// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry.form;
import java.awt.Point;
import org.apache.tapestry.IAsset;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
/**
* Used to create an image button inside a {@link Form}. Although it is occasionally useful to know
* the {@link Point}on the image that was clicked (i.e., use the image as a kind of image map,
* which was the original intent of the HTML element), it is more commonly used to provide a graphic
* image for the user to click, rather than the rather plain <input type=submit>. [ <a
* href="../../../../../ComponentReference/ImageSubmit.html">Component Reference </a>]
*
* @author Howard Lewis Ship
*/
public abstract class ImageSubmit extends Submit
{
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = getForm(cycle);
if (form.wasPrerendered(writer, this))
return;
boolean rewinding = form.isRewinding();
String nameOverride = getNameOverride();
String name = nameOverride == null ? form.getElementId(this) : form.getElementId(
this,
nameOverride);
setName(name);
if (rewinding)
{
// If disabled, do nothing.
if (isDisabled())
return;
// Image clicks get submitted as two request parameters:
// foo.x and foo.y
String parameterName = name + ".x";
String value = cycle.getParameter(parameterName);
if (value != null)
handleClick(cycle, form);
return;
}
// Not rewinding, do the real render
boolean disabled = isDisabled();
IAsset disabledImage = getDisabledImage();
IAsset finalImage = (disabled && disabledImage != null) ? disabledImage : getImage();
String imageURL = finalImage.buildURL(cycle);
writer.beginEmpty("input");
writer.attribute("type", "image");
writer.attribute("name", name);
if (disabled)
writer.attribute("disabled", "disabled");
// NN4 places a border unless you tell it otherwise.
// IE ignores the border attribute and never shows a border.
writer.attribute("border", 0);
writer.attribute("src", imageURL);
renderInformalParameters(writer, cycle);
writer.closeTag();
}
void handleClick(IRequestCycle cycle, IForm form)
{
// The point parameter is not really used, unless the
// ImageButton is used for its original purpose (as a kind
// of image map). In modern usage, we only care about
// whether the user clicked on the image (and thus submitted
// the form), not where in the image the user actually clicked.
if (isParameterBound("point"))
{
int x = Integer.parseInt(cycle.getParameter(getName() + ".x"));
int y = Integer.parseInt(cycle.getParameter(getName() + ".y"));
setPoint(new Point(x, y));
}
super.handleClick(cycle, form);
}
/** parameter */
public abstract IAsset getDisabledImage();
/** parameter */
public abstract IAsset getImage();
/** parameter */
public abstract String getNameOverride();
/** parameter */
public abstract void setPoint(Point point);
protected void prepareForRender(IRequestCycle cycle)
{
super.prepareForRender(cycle);
if (getImage() == null)
throw Tapestry.createRequiredParameterException(this, "image");
}
}