Platform

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.

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 the rval 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 javafx.application.Platform.runLater. It must not be called during animation or layout processing.

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.

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.

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.

Run the specified code block on the JavaFX Application Thread at some unspecified time in the future. Returns immediately.

Example use:

Platform.runLater {
println("Running on application thread.")
}

Run the specified Runnable on the JavaFX Application Thread at some unspecified time in the future. Returns immediately.

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, 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 the Application class is loaded.
• For Swing applications that use javafx.embed.swing.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.

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.