Javafx combobox not updating dropdown size upon change on realtime?

Question

I am using Javafx v8.0.25-b18.

The problem I occur is that the size of the dynamic combox\'s dropdown list doesn\'t change, so if I had initially two items in the dropdo

Answer 1

You can use two JavaFx list. First one is previous com box list, another one is final combo box list. then you can change dynamically using yourCombo.getItems().setAll(Your List);

Here is my sample code:

import java.util.ArrayList;
import java.util.List;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.Region;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class ComboBoxTest extends Application {

   @Override
   public void start(final Stage primaryStage) throws Exception {

      primaryStage.centerOnScreen();
      primaryStage.setHeight(200);
      primaryStage.setWidth(300);

      List list1 = new ArrayList<>();
      list1.add("one");
      list1.add("two");
      list1.add("three");

      List list2 = new ArrayList<>();
      list2.add("one");
      list2.add("two");
      list2.add("three");
      list2.add("four");

      final ComboBox combo = new ComboBox();
      combo.getItems().setAll(list1);


      Button button = new Button("Change combo contents");
      button.setOnAction(event -> {
         if ( combo.getItems().size() == 3 ) {
            combo.getItems().setAll(list2);
         } else {
            combo.getItems().setAll(list1);
         }
         combo.show();
      });

      VBox box = new VBox(20, combo, button );
      box.setMaxSize(Region.USE_PREF_SIZE, Region.USE_PREF_SIZE);
      primaryStage.setScene(new Scene( new StackPane(box) ));

      primaryStage.show();

   }

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

}