/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.openjpa.trader.client.ui;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.Widget;
/**
* Fun stuff to fade-in, fade-out a changing label.
*
* @author Pinaki Poddar
*
*/
public class FadeEffect extends Timer {
static final String OPACITY = "opacity";
final Element elem;
final Widget html;
double opacity = 0.0;
double delta = 0.01;
int sign = -1;
FadeEffect(Widget html, boolean appear) {
this.html = html;
elem = html.getElement();
sign = appear ? 1 : -1;
opacity = appear ? 0.0 : 1.0;
}
@Override
public void run() {
DOM.setStyleAttribute(elem, OPACITY, "" + opacity);
opacity = opacity + sign * delta;
if (ended()) {
cancel();
}
}
boolean ended() {
if (sign == -1) {
return opacity <= 0.0;
} else {
return opacity >= 1.0;
}
}
}