I Hate JavaFX; I Love JavaFX!

I’ve posted a few places and gotten into more than a few rants publicly about how awful I think it is that Sun has been pushing JavaFX to the Java community. This has not been based on what JavaFX provides, because I think that’s absolutely spectacular, but rather that they created a whole new language (JavaFX Script) that they force you into using rather than Java code itself. I’ve heard all the well reasoned arguments for why this is from the binding support to simplified UI design concepts, but as a professional ActionScript developer as well as a professional Java developer, I believe that using a language that stinks of ActionScript is a major step backwards for the Java community. However, like I said, JavaFX has done an absolutely wonderful job of adding to the UI power of the Java arsenal though, and I want to use it. Since I know that the JavaFX Script compiles into Java byte-code, I knew there had to be some level of access to the underlying API structure directly from Java, but nobody seems to know how or where to do it. After quite a bit of digging I stumbled upon these two pages:

http://blogs.sun.com/javafx/entry/how_to_use_javafx_in

http://forums.sun.com/thread.jspa?threadID=5354921&tstart=1

They looked pretty ugly to me, but put me on the track to actually using JavaFX directly in Java without scripting. I sort of combined those two together to come up with what I think is a little bit more concise example:

package test;

import java.awt.BorderLayout;

import javax.swing.JFrame;
import javax.swing.JPanel;

import com.sun.scenario.scenegraph.JSGPanel;
import com.sun.scenario.scenegraph.SGNode;

import javafx.scene.Group;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Text;

public class TestJFX {
 public static void main(String[] args) throws Exception {
  Group group = new Group(); {
  }
  Rectangle rect = new Rectangle(); {
   rect.$width.setAsFloat(200.0f);
   rect.$height.setAsFloat(200.0f);
   rect.$fill.set(Color.$BLUE);
  }
  Text text = new Text(); {
   text.$x.setAsFloat(20.0f);
   text.$y.setAsFloat(20.0f);
   text.$content.set("Greetings Earthling!");
   text.$fill.set(Color.$WHITE);
  }
  group.$content.insert(rect);
  group.$content.insert(text);
  SGNode node = group.getSGGroup();
  JSGPanel sgPanel = new JSGPanel();
  sgPanel.setScene(node);
  
  JPanel panel = new JPanel();
  panel.setLayout(new BorderLayout());
  panel.add(sgPanel, BorderLayout.CENTER);
  
  JFrame frame = new JFrame("Test JavaFX");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.add(panel);
  frame.setSize(800, 600);
  frame.setVisible(true);
 }
}

This isn’t the prettiest or most efficient way to code, but it’s a start. Next I decided that I’d like to reproduce the Clock example that JavaFX shows here:

http://java.sun.com/javafx/1/tutorials/build-javafx-nb-app/

This gave me a much more practical run through JavaFX from the programmatic perspective and allowed me to verify that it is in fact possible to write a complete application using Java making calls to JavaFX:

package test;

import java.awt.BorderLayout;
import java.io.IOException;
import java.util.Calendar;

import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

import com.sun.javafx.functions.Function0;
import com.sun.javafx.runtime.location.FloatBindingExpression;
import com.sun.javafx.runtime.location.FloatVariable;
import com.sun.scenario.scenegraph.JSGPanel;
import com.sun.scenario.scenegraph.SGNode;

import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.lang.Duration;
import javafx.scene.Group;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.paint.Color;
import javafx.scene.shape.ArcTo;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Path;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.Translate;

/**
 * @author Matt Hicks ([email protected])
 */
public class Clock {
 private float radius;
 private float centerX;
 private float centerY;
 
 private Calendar calendar;
 private int hours;
 private int minutes;
 private int seconds;
 
 private FloatVariable hoursVariable;
 private FloatVariable minutesVariable;
 private FloatVariable secondsVariable;
 
 public Clock() throws IOException {
  // Initial setup
  calendar = Calendar.getInstance();
  radius = 77;
  centerX = 144;
  centerY = 144;
  
  nextTick();
  
  // Build JavaFX clock
  Group group = new Group(); {
   ImageView imageView = new ImageView(); {
    Image image = new Image(); {
     image.$bufferedImage.set(ImageIO.read(getClass().getClassLoader().getResource("resource/clock_background.png")));
    }
    imageView.$image.set(image);
    
    group.$content.insert(imageView);
   }
   
   Group face = new Group(); {
    Translate translate = new Translate(); {
     translate.$x.setAsFloat(centerX);
     translate.$y.setAsFloat(centerY);
    }
    face.$transforms.insert(translate);
    
    // Every third hour
    for (int i = 3; i <= 12; i += 3) {
     Text text = new Text(); {
      translate = new Translate(); {
       translate.$x.setAsFloat(-5.0f);
       translate.$y.setAsFloat(5.0f);
      }
      text.$transforms.insert(translate);
      
      text.$font.set(Font.font("Arial", 16));
      
      text.$x.setAsFloat(radius * ((i + 0) % 2 * (2 - i / 3)));
      text.$y.setAsFloat(radius * ((i + 1) % 2 * (3 - i / 3)));
      text.$content.set(String.valueOf(i));
     }
     face.$content.insert(text);
    }
    
    // Black circle for the rest of the hours
    for (int i = 1; i < 12; i++) {
     if (i % 3 == 0) {
      continue; // Don't show a circle on every third hour
     }
     
     Circle circle = new Circle(); {
      Rotate rotate = new Rotate(); {
       rotate.$angle.setAsFloat(30.0f * i);
      }
      circle.$transforms.insert(rotate);
      circle.$centerX.setAsFloat(radius);
      circle.$radius.setAsFloat(3.0f);
      circle.$fill.set(Color.$BLACK);
     }
     face.$content.insert(circle);
    }
    
    // Center circles
    Circle circle = new Circle(); {
     circle.$radius.setAsFloat(5.0f);
     circle.$fill.set(Color.$DARKRED);
    }
    face.$content.insert(circle);
    circle = new Circle(); {
     circle.$radius.setAsFloat(3.0f);
     circle.$fill.set(Color.$RED);
    }
    face.$content.insert(circle);
    
    // Second hand
    Line line = new Line(); {
     Rotate rotate = new Rotate(); {
      FloatBindingExpression exp = new FloatBindingExpression() {
       public float computeValue() {
        return seconds * 6;
       }
      };
      secondsVariable = FloatVariable.make(exp);
      rotate.$angle.bind(false, secondsVariable);
     }
     line.$transforms.insert(rotate);
     
     line.$endY.setAsFloat(-radius - 3.0f);
     line.$strokeWidth.setAsFloat(2.0f);
     line.$stroke.set(Color.$RED);
    }
    face.$content.insert(line);
    
    // Hour hand
    Path path = new Path(); {
     Rotate rotate = new Rotate(); {
      FloatBindingExpression exp = new FloatBindingExpression() {
       public float computeValue() {
        return (hours + minutes / 60) * 30 - 90;
       }
      };
      hoursVariable = FloatVariable.make(exp);
      rotate.$angle.bind(false, hoursVariable);
     }
     path.$transforms.insert(rotate);
     
     path.$fill.set(Color.$BLACK);
     
     MoveTo e1 = new MoveTo(); {
      e1.$x.setAsFloat(4.0f);
      e1.$y.setAsFloat(4.0f);
     }
     path.$elements.insert(e1);
     ArcTo e2 = new ArcTo(); {
      e2.$x.setAsFloat(4.0f);
      e2.$y.setAsFloat(-4.0f);
      e2.$radiusX.setAsFloat(1.0f);
      e2.$radiusY.setAsFloat(1.0f);
     }
     path.$elements.insert(e2);
     LineTo e3 = new LineTo(); {
      e3.$x.setAsFloat(radius - 15.0f);
      e3.$y.setAsFloat(0.0f);
     }
     path.$elements.insert(e3);
    }
    face.$content.insert(path);
    
    // Minute hand
    path = new Path(); {
     Rotate rotate = new Rotate(); {
      FloatBindingExpression exp = new FloatBindingExpression() {
       public float computeValue() {
        return minutes * 6 - 90;
       }
      };
      minutesVariable = FloatVariable.make(exp);
      rotate.$angle.bind(false, minutesVariable);
     }
     path.$transforms.insert(rotate);
     
     path.$fill.set(Color.$BLACK);
     
     MoveTo e1 = new MoveTo(); {
      e1.$x.setAsFloat(4.0f);
      e1.$y.setAsFloat(4.0f);
     }
     path.$elements.insert(e1);
     ArcTo e2 = new ArcTo(); {
      e2.$x.setAsFloat(4.0f);
      e2.$y.setAsFloat(-4.0f);
      e2.$radiusX.setAsFloat(1.0f);
      e2.$radiusY.setAsFloat(1.0f);
     }
     path.$elements.insert(e2);
     LineTo e3 = new LineTo(); {
      e3.$x.setAsFloat(radius);
      e3.$y.setAsFloat(0.0f);
     }
     path.$elements.insert(e3);
    }
    face.$content.insert(path);
    
    group.$content.insert(face);
   }
  }
  
  Timeline timeline = new Timeline(); {
   timeline.$repeatCount.setAsFloat(Timeline.$INDEFINITE);
   
   KeyFrame kf = new KeyFrame(); {
    kf.$time.set(Duration.valueOf(1000.0f));
    kf.$canSkip.set(true);
    kf.$action.set(new Function0() {
     public Void invoke() {
      nextTick();
      return null;
     }
    });
   }
   timeline.$keyFrames.insert(kf);
  }
  
  // Display in Swing
  SGNode node = group.getSGGroup();
  JSGPanel sgPanel = new JSGPanel();
  sgPanel.setScene(node);
  
  JPanel panel = new JPanel();
  panel.setLayout(new BorderLayout());
  panel.add(sgPanel, BorderLayout.CENTER);
  
  JFrame frame = new JFrame("JavaFX Clock Example");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.add(panel);
  frame.setSize(800, 600);
  frame.setVisible(true);
  
  timeline.play();
 }
 
 public void nextTick() {
  calendar.setTimeInMillis(System.currentTimeMillis());
  seconds = calendar.get(Calendar.SECOND);
  minutes = calendar.get(Calendar.MINUTE);
  hours = calendar.get(Calendar.HOUR_OF_DAY);
  
  if (secondsVariable != null) {
   secondsVariable.invalidate();
   minutesVariable.invalidate();
   hoursVariable.invalidate();
  }
 }
 
 public static void main(String[] args) throws Exception {
  new Clock();
 }
}

Now, I did make some slight alterations as the original example uses java.util.Date calls that are deprecated, so I updated to using Calendar instead. Also, I had a little trouble with the binding functionality and had to make calls to invalidate in the nextTick() method. Other than that I stayed quite true to the example and the code works quite nicely.

This is the first step in what I’m ultimately planning as a wrapper around Swing and JavaFX to make more powerful UIs without using a crappy scripting language. 🙂

See this re-output as an Applet:
http://captiveimagination.com/download/clock/clock.html