this event is dispatched for. While this window_id matches
  // with AccessibilityNodeInfo.getWindowId now, do not expect that it always
  // matches with it.
  [MinVersion=6]int32 window_id;

  // Task associated with this event (usually the front task when this event
  // gets dispatched).
  [MinVersion=8]int32 task_id;
};

// AccessibilityActionData is a struct to contain info of AccessibilityAction in
// Android.
// https://developer.android.com/reference/android/view/accessibility/AccessibilityNodeInfo.AccessibilityAction.html
struct AccessibilityActionData {
  int32 node_id;

  AccessibilityActionType action_type;

  // custom_action_id must be set if action_type is CUSTOM_ACTION.
  int32 custom_action_id;

  // window_id where the action is performed on.
  [MinVersion=6]int32 window_id;
};

// Next method ID: 2
interface AccessibilityHelperHost {
  OnAccessibilityEventDeprecated@0(AccessibilityEventType event_type,
                                   AccessibilityNodeInfoData? event_source);

  // OnAccessibilityEvent is called when a converted Android accessibility event
  // is sent from Android.
  OnAccessibilityEvent@1(AccessibilityEventData event_data);
};

// Next method ID: 7
interface AccessibilityHelperInstance {
  Init@0(AccessibilityHelperHost host);

  PerformActionDeprecated@1(int32 id, AccessibilityActionType action);

  // Set a filter on the event types received.
  SetFilter@2(AccessibilityFilterType filter_type);

  [MinVersion=3]PerformActionDeprecated2@3(AccessibilityActionData action_data);

  // Perform an action on a node requested by a Chrome client.
  [MinVersion=4]PerformAction@4(AccessibilityActionData action_data)
      => (bool result);

  // Sets the package to use ChromeVox (true) or TalkBack (false). Returns true
  // if the request was processed.
  [MinVersion=7]SetNativeChromeVoxArcSupportDeprecated@5(
      string package_name, bool enabled) => (bool processed);

  // Sets the focused window's package to use ChromeVox (true) or TalkBack
  // (false).
  [MinVersion=8]SetNativeChromeVoxArcSupportForFocusedWindow@6(
      bool enabled) => (bool processed);
};