Resize a shape : Shape « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. Shape

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Rectangle2D;

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

public class ResizeRectangle extends JPanel {
  private int SIZE = 8;
  private Rectangle2D[] points = { new Rectangle2D.Double(50, 50,SIZE, SIZE), new Rectangle2D.Double(150, 100,SIZE, SIZE) };
  Rectangle2D s = new Rectangle2D.Double();

  ShapeResizeHandler ada = new ShapeResizeHandler();

  public ResizeRectangle() {
    addMouseListener(ada);
    addMouseMotionListener(ada);
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);

    Graphics2D g2 = (Graphics2D) g;

    for (int i = 0; i < points.length; i++) {
      g2.fill(points[i]);
    }
    s.setRect(points[0].getCenterX(), points[0].getCenterY(),
        Math.abs(points[1].getCenterX()-points[0].getCenterX()),
        Math.abs(points[1].getCenterY()- points[0].getCenterY()));

    g2.draw(s);
  }

  class ShapeResizeHandler extends MouseAdapter {
    Rectangle2D r = new Rectangle2D.Double(0,0,SIZE,SIZE);
    private int pos = -1;
    public void mousePressed(MouseEvent event) {
      Point p = event.getPoint();

      for (int i = 0; i < points.length; i++) {
        if (points[i].contains(p)) {
          pos = i;
          return;
        }
      }
    }

    public void mouseReleased(MouseEvent event) {
      pos = -1;
    }

    public void mouseDragged(MouseEvent event) {
      if (pos == -1)
        return;

      points[pos].setRect(event.getPoint().x,event.getPoint().y,points[pos].getWidth(),
          points[pos].getHeight());
      repaint();
    }
  }

  public static void main(String[] args) {

    JFrame frame = new JFrame("Resize Rectangle");

    frame.add(new ResizeRectangle());
    frame.setSize(300, 300);
    frame.setLocationRelativeTo(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
}

16.17.Shape
	16.17.1.	Creating Basic Shapes
	16.17.2.	Creating a Shape Using Lines and Curves
	16.17.3.	Combining Shapes
	16.17.4.	Scaling a Shape
	16.17.5.	Shearing a Shape
	16.17.6.	Translating a Shape
	16.17.7.	Rotating a Shape
	16.17.8.	Add Round Rectangle, Ellipse Arc to a shape
	16.17.9.	GlyphVector.getNumGlyphs()
	16.17.10.	Resize a shape
	16.17.11.	Creates a diagonal cross shape.
	16.17.12.	Creates a diamond shape.
	16.17.13.	Creates a triangle shape that points downwards.
	16.17.14.	Creates a triangle shape that points upwards.
	16.17.15.	Draws a shape with the specified rotation about (x, y).
	16.17.16.	Creates and returns a translated shape.