Tag Archives: javafx8

JavaFX 8u20 Days of Future Past (Always On Top)

It’s been a long time since I’ve posted topics relating to JavaFX. So, if you are still following along, awesome!

Introduction

In this blog post I want to blog about a very cool feature starting with JavaFX 8 update 20 that allows your application to always be on top of other applications. What this means is that on your desktop your JavaFX based application can be a floating widget that will remain above all other applications (z-order). An example would be a weather widget in the upper right corner never to be obscured by other applications. So, I’m very excited to share with you this amazing feature ‘Always On Top’.

History

In the past Java Swing developers would rely on the method Window.setAlwaysOnTop(boolean).  This feature allowed Swing developers to build native looking and native behaving desktop applications. Ever since JavaFX 1.x this very feature was highly requested (originally requested by Stephen Chin @steveonjava for the WidgetFX framework). This feature request is JIRA ticket RT-153. Figure 1 is the feature request shown with a status of ‘Resolved’.

Jira ticket RT-153

figure 1: Jira ticket RT-153

 

Although this feature didn’t get into JavaFX versions 1.x, 2.x and the version prior to Java 8u20, it is finally here now. For those who don’t know how to report bugs or file new features requests I encourage you to head over to the JavaFX JIRA system.

Example: Weather Widget

Assuming you know the basics of JavaFX since version 2.0 a typical application would consist of extending from the javafx.application.Application class. When developing JavaFX desktop applications the platform API would provide you with a (javafx.stage.Stage) window. The Stage object will have the following methods to access the always on top property.

  • alwaysOnTopProperty()
  • setAlwaysOnTop(boolean)
  • isAlwaysOnTop()

The following code snippet sets the Stage to be always on top using the method setAlwaysOnTop(boolean).

public class KeyholeDemo extends Application {

   @Override public void start(Stage primaryStage) {
      primaryStage.initStyle(StageStyle.TRANSPARENT);
      primaryStage.setAlwaysOnTop(true);
      // code omitted...
   }

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

How it works

Shown in the listing above the start() method sets the stage to be transparent to be a JavaFX window without a title bar. This allows applications to have irregular shaped windows on the desktop. If a web person trolls you again about JavaFX ask them the following question: “Can  HTML5 create irregular shaped windows on the desktop? (always on top)”. Next, the stage is setup to be always on top via the setAlwaysOnTop() method.

Demo

After realizing that this highly requested feature was available I basically updated my old ‘KeyholeWidget‘ project at the Github and created a video demonstrating the widget on my desktop. Here is the video:

To see the full code listing visit the Github project ‘KeyholeWidget‘.

 

I hope you’ve enjoyed this cool feature (I know I did). As usual please leave comments below.

Happy coding,

Carl

Introduction by Example: JavaFX 8 Printing

I‘ve not blogged in awhile, and I miss sharing with others about all things JavaFX (My day job and family are likely excuses). For those who are new to this blog, I am the author of JavaFX 2 Introduction by Example (JIBE), co-author of Java 7 Recipes, and technical reviewer of the Pro JavaFX 2 books from Apress publishing. For those who already know me, I’d like to thank you for supporting me and the other authors by purchasing these books. More importantly, my hope is to reach out to  Java enthusiasts and share ideas.

The book JavaFX 2 Introduction by Example, was published in Nov. 2011 and many more APIs were added since then. During the writing of the book, I was working on the early editions of JavaFX 2.0 up until the announcement at JavaOne Oct. 2011. It was pretty crazy trying to update the book based on API changes as things were almost set in stone. I thought it was amazing how it even got out the door. However, I was pretty pleased. Some of you who have read the beginning of the book (JIBE) understand that the chapters of JIBE are also found in the book Java 7 Recipes (actually it is originally taken from Java 7 recipes). This little fact explains why the book, JavaFX 2 Introduction by Example, is reminiscent of recipe or cookbook style technical books. My intent was to help the reader get introduced quickly without a lot of tech blather. Instead of trying to convince people about the JavaFX platform, I’d rather demonstrate things with useful examples. I find it counter productive discussing  deep philosophical debates regarding why one particular technology is superior to the other (cheesy 80’s Highlander reference).

After the release of JavaFX 2.0, there came subsequent versions such as JavaFX 2.1, 2.2 and the upcoming release of JavaFX 8 (January 2014). In this blog entry, I will provide a recipe for the JavaFX 8’s Printing API. Similar to my book (JIBE), I will follow the same pattern as before where I present a problem, solution, code, and a “How it Works” section.

Declaimer: In this blog you will encounter Java Functional Interfaces using Lambda expressions. I will not be discussing them here, but will refer you to Oracle’s tutorials on Project Lambda .

Prerequisite software:

JDK 8 – https://jdk8.java.net/download.html

 

Problem

You want to create a JavaFX application that prints out a visited website.

Solution

Use the JavaFX 8 PrintJob and Printer APIs to print any JavaFX scene graph node. Also, use the WebView and WebEngine APIs to display a Website or Web page.

Instructions

Assuming you’ve compiled and have run the application, follow the instruction below:

  1. Enter website address or url into the text field.
  2. Hit the enter key
  3. After the page is loaded, click on the “Print” button
  4. Go to the printer to get the printed web page

Code

package org.carlfx;

import javafx.application.Application;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.value.ChangeListener;
import javafx.concurrent.Worker.State;
import javafx.print.*;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.transform.Scale;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

/**
 * Demo to use JavaFX 8 Printer API.
 *
 * @author cdea
 */
public class PrintDemo extends Application {
    @Override
    public void start(Stage primaryStage) {

        final TextField urlTextField = new TextField();
        final Button printButton = new Button("Print");
        final WebView webPage = new WebView();
        final WebEngine webEngine = webPage.getEngine();

        HBox hbox = new HBox();
        hbox.getChildren().addAll(urlTextField, printButton);
        BorderPane borderPane = new BorderPane();
        borderPane.setTop(hbox);
        borderPane.setCenter(webPage);
        Scene scene = new Scene(borderPane, 300, 250);
        primaryStage.setTitle("Print Demo");
        primaryStage.setScene(scene);

        // print button pressed, page loaded
        final BooleanProperty printButtonClickedProperty = new SimpleBooleanProperty(false);
        final BooleanProperty pageLoadedProperty = new SimpleBooleanProperty(false);

        // when the a page is loaded and the button was pressed call the print() method.
        final BooleanProperty printActionProperty = new SimpleBooleanProperty(false);
        printActionProperty.bind(pageLoadedProperty.and(printButtonClickedProperty));

        // WebEngine updates flag when finished loading web page.
        webEngine.getLoadWorker()
                 .stateProperty()
                 .addListener( (ChangeListener) (obsValue, oldState, newState) -> {
                    if (newState == State.SUCCEEDED) {
                        pageLoadedProperty.set(true);
                    }
                 });

        // When user enters a url and hits the enter key.
        urlTextField.setOnAction( aEvent ->  {
            pageLoadedProperty.set(false);
            printButtonClickedProperty.set(false);
            webEngine.load(urlTextField.getText());
        });

        // When the user clicks the print button the webview node is printed
        printButton.setOnAction( aEvent -> {
            printButtonClickedProperty.set(true);
        });

        // Once the print action hears a true go print the WebView node.
        printActionProperty.addListener( (ChangeListener) (obsValue, oldState, newState) -> {
            if (newState) {
                print(webPage);
            }
        });

        primaryStage.show();

    }

    /** Scales the node based on the standard letter, portrait paper to be printed.
     * @param node The scene node to be printed.
     */
    public void print(final Node node) {
        Printer printer = Printer.getDefaultPrinter();
        PageLayout pageLayout = printer.createPageLayout(Paper.NA_LETTER, PageOrientation.PORTRAIT, Printer.MarginType.DEFAULT);
        double scaleX = pageLayout.getPrintableWidth() / node.getBoundsInParent().getWidth();
        double scaleY = pageLayout.getPrintableHeight() / node.getBoundsInParent().getHeight();
        node.getTransforms().add(new Scale(scaleX, scaleY));

        PrinterJob job = PrinterJob.createPrinterJob();
        if (job != null) {
            boolean success = job.printPage(node);
            if (success) {
                job.endJob();
            }
        }
    }

    /**
     * The main() method is ignored in correctly deployed JavaFX application.
     * main() serves only as fallback in case the application can not be
     * launched through deployment artifacts, e.g., in IDEs with limited FX
     * support. NetBeans ignores main().
     *
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
}
Print Demo using JavaFX 8

Print Demo using JavaFX 8

How it Works

The code begins by creating a TextField, a Button, and a WebView control to be placed into a BorderPane. When using the BorderPane layout, you will be able to place controls into the following regions: Top, Right, Left, Bottom, and Center.

Similar to a web browser, the text field allows the user to enter a website url. Once the url is entered, the user will hit the enter key to load the web page into the WebView node. When placing controls on any of the side regions, the BorderPane layout will take on the preferred height of any controls that are added. The center region will allow a node to take up the available space minus the remaining space taken up by the width and height of the bordering side regions. In other words, if the side regions contain no nodes (empty), a node in the center region has the opportunity to take all the available width and height space provided by its parent (Scene). Since the WebView node will occupy the center region, it will take all the available width and height (minus top region) when the web page is fully loaded. You’ll also notice scroll bars allowing the user to view pages larger than the current view port.

After laying out all the components for the UI, you will need to wire things up. Here you will simply create three boolean property
(javafx.beans.property.SimpleBooleanProperty) instances. The first property variable printButtonClickedProperty is a flag indicating when the print button was clicked. The second property pageLoadedProperty is a flag indicating that the web page was finished loading. Lastly, you will want to note the printActionProperty which binds the printButtonClickedProperty and the pageLoadedProperty by using the fluent API. As they evaluate, the printActionProperty will be true if both the printLoadedProperty and the printLoadedProperty are true values.

// print button pressed, page loaded
final BooleanProperty printButtonClickedProperty = new SimpleBooleanProperty(false);
final BooleanProperty pageLoadedProperty = new SimpleBooleanProperty(false);

// when the a page is loaded and the button was pressed call the print() method.
final BooleanProperty printActionProperty = new SimpleBooleanProperty(false);
printActionProperty.bind(pageLoadedProperty.and(printButtonClickedProperty));

Continuing the wiring up of the UI, I took an event driven approach where the handler code will respond to events and property changes. Starting with the WebView node, I attached handler code to the statePropery instance (ChangeListener) in order that the pageLoadedProperty will be set to true once the web page is loaded successfully.

  // WebEngine updates flag when finished loading web page.
  webEngine.getLoadWorker()
           .stateProperty()
           .addListener( (ChangeListener) (obsValue, oldState, newState) -> {
               if (newState == State.SUCCEEDED) {
                    pageLoadedProperty.set(true);
               }
           });

Next, you will see the text field’s ‘setOnAction‘ method containing handler code that resets the pageLoadedProperty and printButtonClickedProperty objects. Also, the code will initiate the loading of the page via the WebView‘s WebEngine load() method.


  // When user enters a url and hits the enter key.
  urlTextField.setOnAction( aEvent ->  {
     pageLoadedProperty.set(false);
     printButtonClickedProperty.set(false);
     webEngine.load(urlTextField.getText());
  });

After the TextField control’s action code is wired up, the print button will also need handler code to set the printButtonClickedProperty flag to true. Lastly, the printActionProperty property will need a ChangeListener to respond when its state evaluates to true. When this evaluates to true, my print() method is invoked.

        // When the user clicks the print button the webview node is printed
        printButton.setOnAction( aEvent -> {
            printButtonClickedProperty.set(true);
        });

        // Once the print action hears a true go print the WebView node.
        printActionProperty.addListener( (ChangeListener) (obsValue, oldState, newState) -> {
            if (newState) {
                print(webPage);
            }
        });

Finally, the print() method takes a JavaFX Node object to be printed. The Printer object has a method which returns the default printer your computer is set to. Before actually printing, we can derive a default page layout to scale the node before printing the node. If you don’t do this, only part of the web page will be printed. With the default printer obtained, the createPrinterJob() method is invoked to return a PrinterJob instance that does the actual printing. To print a JavaFX displayable type node, you simply invoke the PrinterJob object’s printPage() method by passing in the Node instance as a parameter.

    /** Scales the node based on the standard letter, portrait paper to be printed.
     * @param node The scene node to be printed.
     */
    public void print(final Node node) {
        Printer printer = Printer.getDefaultPrinter();
        PageLayout pageLayout = printer.createPageLayout(Paper.NA_LETTER, PageOrientation.PORTRAIT, Printer.MarginType.DEFAULT);
        double scaleX = pageLayout.getPrintableWidth() / node.getBoundsInParent().getWidth();
        double scaleY = pageLayout.getPrintableHeight() / node.getBoundsInParent().getHeight();
        node.getTransforms().add(new Scale(scaleX, scaleY));

        PrinterJob job = PrinterJob.createPrinterJob();
        if (job != null) {
            boolean success = job.printPage(node);
            if (success) {
                job.endJob();
            }
        }
    }

In conclusion, I find that the APIs are simpler to use compared to Java Swing/AWT APIs. I would like to mention that there are many features you can play around with since this blog entry only scratches the surface on the APIs currently available.

NOTE: JavaFX 8 printer API is still in the early stages and there are still outstanding issues (Jira issues).

Please visit to vote and help test functionality at https://javafx-jira.kenai.com

Outstanding Tickets: http://bit.ly/1dw7Vc8

A Case Study: A JavaFX Widget Framework API

A prototype of a widget container

A prototype of a widget container

Building a better mousetrap

In short I want to revisit the idea of a cross platform widget framework using JavaFX. In this article I’d like to share some ideas, concepts and prototypes that might invigorate this old but ingenious idea for the desktop and embedded world. An old idea you say? Does anyone remember WidgetFX?

In the early days of JavaFX there were a few Java Champions and community members who decided to create a cross platform JavaFX 1.x widget framework for the desktop (year 2008). I was fortunate enough to know many of those contributors involved.  I grew to love the capabilities the framework and widgets were able to provide.  However, as we all know JavaFX is now redone as Java APIs as opposed to the JavaFX script language. This eventually became apparent regarding to the future of most frameworks back then. Before I begin I would like to give credit to the folks who contributed to the WidgetFX framework project.  I want to thank them for their enthusiasm and their tireless efforts on building the community to what it is today. To see some of their cool widgets please visit the site http://widgetfx.org (catch them before they’re gone). Two of the original founders of the project are Stephen Chin and Keith Combs. Even though I did not partake in the fun during the height of the project I was quite inspired.

Inception phase

To fast forward just last year at the JavaOne 2012 conference I was able to catch up with Keith Combs (Silicon Valley JavaFX User Group organizer) and Stephen Chin (Java Technology Evangelist at Oracle) after his keynote speaking to inquire about the WidgetFX project now that JavaFX 1.x is no more. Steve kindly asked if anyone would be interested in giving it a reboot on the JavaFX 2.x platform (As he peered over towards Keith and me). I believe I said, “I don’t think, so… “. I thought it might be too much to bite off than I could possibly chew. So I politely declined the offer. During the conference I was later enamored by all things Java embedded which later fueled to some of my home automation project ideas using JavaFX with (Arduino, Raspberry Pi, and Beagle Board).

After returning home I was not only excited about the things I’ve learned at the conference but, I also was in the middle of transitioning to a new job and company. Working as a UI and Visualization developer for cloud based monitoring software I often encountered stakeholders/SMEs mentioning the term “SPOG” or single pane of glass.

What does the term “SPOG” mean?

According to Floyd Strimling a cloud technical evangelist at Zenoss explains how so many organizations will create desperate (silos) systems and he goes on to say, “The Holy Grail is a single pane of glass that provides IT managers with a single access point to make sense of their entire underlying infrastructure in real time”. (Searching for the Mythical Single Pane of Glass)

Isn’t “SPOG” an interesting concept for large operation centers? So, I continued to rethink of the old idea of a flexible widget framework that would provide richer interfaces that would allow better desktop integration, decoupled services, higher performance, and capable of empowering users with many of the modern UI metaphors that they’d expect on their favorite OS platform. I believe such a framework should also work on embedded devices for home automation.  Actually I got the idea of a widget framework for embedded devices from my good friend Gerrit Grunwald (Java Champion and author of the popular Steel Series API) while exchanging ideas about graphics performance and launching JavaFX applications on embedded devices.

Wow, with so many different problem domains and so many perspectives could such a widget framework truly exist? Could such a widget framework be able to make everyone happy? Is it possible to create a simple widget framework to rule them all? I believe it is possible.

eWidgetFX is born

In the back of my mind I noticed similar use cases with many customers wanting widget frameworks having this concept of a “SPOG”, but also provide a framework that I could use myself on my own desktop or touch device. So, I kept going back and forth on the possibility of rebooting the old project WidgetFX. Instead I wanted to throw a monkey wrench into the whole business of widget frameworks. Since there are so many kinds of ways to launch, display, and manage widgets it would also be a good idea to build a single widget framework SPI (service provider interface API) which would enable developers to build their own widget containers thus allowing widget developers to run their widgets in any widget container. There would basically be two developer perspectives: Container Developers and Widget Developers. So, I’d like to propose a new API called eWidgetFX (core) that would allow the developers to create widget containers and widgets.

For now I will defer the work of designing the core APIs and make it a future post. So, in this article I’ve decided to generate some prototypes of widget containers that would basically depend on the future eWidgetFX framework API.

Prototyping Widget Containers

Prototyping is probably the most fun part during any software development activity. Shown below are videos I recently uploaded to Youtube.com to kick some ideas around for different kinds of widget containers (Icon App tray) on a desktop environment.

Conclusion

One of the main issue I found in UI development is that customers will often know what they want, but aren’t able to communicate what they ultimately want. It’s almost like playing a game of Charades or a game of Pictionary where guessing is a sought after skill in software design.  We are often faced with providing prototypes and end up settling on one particular view (one view, one way, one silo). The problem became pretty apparent where everyone had an opinion or philosophical stance on a particular GUI interface, usability aspect or UI metaphor. Sometimes it’s based on subjective personal preferences that can go into long discussions. No one person in the room was completely happy, but at the end of the day we compromised and we settled.

I believe that by creating a widget API it would allow organizations to build different single pane of glass instances (widget containers) and capable of sharing all widgets across other panes.

So, imagine seeing different types of widget containers in the wild. Some future widget containers could look like interfaces similar to the following movies: Avengers, Tron, or Minority Report

A final note: Many of of the ideas expressed and proposed are a collective effort from some of my friends (team members) of the JFXtras.org project (Mark Heckler, Hendrik Ebbers, and Gerrit Grunwald).

Would you like to see a talk regarding widget frameworks at JavaOne?

As always comments are welcome.

Carl 😉

Resources

JavaFX: http://www.oracle.com/technetwork/java/javafx/overview/index.html
Java Champions: https://java.net/website/java-champions/bios.html
WidgetFX: http://widgetfx.org
Keith Combs from the Silicon Valley JavaFX user group: http://www.svjugfx.org/member/10394895/?op=&memberId=10394895
Steve on Java by Stephen Chin: http://steveonjava.com
Arduino : http://www.arduino.cc
Raspberry Pi: http://www.raspberrypi.org
Beagle Board: http://beagleboard.org
Guest Post: Searching for the Mythical Single Pane of Glass: http://siliconangle.com/blog/2012/02/29/guest-post-searching-for-the-mythical-single-pane-of-glass
Anti-patterns: http://en.wikibooks.org/wiki/Introduction_to_Software_Engineering/Architecture/Anti-Patterns
Google Images of Operation centers: http://bit.ly/106p3h0
Avengers UI design: http://cargocollective.com/jayse/Avengers
Tron UI design: http://dlew.me/Tron-Legacy-Boardroom
Minority Report UI designer demos his tech at TED (video): http://www.engadget.com/2010/06/03/minority-report-ui-designer-demos-his-tech-at-ted
The Java Jungle by Mark Heckler: https://blogs.oracle.com/javajungle/entry/welcome_to_the_jungle
Gui Garage by Hendrik Ebbers: http://www.guigarage.com
Harmonic Code by Gerrit Grunwald: http://harmoniccode.blogspot.de
JFXtras.org : http://jfxtras.orgLeap Motion: https://www.leapmotion.comLeap Motion: https://www.leapmotion.com