Trammel Archimedes di JavaFX

Berikut ini saya berikan contoh animasi javaFX yakni dalam membuat trammel Archimedes.



Adapun source code nya adalah

package fjr.ellipse;

import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.util.Duration;


// @author moh_fajar 
// @date: 31-1-2014

public class EllipseExp extends Application {

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

 Timeline animation;
 GraphicsContext gc; 
 Canvas canvas; 
 Trammel tr ;
 
 double angle; 

 double canvasWidth = 450 , canvasHeight = 350 ; 
 @Override
 public void start(Stage primaryStage) throws Exception {
  Group root = new Group();
  Group child = new Group(); 
  primaryStage.setScene(new Scene(root,500, 500));
  angle = 45; 
  tr = new Trammel(200, 150 , 100, 60, angle);
  canvas = new Canvas(canvasWidth, canvasHeight); 
  gc = canvas.getGraphicsContext2D(); 
  root.getChildren().add(child); 
  child.getChildren().addAll(canvas);
  animation = new Timeline();
  animation.getKeyFrames().addAll(
    new KeyFrame(Duration.millis(10),
      new EventHandler() {
       @Override
       public void handle(ActionEvent arg0) {
        angle-= Math.PI/200 ; 
        tr.setAngle(angle);
        tr.calculatePosition();
        draw(gc);
       }
      }));

  primaryStage.show();
  
  animation.setCycleCount(Timeline.INDEFINITE);
  animation.setAutoReverse(false);
  animation.play(); 
 }
 
 void draw(GraphicsContext gc){
  gc.setFill(Color.WHITE);
  gc.fillRect(0, 0, canvasWidth, canvasHeight);
  gc.setStroke(Color.BLACK);
  gc.strokeRect(0, 0, canvasWidth, canvasHeight);
  gc.setFill(Color.RED);
  gc.fillRect(tr.x, tr.y, 5, 5);
  gc.setFill(Color.BLUE);
  gc.fillRect(tr.x1, tr.y1, 5, 5);
  
  gc.setFill(Color.GREENYELLOW);
  gc.fillRect(tr.x2, tr.y2, 5, 5);
  
  gc.setStroke(Color.RED);
  gc.strokeLine(tr.x, tr.y, tr.x2, tr.y2);
  
  
  gc.setStroke(Color.BLACK);
  gc.strokeLine(tr.x2, tr.y1 - 110 , tr.x2, tr.y1 + 110);
  gc.strokeLine(tr.x2- 200, tr.y1  , tr.x2 + 200, tr.y1 );
  
  gc.setStroke(Color.BLACK);
  gc.strokeOval(tr.getXCorrection() -   tr.getA(), tr.getYCorrection() -  
      tr.getB(), 2 * tr.getA() , 2 * tr.getB());
 }

 class Trammel {

  double angle;
  double p, q;

  public double x, y; // posisi dari rod
  public double x1, y1 ; // posisi dari pivot 1 
  public double x2, y2 ; // posisi dari pivot 2

  
  double xCorrection; 
  double yCorrection; 
  /*
   * Dalam Trammel Archimedes, terdapat dua titik pivot yakni A dan B.
   * Sementara yang men-trace elipse adalah titik C pada ujung trammel.
   * Jarak A ke B adalah p, sementara jarak B ke C adalah q, dengan
   * demikian lintasan titik C ditentukan oleh x = (p + q) cos \theta y =
   * q sin theta.  lihat: http://en.wikipedia.org/wiki/Trammel_of_Archimedes
   */

  public Trammel(double x, double y, double p, double q, double angle) {
   this.xCorrection = x; 
   this.yCorrection = y; 
   
   this.p = p;
   this.q = q;
   this.angle = angle; 
  }

  
  public void setAngle(double angle) {
   this.angle = angle;
  }

  public void calculatePosition() {
   x = xCorrection+  (p + q) * Math.cos(angle);
   y = yCorrection + (q) * Math.sin(angle);
   
   x1 = x - q * Math.cos(angle); 
   y1 = y -  q * Math.sin(angle);
   
   x2 = x1 -   p * Math.cos(angle); 
   y2 = y1 -   p * Math.sin(angle); 
  }
  
  public double getA(){return (p+q);}
  public double getB(){return q ;}
  public double getXCorrection() {return xCorrection;}
  public double getYCorrection() {return yCorrection; }
 }

}

Mengganti access modifier (tipe variabel: private, protected, final menjadi public) di Java

Berikut ini saya berikan contoh kegunaan Reflection di java. Yakni untuk mengganti tipe access modifier. Misalnya kita mempunyai kelas yang field-nya dibuat private, maka kita dapat menggunakan reflection untuk membuatnya jadi public. Perhatikan contoh berikut

Kita dapat merubah nilai field name yang private sekaligus final dalam kelas tersebut dengan bantuan reflection di Java. Perhatikan contoh berikut

Hasil eksekusinya adalah:

Menggunakan generic untuk conversi list di Java

Salah satu dari kegunaan generic di java adalah untuk mengkonversi list objek tipe tertentu menjadi list objek tipe turunannya.  Jika kita ingin mengkonversi list yang berisi objek tipe A menjadi list objek tipe B (yang mengekstends A), itu tidak bisa dilakukan secara langsung, seperti contoh berikut

Pada contoh di atas method convert tersebut tidak bisa dituliskan seperti itu, walaupun kelas B mengekstends kelas A. Yang harus dilakukan adalah dengan menggunakan generic seperti potongan berikut

Dan itupun hanya berlaku jika kelas B mengekstends kelas A. Jika tidak akan terjadi error misalnya:

Yang akan menghasilkan output

Menyimpan gambar di canvas ke file di javaFX

Berikut ini saya berikan contoh bagaimana menyimpan hasil penggambaran free-form kita dalam javaFx canvas ke dalam file.

package fjr.test.testIO;
   import java.io.File;

import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.*;
import javafx.scene.image.*;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.HBox;
import javafx.stage.*;

import javax.imageio.ImageIO;

import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.control.Button;
import javafx.scene.paint.Color;


public class PrintCanvas extends Application {

 GraphicsContext gc; 
 Canvas canvas; 
 double canvaswidth  = 300 , canvasheight = 350 ; 
 
    @Override
    public void start(Stage primaryStage) {
        Group root = new Group();
        Scene scene = new Scene(root, 400, 450);
        canvas = new Canvas(canvaswidth, canvasheight);
        canvas.setTranslateX(10);
        canvas.setTranslateY(50);
        gc = canvas.getGraphicsContext2D();
        gc.setLineWidth(23);
        gc.setFill(Color.GREEN);
        gc.setStroke(Color.BLUE);
        gc.setLineWidth(6);
        
        gc.strokeRect(0, 0, canvaswidth, canvasheight);
                
        gc.setStroke(Color.BLACK);
        
        final WritableImage wim = new WritableImage((int)canvaswidth, (int)canvasheight);
        root.getChildren().add(canvas); 
        primaryStage.setScene(scene);
        primaryStage.show();
        
        final  Button simpan = new Button();
        simpan.setTranslateX(10);
        simpan.setTranslateY(10);
        simpan.setPrefSize(100, 30);
        simpan.setText("SIMPAN");
  simpan.setOnAction(new EventHandler() {
   @Override
   public void handle(ActionEvent arg0) {
    canvas.snapshot(null, wim);
    File file = new File("E:/CanvasImage.png");
    try {
     ImageIO.write(SwingFXUtils.fromFXImage(wim, null), "png",
       file);
     System.out.println("File sudah disimpan"); 
    } catch (Exception s) {
    }
   }
  });

  root.getChildren().add(new HBox(){{
   getChildren().add(simpan);
  }}); 
  

  canvas.addEventHandler(MouseEvent.MOUSE_DRAGGED, new EventHandler() {
            @Override
            public void handle(MouseEvent e) {
             gc.lineTo(e.getX(), e.getY());
             gc.stroke(); 
            }
        });
  
  canvas.addEventHandler(MouseEvent.MOUSE_PRESSED, new EventHandler() {
            @Override
            public void handle(MouseEvent e) {
             gc.beginPath();
             gc.moveTo(e.getX(), e.getY());
             gc.stroke();
            }
        });

    }

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

}

Hasilnya adalah

Cara menggabungkan javaFX dengan java Swing

Tanpa perlu berbasa-basi berikut saya berikan contoh menggabungkan teknologi javaFX dengan java Swing. Berdasarkan informasi yang saya peroleh javaFX mungkin kedepannya dipake untuk menggantikan Swing.

package fjr.test.javafxpanel;

import java.awt.Dimension;

import javafx.animation.Animation;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.util.Duration;

import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class TestJavaFXPanel {

 private XYChart.Series hourDataSeries;
    private XYChart.Series minuteDataSeries;
    private NumberAxis xAxis;
    private Timeline animation;

    private double hours = 0;
    private double minutes = 0;
    private double timeInHours = 0;
    private double prevY = 10;
    private double y = 10;
    
 public TestJavaFXPanel() {
  initAndShowGUI();
 }

 private void initAndShowGUI() {
  JFrame frame = new JFrame("Test Swing");
  frame.setPreferredSize(new Dimension(600, 400));
  frame.pack();
  final JFXPanel fxPanel = new JFXPanel();
  frame.add(fxPanel);
  frame.setVisible(true);

  Platform.runLater(new Runnable() {
   @Override
   public void run() {
    initFX(fxPanel);
   }
  });
 }

 private void initFX(JFXPanel fxPanel) {
  Scene scene = createScene();
  fxPanel.setScene(scene);
  
   animation = new Timeline();
         animation.getKeyFrames().add(new KeyFrame(Duration.millis(1000/60), new EventHandler() {
             @Override public void handle(ActionEvent actionEvent) {
                 for(int count=0; count < 6; count++) {
                     nextTime();
                     plotTime();
                 }
             }
         }));

         animation.setCycleCount(Animation.INDEFINITE);
 }

 private Scene createScene() {
  StackPane root = new StackPane(){{
   setTranslateX(0);
   setTranslateY(0);
  }};
  
  Button button = new Button("PLAY"){{
   setMinSize(100, 30);
   setOnAction(new EventHandler() {
    
    @Override
    public void handle(ActionEvent arg0) {
      play();
    }
   });
  }};
  
  
  Button button2 = new Button("STOP"){{
   setMinSize(100, 30);
   setOnAction(new EventHandler() {
    
    @Override
    public void handle(ActionEvent arg0) {
     // TODO Auto-generated method stub
      stop();
    }
   } );
  }};
  
  HBox box = new HBox(){{
   setSpacing(10);
   setTranslateX(10);
   setTranslateY(10);
  }}; 
  
  box.getChildren().addAll(button, button2);
  
  root.getChildren().addAll( new BorderPane(){{
   setLeft(createChart());
  }} , box); 
  
  Scene sc = new Scene(root);
  return sc;
 }

 public static void main(String[] args) {
  SwingUtilities.invokeLater(new Runnable() {
   @Override
   public void run() {
    new TestJavaFXPanel();
   }
  });
 }
    protected LineChart createChart() {
         xAxis = new NumberAxis(0,24,3);
         final NumberAxis yAxis = new NumberAxis(0,100,10);
         final LineChart lc = new LineChart(xAxis,yAxis);
         lc.setCreateSymbols(false);
         lc.setAnimated(false);
         lc.setLegendVisible(false);
         lc.setTitle("PLOT GRAFIK");
         xAxis.setForceZeroInRange(false);
         yAxis.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis,"$",null));
         hourDataSeries = new XYChart.Series();
         minuteDataSeries = new XYChart.Series();
         hourDataSeries.getData().add(new XYChart.Data(timeInHours,prevY));
         minuteDataSeries.getData().add(new XYChart.Data(timeInHours,prevY));
         for (double m=0; m<(60); m++) {
             nextTime();
             plotTime();
         }
         lc.getData().add(minuteDataSeries);
         lc.getData().add(hourDataSeries);
         
         lc.setTranslateX(10);
         lc.setTranslateY(40);
         lc.setMaxWidth(400);
         lc.setMaxHeight(330);
         return lc;
     }

     private void nextTime() {
         if (minutes == 59) {
             hours ++;
             minutes = 0;
         } else {
             minutes ++;
         }
         timeInHours = hours + ((1d/60d)*minutes);
     }
     private void plotTime() {
         if ((timeInHours % 1) == 0) {
             double oldY = y;
             y = prevY - 10 + (Math.random()*20);
             prevY = oldY;
             while (y < 10 || y > 90) y = y - 10 + (Math.random()*20);
             hourDataSeries.getData().add(new XYChart.Data(timeInHours, prevY));
             if (timeInHours > 25) hourDataSeries.getData().remove(0);
             if (timeInHours > 24) {
                 xAxis.setLowerBound(xAxis.getLowerBound()+1);
                 xAxis.setUpperBound(xAxis.getUpperBound()+1);
             }
         }
         double min = (timeInHours % 1);
         double randomPickVariance = Math.random();
         if (randomPickVariance < 0.3) {
             double minY = prevY + ((y-prevY) * min) - 4 + (Math.random()*8);
             minuteDataSeries.getData().add(new XYChart.Data(timeInHours,minY));
         } else if (randomPickVariance < 0.7) {
             double minY = prevY + ((y-prevY) * min) - 6 + (Math.random()*12);
             minuteDataSeries.getData().add(new XYChart.Data(timeInHours,minY));
         } else if (randomPickVariance < 0.95) {
             double minY = prevY + ((y-prevY) * min) - 10 + (Math.random()*20);
             minuteDataSeries.getData().add(new XYChart.Data(timeInHours,minY));
         } else {
             double minY = prevY + ((y-prevY) * min) - 15 + (Math.random()*30);
             minuteDataSeries.getData().add(new XYChart.Data(timeInHours,minY));
         }
         if (timeInHours > 25) minuteDataSeries.getData().remove(0);
     }
    public void play() {
         animation.play();

     }
    
      public void stop() {
         animation.pause();
     }    

  
}

Potongan hasil eksekusinya adalah sebagai berikut

Menggunakan radio button dengan benar di JavaFX

Berikut ini adalah contoh source cara menggunakan radio button yang benar di JavaFX:

package fjr.test.toggle;

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.RadioButton;
import javafx.scene.control.Toggle;
import javafx.scene.control.ToggleGroup;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class TestToggleA extends Application {
 
 static enum Cuaca{
  CERAH , BERAWAN
 }

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

 ToggleGroup groupToggle ; 
 
 RadioButton radio1 , radio2 ; 

 @Override
 public void start(Stage stage) throws Exception {
  Group root = new Group(); 
  
  groupToggle = new ToggleGroup(); 

  HBox box = new HBox(){{
   setTranslateX(30);
   setTranslateY(30);
   setSpacing(10);
   
   getChildren().addAll(
     radio1 = new RadioButton("BERSINAR"){{
      setToggleGroup(groupToggle);
      setUserData(Cuaca.CERAH);
     }}, 
     
     radio2 = new RadioButton("GELAP"){{
      setToggleGroup(groupToggle);
      setUserData(Cuaca.BERAWAN);
     }}); 
  }}; 
  
  
  switch(cuaca_now){
  case CERAH:
   radio1.setSelected(true);
   break; 
  case BERAWAN:
   radio2.setSelected(true);
   break; 
  }
  
  root.getChildren().add(box); 
  stage.setScene(new Scene(root, 200,200));
  stage.show(); 
  
  
  System.out.println("Type cuaca saat inisialisasi: "+ cuaca_now); 
  
  groupToggle.selectedToggleProperty().addListener(new ChangeListener() {
   @Override
   public void changed(ObservableValue arg0,
     Toggle arg1, Toggle toggle) {
    // TODO Auto-generated method stub
    RadioButton radio = (RadioButton) toggle; 
    Cuaca c = (Cuaca) radio.getUserData(); 
    cuaca_now = c; 
    System.out.println("Type cuaca saat pergantian button: "+cuaca_now);
   }
  });
  
 }
}