title: Java setText from another Controller, but UI dont refresh
body: <p>i have 2 controllers. I want to set the value of tf_fileName from my GlobalOptionsFileNameController. The value is set and i can work with it, but the TextField dont Update the View (i dont see the new value).</p>
  
  <p>Here is my Code. Sry it could be a duplicate, but i dont found a working way for me at the other posts.</p>
  
  <pre><code>package configHelp;
  
  import burninbuilder.GlobalOptionsController;
  import java.io.IOException;
  import java.net.URL;
  import java.util.ResourceBundle;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import javafx.event.ActionEvent;
  import javafx.fxml.FXML;
  import javafx.fxml.FXMLLoader;
  import javafx.fxml.Initializable;
  import javafx.scene.Parent;
  import javafx.scene.control.Button;
  import javafx.scene.control.RadioButton;
  import javafx.scene.control.TextField;
  import javafx.stage.Stage;
  
  /**
   * FXML Controller class
   *
   * @author Sandro
   */
  public class GlobalOptionsFileNameController implements Initializable {
  
      @FXML Button btn_help;
      @FXML RadioButton rb_local;
      @FXML RadioButton rb_server;
      @FXML TextField txt_filename;
      @FXML TextField txt_serverName;
      @FXML TextField txt_path;
      @FXML Button btn_addNr;
      @FXML Button btn_addDriveSN;
      @FXML Button btn_ok;
  
      Stage test = new Stage();
  
      GlobalOptionsController optionsController;
      public void getController() throws IOException{
          FXMLLoader loader = new FXMLLoader(getClass().getResource("/burninbuilder/GlobalOptions.fxml"));
          Parent root = (Parent) loader.load();
          optionsController = loader.getController();
          System.out.println(this.optionsController);
      }
  
      public void setFileName(ActionEvent ev){
          if(rb_local.isSelected()){
              optionsController.setNameLocal(txt_filename.getText());
              System.out.println(optionsController.tf_fileName.getText());
          }else if(rb_server.isSelected()){
              String fileNameServer="//"+txt_serverName.getText()+"/"+txt_path.getText();
              optionsController.setNameLocal(fileNameServer);
          }   
      }
  
      public void test(){
          txt_filename.setText("test");
      }
  
      @Override
      public void initialize(URL url, ResourceBundle rb) {
          btn_ok.setOnAction(this::setFileName);
          try {
              getController();
          } catch (IOException ex) {
              Logger.getLogger(GlobalOptionsFileNameController.class.getName()).log(Level.SEVERE, null, ex);
          }
      }    
  
  }
  </code></pre>
  
  <p>Class where i want to set and refresh the TextField.</p>
  
  <pre><code>    package burninbuilder;
  
  import configHelp.GlobalOptionsFileNameController;
  import java.io.IOException;
  import java.net.URL;
  import java.util.ResourceBundle;
  import javafx.application.Platform;
  import javafx.event.ActionEvent;
  import javafx.fxml.FXML;
  import javafx.fxml.FXMLLoader;
  import javafx.fxml.Initializable;
  import javafx.scene.Parent;
  import javafx.scene.Scene;
  import javafx.scene.control.Button;
  import javafx.scene.control.CheckBox;
  import javafx.scene.control.RadioButton;
  import javafx.scene.control.TabPane;
  import javafx.scene.control.TextField;
  import javafx.scene.input.KeyEvent;
  import javafx.scene.input.MouseEvent;
  import javafx.stage.Modality;
  import javafx.stage.Stage;
  import logic.GlobalOptions;
  
  public class GlobalOptionsController implements Initializable {
  
  //
  GlobalOptions globalOptionsSingleton = GlobalOptions.getInstance();
  
  Stage fileNameOptions = new Stage();
  
  @FXML public TextField tf_fileName;
  
      }
  }
  
  GlobalOptionsFileNameController fileAssistentController;
  public void fileNameOptions(ActionEvent ev){
      try {
          if(fileNameOptions.getScene()==null){
              FXMLLoader loader = new FXMLLoader(getClass().getResource("/configHelp/globalOptionsFileName.fxml")); 
              Parent root = (Parent) loader.load();
              fileAssistentController = loader.getController();
              Scene scene = new Scene(root);
              fileNameOptions.setTitle("Assistent zum festlegen der Speicherorte und Dateinamen");
              fileNameOptions.getIcons().add(new javafx.scene.image.Image("pictures/app-icon.png")); 
              fileNameOptions.setScene(scene);
              fileNameOptions.setResizable(false);
              fileNameOptions.setAlwaysOnTop(true);
              fileNameOptions.initModality(Modality.APPLICATION_MODAL);
  
              fileNameOptions.show();
          }else{
              fileNameOptions.show();
          }             
          } catch (IOException ex) {
              System.out.println("AddWindow: "+ex);
          }
  }
  
  @FXML
  public void setFileName(String name){
      Platform.runLater(new Runnable() {
      @Override
      public void run() {
          tf_fileName.setText("test");
          System.out.println("TextField:"+tf_fileName.getText());
      }
  });
  }
  
  @FXML
  public void setNameLocal(String name){
  Platform.runLater(new Runnable() {
      public void run() {
          tf_fileName.setText(null);
          tf_fileName.setText(name);
      }
  });
  }
  
  
  @Override
  public void initialize(URL url, ResourceBundle rb) {
      filename_options.setOnAction(this::fileNameOptions);
      tabpane.setTabMinWidth(94);
      btn_ok.setOnAction(this::getGlobalOptions);
      cb_html.setOnMousePressed(this::setFileEx);
      tf_fileName.setOnMouseExited(this::addExTextField);
      tf_hour.setOnKeyTyped(this::onlyNumber);
      tf_min.setOnKeyTyped(this::onlyNumber);
      tf_duration.setOnKeyTyped(this::onlyNumber);
      tf_fail.setOnKeyTyped(this::onlyNumber);
      }
  }
  </code></pre>