com.vaadin.client.ui.JsniMousewheelHandler Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of vaadin-client Show documentation
Show all versions of vaadin-client Show documentation
Vaadin is a web application framework for Rich Internet Applications (RIA).
Vaadin enables easy development and maintenance of fast and
secure rich web
applications with a stunning look and feel and a wide browser support.
It features a server-side architecture with the majority of the logic
running
on the server. Ajax technology is used at the browser-side to ensure a
rich
and interactive user experience.
/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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.
*/
package com.vaadin.client.ui;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.widgets.Escalator;
/**
* A mousewheel handling class to get around the limits of
* {@link Event#ONMOUSEWHEEL}.
*
* For internal use only. May be removed or replaced in the future.
*
* @see Escalator.JsniWorkaround
*/
// FIXME remove the copy in v7 package
abstract class JsniMousewheelHandler {
/**
* A JavaScript function that handles the mousewheel DOM event, and passes
* it on to Java code.
*
* @see #createMousewheelListenerFunction(Widget)
*/
protected final JavaScriptObject mousewheelListenerFunction;
protected JsniMousewheelHandler(final Widget widget) {
mousewheelListenerFunction = createMousewheelListenerFunction(widget);
}
/**
* A method that constructs the JavaScript function that will be stored into
* {@link #mousewheelListenerFunction}.
*
* @param widget
* a reference to the current instance of {@link Widget}
*/
protected abstract JavaScriptObject createMousewheelListenerFunction(
Widget widget);
public native void attachMousewheelListener(Element element)
/*-{
if (element.addEventListener) {
// FireFox likes "wheel", while others use "mousewheel"
var eventName = 'onmousewheel' in element ? 'mousewheel' : 'wheel';
element.addEventListener(eventName, [email protected]::mousewheelListenerFunction);
}
}-*/;
public native void detachMousewheelListener(Element element)
/*-{
if (element.addEventListener) {
// FireFox likes "wheel", while others use "mousewheel"
var eventName = element.onwheel===undefined?"mousewheel":"wheel";
element.removeEventListener(eventName, [email protected]::mousewheelListenerFunction);
}
}-*/;
}