/*
* Copyright (c) 2002-2010 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.javascript.background;
import java.lang.ref.WeakReference;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.gargoylesoftware.htmlunit.WebWindow;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
/**
* A JavaScript-triggered background job representing the execution of some JavaScript code.
*
* @version $Revision: 5301 $
* @author Daniel Gredler
* @see MemoryLeakTest
*/
public abstract class JavaScriptExecutionJob extends JavaScriptJob {
/** Logging support. */
private static final Log LOG = LogFactory.getLog(JavaScriptExecutionJob.class);
/** The label for this job. */
private final String label_;
/** The window to which this job belongs (weakly referenced, so as not to leak memory). */
private final WeakReference<WebWindow> window_;
/**
* Creates a new JavaScript execution job, where the JavaScript code to execute is a string.
* @param initialDelay the initial amount of time to wait before executing this job
* @param period the amount of time to wait between executions of this job (may be <tt>null</tt>)
* @param label the label for the job
* @param window the window to which the job belongs
*/
public JavaScriptExecutionJob(final int initialDelay, final Integer period, final String label,
final WebWindow window) {
super(initialDelay, period);
label_ = label;
window_ = new WeakReference<WebWindow>(window);
}
/** {@inheritDoc} */
public void run() {
final WebWindow w = window_.get();
if (w == null) {
// The window has been garbage collected! No need to execute, obviously.
return;
}
if (LOG.isDebugEnabled()) {
LOG.debug("Executing " + this + ".");
}
try {
// Verify that the window is still open and the current page is the same.
final HtmlPage page = (HtmlPage) w.getEnclosedPage();
if (w.getEnclosedPage() != page || !w.getWebClient().getWebWindows().contains(w)) {
LOG.debug("The page that originated this job doesn't exist anymore. Execution cancelled.");
return;
}
runJavaScript(page);
}
finally {
if (LOG.isDebugEnabled()) {
LOG.debug("Finished executing " + this + ".");
}
}
}
/** {@inheritDoc} */
@Override
public String toString() {
return "JavaScript Execution Job " + getId() + ": " + label_;
}
/**
* Run the JavaScript from the concrete class.
* @param page the {@link HtmlPage} that owns the script
*/
protected abstract void runJavaScript(final HtmlPage page);
}