Contents:
SceneEditor.java
import java.awt.*; import java.awt.geom.*; import java.awt.event.*; import javax.swing.*; /** A program that allows users to edit a scene composed of items. */ public class SceneEditor extends JApplet { ScenePanel panel; JPanel buttons; public void make_scene(Container contentPane) { final ScenePanel panel = new ScenePanel(); JButton houseButton = new JButton("House"); houseButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { panel.add(new HouseShape(20, 20, 50)); } }); JButton carButton = new JButton("Car"); carButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { panel.add(new CarShape(20, 20, 50)); } }); JButton removeButton = new JButton("Remove"); removeButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { panel.removeSelected(); } }); buttons = new JPanel(); buttons.add(houseButton); buttons.add(carButton); buttons.add(removeButton); contentPane.add(panel, BorderLayout.CENTER); contentPane.add(buttons, BorderLayout.NORTH); } public void init() { Container contentPane = getContentPane(); make_scene(contentPane); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Container contentPane = frame.getContentPane(); SceneEditor scene = new SceneEditor(); scene.make_scene(contentPane); frame.setSize(300, 300); frame.setVisible(true); } }
ScenePanel.java
import java.awt.*; import java.awt.event.*; import java.awt.geom.*; import javax.swing.*; import java.util.*; /** A panel that shows a scene composed of shapes. */ public class ScenePanel extends JPanel { public ScenePanel() { shapes = new ArrayList<SceneShape>(); addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent event) { mousePoint = event.getPoint(); for (int i = 0; i < shapes.size(); i++) { SceneShape s = (SceneShape) shapes.get(i); if (s.contains(mousePoint)) s.setSelected(!s.isSelected()); } repaint(); } }); addMouseMotionListener(new MouseMotionAdapter() { public void mouseDragged(MouseEvent event) { Point lastMousePoint = mousePoint; mousePoint = event.getPoint(); for (int i = 0; i < shapes.size(); i++) { SceneShape s = (SceneShape) shapes.get(i); if (s.isSelected()) s.translate( mousePoint.getX() - lastMousePoint.getX(), mousePoint.getY() - lastMousePoint.getY()); } repaint(); } }); } /** Adds an shape to the scene. @param s the shape to add */ public void add(SceneShape s) { shapes.add(s); repaint(); } /** Removes all selected shapes from the scene. */ public void removeSelected() { for (int i = shapes.size() - 1; i >= 0; i--) { SceneShape s = (SceneShape) shapes.get(i); if (s.isSelected()) shapes.remove(i); } repaint(); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; for (int i = 0; i < shapes.size(); i++) { SceneShape s = (SceneShape) shapes.get(i); s.draw(g2); if (s.isSelected()) s.drawSelection(g2); } } private ArrayList<SceneShape> shapes; private Point mousePoint; }
SelectableShape.java
import java.awt.*; import java.awt.geom.*; /** A shape that manages its selection state. */ public abstract class SelectableShape implements SceneShape { public void setSelected(boolean b) { selected = b; } public boolean isSelected() { return selected; } public void drawSelection(Graphics2D g2) { translate(1, 1); draw(g2); translate(1, 1); draw(g2); translate(-2, -2); } private boolean selected; }
SceneShape.java
import java.awt.*; import java.awt.geom.*; /** A shape that is a part of a scene. */ public interface SceneShape { /** Draws this item. @param g2 the graphics context */ void draw(Graphics2D g2); /** Draws the selection adornment of this item. @param g2 the graphics context */ void drawSelection(Graphics2D g2); /** Sets the selection state of this item. @param b true if this item is selected */ void setSelected(boolean b); /** Gets the selection state of this item. @return true if this item is selected */ boolean isSelected(); /** Translates this item by a given amount. @param dx the amount to translate in x-direction @param dy the amount to translate in y-direction */ void translate(double dx, double dy); /** Tests whether this item contains a given point. @param p a point @return true if this item contains p */ boolean contains(Point2D p); }
CarShape.java
import java.awt.*; import java.awt.geom.*; /** A car shape. */ public class CarShape extends SelectableShape { /** Constructs a car shape. @param x the left of the bounding rectangle @param y the top of the bounding rectangle @param width the width of the bounding rectangle */ public CarShape(int x, int y, int width) { this.x = x; this.y = y; this.width = width; } public void draw(Graphics2D g2) { Rectangle2D.Double body = new Rectangle2D.Double(x, y + width / 6, width - 1, width / 6); Ellipse2D.Double frontTire = new Ellipse2D.Double(x + width / 6, y + width / 3, width / 6, width / 6); Ellipse2D.Double rearTire = new Ellipse2D.Double(x + width * 2 / 3, y + width / 3, width / 6, width / 6); // the bottom of the front windshield Point2D.Double r1 = new Point2D.Double(x + width / 6, y + width / 6); // the front of the roof Point2D.Double r2 = new Point2D.Double(x + width / 3, y); // the rear of the roof Point2D.Double r3 = new Point2D.Double(x + width * 2 / 3, y); // the bottom of the rear windshield Point2D.Double r4 = new Point2D.Double(x + width * 5 / 6, y + width / 6); Line2D.Double frontWindshield = new Line2D.Double(r1, r2); Line2D.Double roofTop = new Line2D.Double(r2, r3); Line2D.Double rearWindshield = new Line2D.Double(r3, r4); g2.draw(body); g2.draw(frontTire); g2.draw(rearTire); g2.draw(frontWindshield); g2.draw(roofTop); g2.draw(rearWindshield); } public boolean contains(Point2D p) { return x <= p.getX() && p.getX() <= x + width && y <= p.getY() && p.getY() <= y + width / 2; } public void translate(double dx, double dy) { x += dx; y += dy; } private int x; private int y; private int width; }
HouseShape.java
import java.awt.*; import java.awt.geom.*; /** A house shape. */ public class HouseShape extends SelectableShape { /** Constructs a house shape. @param x the left of the bounding rectangle @param y the top of the bounding rectangle @param width the width of the bounding rectangle */ public HouseShape(int x, int y, int width) { this.x = x; this.y = y; this.width = width; } public void draw(Graphics2D g2) { Rectangle2D.Double base = new Rectangle2D.Double(x, y + width, width, width); // the left bottom of the roof Point2D.Double r1 = new Point2D.Double(x, y + width); // the top of the roof Point2D.Double r2 = new Point2D.Double(x + width / 2, y); // the right bottom of the roof Point2D.Double r3 = new Point2D.Double(x + width, y + width); Line2D.Double roofLeft = new Line2D.Double(r1, r2); Line2D.Double roofRight = new Line2D.Double(r2, r3); g2.draw(base); g2.draw(roofLeft); g2.draw(roofRight); } public boolean contains(Point2D p) { return x <= p.getX() && p.getX() <= x + width && y <= p.getY() && p.getY() <= y + 2 * width; } public void translate(double dx, double dy) { x += dx; y += dy; } private int x; private int y; private int width; }
Maintained by John Loomis, updated Mon Feb 26 09:29:18 2007