/*
* 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.wicket.extensions.ajax.markup.html;
import org.apache.wicket.Component;
import org.apache.wicket.ajax.AbstractDefaultAjaxBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.IAjaxIndicatorAware;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.handler.resource.ResourceReferenceRequestHandler;
/**
* A behavior that adds a span with wicket's default indicator gif to the end of the component's
* markup. This span can be used as an ajax busy indicator. For an example usage see
* {@link IndicatingAjaxLink}
* <p>
* Instances of this behavior must not be shared between components.
*
* @see IndicatingAjaxLink
* @see IAjaxIndicatorAware
*
* @since 1.2
*
* @author Igor Vaynberg (ivaynberg)
*/
public class AjaxIndicatorAppender extends Behavior
{
/**
* Component instance this behavior is bound to
*/
private Component component;
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* Construct.
*/
public AjaxIndicatorAppender()
{
}
@Override
public void renderHead(final Component component, final IHeaderResponse response)
{
super.renderHead(component, response);
AjaxRequestTarget target = component.getRequestCycle().find(AjaxRequestTarget.class);
if (target != null)
{
final String javascript = "var e = Wicket.$('" + getMarkupId() +
"'); if (e != null && typeof(e.parentNode) != 'undefined') e.parentNode.removeChild(e);";
target.prependJavaScript(javascript);
}
}
@Override
public void afterRender(final Component component)
{
super.afterRender(component);
final Response r = component.getResponse();
r.write("<span style=\"display:none;\" class=\"");
r.write(getSpanClass());
r.write("\" ");
r.write("id=\"");
r.write(getMarkupId());
r.write("\">");
r.write("<img src=\"");
r.write(getIndicatorUrl());
r.write("\" alt=\"\"/></span>");
}
/**
* @return url of the animated indicator image
*/
protected CharSequence getIndicatorUrl()
{
IRequestHandler handler = new ResourceReferenceRequestHandler(
AbstractDefaultAjaxBehavior.INDICATOR);
return RequestCycle.get().urlFor(handler);
}
/**
* @return css class name of the generated outer span
*/
protected String getSpanClass()
{
return "wicket-ajax-indicator";
}
/**
* Returns the markup id attribute of the outer most span of this indicator. This is the id of
* the span that should be hidden or show to hide or show the indicator.
*
* @return markup id of outer most span
*/
public String getMarkupId()
{
return component.getMarkupId() + "--ajax-indicator";
}
/**
* @see org.apache.wicket.behavior.Behavior#bind(org.apache.wicket.Component)
*/
@Override
public final void bind(final Component component)
{
this.component = component;
}
}