| // Copyright 2004 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.IActionListener; |
| import org.apache.tapestry.IAsset; |
| import org.apache.tapestry.IBinding; |
| import org.apache.tapestry.IForm; |
| import org.apache.tapestry.IMarkupWriter; |
| import org.apache.tapestry.IRequestCycle; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.request.RequestContext; |
| |
| /** |
| * 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 |
| * @version $Id$ |
| **/ |
| |
| public abstract class ImageSubmit extends AbstractFormComponent |
| { |
| |
| public abstract IBinding getPointBinding(); |
| |
| public abstract IBinding getSelectedBinding(); |
| |
| protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle) |
| { |
| IForm form = getForm(cycle); |
| |
| boolean rewinding = form.isRewinding(); |
| |
| String nameOverride = getNameOverride(); |
| |
| String name = |
| nameOverride == null ? form.getElementId(this) : form.getElementId(this, nameOverride); |
| |
| if (rewinding) |
| { |
| // If disabled, do nothing. |
| |
| if (isDisabled()) |
| return; |
| |
| RequestContext context = cycle.getRequestContext(); |
| |
| // Image clicks get submitted as two request parameters: |
| // foo.x and foo.y |
| |
| String parameterName = name + ".x"; |
| |
| String value = context.getParameter(parameterName); |
| |
| if (value == null) |
| return; |
| |
| // 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. |
| |
| IBinding pointBinding = getPointBinding(); |
| |
| if (pointBinding != null) |
| { |
| int x = Integer.parseInt(value); |
| |
| parameterName = name + ".y"; |
| value = context.getParameter(parameterName); |
| |
| int y = Integer.parseInt(value); |
| |
| pointBinding.setObject(new Point(x, y)); |
| } |
| |
| // Notify the application, by setting the select parameter |
| // to the tag parameter. |
| |
| IBinding selectedBinding = getSelectedBinding(); |
| |
| if (selectedBinding != null) |
| selectedBinding.setObject(getTag()); |
| |
| IActionListener listener = getListener(); |
| |
| if (listener != null) |
| listener.actionTriggered(this, cycle); |
| |
| 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(); |
| } |
| |
| public abstract boolean isDisabled(); |
| |
| public abstract IAsset getDisabledImage(); |
| |
| public abstract IAsset getImage(); |
| |
| public abstract IActionListener getListener(); |
| |
| public abstract Object getTag(); |
| |
| public abstract String getNameOverride(); |
| |
| protected void prepareForRender(IRequestCycle cycle) |
| { |
| super.prepareForRender(cycle); |
| |
| if (getImage() == null) |
| throw Tapestry.createRequiredParameterException(this, "image"); |
| } |
| |
| } |