Java Tutorial/SWT 2D Graphics/Sine

Plotting the sine function: Use the drawPoint() method to plot points

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.events.PaintEvent; import org.eclipse.swt.events.PaintListener; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Canvas; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class SineFunctionPlotting {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setText("Canvas Example");
   shell.setLayout(new FillLayout());
   Canvas canvas = new Canvas(shell, SWT.NONE);
   canvas.addPaintListener(new PaintListener() {
     public void paintControl(PaintEvent e) {
       Canvas canvas = (Canvas) e.widget;
       int maxX = canvas.getSize().x;
       int maxY = canvas.getSize().y;
       // Calculate the middle
       int halfX = (int) maxX / 2;
       int halfY = (int) maxY / 2;
       // Set the line color and draw a horizontal axis
       e.gc.setForeground(e.display.getSystemColor(SWT.COLOR_BLACK));
       e.gc.drawLine(0, halfY, maxX, halfY);
       // Draw the sine wave
       for (int i = 0; i < maxX; i++) {
         e.gc.drawPoint(i, getNormalizedSine(i, halfY, maxX));
       }
     }
   });
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch()) {
       display.sleep();
     }
   }
   display.dispose();
 }
 static int getNormalizedSine(int x, int halfY, int maxX) {
   double piDouble = 2 * Math.PI;
   double factor = piDouble / maxX;
   return (int) (Math.sin(x * factor) * halfY + halfY);
 }

}</source>