blob: 81b59b6a38a4cda1eec39258773f3e83d0b58ad7 [file] [log] [blame]
/**
* @license
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
(function(window) {
'use strict';
function GrEventHelper(element) {
this.element = element;
this._unsubscribers = [];
}
/**
* Add a callback to arbitrary event.
* The callback may return false to prevent event bubbling.
*
* @param {string} event Event name
* @param {function(Event):boolean} callback
* @return {function()} Unsubscribe function.
*/
GrEventHelper.prototype.on = function(event, callback) {
return this._listen(this.element, callback, {event});
};
/**
* Add a callback to element click or touch.
* The callback may return false to prevent event bubbling.
*
* @param {function(Event):boolean} callback
* @return {function()} Unsubscribe function.
*/
GrEventHelper.prototype.onTap = function(callback) {
return this._listen(this.element, callback);
};
/**
* Add a callback to element click or touch ahead of normal flow.
* Callback is installed on parent during capture phase.
* https://www.w3.org/TR/DOM-Level-3-Events/#event-flow
* The callback may return false to cancel regular event listeners.
*
* @param {function(Event):boolean} callback
* @return {function()} Unsubscribe function.
*/
GrEventHelper.prototype.captureTap = function(callback) {
return this._listen(this.element.parentElement, callback, {capture: true});
};
GrEventHelper.prototype._listen = function(container, callback, opt_options) {
const capture = opt_options && opt_options.capture;
const event = opt_options && opt_options.event || 'tap';
const handler = e => {
if (e.path.indexOf(this.element) !== -1) {
let mayContinue = true;
try {
mayContinue = callback(e);
} catch (e) {
console.warn(`Plugin error handing event: ${e}`);
}
if (mayContinue === false) {
e.stopImmediatePropagation();
e.stopPropagation();
e.preventDefault();
}
}
};
container.addEventListener(event, handler, capture);
const unsubscribe = () =>
container.removeEventListener(event, handler, capture);
this._unsubscribers.push(unsubscribe);
return unsubscribe;
};
window.GrEventHelper = GrEventHelper;
})(window);