import javafx.application.Application; 
import javafx.application.Platform; 
import javafx.stage.Stage; 

public class SetIconifiedTest extends Application { 

    Stage stage; 

    public static void main ( String[] args ) { 
        launch ( args ); 
    } 

    @Override 
    public void start ( Stage stage ) throws Exception { 
        this.stage = stage; 
        stage.setResizable( true ); 
        stage.show( ); 

        Thread thread = new Thread ( () -> { 
            while ( true ) { 
                Platform.runLater( () -> { 
                    toggleMinimized(); 
                } ); 
                try { 
                    Thread.sleep ( 1000 ); 
                } catch ( InterruptedException e ) { 
                    // TODO Auto-generated catch block 
                    e.printStackTrace(); 
                } 
            } 
        }); 

        thread.setDaemon( true ); 
        thread.start(); 

    } 

    public void toggleMinimized() { 

        System.out.println ( "Before call" ); 
        System.out.println ( "\tisIconified(): " + stage.isIconified() ); 
        System.out.println ( "\tisMaximized(): " + stage.isMaximized() ); 
        System.out.println (); 

        if ( stage.isIconified() ) { 
            System.out.println ( "Setting iconified to false" ); 
            System.out.println (); 
            stage.setIconified( false ); 
        } else { 
            System.out.println ( "Setting iconified to true" ); 
            System.out.println (); 
            stage.setIconified( true ); 
        } 


        System.out.println ( "After call" ); 
        System.out.println ( "\tisIconified(): " + stage.isIconified() ); 
        System.out.println ( "\tisMaximized(): " + stage.isMaximized() ); 
        System.out.println (); 
        System.out.println (); 
    } 
}