10 files changed, 647 insertions, 0 deletions
diff --git a/docs/teaching/exercises/figures/Box.java b/docs/teaching/exercises/figures/Box.java
new file mode 100644
index 000000000..b10faa612
--- /dev/null
+++ b/docs/teaching/exercises/figures/Box.java
@@ -0,0 +1,64 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+public class Box extends ShapeFigureElement {
+    private Point _p0;
+    private Point _p1;
+    private Point _p2;
+    private Point _p3;
+
+    public Box(int x0, int y0, int width, int height) {
+        _p0 = new Point(x0, y0);
+        _p1 = new Point(x0+width, y0);
+        _p2 = new Point(x0+width, y0+height);
+        _p3 = new Point(x0, y0+height);
+    }
+
+    public Point getP0() { return _p0; }
+    public Point getP1() { return _p1; }
+    public Point getP2() { return _p2; }
+    public Point getP3() { return _p3; }
+
+    public void move(int dx, int dy) {
+        _p0.move(dx, dy);
+        _p1.move(dx, dy);
+        _p2.move(dx, dy);
+        _p3.move(dx, dy);
+    }
+
+    public void checkBoxness() {
+        if ((_p0.getX() == _p3.getX()) &&
+            (_p1.getX() == _p2.getX()) &&
+            (_p0.getY() == _p1.getY()) &&
+            (_p2.getY() == _p3.getY()))
+          return;
+        throw new IllegalStateException("This is not a square.");
+    }
+
+    public String toString() {
+        return "Box(" + _p0 + ", " + _p1 + ", " + _p2 + ", " + _p3 + ")";
+    }
+
+    public Shape getShape() {
+        return new Rectangle(getP1().getX(),
+                             getP1().getY(),
+                             getP3().getX() - getP1().getX(),
+                             getP3().getY() - getP1().getY());
+    }
+}
+
diff --git a/docs/teaching/exercises/figures/FigureElement.java b/docs/teaching/exercises/figures/FigureElement.java
new file mode 100644
index 000000000..d6d5c261c
--- /dev/null
+++ b/docs/teaching/exercises/figures/FigureElement.java
@@ -0,0 +1,30 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+public interface FigureElement {
+    public static final int MIN_VALUE = 0;
+    public static final int MAX_VALUE = 500;
+
+    public abstract void move(int dx, int dy);
+
+    public abstract Rectangle getBounds();
+
+    public abstract boolean contains(Point2D p);
+
+    public abstract void paint(Graphics2D g2);
+}
diff --git a/docs/teaching/exercises/figures/Group.java b/docs/teaching/exercises/figures/Group.java
new file mode 100644
index 000000000..ad2f224c6
--- /dev/null
+++ b/docs/teaching/exercises/figures/Group.java
@@ -0,0 +1,97 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.util.*;
+import java.awt.*;
+import java.awt.geom.*;
+
+public class Group implements FigureElement {
+    private Collection _members;
+    private String _identifier;
+
+    public Group(FigureElement first) {
+        this._members = new ArrayList();
+        add(first);
+    }
+
+    public void add(FigureElement fe) {
+        _members.add(fe);
+    }
+
+    public Iterator members() {
+        return _members.iterator();
+    }
+
+    public void move(int dx, int dy) {
+        for (Iterator i = _members.iterator(); i.hasNext(); ) {
+            FigureElement fe = (FigureElement)i.next();
+            fe.move(dx, dy);
+        }
+    }
+
+    public void setIdentifier(String identifier) {
+        _identifier = identifier;
+    }
+
+    public String toString() {
+        if (_identifier != null) {
+            return _identifier;
+        }
+
+        StringBuffer buf = new StringBuffer("Group(");
+        for (Iterator i = _members.iterator(); i.hasNext(); ) {
+            buf.append(i.next().toString());
+            if (i.hasNext()) {
+                buf.append(", ");
+            }
+        }
+        buf.append(")");
+        return buf.toString();
+    }
+
+    public Rectangle getBounds() {
+        Rectangle previous = null;
+        for (Iterator i = _members.iterator(); i.hasNext(); ) {
+            FigureElement fe = (FigureElement)i.next();
+            Rectangle rect = fe.getBounds();
+            if (previous != null) {
+                previous = previous.union(rect);
+            } else {
+                previous = rect;
+            }
+        }
+        return previous;
+    }
+
+    public boolean contains(Point2D p) {
+        for (Iterator i = _members.iterator(); i.hasNext(); ) {
+            FigureElement fe = (FigureElement)i.next();
+            if (fe.contains(p)) return true;
+        }
+        return false;
+    }
+
+    public void paint(Graphics2D g2) {
+        for (Iterator i = _members.iterator(); i.hasNext(); ) {
+            FigureElement fe = (FigureElement)i.next();
+            fe.paint(g2);
+        }
+    }
+
+    public int size() {
+        return _members.size();
+    }
+}
+
diff --git a/docs/teaching/exercises/figures/Line.java b/docs/teaching/exercises/figures/Line.java
new file mode 100644
index 000000000..f21c1eff1
--- /dev/null
+++ b/docs/teaching/exercises/figures/Line.java
@@ -0,0 +1,64 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+public class Line extends ShapeFigureElement {
+    private Point _p1;
+    private Point _p2;
+
+    public Line(Point p1, Point p2) {
+        _p1 = p1;
+        _p2 = p2;
+    }
+
+    public Point getP1() { return _p1; }
+    public Point getP2() { return _p2; }
+
+    public void move(int dx, int dy) {
+        _p1.move(dx, dy);
+        _p2.move(dx, dy);
+    }
+
+    public String toString() {
+        return "Line(" + _p1 + ", " + _p2 + ")";
+    }
+
+    /**
+     * Used to determine if this line {@link contains(Point2D)} a point.
+     */
+    final static int THRESHHOLD = 5;
+
+    /**
+     * Returns <code>true</code> if the point segment distance is less than
+     * {@link THRESHHOLD}.
+     */
+    public boolean contains(Point2D p) {
+        return getLine2D().ptLineDist(p) < THRESHHOLD;
+    }
+
+    private Line2D getLine2D() {
+	return new Line2D.Float((float)getP1().getX(),
+                                (float)getP1().getY(),
+                                (float)getP2().getX(),
+                                (float)getP2().getY());
+    }
+
+    public Shape getShape() {
+        return getLine2D();
+    }
+}
+
diff --git a/docs/teaching/exercises/figures/Point.java b/docs/teaching/exercises/figures/Point.java
new file mode 100644
index 000000000..63126d96f
--- /dev/null
+++ b/docs/teaching/exercises/figures/Point.java
@@ -0,0 +1,58 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+public class Point extends ShapeFigureElement {
+    private int _x;
+    private int _y;
+
+    public Point(int x, int y) {
+        _x = x;
+        _y = y;
+    }
+
+    public int getX() { return _x; }
+
+    public int getY() { return _y; }
+
+    public void setX(int x) { _x = x; }
+
+    public void setY(int y) { _y = y; }
+
+    public void move(int dx, int dy) {
+        _x += dx;
+        _y += dy;
+    }
+
+    public String toString() {
+        return "Point(" + _x + ", " + _y + ")";
+    }
+
+    /** The height of displayed {@link Point}s. */
+    private final static int HEIGHT = 10;
+
+    /** The width of displayed {@link Point}s. -- same as {@link HEIGHT}. */
+    private final static int WIDTH  = Point.HEIGHT;
+
+    public Shape getShape() {
+	return new Ellipse2D.Float((float)getX()-Point.WIDTH/2,
+                                   (float)getY()-Point.HEIGHT/2,
+                                   (float)Point.HEIGHT,
+                                   (float)Point.WIDTH);
+    }
+}
+
diff --git a/docs/teaching/exercises/figures/ShapeFigureElement.java b/docs/teaching/exercises/figures/ShapeFigureElement.java
new file mode 100644
index 000000000..b09bad10e
--- /dev/null
+++ b/docs/teaching/exercises/figures/ShapeFigureElement.java
@@ -0,0 +1,47 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+public abstract class ShapeFigureElement implements FigureElement {
+    public abstract void move(int dx, int dy);
+
+    public abstract Shape getShape();
+
+    public Rectangle getBounds() {
+        return getShape().getBounds();
+    }
+
+    public boolean contains(Point2D p) {
+        return getShape().contains(p);
+    }
+
+    public Color getLineColor() {
+        return Color.black;
+    }
+
+    public Color getFillColor() {
+        return Color.red;
+    }
+
+    public final void paint(Graphics2D g2) {
+        Shape shape = getShape();
+        g2.setPaint(getFillColor());
+        g2.fill(shape);
+        g2.setPaint(getLineColor());
+        g2.draw(shape);
+    }
+}
diff --git a/docs/teaching/exercises/figures/SlothfulPoint.java b/docs/teaching/exercises/figures/SlothfulPoint.java
new file mode 100644
index 000000000..ede073b24
--- /dev/null
+++ b/docs/teaching/exercises/figures/SlothfulPoint.java
@@ -0,0 +1,50 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures;
+
+import java.awt.*;
+import java.awt.geom.*;
+
+/**
+ * This class makes mistakes to be caught by invariant checkers.
+ */
+public class SlothfulPoint extends ShapeFigureElement {
+    private int _x;
+    private int _y;
+
+    public SlothfulPoint(int x, int y) {
+    }
+
+    public int getX() { return _x; }
+
+    public int getY() { return _y; }
+
+    public void setX(int x) { }
+
+    public void setY(int y) { }
+
+    public void move(int dx, int dy) {
+	System.out.println("Slothful moving");
+    }
+
+    public String toString() {
+        return "SlothfulPoint";
+    }
+
+    public Shape getShape() {
+	return new Ellipse2D.Float((float)_x,
+                                   (float)_y, 1.0f, 1.0f);
+    }
+}
+
diff --git a/docs/teaching/exercises/figures/gui/FigurePanel.java b/docs/teaching/exercises/figures/gui/FigurePanel.java
new file mode 100644
index 000000000..4746bc057
--- /dev/null
+++ b/docs/teaching/exercises/figures/gui/FigurePanel.java
@@ -0,0 +1,181 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures.gui;
+
+import figures.Point;
+import figures.Line;
+import figures.FigureElement;
+import figures.Group;
+
+
+import java.awt.*;
+import java.awt.geom.*;
+import java.awt.event.*;
+import java.io.*;
+import java.util.*;
+import javax.swing.*;
+import javax.swing.text.*;
+import javax.swing.border.*;
+
+public class FigurePanel extends JComponent {
+
+    ButtonsPanel bp = new ButtonsPanel();
+    FigureSurface fs = new FigureSurface();
+    ConsolePanel cp = new ConsolePanel();
+
+
+    public FigurePanel() {
+        setLayout(new BorderLayout());
+        JPanel panel = new JPanel();
+        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
+        panel.add(fs);
+        panel.add(bp);
+        JSplitPane sp = new JSplitPane(JSplitPane.VERTICAL_SPLIT, panel, cp);
+        sp.setPreferredSize(new Dimension(500, 400));
+        sp.setDividerLocation(250);
+        add(BorderLayout.CENTER, sp);
+    }
+
+    class ButtonsPanel extends JPanel {
+        JLabel msgs = new JLabel("click to add a point or line");
+        public ButtonsPanel() {
+            setLayout(new FlowLayout(FlowLayout.LEFT));
+            add(new JButton(new AbstractAction("Main") {
+                    public void actionPerformed(ActionEvent e) {
+                        Main.main(new String[]{});
+                        fs.repaint();
+                    }
+                }));
+            add(msgs);
+        }
+
+        public void log(String msg) {
+            msgs.setText(msg);
+        }
+    }
+
+    static class ConsolePanel extends JPanel {
+
+        JTextArea text = new JTextArea();
+
+        public ConsolePanel() {
+            super(new BorderLayout());
+            text.setFont(StyleContext.getDefaultStyleContext().getFont("SansSerif", Font.PLAIN, 10));
+            JScrollPane scroller = new JScrollPane(text);
+            scroller.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
+            add(BorderLayout.CENTER, scroller);
+        }
+
+        public void println(String msg) {
+            text.append(msg + '\n');
+        }
+    }
+
+    final static Color BACKGROUND = Color.white;
+
+    static class FigureSurface extends JPanel implements MouseListener, MouseMotionListener {
+        Group canvas;
+
+        public FigureSurface() {
+            canvas = new Group(new Point(250, 250));
+            addMouseMotionListener(this);
+            addMouseListener(this);
+            setPreferredSize(new Dimension(500,500));
+        }
+
+        private Point addPoint(int x, int y) {
+            Point p = new Point(x, y);
+            canvas.add(p);
+            repaint();
+            return p;
+        }
+
+        private Line addLine(Point p1, Point p2) {
+            if (Math.abs(p1.getX()-p2.getX()) < 5 ||
+                Math.abs(p1.getY()-p2.getY()) < 5) {
+                return null;
+            }
+
+            Line line = null;
+            if (p1 != null && p2 != null) {
+                line = new Line(p1, p2);
+                canvas.add(line);
+            }
+            repaint();
+            return line;
+        }
+
+        public void paint(Graphics g) {
+            Graphics2D g2 = (Graphics2D) g;
+            g2.setPaint(BACKGROUND);
+            g2.fill(new Rectangle2D.Float(0f, 0f, (float)g2.getClipBounds().width, (float)g2.getClipBounds().height));
+            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+            canvas.paint(g2);
+        }
+
+
+        int lastX, lastY;
+        int pressX, pressY;
+
+        FigureElement first = null;
+        Point point1 = null;
+
+        public void mousePressed(MouseEvent e){
+            int x = e.getX(), y = e.getY();
+            pressX = lastX = x; pressY = lastY = y;
+            first = findFigureElement(x, y);
+            if (first == null) {
+                point1 = addPoint(x, y);
+            }
+        }
+
+        public void mouseDragged(MouseEvent e) {
+            int x = e.getX(), y = e.getY(), dx = lastX-x, dy = lastY-y;
+            lastX = x;
+            lastY = y;
+            if (first == null) {
+                Line line = addLine(point1, new Point(x, y));
+                if (line != null) {
+                    canvas.add(line.getP2());
+                    first = line.getP2();
+                    canvas.add(line);
+                }
+            } else {
+                first.move(-dx, -dy);
+            }
+            repaint();
+        }
+
+        public void mouseReleased(MouseEvent e){
+            mouseDragged(e);
+            first = null;
+            point1 = null;
+        }
+
+
+        public void mouseMoved(MouseEvent e){}
+        public void mouseClicked(MouseEvent e){}
+        public void mouseExited(MouseEvent e){}
+        public void mouseEntered(MouseEvent e){}
+
+        private FigureElement findFigureElement(int x, int y) {
+            Point2D p = new Point2D.Float((float)x, (float)y);
+            for (Iterator i = canvas.members(); i.hasNext(); ) {
+                FigureElement fe = (FigureElement)i.next();
+                if (fe.contains(p)) return fe;
+            }
+            return null;
+        }
+    }
+}
diff --git a/docs/teaching/exercises/figures/gui/LogAdapter.java b/docs/teaching/exercises/figures/gui/LogAdapter.java
new file mode 100644
index 000000000..9d7d7d94d
--- /dev/null
+++ b/docs/teaching/exercises/figures/gui/LogAdapter.java
@@ -0,0 +1,25 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures.gui;
+
+import support.Log;
+
+aspect LogAdapter {
+
+    before(String s): call(void Log.log(String)) && args(s) {
+        if (Main.panel != null) {
+            Main.panel.cp.println(s);
+        }
+    }
+}
diff --git a/docs/teaching/exercises/figures/gui/Main.java b/docs/teaching/exercises/figures/gui/Main.java
new file mode 100644
index 000000000..c2d41c3b0
--- /dev/null
+++ b/docs/teaching/exercises/figures/gui/Main.java
@@ -0,0 +1,31 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Common Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/cpl-v10.html 
+ *  
+ * Contributors: 
+ *     PARC     initial implementation 
+ * ******************************************************************/
+
+
+package figures.gui;
+
+import javax.swing.*;
+import support.Log;
+
+public class Main {
+    static FigurePanel panel;
+
+    public static void main(String[] args) {
+        JFrame figureFrame = new JFrame("Figure Editor");
+        panel = new FigurePanel();
+        figureFrame.setContentPane(panel);
+        figureFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        figureFrame.pack();
+        figureFrame.setVisible(true);
+    }
+
+}