JavaFX Tutorial - JavaFX ProgressBar








A progress bar visualizes progress of an operations in JavaFX applications. 

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ProgressBar;
import javafx.stage.Stage;
/* www  .j av a  2s .  c  o  m*/
public class Main extends Application {

  @Override
  public void start(Stage stage) {
    Group root = new Group();
    Scene scene = new Scene(root, 260, 80);
    stage.setScene(scene);

    Group g = new Group();

    ProgressBar p2 = new ProgressBar();

    
    g.getChildren().add(p2);
    
    scene.setRoot(g);
    stage.show();
  }

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

The code above generates the following result.

null




Creating ProgressBar

The following code shows how to create a ProgressBar by passing in the progress value.

ProgressBar pb = new ProgressBar(0.6);

You can also create the progress bar without parameters by using an empty constructor. Then assign the value by using the setProgress method.

If we cannot determine the full completion time of a task we can set progress bar in indeterminate mode until the length of the task is determined.

The following code shows how to create a ProgressBar which is 25% complete. 

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ProgressBar;
import javafx.stage.Stage;
//from w w w.  java2s .  c o  m
public class Main extends Application {

  @Override
  public void start(Stage stage) {
    Group root = new Group();
    Scene scene = new Scene(root, 260, 80);
    stage.setScene(scene);

    Group g = new Group();

    ProgressBar p2 = new ProgressBar();
    p2.setProgress(0.25F);
    
    g.getChildren().add(p2);
    
    scene.setRoot(g);
    stage.show();
  }

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

The code above generates the following result.

null




Example

The following code shows how to use a ProgressBar with background Processes. 

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Task;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
//from  w  w w .  j a  v a2  s .  c o m
public class Main extends Application {
  Task copyWorker;

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

  @Override
  public void start(Stage primaryStage) {
    Group root = new Group();
    Scene scene = new Scene(root, 330, 120, Color.WHITE);

    BorderPane mainPane = new BorderPane();
    root.getChildren().add(mainPane);

    final Label label = new Label("Files Transfer:");
    final ProgressBar progressBar = new ProgressBar(0);

    final HBox hb = new HBox();
    hb.setSpacing(5);
    hb.setAlignment(Pos.CENTER);
    hb.getChildren().addAll(label, progressBar);
    mainPane.setTop(hb);

    final Button startButton = new Button("Start");
    final Button cancelButton = new Button("Cancel");
    final HBox hb2 = new HBox();
    hb2.setSpacing(5);
    hb2.setAlignment(Pos.CENTER);
    hb2.getChildren().addAll(startButton, cancelButton);
    mainPane.setBottom(hb2);
    startButton.setOnAction(new EventHandler<ActionEvent>() {
      public void handle(ActionEvent event) {
        startButton.setDisable(true);
        progressBar.setProgress(0);
        cancelButton.setDisable(false);
        copyWorker = createWorker();
        progressBar.progressProperty().unbind();
        progressBar.progressProperty().bind(copyWorker.progressProperty());
        copyWorker.messageProperty().addListener(new ChangeListener<String>() {
          public void changed(ObservableValue<? extends String> observable,
              String oldValue, String newValue) {
            System.out.println(newValue);
          }
        });
        new Thread(copyWorker).start();
      }
    });
    cancelButton.setOnAction(new EventHandler<ActionEvent>() {
      public void handle(ActionEvent event) {
        startButton.setDisable(false);
        cancelButton.setDisable(true);
        copyWorker.cancel(true);
        progressBar.progressProperty().unbind();
        progressBar.setProgress(0);
        System.out.println("cancelled.");
      }
    });
    primaryStage.setScene(scene);
    primaryStage.show();
  }

  public Task createWorker() {
    return new Task() {
      @Override
      protected Object call() throws Exception {
        for (int i = 0; i < 10; i++) {
          Thread.sleep(2000);
          updateMessage("2000 milliseconds");
          updateProgress(i + 1, 10);
        }
        return true;
      }
    };
  }
}

The code above generates the following result.

null