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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 (c) 2002-2011 Gargoyle Software Inc.
*
* 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.gargoylesoftware.htmlunit.html;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpStatus;
import com.gargoylesoftware.htmlunit.Page;
import com.gargoylesoftware.htmlunit.SgmlPage;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.WebRequest;
import com.gargoylesoftware.htmlunit.WebResponse;
import com.gargoylesoftware.htmlunit.javascript.PostponedAction;
import com.gargoylesoftware.htmlunit.javascript.host.Event;
import com.gargoylesoftware.htmlunit.javascript.host.Node;
/**
* Wrapper for the HTML element "img".
*
* @version $Revision: 6204 $
* @author Mike Bowler
* @author David K. Taylor
* @author Christian Sell
* @author Ahmed Ashour
* @author Knut Johannes Dahle
*/
public class HtmlImage extends HtmlElement {
private static final Log LOG = LogFactory.getLog(HtmlImage.class);
/** The HTML tag represented by this element. */
public static final String TAG_NAME = "img";
private int lastClickX_;
private int lastClickY_;
private WebResponse imageWebResponse_;
private ImageReader imageReader_;
private boolean downloaded_;
private boolean onloadInvoked_;
/**
* Creates a new instance.
*
* @param namespaceURI the URI that identifies an XML namespace
* @param qualifiedName the qualified name of the element type to instantiate
* @param page the page that contains this element
* @param attributes the initial attributes
*/
HtmlImage(final String namespaceURI, final String qualifiedName, final SgmlPage page,
final Map attributes) {
super(namespaceURI, qualifiedName, page, attributes);
}
/**
* {@inheritDoc}
*/
@Override
protected void onAddedToPage() {
doOnLoad();
super.onAddedToPage();
}
/**
* {@inheritDoc}
*/
@Override
public void setAttributeNS(final String namespaceURI, final String qualifiedName, final String value) {
if ("src".equals(qualifiedName) && value != ATTRIBUTE_NOT_DEFINED && getPage() instanceof HtmlPage) {
final String oldValue = getAttributeNS(namespaceURI, qualifiedName);
if (!oldValue.equals(value)) {
// onload handlers may need to be invoked again, and a new image may need to be downloaded
onloadInvoked_ = false;
downloaded_ = false;
}
}
super.setAttributeNS(namespaceURI, qualifiedName, value);
}
/**
* INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.
*
* Executes this element's onload handler if it has one. This method also downloads the image
* if this element has an onload handler (prior to invoking said handler), because applications
* sometimes use images to send information to the server and use the onload handler to get notified
* when the information has been received by the server.
*
* See here and
* here for the discussion which
* lead up to this method.
*
* This method may be called multiple times, but will only attempt to execute the onload
* handler the first time it is invoked.
*/
public void doOnLoad() {
if (!(getPage() instanceof HtmlPage)) {
return; // nothing to do if embedded in XML code
}
else if (onloadInvoked_) {
return;
}
onloadInvoked_ = true;
final HtmlPage htmlPage = (HtmlPage) getPage();
if (hasEventHandlers("onload")) {
// An onload handler is defined; we need to download the image and then call the onload handler.
boolean ok;
try {
downloadImageIfNeeded();
final int i = imageWebResponse_.getStatusCode();
ok = (i >= HttpStatus.SC_OK && i < HttpStatus.SC_MULTIPLE_CHOICES) || i == HttpStatus.SC_USE_PROXY;
}
catch (final IOException e) {
ok = false;
}
// If the download was a success, trigger the onload handler.
if (ok) {
final Event event = new Event(this, Event.TYPE_LOAD);
final Node scriptObject = (Node) getScriptObject();
final PostponedAction action = new PostponedAction(getPage()) {
@Override
public void execute() throws Exception {
scriptObject.executeEvent(event);
}
};
final String readyState = htmlPage.getReadyState();
if (READY_STATE_LOADING.equals(readyState)) {
htmlPage.addAfterLoadAction(action);
}
else {
htmlPage.getWebClient().getJavaScriptEngine().addPostponedAction(action);
}
}
else {
if (LOG.isDebugEnabled()) {
LOG.debug("Unable to download image for tag " + this + "; not firing onload event.");
}
}
}
}
/**
* Returns the value of the attribute "src". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "src" or an empty string if that attribute isn't defined
*/
public final String getSrcAttribute() {
return getAttribute("src");
}
/**
* Returns the value of the attribute "alt". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "alt" or an empty string if that attribute isn't defined
*/
public final String getAltAttribute() {
return getAttribute("alt");
}
/**
* Returns the value of the attribute "name". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "name" or an empty string if that attribute isn't defined
*/
public final String getNameAttribute() {
return getAttribute("name");
}
/**
* Returns the value of the attribute "longdesc". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "longdesc" or an empty string if that attribute isn't defined
*/
public final String getLongDescAttribute() {
return getAttribute("longdesc");
}
/**
* Returns the value of the attribute "height". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "height" or an empty string if that attribute isn't defined
*/
public final String getHeightAttribute() {
return getAttribute("height");
}
/**
* Returns the value of the attribute "width". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "width" or an empty string if that attribute isn't defined
*/
public final String getWidthAttribute() {
return getAttribute("width");
}
/**
* Returns the value of the attribute "usemap". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "usemap" or an empty string if that attribute isn't defined
*/
public final String getUseMapAttribute() {
return getAttribute("usemap");
}
/**
* Returns the value of the attribute "ismap". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "ismap" or an empty string if that attribute isn't defined
*/
public final String getIsmapAttribute() {
return getAttribute("ismap");
}
/**
* Returns the value of the attribute "align". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "align" or an empty string if that attribute isn't defined
*/
public final String getAlignAttribute() {
return getAttribute("align");
}
/**
* Returns the value of the attribute "border". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "border" or an empty string if that attribute isn't defined
*/
public final String getBorderAttribute() {
return getAttribute("border");
}
/**
* Returns the value of the attribute "hspace". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "hspace" or an empty string if that attribute isn't defined
*/
public final String getHspaceAttribute() {
return getAttribute("hspace");
}
/**
* Returns the value of the attribute "vspace". Refer to the
* HTML 4.01
* documentation for details on the use of this attribute.
*
* @return the value of the attribute "vspace" or an empty string if that attribute isn't defined
*/
public final String getVspaceAttribute() {
return getAttribute("vspace");
}
/**
* Returns the image's actual height (not the image's {@link #getHeightAttribute() height attribute}).
* POTENTIAL PERFORMANCE KILLER - DOWNLOADS THE IMAGE - USE AT YOUR OWN RISK
* If the image has not already been downloaded, this method triggers a download and caches the image.
*
* @return the image's actual height
* @throws IOException if an error occurs while downloading or reading the image
*/
public int getHeight() throws IOException {
readImageIfNeeded();
return imageReader_.getHeight(0);
}
/**
* Returns the image's actual width (not the image's {@link #getWidthAttribute() width attribute}).
* POTENTIAL PERFORMANCE KILLER - DOWNLOADS THE IMAGE - USE AT YOUR OWN RISK
* If the image has not already been downloaded, this method triggers a download and caches the image.
*
* @return the image's actual width
* @throws IOException if an error occurs while downloading or reading the image
*/
public int getWidth() throws IOException {
readImageIfNeeded();
return imageReader_.getWidth(0);
}
/**
* Returns the ImageReader which can be used to read the image contained by this image element.
* POTENTIAL PERFORMANCE KILLER - DOWNLOADS THE IMAGE - USE AT YOUR OWN RISK
* If the image has not already been downloaded, this method triggers a download and caches the image.
*
* @return the ImageReader which can be used to read the image contained by this image element
* @throws IOException if an error occurs while downloading or reading the image
*/
public ImageReader getImageReader() throws IOException {
readImageIfNeeded();
return imageReader_;
}
/**
* Returns the WebResponse for the image contained by this image element.
* POTENTIAL PERFORMANCE KILLER - DOWNLOADS THE IMAGE - USE AT YOUR OWN RISK
* If the image has not already been downloaded and downloadIfNeeded is true, this method
* triggers a download and caches the image.
*
* @param downloadIfNeeded whether or not the image should be downloaded (if it hasn't already been downloaded)
* @return null if no download should be performed and one hasn't already been triggered; otherwise,
* the response received when performing a request for the image referenced by this element
* @throws IOException if an error occurs while downloading the image
*/
public WebResponse getWebResponse(final boolean downloadIfNeeded) throws IOException {
if (downloadIfNeeded) {
downloadImageIfNeeded();
}
return imageWebResponse_;
}
/**
* Downloads the image contained by this image element.
* POTENTIAL PERFORMANCE KILLER - DOWNLOADS THE IMAGE - USE AT YOUR OWN RISK
* If the image has not already been downloaded, this method triggers a download and caches the image.
*
* @throws IOException if an error occurs while downloading the image
*/
private void downloadImageIfNeeded() throws IOException {
if (!downloaded_) {
final HtmlPage page = (HtmlPage) getPage();
final WebClient webclient = page.getWebClient();
final URL url = page.getFullyQualifiedUrl(getSrcAttribute());
final WebRequest request = new WebRequest(url);
request.setAdditionalHeader("Referer", page.getWebResponse().getWebRequest().getUrl().toExternalForm());
imageWebResponse_ = webclient.loadWebResponse(request);
imageReader_ = null;
downloaded_ = true;
}
}
private void readImageIfNeeded() throws IOException {
downloadImageIfNeeded();
if (imageReader_ == null) {
final ImageInputStream iis = ImageIO.createImageInputStream(imageWebResponse_.getContentAsStream());
final Iterator iter = ImageIO.getImageReaders(iis);
if (!iter.hasNext()) {
throw new IOException("No image detected in response");
}
imageReader_ = iter.next();
imageReader_.setInput(iis);
}
}
/**
* Simulates clicking this element at the specified position. This only makes sense for
* an image map (currently only server side), where the position matters. This method
* returns the page contained by this image's window after the click, which may or may not
* be the same as the original page, depending on JavaScript event handlers, etc.
*
* @param x the x position of the click
* @param y the y position of the click
* @return the page contained by this image's window after the click
* @exception IOException if an IO error occurs
*/
public Page click(final int x, final int y) throws IOException {
lastClickX_ = x;
lastClickY_ = y;
return super.click();
}
/**
* Simulates clicking this element at the position (0, 0). This method returns
* the page contained by this image's window after the click, which may or may not be the
* same as the original page, depending on JavaScript event handlers, etc.
*
* @return the page contained by this image's window after the click
* @exception IOException if an IO error occurs
*/
@Override
@SuppressWarnings("unchecked")
public Page click() throws IOException {
return click(0, 0);
}
/**
* Performs the click action on the enclosing A tag (if any).
* @throws IOException if an IO error occurred
*/
@Override
protected void doClickAction() throws IOException {
if (getUseMapAttribute() != ATTRIBUTE_NOT_DEFINED) {
// remove initial '#'
final String mapName = getUseMapAttribute().substring(1);
final HtmlElement doc = ((HtmlPage) getPage()).getDocumentElement();
final HtmlMap map = doc.getOneHtmlElementByAttribute("map", "name", mapName);
for (final HtmlElement element : map.getChildElements()) {
if (element instanceof HtmlArea) {
final HtmlArea area = (HtmlArea) element;
if (area.containsPoint(lastClickX_, lastClickY_)) {
area.doClickAction();
return;
}
}
}
}
final HtmlAnchor anchor = (HtmlAnchor) getEnclosingElement("a");
if (anchor == null) {
return;
}
if (getIsmapAttribute() != ATTRIBUTE_NOT_DEFINED) {
final String suffix = "?" + lastClickX_ + "," + lastClickY_;
anchor.doClickAction(suffix);
return;
}
anchor.doClickAction();
}
/**
* Saves this image as the specified file.
* @param file the file to save to
* @throws IOException if an IO error occurs
*/
public void saveAs(final File file) throws IOException {
final ImageReader reader = getImageReader();
ImageIO.write(reader.read(0), reader.getFormatName(), file);
}
}