Re: Regarding issue with JavaFX 8 ScrollPane

[Mong Hang Vo]

Vadala,

I don't have a good answer to your question. So I am adding the 
openjfx-dev@openjdk.java.net alias.

In the future, please send your question to this alias.

Thank you very much,
Mong

Vadala, Sirish wrote:

Hello Hang,

 

My name is Sirish Vadala, working for Legislative Data Center, 
Sacramento, California. Right now I am working on a project 
implemented on JavaFX 8 (jdk1.8.0_05) and have a quick question on one 
of the UI related issues that my team is facing.

 

Coming to the issue I am not able to programmatically place the 
ScrollPane's scroll position using setVValue(double) method of 
ScrollPane. For example, if you look at the sample program below, the 
vertical scroll bar position always remains on the top what so ever 
the vValue is set to. Can you please let me know if this is an 
existing issue being worked on or if I am doing something wrong in 
implementation?

 

I highly appreciate your response at your convenience on this issue.

 

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

import java.util.logging.Level;

import java.util.logging.Logger;

import javafx.application.Application;

import javafx.embed.swing.SwingFXUtils;

import javafx.event.ActionEvent;

import javafx.event.EventHandler;

import javafx.scene.Scene;

import javafx.scene.control.Button;

import javafx.scene.control.ScrollPane;

import javafx.scene.control.ScrollPane.ScrollBarPolicy;

import javafx.scene.image.Image;

import javafx.scene.image.ImageView;

import javafx.scene.layout.VBox;

import javafx.stage.FileChooser;

import javafx.stage.Stage;

import javax.imageio.ImageIO;

public class JavaFXPixel extends Application {

    

    private ImageView myImageView;

    private ScrollPane scrollPane;

    

    @Override

    public void start(Stage primaryStage) {

        

        Button btnLoad = new Button("Load");

        btnLoad.setOnAction(btnLoadEventListener);

        

        myImageView = new ImageView();

        

        scrollPane = new ScrollPane();

        scrollPane.setPrefSize(300, 250);

        scrollPane.setVbarPolicy(ScrollBarPolicy.AS_NEEDED);

        scrollPane.setHbarPolicy(ScrollBarPolicy.AS_NEEDED);

        scrollPane.setContent(myImageView);

       

       // STILL MY VERTICAL SCROLL POSITION IS ALWAYS PLACED ON THE TOP

        scrollPane.setVvalue(1.0);

       

        VBox rootBox = new VBox();

        rootBox.getChildren().addAll(btnLoad, scrollPane);

        

        Scene scene = new Scene(rootBox, 300, 300);

        

        primaryStage.setTitle("My Test Program");

        primaryStage.setScene(scene);

        primaryStage.show();

       

    }

    public static void main(String[] args) {

        launch(args);

    }

    

    private final EventHandler<ActionEvent> btnLoadEventListener = 
(ActionEvent t) -> {

        FileChooser fileChooser = new FileChooser();

       

        //Set extension filter

        FileChooser.ExtensionFilter extFilterJPG = new 
FileChooser.ExtensionFilter("JPG files (*.jpg)", "*.JPG");

        FileChooser.ExtensionFilter extFilterPNG = new 
FileChooser.ExtensionFilter("PNG files (*.png)", "*.PNG");

        fileChooser.getExtensionFilters().addAll(extFilterJPG, 
extFilterPNG);

       

        //Show open file dialog

        File file = fileChooser.showOpenDialog(null);

       

        try {

            BufferedImage bufferedImage = ImageIO.read(file);

            Image image = SwingFXUtils.toFXImage(bufferedImage, null);

            myImageView.setImage(image);

            scrollPane.setContent(null);

            scrollPane.setContent(myImageView);

            scrollPane.setVvalue(1.0);

        } catch (IOException ex) {

            
Logger.getLogger(JavaFXPixel.class.getName()).log(Level.SEVERE, null, ex);

        }

    };

}

 

Thanks.

Sirish Vadala

916 341 8878