chrome/browser/resources/chromeos/accessibility/common/event_generator.js

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import {KeyCode} from './key_code.js';

/** Functions to send synthetic key and mouse events. */
export class EventGenerator {
  /**
   * Sends a single key stroke (down and up) with the given key code and
   *     keyboard modifiers (whether or not CTRL, ALT, SEARCH, and SHIFT are
   *     being held).
   * @param {!KeyCode} keyCode
   * @param {!chrome.accessibilityPrivate.SyntheticKeyboardModifiers} modifiers
   * @param {boolean} useRewriters If true, uses rewriters for the key event;
   *     only allowed if used from Dictation. Otherwise indicates that rewriters
   *     should be skipped.
   */
  static sendKeyPress(keyCode, modifiers = {}, useRewriters = false) {
    let type = chrome.accessibilityPrivate.SyntheticKeyboardEventType.KEYDOWN;
    chrome.accessibilityPrivate.sendSyntheticKeyEvent(
        {type, keyCode, modifiers}, useRewriters);

    type = chrome.accessibilityPrivate.SyntheticKeyboardEventType.KEYUP;
    chrome.accessibilityPrivate.sendSyntheticKeyEvent(
        {type, keyCode, modifiers}, useRewriters);
  }

  /**
   * Sends two synthetic mouse events (a mouse press and and a mouse release)
   *     to simulate a mouse click.
   * @param {number} x
   * @param {number} y
   * @param {!{
   *  delayMs: (number|undefined),
   *  mouseButton:
   *   (!chrome.accessibilityPrivate.SyntheticMouseEventButton|undefined)
   * }} params
   */
  static sendMouseClick(x, y, params = {
    delayMs: 0,
    mouseButton: chrome.accessibilityPrivate.SyntheticMouseEventButton.LEFT,
  }) {
    if (EventGenerator.currentlyMidMouseClick) {
      EventGenerator.mouseClickQueue.push(arguments);
      return;
    }
    EventGenerator.currentlyMidMouseClick = true;

    // chrome.accessibilityPrivate.sendSyntheticMouseEvent only accepts
    // integers.
    x = Math.round(x);
    y = Math.round(y);

    const {delayMs, mouseButton} = params;
    let type = chrome.accessibilityPrivate.SyntheticMouseEventType.PRESS;
    chrome.accessibilityPrivate.sendSyntheticMouseEvent(
        {type, x, y, mouseButton});

    const callback = () => {
      type = chrome.accessibilityPrivate.SyntheticMouseEventType.RELEASE;
      chrome.accessibilityPrivate.sendSyntheticMouseEvent(
          {type, x, y, mouseButton});

      EventGenerator.currentlyMidMouseClick = false;
      if (EventGenerator.mouseClickQueue.length > 0) {
        EventGenerator.sendMouseClick(
            ...EventGenerator.mouseClickQueue.shift());
      }
    };
    if (delayMs > 0) {
      setTimeout(callback, delayMs);
    } else {
      callback();
    }
  }

  /**
   * Sends a synthetic mouse event to simulate a move event.
   * @param {number} x
   * @param {number} y
   * @param {boolean} touchAccessibility
   */
  static sendMouseMove(x, y, touchAccessibility = false) {
    const type = chrome.accessibilityPrivate.SyntheticMouseEventType.MOVE;
    chrome.accessibilityPrivate.sendSyntheticMouseEvent(
        {type, x, y, touchAccessibility});
  }
}

EventGenerator.mouseClickQueue = [];