https://openjdk.java.net/projects/openjfx/javafx-web/: OpenJFX JavaFX
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/*
 * Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javafx.scene.web;

import com.sun.javafx.logging.PlatformLogger;
import com.sun.javafx.scene.web.Debugger;
import com.sun.javafx.scene.web.Printable;
import com.sun.javafx.tk.TKPulseListener;
import com.sun.javafx.tk.Toolkit;
import com.sun.javafx.webkit.*;
import com.sun.javafx.webkit.prism.PrismGraphicsManager;
import com.sun.javafx.webkit.prism.PrismInvoker;
import com.sun.javafx.webkit.prism.theme.PrismRenderer;
import com.sun.javafx.webkit.theme.RenderThemeImpl;
import com.sun.javafx.webkit.theme.Renderer;
import com.sun.webkit.*;
import com.sun.webkit.graphics.WCGraphicsManager;
import com.sun.webkit.network.URLs;
import com.sun.webkit.network.Util;
import javafx.animation.AnimationTimer;
import javafx.application.Platform;
import javafx.beans.InvalidationListener;
import javafx.beans.property.*;
import javafx.concurrent.Worker;
import javafx.event.EventHandler;
import javafx.event.EventType;
import javafx.geometry.Rectangle2D;
import javafx.print.JobSettings;
import javafx.print.PageLayout;
import javafx.print.PageRange;
import javafx.print.PrinterJob;
import javafx.scene.Node;
import javafx.util.Callback;
import org.w3c.dom.Document;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import static java.lang.String.format;
import java.lang.ref.WeakReference;
import java.net.MalformedURLException;
import java.net.URLConnection;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.PosixFilePermissions;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Base64;
import java.util.List;
import java.util.Objects;

import static com.sun.webkit.LoadListenerClient.*;


WebEngine is a non-visual object capable of managing one Web page at a time. It loads Web pages, creates their document models, applies styles as necessary, and runs JavaScript on pages. It provides access to the document model of the current page, and enables two-way communication between a Java application and JavaScript code of the page. 
Loading Web Pages


The WebEngine class provides two ways to load content into a WebEngine object: 


Loading always happens on a background thread. Methods that initiate loading return immediately after scheduling a background job. To track progress and/or cancel a job, use the Worker instance available from the getLoadWorker method. 
The following example changes the stage title when loading completes
successfully:


import javafx.concurrent.Worker.State;
final Stage stage;
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<State>() {
public void changed(ObservableValue ov, State oldState, State newState) {
if (newState == State.SUCCEEDED) {
stage.setTitle(webEngine.getLocation());
 }
 }
 });
webEngine.load("http://javafx.com");



User Interface Callbacks


A number of user interface callbacks may be registered with a WebEngine object. These callbacks are invoked when a script running on the page requests a user interface operation to be performed, for example, opens a popup window or changes status text. A WebEngine object cannot handle such requests internally, so it passes the request to the corresponding callbacks. If no callback is defined for a specific operation, the request is silently ignored. 
The table below shows JavaScript user interface methods and properties with their corresponding WebEngine callbacks: 

JavaScript Callback Table


    JavaScript method/property
    WebEngine callback



window.alert()onAlert


window.confirm()confirmHandler


window.open()createPopupHandler


window.open() and
 window.close()		onVisibilityChanged


window.prompt()promptHandler


Setting window.statusonStatusChanged


Setting any of the following:
 window.innerWidth, window.innerHeight,
 window.outerWidth, window.outerHeight,
 window.screenX, window.screenY,
 window.screenLeft, window.screenTop		
        onResized




The following example shows a callback that resizes a browser window:


Stage stage;
webEngine.setOnResized(
new EventHandler<WebEvent<Rectangle2D>>() {
public void handle(WebEvent<Rectangle2D> ev) {
Rectangle2D r = ev.getData();
stage.setWidth(r.getWidth());
stage.setHeight(r.getHeight());
 }
 });



Access to Document Model


The WebEngine objects create and manage a Document Object Model (DOM) for their Web pages. The model can be accessed and modified using Java DOM Core classes. The getDocument() method provides access to the root of the model. Additionally DOM Event specification is supported to define event handlers in Java code. 
The following example attaches a Java event listener to an element of
a Web page. Clicking on the element causes the application to exit:


EventListener listener = new EventListener() {
public void handleEvent(Event ev) {
Platform.exit();
 }
 };
Document doc = webEngine.getDocument();
Element el = doc.getElementById("exit-app");
((EventTarget) el).addEventListener("click", listener, false);



Evaluating JavaScript expressions


It is possible to execute arbitrary JavaScript code in the context of the current page using the executeScript method. For example: 

webEngine.executeScript("history.back()");



The execution result is returned to the caller,
as described in the next section.

Mapping JavaScript values to Java objects
 JavaScript values are represented using the obvious Java classes: null becomes Java null; a boolean becomes a java.lang.Boolean; and a string becomes a java.lang.String. A number can be java.lang.Double or a java.lang.Integer, depending. The undefined value maps to a specific unique String object whose value is "undefined". 
 If the result is a JavaScript object, it is wrapped as an instance of the JSObject class. (As a special case, if the JavaScript object is a JavaRuntimeObject as discussed in the next section, then the original Java object is extracted instead.) The JSObject class is a proxy that provides access to methods and properties of its underlying JavaScript object. The most commonly used JSObject methods are getMember (to read a named property), setMember (to set or define a property), and call (to call a function-valued property). 
 A DOM Node is mapped to an object that both extends JSObject and implements the appropriate DOM interfaces. To get a JSObject object for a Node just do a cast: 
JSObject jdoc = (JSObject) webEngine.getDocument();



 In some cases the context provides a specific Java type that guides the conversion. For example if setting a Java String field from a JavaScript expression, then the JavaScript value is converted to a string. 
Mapping Java objects to JavaScript values
 The arguments of the JSObject methods setMember and call pass Java objects to the JavaScript environment. This is roughly the inverse of the JavaScript-to-Java mapping described above: Java String, Number, or Boolean objects are converted to the obvious JavaScript values. A JSObject object is converted to the original wrapped JavaScript object. Otherwise a JavaRuntimeObject is created. This is a JavaScript object that acts as a proxy for the Java object, in that accessing properties of the JavaRuntimeObject causes the Java field or method with the same name to be accessed. 
 Note that the Java objects bound using JSObject.setMember, JSObject.setSlot, and JSObject.call are implemented using weak references. This means that the Java object can be garbage collected, causing subsequent accesses to the JavaScript objects to have no effect. 
Calling back to Java from JavaScript


The JSObject.setMember method is useful to enable upcalls from JavaScript into Java code, as illustrated by the following example. The Java code establishes a new JavaScript object named app. This object has one public member, the method exit. 

public class JavaApplication {
public void exit() {
Platform.exit();
}
}
...
JavaApplication javaApp = new JavaApplication();
JSObject window = (JSObject) webEngine.executeScript("window");
window.setMember("app", javaApp);


You can then refer to the object and the method from your HTML page:


<a href="" onclick="app.exit()">Click here to exit application</a>



When a user clicks the link the application is closed.

 Note that in the above example, the application holds a reference to the JavaApplication instance. This is required for the callback from JavaScript to execute the desired method. 
 In the following example, the application does not hold a reference
to the Java object:


JSObject window = (JSObject) webEngine.executeScript("window");
window.setMember("app", new JavaApplication());



 In this case, since the property value is a local object, "new JavaApplication()", the value may be garbage collected in next GC cycle. 
 When a user clicks the link, it does not guarantee to execute the callback method exit. 

If there are multiple Java methods with the given name,
then the engine selects one matching the number of parameters
in the call.  (Varargs are not handled.) An unspecified one is
chosen if there are multiple ones with the correct number of parameters.


You can pick a specific overloaded method by listing the
parameter types in an "extended method name", which has the
form "method_name(param_type1,...,param_typen)".  Typically you'd write the JavaScript expression:

receiver["method_name(param_type1,...,param_typeN)"](arg1,...,argN)




The Java class and method must both be declared public.



Deploying an Application as a Module


 If any Java class passed to JavaScript is in a named module, then it must be reflectively accessible to the javafx.web module. A class is reflectively accessible if the module opens the containing package to at least the javafx.web module. Otherwise, the method will not be called, and no error or warning will be produced. 


 For example, if com.foo.MyClass is in the foo.app module, the module-info.java might look like this: 


module foo.app {
opens com.foo to javafx.web;



 Alternatively, a class is reflectively accessible if the module exports the containing package unconditionally. 



Starting with JavaFX 14, HTTP/2 support has been added to WebEngine. This is achieved by using HttpClient instead of URLConnection. HTTP/2 is activated by default when JavaFX 14 (or later) is used with JDK 12 (or later). 


Threading


WebEngine objects must be created and accessed solely from the JavaFX Application thread. This rule also applies to any DOM and JavaScript objects obtained from the WebEngine object. 
Since:JavaFX 2.0
/**
 * {@code WebEngine} is a non-visual object capable of managing one Web page
 * at a time. It loads Web pages, creates their document models, applies
 * styles as necessary, and runs JavaScript on pages. It provides access
 * to the document model of the current page, and enables two-way
 * communication between a Java application and JavaScript code of the page.
 *
 * <p><b>Loading Web Pages</b></p>
 * <p>The {@code WebEngine} class provides two ways to load content into a
 * {@code WebEngine} object:
 * <ul>
 * <li>From an arbitrary URL using the {@link #load} method. This method uses
 *     the {@code java.net} package for network access and protocol handling.
 * <li>From an in-memory String using the
 *     {@link #loadContent(java.lang.String, java.lang.String)} and
 *     {@link #loadContent(java.lang.String)} methods.
 * </ul>
 * <p>Loading always happens on a background thread. Methods that initiate
 * loading return immediately after scheduling a background job. To track
 * progress and/or cancel a job, use the {@link javafx.concurrent.Worker}
 * instance available from the {@link #getLoadWorker} method.
 *
 * <p>The following example changes the stage title when loading completes
 * successfully:
 * <pre>{@code
    import javafx.concurrent.Worker.State;
    final Stage stage;
    webEngine.getLoadWorker().stateProperty().addListener(
        new ChangeListener<State>() {
            public void changed(ObservableValue ov, State oldState, State newState) {
                if (newState == State.SUCCEEDED) {
                    stage.setTitle(webEngine.getLocation());
                }
            }
        });
    webEngine.load("http://javafx.com");
 * }</pre>
 *
 * <p><b>User Interface Callbacks</b></p>
 * <p>A number of user interface callbacks may be registered with a
 * {@code WebEngine} object. These callbacks are invoked when a script running
 * on the page requests a user interface operation to be performed, for
 * example, opens a popup window or changes status text. A {@code WebEngine}
 * object cannot handle such requests internally, so it passes the request to
 * the corresponding callbacks. If no callback is defined for a specific
 * operation, the request is silently ignored.
 *
 * <p>The table below shows JavaScript user interface methods and properties
 * with their corresponding {@code WebEngine} callbacks:
 * <table border="1">
 * <caption>JavaScript Callback Table</caption>
 * <tr>
 *     <th scope="col">JavaScript method/property</th>
 *     <th scope="col">WebEngine callback</th>
 * </tr>
 * <tr><th scope="row">{@code window.alert()}</th><td>{@code onAlert}</td></tr>
 * <tr><th scope="row">{@code window.confirm()}</th><td>{@code confirmHandler}</td></tr>
 * <tr><th scope="row">{@code window.open()}</th><td>{@code createPopupHandler}</td></tr>
 * <tr><th scope="row">{@code window.open()} and<br>
 *         {@code window.close()}</th><td>{@code onVisibilityChanged}</td></tr>
 * <tr><th scope="row">{@code window.prompt()}</th><td>{@code promptHandler}</td></tr>
 * <tr><th scope="row">Setting {@code window.status}</th><td>{@code onStatusChanged}</td></tr>
 * <tr><th scope="row">Setting any of the following:<br>
 *         {@code window.innerWidth}, {@code window.innerHeight},<br>
 *         {@code window.outerWidth}, {@code window.outerHeight},<br>
 *         {@code window.screenX}, {@code window.screenY},<br>
 *         {@code window.screenLeft}, {@code window.screenTop}</th>
 *         <td>{@code onResized}</td></tr>
 * </table>
 *
 * <p>The following example shows a callback that resizes a browser window:
 * <pre>{@code
    Stage stage;
    webEngine.setOnResized(
        new EventHandler<WebEvent<Rectangle2D>>() {
            public void handle(WebEvent<Rectangle2D> ev) {
                Rectangle2D r = ev.getData();
                stage.setWidth(r.getWidth());
                stage.setHeight(r.getHeight());
            }
        });
 * }</pre>
 *
 * <p><b>Access to Document Model</b></p>
 * <p>The {@code WebEngine} objects create and manage a Document Object Model
 * (DOM) for their Web pages. The model can be accessed and modified using
 * Java DOM Core classes. The {@link #getDocument()} method provides access
 * to the root of the model. Additionally DOM Event specification is supported
 * to define event handlers in Java code.
 *
 * <p>The following example attaches a Java event listener to an element of
 * a Web page. Clicking on the element causes the application to exit:
 * <pre>{@code
    EventListener listener = new EventListener() {
        public void handleEvent(Event ev) {
            Platform.exit();
        }
    };

    Document doc = webEngine.getDocument();
    Element el = doc.getElementById("exit-app");
    ((EventTarget) el).addEventListener("click", listener, false);
 * }</pre>
 *
 * <p><b>Evaluating JavaScript expressions</b></p>
 * <p>It is possible to execute arbitrary JavaScript code in the context of
 * the current page using the {@link #executeScript} method. For example:
 * <pre>{@code
    webEngine.executeScript("history.back()");
 * }</pre>
 *
 * <p>The execution result is returned to the caller,
 * as described in the next section.
 *
 * <p><b>Mapping JavaScript values to Java objects</b></p>
 *
 * JavaScript values are represented using the obvious Java classes:
 * null becomes Java null; a boolean becomes a {@code java.lang.Boolean};
 * and a string becomes a {@code java.lang.String}.
 * A number can be {@code java.lang.Double} or a {@code java.lang.Integer},
 * depending.
 * The undefined value maps to a specific unique String
 * object whose value is {@code "undefined"}.
 * <p>
 * If the result is a
 * JavaScript object, it is wrapped as an instance of the
 * {@link netscape.javascript.JSObject} class.
 * (As a special case, if the JavaScript object is
 * a {@code JavaRuntimeObject} as discussed in the next section,
 * then the original Java object is extracted instead.)
 * The {@code JSObject} class is a proxy that provides access to
 * methods and properties of its underlying JavaScript object.
 * The most commonly used {@code JSObject} methods are
 * {@link netscape.javascript.JSObject#getMember getMember}
 * (to read a named property),
 * {@link netscape.javascript.JSObject#setMember setMember}
 * (to set or define a property),
 * and {@link netscape.javascript.JSObject#call call}
 * (to call a function-valued property).
 * <p>
 * A DOM {@code Node} is mapped to an object that both extends
 * {@code JSObject} and implements the appropriate DOM interfaces.
 * To get a {@code JSObject} object for a {@code Node} just do a cast:
 * <pre>
 * JSObject jdoc = (JSObject) webEngine.getDocument();
 * </pre>
 * <p>
 * In some cases the context provides a specific Java type that guides
 * the conversion.
 * For example if setting a Java {@code String} field from a JavaScript
 * expression, then the JavaScript value is converted to a string.
 *
 * <p><b>Mapping Java objects to JavaScript values</b></p>
 *
 * The arguments of the {@code JSObject} methods {@code setMember} and
 * {@code call} pass Java objects to the JavaScript environment.
 * This is roughly the inverse of the JavaScript-to-Java mapping
 * described above:
 * Java {@code String},  {@code Number}, or {@code Boolean} objects
 * are converted to the obvious JavaScript values. A  {@code JSObject}
 * object is converted to the original wrapped JavaScript object.
 * Otherwise a {@code JavaRuntimeObject} is created.  This is
 * a JavaScript object that acts as a proxy for the Java object,
 * in that accessing properties of the {@code JavaRuntimeObject}
 * causes the Java field or method with the same name to be accessed.
 * <p> Note that the Java objects bound using
 * {@link netscape.javascript.JSObject#setMember JSObject.setMember},
 * {@link netscape.javascript.JSObject#setSlot JSObject.setSlot}, and
 * {@link netscape.javascript.JSObject#call JSObject.call}
 * are implemented using weak references. This means that the Java object
 * can be garbage collected, causing subsequent accesses to the JavaScript
 * objects to have no effect.
 *
 * <p><b>Calling back to Java from JavaScript</b></p>
 *
 * <p>The {@link netscape.javascript.JSObject#setMember JSObject.setMember}
 * method is useful to enable upcalls from JavaScript
 * into Java code, as illustrated by the following example. The Java code
 * establishes a new JavaScript object named {@code app}. This object has one
 * public member, the method {@code exit}.
 * <pre><code>
public class JavaApplication {
    public void exit() {
        Platform.exit();
    }
}
...
JavaApplication javaApp = new JavaApplication();
JSObject window = (JSObject) webEngine.executeScript("window");
window.setMember("app", javaApp);
 * </code></pre>
 * You can then refer to the object and the method from your HTML page:
 * <pre>{@code
    <a href="" onclick="app.exit()">Click here to exit application</a>
 * }</pre>
 * <p>When a user clicks the link the application is closed.
 * <p>
 * Note that in the above example, the application holds a reference
 * to the {@code JavaApplication} instance. This is required for the callback
 * from JavaScript to execute the desired method.
 * <p> In the following example, the application does not hold a reference
 * to the Java object:
 * <pre><code>
 * JSObject window = (JSObject) webEngine.executeScript("window");
 * window.setMember("app", new JavaApplication());
 * </code></pre>
 * <p> In this case, since the property value is a local object, {@code "new JavaApplication()"},
 * the value may be garbage collected in next GC cycle.
 * <p>
 * When a user clicks the link, it does not guarantee to execute the callback method {@code exit}.
 * <p>
 * If there are multiple Java methods with the given name,
 * then the engine selects one matching the number of parameters
 * in the call.  (Varargs are not handled.) An unspecified one is
 * chosen if there are multiple ones with the correct number of parameters.
 * <p>
 * You can pick a specific overloaded method by listing the
 * parameter types in an "extended method name", which has the
 * form <code>"<var>method_name</var>(<var>param_type1</var>,...,<var>param_typen</var>)"</code>.  Typically you'd write the JavaScript expression:
 * <pre>
 * <code><var>receiver</var>["<var>method_name</var>(<var>param_type1</var>,...,<var>param_typeN</var>)"](<var>arg1</var>,...,<var>argN</var>)</code>
 * </pre>
 *
 * <p>
 * The Java class and method must both be declared public.
 * </p>
 *
 * <p><b>Deploying an Application as a Module</b></p>
 * <p>
 * If any Java class passed to JavaScript is in a named module, then it must
 * be reflectively accessible to the {@code javafx.web} module.
 * A class is reflectively accessible if the module
 * {@link Module#isOpen(String,Module) opens} the containing package to at
 * least the {@code javafx.web} module.
 * Otherwise, the method will not be called, and no error or
 * warning will be produced.
 * </p>
 * <p>
 * For example, if {@code com.foo.MyClass} is in the {@code foo.app} module,
 * the {@code module-info.java} might
 * look like this:
 * </p>
 *
<pre>{@code module foo.app {
    opens com.foo to javafx.web;
}}</pre>
 *
 * <p>
 * Alternatively, a class is reflectively accessible if the module
 * {@link Module#isExported(String) exports} the containing package
 * unconditionally.
 * </p>
 *
 * <p>
 * Starting with JavaFX 14, <a href="https://tools.ietf.org/html/rfc7540">HTTP/2</a> support has been added to WebEngine.
 * This is achieved by using {@link java.net.http.HttpClient} instead of {@link URLConnection}. HTTP/2 is activated
 * by default when JavaFX 14 (or later) is used with JDK 12 (or later).
 * </p>
 *
 * <p><b>Threading</b></p>
 * <p>{@code WebEngine} objects must be created and accessed solely from the
 * JavaFX Application thread. This rule also applies to any DOM and JavaScript
 * objects obtained from the {@code WebEngine} object.
 * @since JavaFX 2.0
 */
final public class WebEngine {
    static {
        Accessor.setPageAccessor(w -> w == null ? null : w.getPage());

        Invoker.setInvoker(new PrismInvoker());
        Renderer.setRenderer(new PrismRenderer());
        WCGraphicsManager.setGraphicsManager(new PrismGraphicsManager());
        CursorManager.setCursorManager(new CursorManagerImpl());
        com.sun.webkit.EventLoop.setEventLoop(new EventLoopImpl());
        ThemeClient.setDefaultRenderTheme(new RenderThemeImpl());
        Utilities.setUtilities(new UtilitiesImpl());
    }

    private static final PlatformLogger logger =
            PlatformLogger.getLogger(WebEngine.class.getName());

    
The number of instances of this class.
Used to start and stop the pulse timer.

/**
     * The number of instances of this class.
     * Used to start and stop the pulse timer.
     */
    private static int instanceCount = 0;

    
The node associated with this engine. There is a one-to-one correspondence
between the WebView and its WebEngine (although not all WebEngines have
a WebView, every WebView has one and only one WebEngine).

/**
     * The node associated with this engine. There is a one-to-one correspondence
     * between the WebView and its WebEngine (although not all WebEngines have
     * a WebView, every WebView has one and only one WebEngine).
     */
    private final ObjectProperty<WebView> view = new SimpleObjectProperty<WebView>(this, "view");

    
The Worker which shows progress of the web engine as it loads pages.

/**
     * The Worker which shows progress of the web engine as it loads pages.
     */
    private final LoadWorker loadWorker = new LoadWorker();

    
The object that provides interaction with the native webkit core.

/**
     * The object that provides interaction with the native webkit core.
     */
    private final WebPage page;

    private final SelfDisposer disposer;

    private final DebuggerImpl debugger = new DebuggerImpl();

    private boolean userDataDirectoryApplied = false;


    
Returns a Worker object that can be used to track loading progress. 
Returns:the Worker object
/**
     * Returns a {@link javafx.concurrent.Worker} object that can be used to
     * track loading progress.
     *
     * @return the {@code Worker} object
     */
    public final Worker<Void> getLoadWorker() {
        return loadWorker;
    }


    /*
     * The final document. This may be null if no document has been loaded.
     */
    private final DocumentProperty document = new DocumentProperty();

    public final Document getDocument() { return document.getValue(); }

    
Document object for the current Web page. The value is null if the Web page failed to load. 
Returns:the document property
/**
     * Document object for the current Web page. The value is {@code null}
     * if the Web page failed to load.
     *
     * @return the document property
     */
    public final ReadOnlyObjectProperty<Document> documentProperty() {
        return document;
    }


    /*
     * The location of the current page. This may return null.
     */
    private final ReadOnlyStringWrapper location = new ReadOnlyStringWrapper(this, "location");

    public final String getLocation() { return location.getValue(); }

    
URL of the current Web page. If the current page has no URL,
the value is an empty String.

Returns:the location property
/**
     * URL of the current Web page. If the current page has no URL,
     * the value is an empty String.
     *
     * @return the location property
     */
    public final ReadOnlyStringProperty locationProperty() { return location.getReadOnlyProperty(); }

    private void updateLocation(String value) {
        this.location.set(value);
        this.document.invalidate(false);
        this.title.set(null);
    }


    /*
     * The page title.
     */
    private final ReadOnlyStringWrapper title = new ReadOnlyStringWrapper(this, "title");

    public final String getTitle() { return title.getValue(); }

    
Title of the current Web page. If the current page has no title, the value is null. 
Returns:the title property
/**
     * Title of the current Web page. If the current page has no title,
     * the value is {@code null}.
     *
     * @return the title property
     */
    public final ReadOnlyStringProperty titleProperty() { return title.getReadOnlyProperty(); }

    private void updateTitle() {
        title.set(page.getTitle(page.getMainFrame()));
    }

    //
    // Settings

    
Specifies whether JavaScript execution is enabled.

@defaultValuetrue
Since:JavaFX 2.2
/**
     * Specifies whether JavaScript execution is enabled.
     *
     * @defaultValue true
     * @since JavaFX 2.2
     */
    private BooleanProperty javaScriptEnabled;

    public final void setJavaScriptEnabled(boolean value) {
        javaScriptEnabledProperty().set(value);
    }

    public final boolean isJavaScriptEnabled() {
        return javaScriptEnabled == null ? true : javaScriptEnabled.get();
    }

    public final BooleanProperty javaScriptEnabledProperty() {
        if (javaScriptEnabled == null) {
            javaScriptEnabled = new BooleanPropertyBase(true) {
                @Override public void invalidated() {
                    checkThread();
                    page.setJavaScriptEnabled(get());
                }

                @Override public Object getBean() {
                    return WebEngine.this;
                }

                @Override public String getName() {
                    return "javaScriptEnabled";
                }
            };
        }
        return javaScriptEnabled;
    }

    
Location of the user stylesheet as a string URL.

This should be a local URL, i.e. either 'data:', 'file:', or 'jar:'. Remote URLs are not allowed for security reasons. 
@defaultValuenull
Since:JavaFX 2.2
/**
     * Location of the user stylesheet as a string URL.
     *
     * <p>This should be a local URL, i.e. either {@code 'data:'},
     * {@code 'file:'}, or {@code 'jar:'}. Remote URLs are not allowed
     * for security reasons.
     *
     * @defaultValue null
     * @since JavaFX 2.2
     */
    private StringProperty userStyleSheetLocation;

    public final void setUserStyleSheetLocation(String value) {
        userStyleSheetLocationProperty().set(value);
    }

    public final String getUserStyleSheetLocation() {
        return userStyleSheetLocation == null ? null : userStyleSheetLocation.get();
    }

    private byte[] readFully(BufferedInputStream in) throws IOException {
        final int BUF_SIZE = 4096;
        int outSize = 0;
        final List<byte[]> outList = new ArrayList<>();
        byte[] buffer = new byte[BUF_SIZE];

        while (true) {
            int nBytes = in.read(buffer);
            if (nBytes < 0) break;

            byte[] chunk;
            if (nBytes == buffer.length) {
                chunk = buffer;
                buffer = new byte[BUF_SIZE];
            } else {
                chunk = new byte[nBytes];
                System.arraycopy(buffer, 0, chunk, 0, nBytes);
            }
            outList.add(chunk);
            outSize += nBytes;
        }

        final byte[] out = new byte[outSize];
        int outPos = 0;
        for (byte[] chunk : outList) {
            System.arraycopy(chunk, 0, out, outPos, chunk.length);
            outPos += chunk.length;
        }

        return out;
    }

    public final StringProperty userStyleSheetLocationProperty() {
        if (userStyleSheetLocation == null) {
            userStyleSheetLocation = new StringPropertyBase(null) {
                private final static String DATA_PREFIX = "data:text/css;charset=utf-8;base64,";

                @Override public void invalidated() {
                    checkThread();
                    String url = get();
                    String dataUrl;
                    if (url == null || url.length() <= 0) {
                        dataUrl = null;
                    } else if (url.startsWith(DATA_PREFIX)) {
                        dataUrl = url;
                    } else if (url.startsWith("file:") ||
                               url.startsWith("jar:")  ||
                               url.startsWith("data:"))
                    {
                        try {
                            URLConnection conn = URLs.newURL(url).openConnection();
                            conn.connect();

                            BufferedInputStream in =
                                    new BufferedInputStream(conn.getInputStream());
                            byte[] inBytes = readFully(in);
                            String out = Base64.getMimeEncoder().encodeToString(inBytes);
                            dataUrl = DATA_PREFIX + out;
                        } catch (IOException e) {
                            throw new RuntimeException(e);
                        }
                    } else {
                        throw new IllegalArgumentException("Invalid stylesheet URL");
                    }
                    page.setUserStyleSheetLocation(dataUrl);
                }

                @Override public Object getBean() {
                    return WebEngine.this;
                }

                @Override public String getName() {
                    return "userStyleSheetLocation";
                }
            };
        }
        return userStyleSheetLocation;
    }

    
Specifies the directory to be used by this WebEngine to store local user data. 
If the value of this property is not null, the WebEngine will attempt to store local user data in the respective directory. If the value of this property is null, the WebEngine will attempt to store local user data in an automatically selected system-dependent user- and application-specific directory. 
When a WebEngine is about to start loading a web page or executing a script for the first time, it checks whether it can actually use the directory specified by this property. If the check fails for some reason, the WebEngine invokes the WebEngine.onError event handler, if any, with a WebErrorEvent describing the reason. If the invoked event handler modifies the userDataDirectory property, the WebEngine retries with the new value as soon as the handler returns. If the handler does not modify the userDataDirectory property (which is the default), the WebEngine continues without local user data. 
Once the WebEngine has started loading a web page or executing a script, changes made to this property have no effect on where the WebEngine stores or will store local user data. 
Currently, the directory specified by this property is used only to store the data that backs the window.localStorage objects. In the future, more types of data can be added. 
@defaultValuenull
Since:JavaFX 8.0
/**
     * Specifies the directory to be used by this {@code WebEngine}
     * to store local user data.
     *
     * <p>If the value of this property is not {@code null},
     * the {@code WebEngine} will attempt to store local user data
     * in the respective directory.
     * If the value of this property is {@code null},
     * the {@code WebEngine} will attempt to store local user data
     * in an automatically selected system-dependent user- and
     * application-specific directory.
     *
     * <p>When a {@code WebEngine} is about to start loading a web
     * page or executing a script for the first time, it checks whether
     * it can actually use the directory specified by this property.
     * If the check fails for some reason, the {@code WebEngine} invokes
     * the {@link WebEngine#onErrorProperty WebEngine.onError} event handler,
     * if any, with a {@link WebErrorEvent} describing the reason.
     * If the invoked event handler modifies the {@code userDataDirectory}
     * property, the {@code WebEngine} retries with the new value as soon
     * as the handler returns. If the handler does not modify the
     * {@code userDataDirectory} property (which is the default),
     * the {@code WebEngine} continues without local user data.
     *
     * <p>Once the {@code WebEngine} has started loading a web page or
     * executing a script, changes made to this property have no effect
     * on where the {@code WebEngine} stores or will store local user
     * data.
     *
     * <p>Currently, the directory specified by this property is used
     * only to store the data that backs the {@code window.localStorage}
     * objects. In the future, more types of data can be added.
     *
     * @defaultValue {@code null}
     * @since JavaFX 8.0
     */
    private final ObjectProperty<File> userDataDirectory =
            new SimpleObjectProperty<>(this, "userDataDirectory");

    public final File getUserDataDirectory() {
        return userDataDirectory.get();
    }

    public final void setUserDataDirectory(File value) {
        userDataDirectory.set(value);
    }

    public final ObjectProperty<File> userDataDirectoryProperty() {
        return userDataDirectory;
    }

    
Specifies user agent ID string. This string is the value of the User-Agent HTTP header. 
@defaultValuesystem dependent
Since:JavaFX 8.0
/**
     * Specifies user agent ID string. This string is the value of the
     * {@code User-Agent} HTTP header.
     *
     * @defaultValue system dependent
     * @since JavaFX 8.0
     */
    private StringProperty userAgent;

    public final void setUserAgent(String value) {
        userAgentProperty().set(value);
    }

    public final String getUserAgent() {
        return userAgent == null ? page.getUserAgent() : userAgent.get();
    }

    public final StringProperty userAgentProperty() {
        if (userAgent == null) {
            userAgent = new StringPropertyBase(page.getUserAgent()) {
                @Override public void invalidated() {
                    checkThread();
                    page.setUserAgent(get());
                }

                @Override public Object getBean() {
                    return WebEngine.this;
                }

                @Override public String getName() {
                    return "userAgent";
                }
            };
        }
        return userAgent;
    }

    private final ObjectProperty<EventHandler<WebEvent<String>>> onAlert
            = new SimpleObjectProperty<EventHandler<WebEvent<String>>>(this, "onAlert");

    public final EventHandler<WebEvent<String>> getOnAlert() { return onAlert.get(); }

    public final void setOnAlert(EventHandler<WebEvent<String>> handler) { onAlert.set(handler); }

    
JavaScript alert handler property. This handler is invoked when a script running on the Web page calls the alert function. 
Returns:the onAlert property
/**
     * JavaScript {@code alert} handler property. This handler is invoked
     * when a script running on the Web page calls the {@code alert} function.
     * @return the onAlert property
     */
    public final ObjectProperty<EventHandler<WebEvent<String>>> onAlertProperty() { return onAlert; }


    private final ObjectProperty<EventHandler<WebEvent<String>>> onStatusChanged
            = new SimpleObjectProperty<EventHandler<WebEvent<String>>>(this, "onStatusChanged");

    public final EventHandler<WebEvent<String>> getOnStatusChanged() { return onStatusChanged.get(); }

    public final void setOnStatusChanged(EventHandler<WebEvent<String>> handler) { onStatusChanged.set(handler); }

    
JavaScript status handler property. This handler is invoked when a script running on the Web page sets window.status property. 
Returns:the onStatusChanged property
/**
     * JavaScript status handler property. This handler is invoked when
     * a script running on the Web page sets {@code window.status} property.
     * @return the onStatusChanged property
     */
    public final ObjectProperty<EventHandler<WebEvent<String>>> onStatusChangedProperty() { return onStatusChanged; }


    private final ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> onResized
            = new SimpleObjectProperty<EventHandler<WebEvent<Rectangle2D>>>(this, "onResized");

    public final EventHandler<WebEvent<Rectangle2D>> getOnResized() { return onResized.get(); }

    public final void setOnResized(EventHandler<WebEvent<Rectangle2D>> handler) { onResized.set(handler); }

    
JavaScript window resize handler property. This handler is invoked when a script running on the Web page moves or resizes the window object. 
Returns:the onResized property
/**
     * JavaScript window resize handler property. This handler is invoked
     * when a script running on the Web page moves or resizes the
     * {@code window} object.
     * @return the onResized property
     */
    public final ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> onResizedProperty() { return onResized; }


    private final ObjectProperty<EventHandler<WebEvent<Boolean>>> onVisibilityChanged
            = new SimpleObjectProperty<EventHandler<WebEvent<Boolean>>>(this, "onVisibilityChanged");

    public final EventHandler<WebEvent<Boolean>> getOnVisibilityChanged() { return onVisibilityChanged.get(); }

    public final void setOnVisibilityChanged(EventHandler<WebEvent<Boolean>> handler) { onVisibilityChanged.set(handler); }

    
JavaScript window visibility handler property. This handler is invoked when a script running on the Web page changes visibility of the window object. 
Returns:the onVisibilityChanged property
/**
     * JavaScript window visibility handler property. This handler is invoked
     * when a script running on the Web page changes visibility of the
     * {@code window} object.
     * @return the onVisibilityChanged property
     */
    public final ObjectProperty<EventHandler<WebEvent<Boolean>>> onVisibilityChangedProperty() { return onVisibilityChanged; }


    private final ObjectProperty<Callback<PopupFeatures, WebEngine>> createPopupHandler
            = new SimpleObjectProperty<Callback<PopupFeatures, WebEngine>>(this, "createPopupHandler",
            p -> WebEngine.this);

    public final Callback<PopupFeatures, WebEngine> getCreatePopupHandler() { return createPopupHandler.get(); }

    public final void setCreatePopupHandler(Callback<PopupFeatures, WebEngine> handler) { createPopupHandler.set(handler); }

    
JavaScript popup handler property. This handler is invoked when a script
running on the Web page requests a popup to be created.

To satisfy this request a handler may create a new WebEngine, attach a visibility handler and optionally a resize handler, and return the newly created engine. To block the popup, a handler should return null. 
By default, a popup handler is installed that opens popups in this WebEngine. 
See Also:
Returns:the createPopupHandler property
/**
     * JavaScript popup handler property. This handler is invoked when a script
     * running on the Web page requests a popup to be created.
     * <p>To satisfy this request a handler may create a new {@code WebEngine},
     * attach a visibility handler and optionally a resize handler, and return
     * the newly created engine. To block the popup, a handler should return
     * {@code null}.
     * <p>By default, a popup handler is installed that opens popups in this
     * {@code WebEngine}.
     *
     * @return the createPopupHandler property
     *
     * @see PopupFeatures
     */
    public final ObjectProperty<Callback<PopupFeatures, WebEngine>> createPopupHandlerProperty() { return createPopupHandler; }


    private final ObjectProperty<Callback<String, Boolean>> confirmHandler
            = new SimpleObjectProperty<Callback<String, Boolean>>(this, "confirmHandler");

    public final Callback<String, Boolean> getConfirmHandler() { return confirmHandler.get(); }

    public final void setConfirmHandler(Callback<String, Boolean> handler) { confirmHandler.set(handler); }

    
JavaScript confirm handler property. This handler is invoked when a script running on the Web page calls the confirm function. 
An implementation may display a dialog box with Yes and No options,
and return the user's choice.

Returns:the confirmHandler property
/**
     * JavaScript {@code confirm} handler property. This handler is invoked
     * when a script running on the Web page calls the {@code confirm} function.
     * <p>An implementation may display a dialog box with Yes and No options,
     * and return the user's choice.
     *
     * @return the confirmHandler property
     */
    public final ObjectProperty<Callback<String, Boolean>> confirmHandlerProperty() { return confirmHandler; }


    private final ObjectProperty<Callback<PromptData, String>> promptHandler
            = new SimpleObjectProperty<Callback<PromptData, String>>(this, "promptHandler");

    public final Callback<PromptData, String> getPromptHandler() { return promptHandler.get(); }

    public final void setPromptHandler(Callback<PromptData, String> handler) { promptHandler.set(handler); }

    
JavaScript prompt handler property. This handler is invoked when a script running on the Web page calls the prompt function. 
An implementation may display a dialog box with an text field,
and return the user's input.

See Also:
Returns:the promptHandler property
/**
     * JavaScript {@code prompt} handler property. This handler is invoked
     * when a script running on the Web page calls the {@code prompt} function.
     * <p>An implementation may display a dialog box with an text field,
     * and return the user's input.
     *
     * @return the promptHandler property
     * @see PromptData
     */
    public final ObjectProperty<Callback<PromptData, String>> promptHandlerProperty() { return promptHandler; }

    
The event handler called when an error occurs.

@defaultValuenull
Since:JavaFX 8.0
/**
     * The event handler called when an error occurs.
     *
     * @defaultValue {@code null}
     * @since JavaFX 8.0
     */
    private final ObjectProperty<EventHandler<WebErrorEvent>> onError =
            new SimpleObjectProperty<>(this, "onError");

    public final EventHandler<WebErrorEvent> getOnError() {
        return onError.get();
    }

    public final void setOnError(EventHandler<WebErrorEvent> handler) {
        onError.set(handler);
    }

    public final ObjectProperty<EventHandler<WebErrorEvent>> onErrorProperty() {
        return onError;
    }


    
Creates a new engine.

/**
     * Creates a new engine.
     */
    public WebEngine() {
        this(null, false);
    }

    
Creates a new engine and loads a Web page into it.

Params:
  • url – the URL of the web page to load
/**
     * Creates a new engine and loads a Web page into it.
     *
     * @param url the URL of the web page to load
     */
    public WebEngine(String url) {
        this(url, true);
    }

    private WebEngine(String url, boolean callLoad) {
        checkThread();
        Accessor accessor = new AccessorImpl(this);
        page = new WebPage(
            new WebPageClientImpl(accessor),
            new UIClientImpl(accessor),
            null,
            new InspectorClientImpl(this),
            new ThemeClientImpl(accessor),
            false);
        page.addLoadListenerClient(new PageLoadListener(this));

        history = new WebHistory(page);

        disposer = new SelfDisposer(page);
        Disposer.addRecord(this, disposer);

        if (callLoad) {
            load(url);
        }

        if (instanceCount == 0 &&
            Timer.getMode() == Timer.Mode.PLATFORM_TICKS)
        {
            PulseTimer.start();
        }
        instanceCount++;
    }

    
Loads a Web page into this engine. This method starts asynchronous
loading and returns immediately.

Params:
  • url – URL of the web page to load
/**
     * Loads a Web page into this engine. This method starts asynchronous
     * loading and returns immediately.
     * @param url URL of the web page to load
     */
    public void load(String url) {
        checkThread();
        loadWorker.cancelAndReset();

        if (url == null || url.equals("") || url.equals("about:blank")) {
            url = "";
        } else {
            // verify and, if possible, adjust the url on the Java
            // side, otherwise it may crash native code
            try {
                url = Util.adjustUrlForWebKit(url);
            } catch (MalformedURLException e) {
                loadWorker.dispatchLoadEvent(getMainFrame(),
                        PAGE_STARTED, url, null, 0.0, 0);
                loadWorker.dispatchLoadEvent(getMainFrame(),
                        LOAD_FAILED, url, null, 0.0, MALFORMED_URL);
                return;
            }
        }
        applyUserDataDirectory();
        page.open(page.getMainFrame(), url);
    }

    
Loads the given HTML content directly. This method is useful when you have an HTML String composed in memory, or loaded from some system which cannot be reached via a URL (for example, the HTML text may have come from a database). As with load(String), this method is asynchronous. 
Params:
  • content – the HTML content to load
/**
     * Loads the given HTML content directly. This method is useful when you have an HTML
     * String composed in memory, or loaded from some system which cannot be reached via
     * a URL (for example, the HTML text may have come from a database). As with
     * {@link #load(String)}, this method is asynchronous.
     *
     * @param content the HTML content to load
     */
    public void loadContent(String content) {
        loadContent(content, "text/html");
    }

    
Loads the given content directly. This method is useful when you have content composed in memory, or loaded from some system which cannot be reached via a URL (for example, the SVG text may have come from a database). As with load(String), this method is asynchronous. This method also allows you to specify the content type of the string being loaded, and so may optionally support other types besides just HTML. 
Params:
  • content – the HTML content to load
  • contentType – the type of content to load
/**
     * Loads the given content directly. This method is useful when you have content
     * composed in memory, or loaded from some system which cannot be reached via
     * a URL (for example, the SVG text may have come from a database). As with
     * {@link #load(String)}, this method is asynchronous. This method also allows you to
     * specify the content type of the string being loaded, and so may optionally support
     * other types besides just HTML.
     *
     * @param content the HTML content to load
     * @param contentType the type of content to load
     */
    public void loadContent(String content, String contentType) {
        checkThread();
        loadWorker.cancelAndReset();
        applyUserDataDirectory();
        page.load(page.getMainFrame(), content, contentType);
    }

    
Reloads the current page, whether loaded from URL or directly from a String in one of the loadContent methods. 
/**
     * Reloads the current page, whether loaded from URL or directly from a String in
     * one of the {@code loadContent} methods.
     */
    public void reload() {
        // TODO what happens if this is called while currently loading a page?
        checkThread();
        page.refresh(page.getMainFrame());
    }

    private final WebHistory history;

    
Returns the session history object.

Returns:history object
Since:JavaFX 2.2
/**
     * Returns the session history object.
     *
     * @return history object
     * @since JavaFX 2.2
     */
    public WebHistory getHistory() {
        return history;
    }

    
Executes a script in the context of the current page.

Params:
  • script – the script
Returns:execution result, converted to a Java object using the following
rules:

    

  • JavaScript Int32 is converted to java.lang.Integer 
  • Other JavaScript numbers to java.lang.Double 
  • JavaScript string to java.lang.String 
  • JavaScript boolean to java.lang.Boolean 
  • JavaScript null to null 
  • Most JavaScript objects get wrapped as netscape.javascript.JSObject 
  • JavaScript JSNode objects get mapped to instances of netscape.javascript.JSObject, that also implement org.w3c.dom.Node 
  • A special case is the JavaScript class JavaRuntimeObject which is used to wrap a Java object as a JavaScript value - in this case we just extract the original Java value. 
/**
     * Executes a script in the context of the current page.
     *
     * @param script the script
     * @return execution result, converted to a Java object using the following
     * rules:
     * <ul>
     * <li>JavaScript Int32 is converted to {@code java.lang.Integer}
     * <li>Other JavaScript numbers to {@code java.lang.Double}
     * <li>JavaScript string to {@code java.lang.String}
     * <li>JavaScript boolean to {@code java.lang.Boolean}
     * <li>JavaScript {@code null} to {@code null}
     * <li>Most JavaScript objects get wrapped as
     *     {@code netscape.javascript.JSObject}
     * <li>JavaScript JSNode objects get mapped to instances of
     *     {@code netscape.javascript.JSObject}, that also implement
     *     {@code org.w3c.dom.Node}
     * <li>A special case is the JavaScript class {@code JavaRuntimeObject}
     *     which is used to wrap a Java object as a JavaScript value - in this
     *     case we just extract the original Java value.
     * </ul>
     */
    public Object executeScript(String script) {
        checkThread();
        applyUserDataDirectory();
        return page.executeScript(page.getMainFrame(), script);
    }

    private long getMainFrame() {
        return page.getMainFrame();
    }

    WebPage getPage() {
        return page;
    }

    void setView(WebView view) {
        this.view.setValue(view);
    }

    private void stop() {
        checkThread();
        page.stop(page.getMainFrame());
    }

    private void applyUserDataDirectory() {
        if (userDataDirectoryApplied) {
            return;
        }
        userDataDirectoryApplied = true;
        File nominalUserDataDir = getUserDataDirectory();
        while (true) {
            File userDataDir;
            String displayString;
            if (nominalUserDataDir == null) {
                userDataDir = defaultUserDataDirectory();
                displayString = format("null (%s)", userDataDir);
            } else {
                userDataDir = nominalUserDataDir;
                displayString = userDataDir.toString();
            }
            logger.fine("Trying to apply user data directory [{0}]", displayString);
            String errorMessage;
            EventType<WebErrorEvent> errorType;
            Throwable error;
            try {
                userDataDir = DirectoryLock.canonicalize(userDataDir);
                File localStorageDir = new File(userDataDir, "localstorage");
                File[] dirs = new File[] {
                    userDataDir,
                    localStorageDir,
                };
                for (File dir : dirs) {
                    createDirectories(dir);
                    // Additional security check to make sure the caller
                    // has permission to write to the target directory
                    File test = new File(dir, ".test");
                    if (test.createNewFile()) {
                        test.delete();
                    }
                }
                disposer.userDataDirectoryLock = new DirectoryLock(userDataDir);

                page.setLocalStorageDatabasePath(localStorageDir.getPath());
                page.setLocalStorageEnabled(true);

                logger.fine("User data directory [{0}] has "
                        + "been applied successfully", displayString);
                return;

            } catch (DirectoryLock.DirectoryAlreadyInUseException ex) {
                errorMessage = "User data directory [%s] is already in use";
                errorType = WebErrorEvent.USER_DATA_DIRECTORY_ALREADY_IN_USE;
                error = ex;
            } catch (IOException ex) {
                errorMessage = "An I/O error occurred while setting up "
                        + "user data directory [%s]";
                errorType = WebErrorEvent.USER_DATA_DIRECTORY_IO_ERROR;
                error = ex;
            } catch (SecurityException ex) {
                errorMessage = "A security error occurred while setting up "
                        + "user data directory [%s]";
                errorType = WebErrorEvent.USER_DATA_DIRECTORY_SECURITY_ERROR;
                error = ex;
            }

            errorMessage = format(errorMessage, displayString);
            logger.fine("{0}, calling error handler", errorMessage);
            File oldNominalUserDataDir = nominalUserDataDir;
            fireError(errorType, errorMessage, error);
            nominalUserDataDir = getUserDataDirectory();
            if (Objects.equals(nominalUserDataDir, oldNominalUserDataDir)) {
                logger.fine("Error handler did not modify user data directory, "
                        + "continuing without user data directory");
                return;
            } else {
                logger.fine("Error handler has set user data directory to [{0}], "
                        + "retrying", nominalUserDataDir);
                continue;
            }
        }
    }

    private static File defaultUserDataDirectory() {
        return new File(
                com.sun.glass.ui.Application.GetApplication()
                        .getDataDirectory(),
                "webview");
    }

    private static void createDirectories(File directory) throws IOException {
        Path path = directory.toPath();
        try {
            Files.createDirectories(path, PosixFilePermissions.asFileAttribute(
                    PosixFilePermissions.fromString("rwx------")));
        } catch (UnsupportedOperationException ex) {
            Files.createDirectories(path);
        }
    }

    private void fireError(EventType<WebErrorEvent> eventType, String message,
                           Throwable exception)
    {
        EventHandler<WebErrorEvent> handler = getOnError();
        if (handler != null) {
            handler.handle(new WebErrorEvent(this, eventType,
                                             message, exception));
        }
    }

    // for testing purposes only
    void dispose() {
        disposer.dispose();
    }

    private static final class SelfDisposer implements DisposerRecord {
        private WebPage page;
        private DirectoryLock userDataDirectoryLock;

        private SelfDisposer(WebPage page) {
            this.page = page;
        }

        @Override public void dispose() {
            if (page == null) {
                return;
            }
            page.dispose();
            page = null;
            if (userDataDirectoryLock != null) {
                userDataDirectoryLock.close();
            }
            instanceCount--;
            if (instanceCount == 0 &&
                Timer.getMode() == Timer.Mode.PLATFORM_TICKS)
            {
                PulseTimer.stop();
            }
        }
    }

    private static final class AccessorImpl extends Accessor {
        private final WeakReference<WebEngine> engine;

        private AccessorImpl(WebEngine w) {
            this.engine = new WeakReference<WebEngine>(w);
        }

        @Override public WebEngine getEngine() {
            return engine.get();
        }

        @Override public WebPage getPage() {
            WebEngine w = getEngine();
            return w == null ? null : w.page;
        }

        @Override public WebView getView() {
            WebEngine w = getEngine();
            return w == null ? null : w.view.get();
        }

        @Override public void addChild(Node child) {
            WebView view = getView();
            if (view != null) {
                view.getChildren().add(child);
            }
        }

        @Override public void removeChild(Node child) {
            WebView view = getView();
            if (view != null) {
                view.getChildren().remove(child);
            }
        }

        @Override public void addViewListener(InvalidationListener l) {
            WebEngine w = getEngine();
            if (w != null) {
                w.view.addListener(l);
            }
        }
    }

    
Drives the Timer when Timer.Mode.PLATFORM_TICKS is set. 
/**
     * Drives the {@code Timer} when {@code Timer.Mode.PLATFORM_TICKS} is set.
     */
    private static final class PulseTimer {

        // Used just to guarantee constant pulse activity. See RT-14433.
        private static final AnimationTimer animation =
            new AnimationTimer() {
                @Override public void handle(long l) {}
            };

        private static final TKPulseListener listener =
                () -> {
                    // Note, the timer event is executed right in the notifyTick(),
                    // that is during the pulse event. This makes the timer more
                    // repsonsive, though prolongs the pulse. So far it causes no
                    // problems but nevertheless it should be kept in mind.

                    // Execute notifyTick in runLater to run outside of pulse so
                    // that events will run in order and be able to display dialogs
                    // or call other methods that require a nested event loop.
                    Platform.runLater(() -> Timer.getTimer().notifyTick());
                };

        private static void start(){
            Toolkit.getToolkit().addSceneTkPulseListener(listener);
            animation.start();
        }

        private static void stop() {
            Toolkit.getToolkit().removeSceneTkPulseListener(listener);
            animation.stop();
        }
    }

    static void checkThread() {
        Toolkit.getToolkit().checkFxUserThread();
    }


    
The page load event listener. This object references the owner
WebEngine weakly so as to avoid referencing WebEngine from WebPage
strongly.

/**
     * The page load event listener. This object references the owner
     * WebEngine weakly so as to avoid referencing WebEngine from WebPage
     * strongly.
     */
    private static final class PageLoadListener implements LoadListenerClient {

        private final WeakReference<WebEngine> engine;


        private PageLoadListener(WebEngine engine) {
            this.engine = new WeakReference<WebEngine>(engine);
        }


        @Override public void dispatchLoadEvent(long frame, int state,
                String url, String contentType, double progress, int errorCode)
        {
            WebEngine w = engine.get();
            if (w != null) {
                w.loadWorker.dispatchLoadEvent(frame, state, url,
                        contentType, progress, errorCode);
            }
        }

        @Override public void dispatchResourceLoadEvent(long frame,
                int state, String url, String contentType, double progress,
                int errorCode)
        {
        }
    }


    private final class LoadWorker implements Worker<Void> {

        private final ReadOnlyObjectWrapper<State> state = new ReadOnlyObjectWrapper<State>(this, "state", State.READY);
        @Override public final State getState() { checkThread(); return state.get(); }
        @Override public final ReadOnlyObjectProperty<State> stateProperty() { checkThread(); return state.getReadOnlyProperty(); }
        private void updateState(State value) {
            checkThread();
            this.state.set(value);
            running.set(value == State.SCHEDULED || value == State.RUNNING);
        }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyObjectWrapper<Void> value = new ReadOnlyObjectWrapper<Void>(this, "value", null);
        @Override public final Void getValue() { checkThread(); return value.get(); }
        @Override public final ReadOnlyObjectProperty<Void> valueProperty() { checkThread(); return value.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyObjectWrapper<Throwable> exception = new ReadOnlyObjectWrapper<Throwable>(this, "exception");
        @Override public final Throwable getException() { checkThread(); return exception.get(); }
        @Override public final ReadOnlyObjectProperty<Throwable> exceptionProperty() { checkThread(); return exception.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyDoubleWrapper workDone = new ReadOnlyDoubleWrapper(this, "workDone", -1);
        @Override public final double getWorkDone() { checkThread(); return workDone.get(); }
        @Override public final ReadOnlyDoubleProperty workDoneProperty() { checkThread(); return workDone.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyDoubleWrapper totalWorkToBeDone = new ReadOnlyDoubleWrapper(this, "totalWork", -1);
        @Override public final double getTotalWork() { checkThread(); return totalWorkToBeDone.get(); }
        @Override public final ReadOnlyDoubleProperty totalWorkProperty() { checkThread(); return totalWorkToBeDone.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyDoubleWrapper progress = new ReadOnlyDoubleWrapper(this, "progress", -1);
        @Override public final double getProgress() { checkThread(); return progress.get(); }
        @Override public final ReadOnlyDoubleProperty progressProperty() { checkThread(); return progress.getReadOnlyProperty(); }
        private void updateProgress(double p) {
            totalWorkToBeDone.set(100.0);
            workDone.set(p * 100.0);
            progress.set(p);
        }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyBooleanWrapper running = new ReadOnlyBooleanWrapper(this, "running", false);
        @Override public final boolean isRunning() { checkThread(); return running.get(); }
        @Override public final ReadOnlyBooleanProperty runningProperty() { checkThread(); return running.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyStringWrapper message = new ReadOnlyStringWrapper(this, "message", "");
        @Override public final String getMessage() { return message.get(); }
        @Override public final ReadOnlyStringProperty messageProperty() { return message.getReadOnlyProperty(); }

        
@InheritDoc
/**
         * @InheritDoc
         */
        private final ReadOnlyStringWrapper title = new ReadOnlyStringWrapper(this, "title", "WebEngine Loader");
        @Override public final String getTitle() { return title.get(); }
        @Override public final ReadOnlyStringProperty titleProperty() { return title.getReadOnlyProperty(); }

        
Cancels the loading of the page. If called after the page has already
been loaded, then this call takes no effect.

/**
         * Cancels the loading of the page. If called after the page has already
         * been loaded, then this call takes no effect.
         */
        @Override public boolean cancel() {
            if (isRunning()) {
                stop(); // this call indirectly sets state
                return true;
            } else {
                return false;
            }
        }

        private void cancelAndReset() {
            cancel();
            exception.set(null);
            message.set("");
            totalWorkToBeDone.set(-1);
            workDone.set(-1);
            progress.set(-1);
            updateState(State.READY);
            running.set(false);
        }

        private void dispatchLoadEvent(long frame, int state,
                String url, String contentType, double workDone, int errorCode)
        {
            if (frame != getMainFrame()) {
                return;
            }
            switch (state) {
                case PAGE_STARTED:
                    message.set("Loading " + url);
                    updateLocation(url);
                    updateProgress(0.0);
                    updateState(State.SCHEDULED);
                    updateState(State.RUNNING);
                    break;
                case PAGE_REDIRECTED:
                    message.set("Loading " + url);
                    updateLocation(url);
                    break;
                case PAGE_REPLACED:
                    message.set("Replaced " + url);
                    // Update only the location, don't change title or document.
                    WebEngine.this.location.set(url);
                    break;
                case PAGE_FINISHED:
                    message.set("Loading complete");
                    updateProgress(1.0);
                    updateState(State.SUCCEEDED);
                    break;
                case LOAD_FAILED:
                    message.set("Loading failed");
                    exception.set(describeError(errorCode));
                    updateState(State.FAILED);
                    break;
                case LOAD_STOPPED:
                    message.set("Loading stopped");
                    updateState(State.CANCELLED);
                    break;
                case PROGRESS_CHANGED:
                    updateProgress(workDone);
                    break;
                case TITLE_RECEIVED:
                    updateTitle();
                    break;
                case DOCUMENT_AVAILABLE:
                    if (this.state.get() != State.RUNNING) {
                        // We have empty load; send a synthetic event (RT-32097)
                        dispatchLoadEvent(frame, PAGE_STARTED, url, contentType, workDone, errorCode);
                    }
                    document.invalidate(true);
                    break;
            }
        }

        private Throwable describeError(int errorCode) {
            String reason = "Unknown error";

            switch (errorCode) {
                case UNKNOWN_HOST:
                    reason = "Unknown host";
                    break;
                case MALFORMED_URL:
                    reason = "Malformed URL";
                    break;
                case SSL_HANDSHAKE:
                    reason = "SSL handshake failed";
                    break;
                case CONNECTION_REFUSED:
                    reason = "Connection refused by server";
                    break;
                case CONNECTION_RESET:
                    reason = "Connection reset by server";
                    break;
                case NO_ROUTE_TO_HOST:
                    reason = "No route to host";
                    break;
                case CONNECTION_TIMED_OUT:
                    reason = "Connection timed out";
                    break;
                case PERMISSION_DENIED:
                    reason = "Permission denied";
                    break;
                case INVALID_RESPONSE:
                    reason = "Invalid response from server";
                    break;
                case TOO_MANY_REDIRECTS:
                    reason = "Too many redirects";
                    break;
                case FILE_NOT_FOUND:
                    reason = "File not found";
                    break;
            }
            return new Throwable(reason);
        }
    }


    private final class DocumentProperty
            extends ReadOnlyObjectPropertyBase<Document> {

        private boolean available;
        private Document document;

        private void invalidate(boolean available) {
            if (this.available || available) {
                this.available = available;
                this.document = null;
                fireValueChangedEvent();
            }
        }

        public Document get() {
            if (!this.available) {
                return null;
            }
            if (this.document == null) {
                this.document = page.getDocument(page.getMainFrame());
                if (this.document == null) {
                    this.available = false;
                }
            }
            return this.document;
        }

        public Object getBean() {
            return WebEngine.this;
        }

        public String getName() {
            return "document";
        }
    }


    /*
     * Returns the debugger associated with this web engine.
     * The debugger is an object that can be used to debug
     * the web page currently loaded into the web engine.
     * <p>
     * All methods of the debugger must be called on
     * the JavaFX Application Thread.
     * The message callback object registered with the debugger
     * is always called on the JavaFX Application Thread.
     * @return the debugger associated with this web engine.
     *         The return value cannot be {@code null}.
     */
    Debugger getDebugger() {
        return debugger;
    }

    
The debugger implementation.

/**
     * The debugger implementation.
     */
    private final class DebuggerImpl implements Debugger {

        private boolean enabled;
        private Callback<String,Void> messageCallback;


        @Override
        public boolean isEnabled() {
            checkThread();
            return enabled;
        }

        @Override
        public void setEnabled(boolean enabled) {
            checkThread();
            if (enabled != this.enabled) {
                if (enabled) {
                    page.setDeveloperExtrasEnabled(true);
                    page.connectInspectorFrontend();
                } else {
                    page.disconnectInspectorFrontend();
                    page.setDeveloperExtrasEnabled(false);
                }
                this.enabled = enabled;
            }
        }

        @Override
        public void sendMessage(String message) {
            checkThread();
            if (!enabled) {
                throw new IllegalStateException("Debugger is not enabled");
            }
            if (message == null) {
                throw new NullPointerException("message is null");
            }
            page.dispatchInspectorMessageFromFrontend(message);
        }

        @Override
        public Callback<String,Void> getMessageCallback() {
            checkThread();
            return messageCallback;
        }

        @Override
        public void setMessageCallback(Callback<String,Void> callback) {
            checkThread();
            messageCallback = callback;
        }
    }

    
The inspector client implementation. This object references the owner
WebEngine weakly so as to avoid referencing WebEngine from WebPage
strongly.

/**
     * The inspector client implementation. This object references the owner
     * WebEngine weakly so as to avoid referencing WebEngine from WebPage
     * strongly.
     */
    private static final class InspectorClientImpl implements InspectorClient {

        private final WeakReference<WebEngine> engine;


        private InspectorClientImpl(WebEngine engine) {
            this.engine = new WeakReference<WebEngine>(engine);
        }


        @Override
        public boolean sendMessageToFrontend(final String message) {
            boolean result = false;
            WebEngine webEngine = engine.get();
            if (webEngine != null) {
                final Callback<String,Void> messageCallback =
                        webEngine.debugger.messageCallback;
                if (messageCallback != null) {
                    AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
                        messageCallback.call(message);
                        return null;
                    }, webEngine.page.getAccessControlContext());
                    result = true;
                }
            }
            return result;
        }
    }

    private static final boolean printStatusOK(PrinterJob job) {
        switch (job.getJobStatus()) {
            case NOT_STARTED:
            case PRINTING:
                return true;
            default:
                return false;
        }
    }

    
Prints the current Web page using the given printer job.

This method does not modify the state of the job, nor does it call PrinterJob.endJob, so the job may be safely reused afterwards. 
Params:
  • job – printer job used for printing
Since:JavaFX 8.0
/**
     * Prints the current Web page using the given printer job.
     * <p>This method does not modify the state of the job, nor does it call
     * {@link PrinterJob#endJob}, so the job may be safely reused afterwards.
     *
     * @param job printer job used for printing
     * @since JavaFX 8.0
     */
    public void print(PrinterJob job) {
        if (!printStatusOK(job)) {
            return;
        }

        PageLayout pl = job.getJobSettings().getPageLayout();
        float width = (float) pl.getPrintableWidth();
        float height = (float) pl.getPrintableHeight();
        int pageCount = page.beginPrinting(width, height);

        JobSettings jobSettings = job.getJobSettings();
        if (jobSettings.getPageRanges() != null) {
            PageRange[] pageRanges = jobSettings.getPageRanges();
            for (PageRange p : pageRanges) {
                for (int i = p.getStartPage(); i <= p.getEndPage() && i <= pageCount; ++i) {
                    if (printStatusOK(job)) {
                        Node printable = new Printable(page, i - 1, width);
                        job.printPage(printable);
                    }
                }
            }
        } else {
            for (int i = 0; i < pageCount; i++) {
                if (printStatusOK(job)) {
                    Node printable = new Printable(page, i, width);
                    job.printPage(printable);
                }
            }
        }
        page.endPrinting();
    }
}