/*
* {{{ header & license
* Copyright (c) 2007 Vianney le Clément
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* }}}
*/
package org.xhtmlrenderer.swt;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Iterator;
import java.util.LinkedHashMap;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Image;
import org.xhtmlrenderer.extend.UserAgentCallback;
import org.xhtmlrenderer.resource.CSSResource;
import org.xhtmlrenderer.resource.ImageResource;
import org.xhtmlrenderer.resource.XMLResource;
import org.xhtmlrenderer.util.ImageUtil;
import org.xhtmlrenderer.util.XRLog;
/**
* Naive user agent, copy of org.xhtmlrenderer.swing.NaiveUserAgent (but
* modified for SWT, of course).
*
* @author Vianney le Clément
*
*/
public class NaiveUserAgent implements UserAgentCallback {
/**
* an LRU cache
*/
private int _imageCacheCapacity = 16;
private LinkedHashMap _imageCache = new LinkedHashMap(_imageCacheCapacity,
0.75f, true);
private String _baseURL;
private final Device _device;
/**
* Creates a new instance of NaiveUserAgent
*/
public NaiveUserAgent(Device device) {
_device = device;
}
/**
* Gets a Reader for the resource identified
*
* @param uri PARAM
* @return The stylesheet value
*/
// TODO implement this with nio.
protected InputStream getInputStream(String uri) {
java.io.InputStream is = null;
uri = resolveURI(uri);
try {
is = new URL(uri).openStream();
} catch (java.net.MalformedURLException e) {
XRLog.exception("bad URL given: " + uri, e);
} catch (java.io.FileNotFoundException e) {
XRLog.exception("item at URI " + uri + " not found");
} catch (java.io.IOException e) {
XRLog.exception("IO problem for " + uri, e);
}
return is;
}
public CSSResource getCSSResource(String uri) {
return new CSSResource(getInputStream(uri));
}
public ImageResource getImageResource(String uri) {
ImageResource ir = null;
if (ImageUtil.isEmbeddedBase64Image(uri)) {
ir = loadEmbeddedBase64ImageResource(uri);
} else {
uri = resolveURI(uri);
ir = (ImageResource) _imageCache.get(uri);
// TODO: check that cached image is still valid
if (ir == null) {
InputStream is = getInputStream(uri);
if (is != null) {
try {
ir = createImageResource(uri, is);
if (_imageCache.size() >= _imageCacheCapacity) {
// prevent the cache from growing too big
ImageResource old = (ImageResource) _imageCache
.remove(_imageCache.keySet().iterator().next());
((SWTFSImage) old.getImage()).getImage().dispose();
}
_imageCache.put(uri, ir);
} catch (SWTException e) {
XRLog.exception(
"Can't read image file; unexpected problem for URI '"
+ uri + "'", e);
} finally {
try {
is.close();
} catch (IOException e) {
// swallow
}
}
}
}
if (ir == null) {
ir = new ImageResource(uri, null);
}
}
return ir;
}
/**
* Factory method to generate ImageResources from a given Image. May be
* overridden in subclass.
*
* @param uri The URI for the image, resolved to an absolute URI.
* @param is Stream of the image; may be null (for example, if image could
* not be loaded).
*
* @return An ImageResource containing the image.
*/
protected ImageResource createImageResource(String uri, InputStream is) {
return new ImageResource(uri, new SWTFSImage(new Image(_device, is), this, uri));
}
private ImageResource loadEmbeddedBase64ImageResource(final String uri) {
byte[] image = ImageUtil.getEmbeddedBase64Image(uri);
if (image != null) {
return createImageResource(null, new ByteArrayInputStream(image));
}
return new ImageResource(null, null);
}
public XMLResource getXMLResource(String uri) {
if (uri == null) {
XRLog.exception("null uri requested");
return null;
}
InputStream inputStream = getInputStream(uri);
if (inputStream == null) {
XRLog.exception("couldn't get InputStream for " + uri);
return null;
}
XMLResource xmlResource;
try {
xmlResource = XMLResource.load(inputStream);
} catch (Exception e) {
XRLog.exception("unable to load xml resource: " + uri, e);
return null;
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
// swallow
}
}
}
return xmlResource;
}
/**
* Gets the visited attribute of the NaiveUserAgent object
*
* @param uri PARAM
* @return The visited value
*/
public boolean isVisited(String uri) {
return false;
}
public void setBaseURL(String url) {
_baseURL = url;
}
public String resolveURI(String uri) {
if (uri == null) return null;
String ret = null;
if (_baseURL == null) {//first try to set a base URL
try {
URI result = new URI(uri);
if (result.isAbsolute()) setBaseURL(result.toString());
} catch (URISyntaxException e) {
XRLog.exception("The default NaiveUserAgent could not use the URL as base url: " + uri, e);
}
if (_baseURL == null) { // still not set -> fallback to current working directory
try {
setBaseURL(new File(".").toURI().toURL().toExternalForm());
} catch (Exception e1) {
XRLog.exception("The default NaiveUserAgent doesn't know how to resolve the base URL for " + uri);
return null;
}
}
}
// test if the URI is valid; if not, try to assign the base url as its parent
try {
URI result = new URI(uri);
if (!result.isAbsolute()) {
XRLog.load(uri + " is not a URL; may be relative. Testing using parent URL " + _baseURL);
result=new URI(_baseURL).resolve(result);
}
ret = result.toString();
} catch (URISyntaxException e) {
XRLog.exception("The default NaiveUserAgent cannot resolve the URL " + uri + " with base URL " + _baseURL);
}
return ret;
}
public String getBaseURL() {
return _baseURL;
}
/**
* Dispose all images in cache and clean the cache.
*/
public void disposeCache() {
for (Iterator iter = _imageCache.values().iterator(); iter.hasNext();) {
ImageResource ir = (ImageResource) iter.next();
((SWTFSImage) ir.getImage()).getImage().dispose();
}
_imageCache.clear();
}
public byte[] getBinaryResource(String uri) {
InputStream is = getInputStream(uri);
if (is==null) return null;
try {
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buf = new byte[10240];
int i;
while ((i = is.read(buf)) != -1) {
result.write(buf, 0, i);
}
is.close();
is = null;
return result.toByteArray();
} catch (IOException e) {
return null;
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
// ignore
}
}
}
}
}