public final class WebEngine extends Object
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.
The WebEngine class provides two ways to load content into a
WebEngine object:
load(java.lang.String) method. This method uses
the java.net package for network access and protocol handling.
loadContent(java.lang.String, java.lang.String) and
loadContent(java.lang.String) methods.
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");
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 method/property | WebEngine callback |
|---|---|
window.alert() | onAlert
|
window.confirm() | confirmHandler
|
window.open() | createPopupHandler
|
window.open() andwindow.close() | onVisibilityChanged
|
window.prompt() | promptHandler
|
Setting window.status | onStatusChanged
|
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());
}
});
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);
It is possible to execute arbitrary JavaScript code in the context of
the current page using the executeScript(java.lang.String) method. For example:
webEngine.executeScript("history.back()");
The execution result is returned to the caller, as described in the next section.
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.
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.
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();
}
}
...
JSObject window = (JSObject) webEngine.executeScript("window");
window.setMember("app", new JavaApplication());
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.
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)
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.
| Type | Property and Description |
|---|---|
ObjectProperty<Callback<String,Boolean>> |
confirmHandler
JavaScript
confirm handler property. |
ObjectProperty<Callback<PopupFeatures,WebEngine>> |
createPopupHandler
JavaScript popup handler property.
|
ReadOnlyObjectProperty<Document> |
document
Document object for the current Web page.
|
BooleanProperty |
javaScriptEnabled
Specifies whether JavaScript execution is enabled.
|
ReadOnlyStringProperty |
location
URL of the current Web page.
|
ObjectProperty<EventHandler<WebEvent<String>>> |
onAlert
JavaScript
alert handler property. |
ObjectProperty<EventHandler<WebErrorEvent>> |
onError
The event handler called when an error occurs.
|
ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> |
onResized
JavaScript window resize handler property.
|
ObjectProperty<EventHandler<WebEvent<String>>> |
onStatusChanged
JavaScript status handler property.
|
ObjectProperty<EventHandler<WebEvent<Boolean>>> |
onVisibilityChanged
JavaScript window visibility handler property.
|
ObjectProperty<Callback<PromptData,String>> |
promptHandler
JavaScript
prompt handler property. |
ReadOnlyStringProperty |
title
Title of the current Web page.
|
StringProperty |
userAgent
Specifies user agent ID string.
|
ObjectProperty<File> |
userDataDirectory
Specifies the directory to be used by this
WebEngine
to store local user data. |
StringProperty |
userStyleSheetLocation
Location of the user stylesheet as a string URL.
|
| Constructor and Description |
|---|
WebEngine()
Creates a new engine.
|
WebEngine(String url)
Creates a new engine and loads a Web page into it.
|
| Modifier and Type | Method and Description |
|---|---|
ObjectProperty<Callback<String,Boolean>> |
confirmHandlerProperty()
JavaScript
confirm handler property. |
ObjectProperty<Callback<PopupFeatures,WebEngine>> |
createPopupHandlerProperty()
JavaScript popup handler property.
|
ReadOnlyObjectProperty<Document> |
documentProperty()
Document object for the current Web page.
|
Object |
executeScript(String script)
Executes a script in the context of the current page.
|
Callback<String,Boolean> |
getConfirmHandler()
Returns the JavaScript
confirm handler. |
Callback<PopupFeatures,WebEngine> |
getCreatePopupHandler()
Returns the JavaScript popup handler.
|
Document |
getDocument()
Returns the document object for the current Web page.
|
WebHistory |
getHistory()
Returns the session history object.
|
Worker<Void> |
getLoadWorker()
Returns a
Worker object that can be used to
track loading progress. |
String |
getLocation()
Returns URL of the current Web page.
|
EventHandler<WebEvent<String>> |
getOnAlert()
Returns the JavaScript
alert handler. |
EventHandler<WebErrorEvent> |
getOnError()
Gets the value of the property onError.
|
EventHandler<WebEvent<Rectangle2D>> |
getOnResized()
Returns the JavaScript window resize handler.
|
EventHandler<WebEvent<String>> |
getOnStatusChanged()
Returns the JavaScript status handler.
|
EventHandler<WebEvent<Boolean>> |
getOnVisibilityChanged()
Returns the JavaScript window visibility handler.
|
Callback<PromptData,String> |
getPromptHandler()
Returns the JavaScript
prompt handler. |
String |
getTitle()
Returns title of the current Web page.
|
String |
getUserAgent()
Gets the value of the property userAgent.
|
File |
getUserDataDirectory()
Gets the value of the property userDataDirectory.
|
String |
getUserStyleSheetLocation()
Gets the value of the property userStyleSheetLocation.
|
boolean |
isJavaScriptEnabled()
Gets the value of the property javaScriptEnabled.
|
BooleanProperty |
javaScriptEnabledProperty()
Specifies whether JavaScript execution is enabled.
|
void |
load(String url)
Loads a Web page into this engine.
|
void |
loadContent(String content)
Loads the given HTML content directly.
|
void |
loadContent(String content,
String contentType)
Loads the given content directly.
|
ReadOnlyStringProperty |
locationProperty()
URL of the current Web page.
|
ObjectProperty<EventHandler<WebEvent<String>>> |
onAlertProperty()
JavaScript
alert handler property. |
ObjectProperty<EventHandler<WebErrorEvent>> |
onErrorProperty()
The event handler called when an error occurs.
|
ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> |
onResizedProperty()
JavaScript window resize handler property.
|
ObjectProperty<EventHandler<WebEvent<String>>> |
onStatusChangedProperty()
JavaScript status handler property.
|
ObjectProperty<EventHandler<WebEvent<Boolean>>> |
onVisibilityChangedProperty()
JavaScript window visibility handler property.
|
void |
print(PrinterJob job)
Prints the current Web page using the given printer job.
|
ObjectProperty<Callback<PromptData,String>> |
promptHandlerProperty()
JavaScript
prompt handler property. |
void |
reload()
Reloads the current page, whether loaded from URL or directly from a String in
one of the
loadContent methods. |
void |
setConfirmHandler(Callback<String,Boolean> handler)
Sets the JavaScript
confirm handler. |
void |
setCreatePopupHandler(Callback<PopupFeatures,WebEngine> handler)
Sets the JavaScript popup handler.
|
void |
setJavaScriptEnabled(boolean value)
Sets the value of the property javaScriptEnabled.
|
void |
setOnAlert(EventHandler<WebEvent<String>> handler)
Sets the JavaScript
alert handler. |
void |
setOnError(EventHandler<WebErrorEvent> handler)
Sets the value of the property onError.
|
void |
setOnResized(EventHandler<WebEvent<Rectangle2D>> handler)
Sets the JavaScript window resize handler.
|
void |
setOnStatusChanged(EventHandler<WebEvent<String>> handler)
Sets the JavaScript status handler.
|
void |
setOnVisibilityChanged(EventHandler<WebEvent<Boolean>> handler)
Sets the JavaScript window visibility handler.
|
void |
setPromptHandler(Callback<PromptData,String> handler)
Sets the JavaScript
prompt handler. |
void |
setUserAgent(String value)
Sets the value of the property userAgent.
|
void |
setUserDataDirectory(File value)
Sets the value of the property userDataDirectory.
|
void |
setUserStyleSheetLocation(String value)
Sets the value of the property userStyleSheetLocation.
|
ReadOnlyStringProperty |
titleProperty()
Title of the current Web page.
|
StringProperty |
userAgentProperty()
Specifies user agent ID string.
|
ObjectProperty<File> |
userDataDirectoryProperty()
Specifies the directory to be used by this
WebEngine
to store local user data. |
StringProperty |
userStyleSheetLocationProperty()
Location of the user stylesheet as a string URL.
|
public final ReadOnlyObjectProperty<Document> documentProperty
null
if the Web page failed to load.public final ReadOnlyStringProperty locationProperty
public final ReadOnlyStringProperty titleProperty
null.public final BooleanProperty javaScriptEnabledProperty
isJavaScriptEnabled(),
setJavaScriptEnabled(boolean)public final StringProperty userStyleSheetLocationProperty
This should be a local URL, i.e. either 'data:',
'file:', or 'jar:'. Remote URLs are not allowed
for security reasons.
getUserStyleSheetLocation(),
setUserStyleSheetLocation(String)public final ObjectProperty<File> userDataDirectoryProperty
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.
nullgetUserDataDirectory(),
setUserDataDirectory(File)public final StringProperty userAgentProperty
User-Agent HTTP header.getUserAgent(),
setUserAgent(String)public final ObjectProperty<EventHandler<WebEvent<String>>> onAlertProperty
alert handler property. This handler is invoked
when a script running on the Web page calls the alert function.getOnAlert(),
setOnAlert(EventHandler)public final ObjectProperty<EventHandler<WebEvent<String>>> onStatusChangedProperty
window.status property.public final ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> onResizedProperty
window object.getOnResized(),
setOnResized(EventHandler)public final ObjectProperty<EventHandler<WebEvent<Boolean>>> onVisibilityChangedProperty
window object.public final ObjectProperty<Callback<PopupFeatures,WebEngine>> createPopupHandlerProperty
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.
public final ObjectProperty<Callback<String,Boolean>> confirmHandlerProperty
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.
getConfirmHandler(),
setConfirmHandler(Callback)public final ObjectProperty<Callback<PromptData,String>> promptHandlerProperty
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.
getPromptHandler(),
setPromptHandler(Callback)public final ObjectProperty<EventHandler<WebErrorEvent>> onErrorProperty
nullgetOnError(),
setOnError(EventHandler)public WebEngine()
public WebEngine(String url)
public final Worker<Void> getLoadWorker()
Worker object that can be used to
track loading progress.public final Document getDocument()
null.public final ReadOnlyObjectProperty<Document> documentProperty()
null
if the Web page failed to load.public final String getLocation()
public final ReadOnlyStringProperty locationProperty()
public final String getTitle()
null.public final ReadOnlyStringProperty titleProperty()
null.public final void setJavaScriptEnabled(boolean value)
public final boolean isJavaScriptEnabled()
public final BooleanProperty javaScriptEnabledProperty()
isJavaScriptEnabled(),
setJavaScriptEnabled(boolean)public final void setUserStyleSheetLocation(String value)
This should be a local URL, i.e. either 'data:',
'file:', or 'jar:'. Remote URLs are not allowed
for security reasons.
public final String getUserStyleSheetLocation()
This should be a local URL, i.e. either 'data:',
'file:', or 'jar:'. Remote URLs are not allowed
for security reasons.
public final StringProperty userStyleSheetLocationProperty()
This should be a local URL, i.e. either 'data:',
'file:', or 'jar:'. Remote URLs are not allowed
for security reasons.
getUserStyleSheetLocation(),
setUserStyleSheetLocation(String)public final File getUserDataDirectory()
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.
nullpublic final void setUserDataDirectory(File value)
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.
nullpublic final ObjectProperty<File> userDataDirectoryProperty()
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.
nullgetUserDataDirectory(),
setUserDataDirectory(File)public final void setUserAgent(String value)
User-Agent HTTP header.public final String getUserAgent()
User-Agent HTTP header.public final StringProperty userAgentProperty()
User-Agent HTTP header.getUserAgent(),
setUserAgent(String)public final EventHandler<WebEvent<String>> getOnAlert()
alert handler.public final void setOnAlert(EventHandler<WebEvent<String>> handler)
alert handler.onAlertProperty(),
getOnAlert()public final ObjectProperty<EventHandler<WebEvent<String>>> onAlertProperty()
alert handler property. This handler is invoked
when a script running on the Web page calls the alert function.getOnAlert(),
setOnAlert(EventHandler)public final EventHandler<WebEvent<String>> getOnStatusChanged()
public final void setOnStatusChanged(EventHandler<WebEvent<String>> handler)
onStatusChangedProperty(),
getOnStatusChanged()public final ObjectProperty<EventHandler<WebEvent<String>>> onStatusChangedProperty()
window.status property.public final EventHandler<WebEvent<Rectangle2D>> getOnResized()
public final void setOnResized(EventHandler<WebEvent<Rectangle2D>> handler)
onResizedProperty(),
getOnResized()public final ObjectProperty<EventHandler<WebEvent<Rectangle2D>>> onResizedProperty()
window object.getOnResized(),
setOnResized(EventHandler)public final EventHandler<WebEvent<Boolean>> getOnVisibilityChanged()
public final void setOnVisibilityChanged(EventHandler<WebEvent<Boolean>> handler)
public final ObjectProperty<EventHandler<WebEvent<Boolean>>> onVisibilityChangedProperty()
window object.public final Callback<PopupFeatures,WebEngine> getCreatePopupHandler()
public final void setCreatePopupHandler(Callback<PopupFeatures,WebEngine> handler)
public final ObjectProperty<Callback<PopupFeatures,WebEngine>> createPopupHandlerProperty()
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.
public final Callback<String,Boolean> getConfirmHandler()
confirm handler.public final void setConfirmHandler(Callback<String,Boolean> handler)
confirm handler.confirmHandlerProperty(),
getConfirmHandler()public final ObjectProperty<Callback<String,Boolean>> confirmHandlerProperty()
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.
getConfirmHandler(),
setConfirmHandler(Callback)public final Callback<PromptData,String> getPromptHandler()
prompt handler.public final void setPromptHandler(Callback<PromptData,String> handler)
prompt handler.promptHandlerProperty(),
getPromptHandler(),
PromptDatapublic final ObjectProperty<Callback<PromptData,String>> promptHandlerProperty()
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.
getPromptHandler(),
setPromptHandler(Callback)public final EventHandler<WebErrorEvent> getOnError()
nullpublic final void setOnError(EventHandler<WebErrorEvent> handler)
nullpublic final ObjectProperty<EventHandler<WebErrorEvent>> onErrorProperty()
nullgetOnError(),
setOnError(EventHandler)public void load(String url)
url - URL of the web page to loadpublic void loadContent(String content)
load(String), this method is asynchronous.public void loadContent(String content, String contentType)
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.public void reload()
loadContent methods.public WebHistory getHistory()
public Object executeScript(String script)
java.lang.Integer
java.lang.Double
java.lang.String
java.lang.Boolean
null to null
netscape.javascript.JSObject
netscape.javascript.JSObject, that also implement
org.w3c.dom.Node
JavaRuntimeObject
which is used to wrap a Java object as a JavaScript value - in this
case we just extract the original Java value.
public void print(PrinterJob 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.
job - printer job used for printingCopyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.