blockly/core/utils/aria.ts

/**
 * @license
 * Copyright 2019 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * ARIA-related constants and utilities.
 * These methods are not specific to Blockly, and could be factored out into
 * a JavaScript framework such as Closure.
 *
 * @namespace Blockly.utils.aria
 */
import * as goog from '../../closure/goog/goog.js';
goog.declareModuleId('Blockly.utils.aria');


/** ARIA states/properties prefix. */
const ARIA_PREFIX = 'aria-';

/** ARIA role attribute. */
const ROLE_ATTRIBUTE = 'role';

/**
 * ARIA role values.
 * Copied from Closure's goog.a11y.aria.Role
 *
 * @alias Blockly.utils.aria.Role
 */
export enum Role {
  // ARIA role for an interactive control of tabular data.
  GRID = 'grid',

  // ARIA role for a cell in a grid.
  GRIDCELL = 'gridcell',
  // ARIA role for a group of related elements like tree item siblings.
  GROUP = 'group',

  // ARIA role for a listbox.
  LISTBOX = 'listbox',

  // ARIA role for a popup menu.
  MENU = 'menu',

  // ARIA role for menu item elements.
  MENUITEM = 'menuitem',
  // ARIA role for a checkbox box element inside a menu.
  MENUITEMCHECKBOX = 'menuitemcheckbox',
  // ARIA role for option items that are  children of combobox, listbox, menu,
  // radiogroup, or tree elements.
  OPTION = 'option',
  // ARIA role for ignorable cosmetic elements with no semantic significance.
  PRESENTATION = 'presentation',

  // ARIA role for a row of cells in a grid.
  ROW = 'row',
  // ARIA role for a tree.
  TREE = 'tree',

  // ARIA role for a tree item that sometimes may be expanded or collapsed.
  TREEITEM = 'treeitem'
}

/**
 * ARIA states and properties.
 * Copied from Closure's goog.a11y.aria.State
 *
 * @alias Blockly.utils.aria.State
 */
export enum State {
  // ARIA property for setting the currently active descendant of an element,
  // for example the selected item in a list box. Value: ID of an element.
  ACTIVEDESCENDANT = 'activedescendant',
  // ARIA property defines the total number of columns in a table, grid, or
  // treegrid.
  // Value: integer.
  COLCOUNT = 'colcount',
  // ARIA state for a disabled item. Value: one of {true, false}.
  DISABLED = 'disabled',

  // ARIA state for setting whether the element like a tree node is expanded.
  // Value: one of {true, false, undefined}.
  EXPANDED = 'expanded',

  // ARIA state indicating that the entered value does not conform. Value:
  // one of {false, true, 'grammar', 'spelling'}
  INVALID = 'invalid',

  // ARIA property that provides a label to override any other text, value, or
  // contents used to describe this element. Value: string.
  LABEL = 'label',
  // ARIA property for setting the element which labels another element.
  // Value: space-separated IDs of elements.
  LABELLEDBY = 'labelledby',

  // ARIA property for setting the level of an element in the hierarchy.
  // Value: integer.
  LEVEL = 'level',
  // ARIA property indicating if the element is horizontal or vertical.
  // Value: one of {'vertical', 'horizontal'}.
  ORIENTATION = 'orientation',

  // ARIA property that defines an element's number of position in a list.
  // Value: integer.
  POSINSET = 'posinset',

  // ARIA property defines the total number of rows in a table, grid, or
  // treegrid.
  // Value: integer.
  ROWCOUNT = 'rowcount',

  // ARIA state for setting the currently selected item in the list.
  // Value: one of {true, false, undefined}.
  SELECTED = 'selected',
  // ARIA property defining the number of items in a list. Value: integer.
  SETSIZE = 'setsize',

  // ARIA property for slider maximum value. Value: number.
  VALUEMAX = 'valuemax',

  // ARIA property for slider minimum value. Value: number.
  VALUEMIN = 'valuemin'
}

/**
 * Sets the role of an element.
 *
 * Similar to Closure's goog.a11y.aria
 *
 * @param element DOM node to set role of.
 * @param roleName Role name.
 * @alias Blockly.utils.aria.setRole
 */
export function setRole(element: Element, roleName: Role) {
  element.setAttribute(ROLE_ATTRIBUTE, roleName);
}

/**
 * Sets the state or property of an element.
 * Copied from Closure's goog.a11y.aria
 *
 * @param element DOM node where we set state.
 * @param stateName State attribute being set.
 *     Automatically adds prefix 'aria-' to the state name if the attribute is
 * not an extra attribute.
 * @param value Value for the state attribute.
 * @alias Blockly.utils.aria.setState
 */
export function setState(
    element: Element, stateName: State, value: string|boolean|number|string[]) {
  if (Array.isArray(value)) {
    value = value.join(' ');
  }
  const attrStateName = ARIA_PREFIX + stateName;
  element.setAttribute(attrStateName, `${value}`);
}