/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation", "Tapestry"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* or "Tapestry", nor may "Apache" or "Tapestry" appear in their
* name, without prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE TAPESTRY CONTRIBUTOR COMMUNITY
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.tapestry.html;
import java.util.HashMap;
import java.util.Map;
import org.apache.tapestry.AbstractComponent;
import org.apache.tapestry.ApplicationRuntimeException;
import org.apache.tapestry.IAsset;
import org.apache.tapestry.IEngine;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.IResourceLocation;
import org.apache.tapestry.IScript;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.components.ILinkComponent;
import org.apache.tapestry.components.LinkEventType;
import org.apache.tapestry.engine.IScriptSource;
/**
* Combines a link component (such as {@link org.apache.tapestry.link.DirectLink})
* with an <img> and JavaScript code
* to create a rollover effect that works with both Netscape Navigator and
* Internet Explorer.
*
* [<a href="../../../../../ComponentReference/Rollover.html">Component Reference</a>]
*
*
* @author Howard Lewis Ship
* @version $Id: Rollover.java,v 1.5 2003/05/28 13:41:42 hlship Exp $
*
**/
public abstract class Rollover extends AbstractComponent
{
private IScript _parsedScript;
/**
* Converts an {@link IAsset} binding into a usable URL. Returns null
* if the binding does not exist or the binding's value is null.
*
**/
protected String getAssetURL(IAsset asset, IRequestCycle cycle)
{
if (asset == null)
return null;
return asset.buildURL(cycle);
}
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
// No body, so we skip it all if not rewinding (assumes no side effects on
// accessors).
if (cycle.isRewinding())
return;
String imageURL = null;
String focusURL = null;
String blurURL = null;
boolean dynamic = false;
String imageName = null;
Body body = Body.get(cycle);
if (body == null)
throw new ApplicationRuntimeException(
Tapestry.getMessage("Rollover.must-be-contained-by-body"),
this);
ILinkComponent serviceLink =
(ILinkComponent) cycle.getAttribute(Tapestry.LINK_COMPONENT_ATTRIBUTE_NAME);
if (serviceLink == null)
throw new ApplicationRuntimeException(
Tapestry.getMessage("Rollover.must-be-contained-by-link"),
this);
boolean linkDisabled = serviceLink.isDisabled();
if (linkDisabled)
{
imageURL = getAssetURL(getDisabled(), cycle);
if (imageURL == null)
imageURL = getAssetURL(getImage(), cycle);
}
else
{
imageURL = getAssetURL(getImage(), cycle);
focusURL = getAssetURL(getFocus(), cycle);
blurURL = getAssetURL(getBlur(), cycle);
dynamic = (focusURL != null) || (blurURL != null);
}
if (imageURL == null)
throw Tapestry.createRequiredParameterException(this, "image");
writer.beginEmpty("img");
writer.attribute("src", imageURL);
writer.attribute("border", 0);
if (dynamic)
{
if (focusURL == null)
focusURL = imageURL;
if (blurURL == null)
blurURL = imageURL;
imageName = writeScript(cycle, body, serviceLink, focusURL, blurURL);
writer.attribute("name", imageName);
}
renderInformalParameters(writer, cycle);
writer.closeTag();
}
private IScript getParsedScript()
{
if (_parsedScript == null)
{
IEngine engine = getPage().getEngine();
IScriptSource source = engine.getScriptSource();
IResourceLocation scriptLocation =
getSpecification().getSpecificationLocation().getRelativeLocation(
"Rollover.script");
_parsedScript = source.getScript(scriptLocation);
}
return _parsedScript;
}
private String writeScript(
IRequestCycle cycle,
Body body,
ILinkComponent link,
String focusURL,
String blurURL)
{
String imageName = body.getUniqueString(getId());
String focusImageURL = body.getPreloadedImageReference(focusURL);
String blurImageURL = body.getPreloadedImageReference(blurURL);
Map symbols = new HashMap();
symbols.put("imageName", imageName);
symbols.put("focusImageURL", focusImageURL);
symbols.put("blurImageURL", blurImageURL);
getParsedScript().execute(cycle, body, symbols);
// Add attributes to the link to control mouse over/out.
// Because the script is written before the <body> tag,
// there won't be any timing issues (such as cause
// bug #113893).
link.addEventHandler(LinkEventType.MOUSE_OVER, (String) symbols.get("onMouseOverName"));
link.addEventHandler(LinkEventType.MOUSE_OUT, (String) symbols.get("onMouseOutName"));
return imageName;
}
public abstract IAsset getBlur();
public abstract IAsset getDisabled();
public abstract IAsset getFocus();
public abstract IAsset getImage();
}