ae7c9618d3
Can be used to listen to tap evens (i.e. click/touch), preventing their
bubbling, or preventing normal execution. To stop either bubbling or
normal execution, callback should explicitly return false. By default,
bubbling and normal execution is not prevented.
onTap() adds a listener to a click or touch event to element wrapped
with event helper.
captureTap() installs a capture phase listener and callback returning
false at that moment intercepts tap before any action is taken by other
listeners (i.e. PolyGerrit buttons).
Sample code
``` js
Gerrit.install(plugin => {
plugin.hook('reply-text').onAttached(element => {
if (!element.content) { return; }
plugin.eventHelper(element.content).onTap(() => {
console.log('reply test tapped!');
});
plugin.eventHelper(element.content).captureTap(() => {
// Prevent onTap() handler from being called.
return false;
});
});
});
```
Change-Id: Ie10169e2c801ce85590e4f700e6041e9c8a02bff
70 lines
2.3 KiB
JavaScript
70 lines
2.3 KiB
JavaScript
// Copyright (C) 2017 The Android Open Source Project
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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(function(window) {
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'use strict';
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function GrEventHelper(element) {
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this.element = element;
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this._unsubscribers = [];
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}
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/**
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* Add a callback to element click or touch.
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* The callback may return false to prevent event bubbling.
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* @param {function(Event):boolean} callback
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* @return {function()} Unsubscribe function.
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*/
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GrEventHelper.prototype.onTap = function(callback) {
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return this._listen(this.element, callback);
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};
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/**
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* Add a callback to element click or touch ahead of normal flow.
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* Callback is installed on parent during capture phase.
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* https://www.w3.org/TR/DOM-Level-3-Events/#event-flow
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* The callback may return false to cancel regular event listeners.
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* @param {function(Event):boolean} callback
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* @return {function()} Unsubscribe function.
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*/
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GrEventHelper.prototype.captureTap = function(callback) {
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return this._listen(this.element.parentElement, callback, {capture: true});
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};
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GrEventHelper.prototype._listen = function(container, callback, opt_options) {
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const capture = opt_options && opt_options.capture;
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const handler = e => {
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if (e.path.indexOf(this.element) !== -1) {
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let mayContinue = true;
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try {
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mayContinue = callback(e);
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} catch (e) {
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console.warn(`Plugin error handing event: ${e}`);
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}
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if (mayContinue === false) {
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e.stopImmediatePropagation();
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e.stopPropagation();
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e.preventDefault();
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}
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}
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};
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container.addEventListener('tap', handler, capture);
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const unsubscribe = () =>
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container.removeEventListener('tap', handler, capture);
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this._unsubscribers.push(unsubscribe);
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return unsubscribe;
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};
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window.GrEventHelper = GrEventHelper;
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})(window);
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