react-native-web
Version:
React Native for Web
63 lines (61 loc) • 2.21 kB
JavaScript
;
/**
* Copyright (c) Nicolas Gallagher.
* 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.
*
*
*/
'use client';
var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault").default;
exports.__esModule = true;
exports.default = void 0;
var _invariant = _interopRequireDefault(require("fbjs/lib/invariant"));
var _EventEmitter = _interopRequireDefault(require("../../vendor/react-native/vendor/emitter/EventEmitter"));
var _canUseDom = _interopRequireDefault(require("../../modules/canUseDom"));
// Android 4.4 browser
var isPrefixed = _canUseDom.default && !document.hasOwnProperty('hidden') && document.hasOwnProperty('webkitHidden');
var EVENT_TYPES = ['change', 'memoryWarning'];
var VISIBILITY_CHANGE_EVENT = isPrefixed ? 'webkitvisibilitychange' : 'visibilitychange';
var VISIBILITY_STATE_PROPERTY = isPrefixed ? 'webkitVisibilityState' : 'visibilityState';
var AppStates = {
BACKGROUND: 'background',
ACTIVE: 'active'
};
var changeEmitter = null;
class AppState {
static get currentState() {
if (!AppState.isAvailable) {
return AppStates.ACTIVE;
}
switch (document[VISIBILITY_STATE_PROPERTY]) {
case 'hidden':
case 'prerender':
case 'unloaded':
return AppStates.BACKGROUND;
default:
return AppStates.ACTIVE;
}
}
static addEventListener(type, handler) {
if (AppState.isAvailable) {
(0, _invariant.default)(EVENT_TYPES.indexOf(type) !== -1, 'Trying to subscribe to unknown event: "%s"', type);
if (type === 'change') {
if (!changeEmitter) {
changeEmitter = new _EventEmitter.default();
document.addEventListener(VISIBILITY_CHANGE_EVENT, () => {
if (changeEmitter) {
changeEmitter.emit('change', AppState.currentState);
}
}, false);
}
return changeEmitter.addListener(type, handler);
}
}
}
}
exports.default = AppState;
AppState.isAvailable = _canUseDom.default && !!document[VISIBILITY_STATE_PROPERTY];
module.exports = exports.default;