domEvents.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @emails react-core
 */

'use strict';

import {
  buttonType,
  buttonsType,
  defaultPointerSize,
  defaultBrowserChromeSize,
} from './constants';

/**
 * Native event object mocks for higher-level events.
 *
 * 1. Each event type defines the exact object that it accepts. This ensures
 * that no arbitrary properties can be assigned to events, and the properties
 * that don't exist on specific event types (e.g., 'pointerType') are not added
 * to the respective native event.
 *
 * 2. Properties that cannot be relied on due to inconsistent browser support (e.g., 'x' and 'y') are not
 * added to the native event. Others that shouldn't be arbitrarily customized (e.g., 'screenX')
 * are automatically inferred from associated values.
 *
 * 3. PointerEvent and TouchEvent fields are normalized (e.g., 'rotationAngle' -> 'twist')
 */

function emptyFunction() {}

function createEvent(type, data = {}) {
  const event = document.createEvent('CustomEvent');
  event.initCustomEvent(type, true, true);
  if (data != null) {
    Object.keys(data).forEach(key => {
      const value = data[key];
      if (key === 'timeStamp' && !value) {
        return;
      }
      Object.defineProperty(event, key, {value});
    });
  }
  return event;
}

function createGetModifierState(keyArg, data) {
  if (keyArg === 'Alt') {
    return data.altKey || false;
  }
  if (keyArg === 'Control') {
    return data.ctrlKey || false;
  }
  if (keyArg === 'Meta') {
    return data.metaKey || false;
  }
// ... (383 more lines)