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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 2000-2014 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;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Timer;
/**
* Class representing the loading indicator for Vaadin applications. The loading
* indicator has four states: "triggered", "first", "second" and "third". When
* {@link #trigger()} is called the indicator moves to its "triggered" state and
* then transitions from one state to the next when the timeouts specified using
* the set*StateDelay methods occur.
*
* @author Vaadin Ltd
* @since 7.1
*/
public class VLoadingIndicator {
private static final String PRIMARY_STYLE_NAME = "v-loading-indicator";
private ApplicationConnection connection;
private int firstDelay = 300;
private int secondDelay = 1500;
private int thirdDelay = 5000;
private Timer firstTimer = new Timer() {
@Override
public void run() {
show();
}
};
private Timer secondTimer = new Timer() {
@Override
public void run() {
getElement().setClassName(PRIMARY_STYLE_NAME);
getElement().addClassName("second");
// For backwards compatibility only
getElement().addClassName(PRIMARY_STYLE_NAME + "-delay");
}
};
private Timer thirdTimer = new Timer() {
@Override
public void run() {
getElement().setClassName(PRIMARY_STYLE_NAME);
getElement().addClassName("third");
// For backwards compatibility only
getElement().addClassName(PRIMARY_STYLE_NAME + "-wait");
}
};
private Element element;
/**
* Returns the delay (in ms) which must pass before the loading indicator
* moves into the "first" state and is shown to the user
*
* @return The delay (in ms) until moving into the "first" state. Counted
* from when {@link #trigger()} is called.
*/
public int getFirstDelay() {
return firstDelay;
}
/**
* Sets the delay (in ms) which must pass before the loading indicator moves
* into the "first" state and is shown to the user
*
* @param firstDelay
* The delay (in ms) until moving into the "first" state. Counted
* from when {@link #trigger()} is called.
*/
public void setFirstDelay(int firstDelay) {
this.firstDelay = firstDelay;
}
/**
* Returns the delay (in ms) which must pass before the loading indicator
* moves to its "second" state.
*
* @return The delay (in ms) until the loading indicator moves into its
* "second" state. Counted from when {@link #trigger()} is called.
*/
public int getSecondDelay() {
return secondDelay;
}
/**
* Sets the delay (in ms) which must pass before the loading indicator moves
* to its "second" state.
*
* @param secondDelay
* The delay (in ms) until the loading indicator moves into its
* "second" state. Counted from when {@link #trigger()} is
* called.
*/
public void setSecondDelay(int secondDelay) {
this.secondDelay = secondDelay;
}
/**
* Returns the delay (in ms) which must pass before the loading indicator
* moves to its "third" state.
*
* @return The delay (in ms) until the loading indicator moves into its
* "third" state. Counted from when {@link #trigger()} is called.
*/
public int getThirdDelay() {
return thirdDelay;
}
/**
* Sets the delay (in ms) which must pass before the loading indicator moves
* to its "third" state.
*
* @param thirdDelay
* The delay (in ms) from the event until changing the loading
* indicator into its "third" state. Counted from when
* {@link #trigger()} is called.
*/
public void setThirdDelay(int thirdDelay) {
this.thirdDelay = thirdDelay;
}
/**
* Triggers displaying of this loading indicator. The loading indicator will
* actually be shown by {@link #show()} when the "first" delay (as specified
* by {@link #getFirstDelay()}) has passed.
*
* The loading indicator will be hidden if shown when calling this method.
*
*/
public void trigger() {
hide();
firstTimer.schedule(getFirstDelay());
}
/**
* Triggers displaying of this loading indicator unless it's already visible
* or scheduled to be shown after a delay.
*
* @since 7.4
*/
public void ensureTriggered() {
if (!isVisible() && !firstTimer.isRunning()) {
trigger();
}
}
/**
* Shows the loading indicator in its standard state and triggers timers for
* transitioning into the "second" and "third" states.
*/
public void show() {
// Reset possible style name and display mode
getElement().setClassName(PRIMARY_STYLE_NAME);
getElement().addClassName("first");
getElement().getStyle().setDisplay(Display.BLOCK);
// Schedule the "second" loading indicator
int secondTimerDelay = getSecondDelay() - getFirstDelay();
if (secondTimerDelay >= 0) {
secondTimer.schedule(secondTimerDelay);
}
// Schedule the "third" loading indicator
int thirdTimerDelay = getThirdDelay() - getFirstDelay();
if (thirdTimerDelay >= 0) {
thirdTimer.schedule(thirdTimerDelay);
}
}
/**
* Returns the {@link ApplicationConnection} which uses this loading
* indicator
*
* @return The ApplicationConnection for this loading indicator
*/
public ApplicationConnection getConnection() {
return connection;
}
/**
* Sets the {@link ApplicationConnection} which uses this loading indicator.
* Only used internally.
*
* @param connection
* The ApplicationConnection for this loading indicator
*/
void setConnection(ApplicationConnection connection) {
this.connection = connection;
}
/**
* Hides the loading indicator (if visible). Cancels any possibly running
* timers.
*/
public void hide() {
firstTimer.cancel();
secondTimer.cancel();
thirdTimer.cancel();
getElement().getStyle().setDisplay(Display.NONE);
}
/**
* Returns whether or not the loading indicator is showing.
*
* @return true if the loading indicator is visible, false otherwise
*/
public boolean isVisible() {
if (getElement().getStyle().getDisplay()
.equals(Display.NONE.getCssName())) {
return false;
}
return true;
}
/**
* Returns the root element of the loading indicator
*
* @return The loading indicator DOM element
*/
public com.google.gwt.user.client.Element getElement() {
if (element == null) {
element = DOM.createDiv();
element.getStyle().setPosition(Position.ABSOLUTE);
getConnection().getUIConnector().getWidget().getElement()
.appendChild(element);
}
return DOM.asOld(element);
}
}