public final class Platform extends Object
- Since:
- JavaFX 2.0
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Property Summary
Properties Type Property Description static ReadOnlyBooleanProperty
accessibilityActive
Indicates whether or not accessibility is active. -
Method Summary
Modifier and Type Method Description static ReadOnlyBooleanProperty
accessibilityActiveProperty()
Indicates whether or not accessibility is active.static Object
enterNestedEventLoop(Object key)
Enter a nested event loop and block until the corresponding exitNestedEventLoop call is made.static void
exit()
Causes the JavaFX application to terminate.static void
exitNestedEventLoop(Object key, Object rval)
Exit a nested event loop and unblock the caller of the corresponding enterNestedEventLoop.static boolean
isAccessibilityActive()
Gets the value of the property accessibilityActive.static boolean
isFxApplicationThread()
Returns true if the calling thread is the JavaFX Application Thread.static boolean
isImplicitExit()
Gets the value of the implicitExit attribute.static boolean
isNestedLoopRunning()
Checks whether a nested event loop is running, returning true to indicate that one is, and false if there are no nested event loops currently running.static boolean
isSupported(ConditionalFeature feature)
Queries whether a specific conditional feature is supported by the platform.static void
requestNextPulse()
Requests the Java Runtime to perform a pulse.static void
runLater(Runnable runnable)
Run the specified Runnable on the JavaFX Application Thread at some unspecified time in the future.static void
setImplicitExit(boolean implicitExit)
Sets the implicitExit attribute to the specified value.static void
startup(Runnable runnable)
This method starts the JavaFX runtime.
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Property Details
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accessibilityActive
Indicates whether or not accessibility is active. This property is typically set to true the first time an assistive technology, such as a screen reader, requests information about any JavaFX window or its children.This method may be called from any thread.
- Since:
- JavaFX 8u40
- See Also:
isAccessibilityActive()
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Method Details
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startup
This method starts the JavaFX runtime. The specified Runnable will then be called on the JavaFX Application Thread. In general it is not necessary to explicitly call this method, since it is invoked as a consequence of how most JavaFX applications are built. However there are valid use cases for calling this method directly. Because this method starts the JavaFX runtime, there is not yet any JavaFX Application Thread, so it is normal that this method is called directly on the main thread of the application.This method may or may not return to the caller before the run method of the specified Runnable has been called. In any case, this method is not blocked on the specified Runnable being executed. Once this method returns, you may call
runLater(Runnable)
with additional Runnables. Those Runnables will be called, also on the JavaFX Application Thread, after the Runnable passed into this method has been called.As noted, it is normally the case that the JavaFX Application Thread is started automatically. It is important that this method only be called when the JavaFX runtime has not yet been initialized. Situations where the JavaFX runtime is started automatically include:
- For standard JavaFX applications that extend
Application
, and use either the Java launcher or one of the launch methods in the Application class to launch the application, the FX runtime is initialized automatically by the launcher before theApplication
class is loaded. - For Swing applications that use
JFXPanel
to display FX content, the FX runtime is initialized when the firstJFXPanel
instance is constructed. - For SWT application that use
FXCanvas
to display FX content, the FX runtime is initialized when the firstFXCanvas
instance is constructed.
When an application does not follow any of these common approaches, then it becomes the responsibility of the developer to manually start the JavaFX runtime by calling this startup method.
Calling this method when the JavaFX runtime is already running will result in an
IllegalStateException
being thrown - it is only valid to request that the JavaFX runtime be started once.Note: The JavaFX classes must be loaded from a set of named
javafx.*
modules on the module path. Loading the JavaFX classes from the classpath is not supported. A warning is logged when the JavaFX runtime is started if the JavaFX classes are not loaded from the expected named module. This warning is logged regardless of whether the JavaFX runtime was started by calling this method or automatically as described above.- Parameters:
runnable
- the Runnable whose run method will be executed on the JavaFX Application Thread once it has been started- Throws:
IllegalStateException
- if the JavaFX runtime is already running- Since:
- 9
- See Also:
Application
- For standard JavaFX applications that extend
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runLater
Run the specified Runnable on the JavaFX Application Thread at some unspecified time in the future. This method, which may be called from any thread, will post the Runnable to an event queue and then return immediately to the caller. The Runnables are executed in the order they are posted. A runnable passed into the runLater method will be executed before any Runnable passed into a subsequent call to runLater. If this method is called after the JavaFX runtime has been shutdown, the call will be ignored: the Runnable will not be executed and no exception will be thrown.NOTE: applications should avoid flooding JavaFX with too many pending Runnables. Otherwise, the application may become unresponsive. Applications are encouraged to batch up multiple operations into fewer runLater calls. Additionally, long-running operations should be done on a background thread where possible, freeing up the JavaFX Application Thread for GUI operations.
This method must not be called before the FX runtime has been initialized. For standard JavaFX applications that extend
Application
, and use either the Java launcher or one of the launch methods in the Application class to launch the application, the FX runtime is initialized by the launcher before the Application class is loaded. For Swing applications that use JFXPanel to display FX content, the FX runtime is initialized when the first JFXPanel instance is constructed. For SWT application that use FXCanvas to display FX content, the FX runtime is initialized when the first FXCanvas instance is constructed. For applications that do not follow any of these approaches, then it is necessary to manually start the JavaFX runtime by callingstartup(Runnable)
once.- Parameters:
runnable
- the Runnable whose run method will be executed on the JavaFX Application Thread- Throws:
IllegalStateException
- if the FX runtime has not been initialized- See Also:
Application
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requestNextPulse
public static void requestNextPulse()Requests the Java Runtime to perform a pulse. This will run a pulse even if there are no animation timers, scene graph modifications, or window events that would otherwise cause the pulse to run. If no pulse is in progress, then one will be scheduled to run the next time the pulse timer fires. If there is already a pulse running, then at least one more pulse after the current pulse will be scheduled. This method may be called on any thread.- Since:
- 9
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isFxApplicationThread
public static boolean isFxApplicationThread()Returns true if the calling thread is the JavaFX Application Thread. Use this call to ensure that a given task is being executed (or not being executed) on the JavaFX Application Thread.- Returns:
- true if running on the JavaFX Application Thread
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exit
public static void exit()Causes the JavaFX application to terminate. If this method is called after the Application start method is called, then the JavaFX launcher will call the Application stop method and terminate the JavaFX application thread. The launcher thread will then shutdown. If there are no other non-daemon threads that are running, the Java VM will exit. If this method is called from the Preloader or the Application init method, then the Application stop method may not be called.This method may be called from any thread.
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setImplicitExit
public static void setImplicitExit(boolean implicitExit)Sets the implicitExit attribute to the specified value. If this attribute is true, the JavaFX runtime will implicitly shutdown when the last window is closed; the JavaFX launcher will call theApplication.stop()
method and terminate the JavaFX application thread. If this attribute is false, the application will continue to run normally even after the last window is closed, until the application callsexit()
. The default value is true.This method may be called from any thread.
- Parameters:
implicitExit
- a flag indicating whether or not to implicitly exit when the last window is closed.- Since:
- JavaFX 2.2
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isImplicitExit
public static boolean isImplicitExit()Gets the value of the implicitExit attribute.This method may be called from any thread.
- Returns:
- the implicitExit attribute
- Since:
- JavaFX 2.2
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isSupported
Queries whether a specific conditional feature is supported by the platform.For example:
// Query whether filter effects are supported if (Platform.isSupported(ConditionalFeature.EFFECT)) { // use effects }
- Parameters:
feature
- the conditional feature in question.- Returns:
- true if a specific conditional feature is supported by the platform, otherwise false
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enterNestedEventLoop
Enter a nested event loop and block until the corresponding exitNestedEventLoop call is made. The key passed into this method is used to uniquely identify the matched enter/exit pair. This method creates a new nested event loop and blocks until the corresponding exitNestedEventLoop method is called with the same key. The return value of this method will be therval
object supplied to the exitNestedEventLoop method call that unblocks it.This method must either be called from an input event handler or from the run method of a Runnable passed to
Platform.runLater
. It must not be called during animation or layout processing.- Parameters:
key
- the Object that identifies the nested event loop, which must not be null- Returns:
- the value passed into the corresponding call to exitEventLoop
- Throws:
IllegalArgumentException
- if the specified key is associated with a nested event loop that has not yet returnedNullPointerException
- if the key is nullIllegalStateException
- if this method is called during animation or layout processing.IllegalStateException
- if this method is called on a thread other than the JavaFX Application Thread.- Since:
- 9
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exitNestedEventLoop
Exit a nested event loop and unblock the caller of the corresponding enterNestedEventLoop. The key passed into this method is used to uniquely identify the matched enter/exit pair. This method causes the nested event loop that was previously created with the key to exit and return control to the caller. If the specified nested event loop is not the inner-most loop then it will not return until all other inner loops also exit.- Parameters:
key
- the Object that identifies the nested event loop, which must not be nullrval
- an Object that is returned to the caller of the corresponding enterNestedEventLoop. This may be null.- Throws:
IllegalArgumentException
- if the specified key is not associated with an active nested event loopNullPointerException
- if the key is nullIllegalStateException
- if this method is called on a thread other than the FX Application thread- Since:
- 9
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isNestedLoopRunning
public static boolean isNestedLoopRunning()Checks whether a nested event loop is running, returning true to indicate that one is, and false if there are no nested event loops currently running. This method must be called on the JavaFX Application thread.- Returns:
- true if there is a nested event loop running, and false otherwise.
- Throws:
IllegalStateException
- if this method is called on a thread other than the JavaFX Application Thread.- Since:
- 9
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isAccessibilityActive
public static boolean isAccessibilityActive()Gets the value of the property accessibilityActive.- Property description:
- Indicates whether or not accessibility is active.
This property is typically set to true the first time an
assistive technology, such as a screen reader, requests
information about any JavaFX window or its children.
This method may be called from any thread.
- Since:
- JavaFX 8u40
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accessibilityActiveProperty
Indicates whether or not accessibility is active. This property is typically set to true the first time an assistive technology, such as a screen reader, requests information about any JavaFX window or its children.This method may be called from any thread.
- Since:
- JavaFX 8u40
- See Also:
isAccessibilityActive()
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