Select the Ellipse to Move It in the Canvas : Mouse Draw « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. Mouse Draw

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;

public class CircleWithHandles extends JFrame {
  DrawingCanvas canvas = new DrawingCanvas();
  public CircleWithHandles() {
    getContentPane().add(canvas);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    pack();
    setVisible(true);
  }

  public static void main(String arg[]) {
    new CircleWithHandles();
  }

  class DrawingCanvas extends Canvas {
    double x = 20, y = 20, w = 50, h = 50;

    int x1, y1, x2, y2;

    Ellipse2D ellipse;

    Ellipse2D selectedShape;

    Rectangle2D handleRectangle;

    Cursor curCursor;

    public DrawingCanvas() {
      setBackground(Color.white);
      addMouseListener(new MyMouseListener());
      addMouseMotionListener(new MyMouseMotionListener());
      setSize(400, 300); 
    }

    public void paint(Graphics g) {
      Graphics2D g2D = (Graphics2D) g;
      ellipse = new Ellipse2D.Double(x, y, w, h);
      g2D.draw(ellipse);
      if (handleRectangle != null) {
        drawHighlightSquares(g2D, handleRectangle);
      }
      if (curCursor != null)
        setCursor(curCursor);
    }

    public void drawHighlightSquares(Graphics2D g2D, Rectangle2D r) {
      double x = r.getX();
      double y = r.getY();
      double w = r.getWidth();
      double h = r.getHeight();
      g2D.setColor(Color.black);

      g2D.fill(new Rectangle.Double(x - 3.0, y - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x + w * 0.5 - 3.0, y - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x + w - 3.0, y - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x - 3.0, y + h * 0.5 - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x + w - 3.0, y + h * 0.5 - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x - 3.0, y + h - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x + w * 0.5 - 3.0, y + h - 3.0, 6.0, 6.0));
      g2D.fill(new Rectangle.Double(x + w - 3.0, y + h - 3.0, 6.0, 6.0));
    }

    class MyMouseListener extends MouseAdapter {
      public void mousePressed(MouseEvent e) {
        if (ellipse.contains(e.getX(), e.getY())) {
          selectedShape = ellipse;
          if (handleRectangle != null)
            handleRectangle = ellipse.getBounds2D();
        } else {
          handleRectangle = null;
        }
        canvas.repaint();
        x1 = e.getX();
        y1 = e.getY();
      }

      public void mouseReleased(MouseEvent e) {
        if (ellipse.contains(e.getX(), e.getY())) {
          handleRectangle = ellipse.getBounds2D();
          selectedShape = ellipse;
        }
        canvas.repaint();
      }

      public void mouseClicked(MouseEvent e) {
        if (ellipse.contains(e.getX(), e.getY())) {
          selectedShape = ellipse;
          handleRectangle = ellipse.getBounds2D();
        } else {
          if (handleRectangle != null)
            handleRectangle = null;
        }
        canvas.repaint();
      }
    }

    class MyMouseMotionListener extends MouseMotionAdapter {
      public void mouseDragged(MouseEvent e) {
        if (ellipse.contains(e.getX(), e.getY())) {
          handleRectangle = null;
          selectedShape = ellipse;
          x2 = e.getX();
          y2 = e.getY();

          x = x + x2 - x1;
          y = y + y2 - y1;

          x1 = x2;
          y1 = y2;
        }
        canvas.repaint();
      }

      public void mouseMoved(MouseEvent e) {
        if (ellipse != null) {
          if (ellipse.contains(e.getX(), e.getY())) {
            curCursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
          } else {
            curCursor = Cursor.getDefaultCursor();
          }
        }
        canvas.repaint();
      }
    }
  }
}

16.43.Mouse Draw
	16.43.1.	Mouse drag and draw
	16.43.2.	The SimpleDraw application
	16.43.3.	Draws a small dot where the user clicks the mouse
	16.43.4.	Save Your Drawing To a File
	16.43.5.	Select the Ellipse to Move It in the Canvas