hw4: add uml class diagram

hw4/.gitignore

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+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

hw4/.idea/.gitignore

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+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

hw4/.idea/codeStyles/codeStyleConfig.xml

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+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
+  </state>
+</component>

hw4/.idea/inspectionProfiles/Project_Default.xml

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+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="Eslint" enabled="true" level="WARNING" enabled_by_default="true" />
+  </profile>
+</component>

hw4/.idea/misc.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="openjdk-22" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

hw4/.idea/modules.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/hw4.iml" filepath="$PROJECT_DIR$/hw4.iml" />
+    </modules>
+  </component>
+</project>

hw4/.idea/vcs.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

hw4/README.md

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+# Programming Assignment 4 - Shape Displayer
+
+## Requirements
+
+The user interacts with the application as follows:
+
+- Initially, the program displays three buttons on the top of the frame and a
+  blank large area of a user-defined JPanel below the buttons. The buttons
+  display a car, a snow man, and a composite shape of your choice, respectively.
+  You are allowed to borrow the CarShape.java from the text book. Make sure to
+  acknowledge that the code is from the text book. The composite shape of your
+  choice should consist of at least 4 primitive shapes, but doesn't have to be
+  fancy.
+- When the user clicks on one of the buttons, the shape displayed on the clicked
+  button becomes the current shape. The icon representing the current shape
+  should outline the shape as shown below in the sample output. When a mouse is
+  clicked on the user-defined JPanel, the current shape is drawn on the position
+  which the mouse was pressed on.
+- The current shape can be changed by clicking one of the buttons.
+- The application should be reusable by any CompositeShape.
+- Your design should be object-oriented including ShapeDisplayer(with main
+  method), CarShape, SnowMan, and Your_own_shape classes. Also, it should
+  include interface CompositeShape.java and a concrete class ShapeIcon. You may
+  include more classes to your design. 

hw4/diagram.uml

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+<?xml version="1.0" encoding="UTF-8"?>
+<Diagram>
+  <ID>JAVA</ID>
+  <OriginalElement />
+  <nodes>
+    <node x="-90.5" y="176.0">ShapeIcon</node>
+    <node x="-76.0" y="-4.0">CompositeShape</node>
+    <node x="-50.0" y="296.0">ShapeDisplayer</node>
+    <node x="12.5" y="116.0">CarShape</node>
+    <node x="208.0" y="116.0">SnowmanShape</node>
+    <node x="101.5" y="176.0">HouseShape</node>
+  </nodes>
+  <notes />
+  <edges>
+    <edge source="CarShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="62.5" y="0.0" />
+      <point x="173.0" y="130.0" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="CompositeShape" relationship="TO_ONE">
+      <point x="-2.0" y="-14.0" />
+      <point x="33.0" y="221.5" />
+      <point x="-108.0" y="221.5" />
+      <point x="-108.0" y="10.0" />
+      <point x="-91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="SnowmanShape" relationship="CREATE">
+      <point x="85.0" y="0.0" />
+      <point x="295.0" y="310.0" />
+      <point x="0.0" y="14.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="HouseShape" relationship="CREATE">
+      <point x="77.5" y="-14.0" />
+      <point x="-62.5" y="14.0" />
+    </edge>
+    <edge source="ShapeIcon" target="CompositeShape" relationship="TO_ONE">
+      <point x="98.125" y="-0.08333333333334281" />
+      <point x="-298.1666666666667" y="189.91666666666666" />
+      <point x="-298.1666666666667" y="212.33333333333337" />
+      <point x="-108.0" y="212.33333333333337" />
+      <point x="-108.0" y="10.0" />
+      <point x="-91.0" y="0.0" />
+    </edge>
+    <edge source="SnowmanShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="-87.0" y="0.0" />
+      <point x="173.0" y="130.0" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="ShapeIcon" relationship="TO_ONE">
+      <point x="-60.0" y="-14.0" />
+      <point x="0.0" y="14.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="CarShape" relationship="CREATE">
+      <point x="-85.0" y="0.0" />
+      <point x="-123.0" y="310.0" />
+      <point x="-123.0" y="130.0" />
+      <point x="-62.5" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="ShapeIcon" relationship="CREATE">
+      <point x="-45.0" y="-14.0" />
+      <point x="15.0" y="14.0" />
+    </edge>
+    <edge source="HouseShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="73.5" y="0.0" />
+      <point x="399.5" y="190.0" />
+      <point x="399.5" y="60.5" />
+      <point x="173.0" y="60.5" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+  </edges>
+  <settings layout="Hierarchic Compact" zoom="1.2" showDependencies="true" x="233.54166666666663" y="134.91666666666666" />
+  <SelectedNodes />
+  <Categories />
+  <SCOPE>All</SCOPE>
+  <VISIBILITY>private</VISIBILITY>
+</Diagram>
+

hw4/hw4.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

hw4/src/CarShape.java

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+import java.awt.*;
+import java.awt.geom.*;
+
+/**
+ * A car shape.
+ * Partially taken from the textbook (Cay S. Horstmann - OO Design & Patterns, 2nd ed.)
+ */
+public class CarShape implements CompositeShape {
+    private final int x; // Base x-coordinate (relative to drawing origin)
+    private final int y; // Base y-coordinate (relative to drawing origin)
+    private final int width;
+
+    public CarShape() {
+        this(0, 0, 60); // Default position and width
+    }
+
+    /**
+     * 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;
+    }
+
+    @Override
+    public int getWidth() {
+        return width; // Width of the car body
+    }
+
+    @Override
+    public int getHeight() {
+        // Approximate height: body height + wheel radius
+        return width / 2 + width / 6;
+    }
+
+    @Override
+    public void draw(Graphics2D g2) {
+        Rectangle2D.Double body = new Rectangle2D.Double(x, y + width / 6.0, width - 1, width / 6.0);
+        Ellipse2D.Double frontTire = new Ellipse2D.Double(
+                x + width / 6.0,
+                y + width / 3.0,
+                width / 6.0,
+                width / 6.0
+        );
+        Ellipse2D.Double rearTire = new Ellipse2D.Double(
+                x + width * 2 / 3.0,
+                y + width / 3.0,
+                width / 6.0,
+                width / 6.0
+        );
+
+        // The bottom of the front windshield
+        Point2D.Double r1 = new Point2D.Double(x + width / 6.0, y + width / 6.0);
+        // The front of the roof
+        Point2D.Double r2 = new Point2D.Double(x + width / 3.0, y);
+        // The rear of the roof
+        Point2D.Double r3 = new Point2D.Double(x + width * 2 / 3.0, y);
+        // The bottom of the rear windshield
+        Point2D.Double r4 = new Point2D.Double(x + width * 5 / 6.0, y + width / 6.0);
+        Line2D.Double frontWindshield = new Line2D.Double(r1, r2);
+        Line2D.Double roofTop = new Line2D.Double(r2, r3);
+        Line2D.Double rearWindshield = new Line2D.Double(r3, r4);
+
+        // Draw the parts
+        g2.draw(body);
+        g2.draw(frontTire);
+        g2.draw(rearTire);
+        g2.draw(frontWindshield);
+        g2.draw(roofTop);
+        g2.draw(rearWindshield);
+    }
+}

hw4/src/CompositeShape.java

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+import java.awt.Graphics2D;
+
+/**
+ * An interface for shapes that can be composed of multiple primitive shapes
+ * and can be drawn.
+ */
+public interface CompositeShape {
+    /**
+     * Draws the shape.
+     * @param g2 the graphics context
+     */
+    void draw(Graphics2D g2);
+
+    /**
+     * Gets the width of the shape's bounding box.
+     * Used for creating icons of a consistent size.
+     * @return the width
+     */
+    int getWidth();
+
+    /**
+     * Gets the height of the shape's bounding box.
+     * Used for creating icons of a consistent size.
+     * @return the height
+     */
+    int getHeight();
+}

hw4/src/HouseShape.java

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+import java.awt.Graphics2D;
+import java.awt.geom.Path2D;
+import java.awt.geom.Rectangle2D;
+
+/**
+ * A simple house shape composed of a body (rectangle), roof (triangle),
+ * door (rectangle), and window (rectangle).
+ */
+public class HouseShape implements CompositeShape {
+    private final int width; // Width of the house body
+    private final int height; // Height of the house body (excluding roof)
+
+    public HouseShape() {
+        this(50, 40); // Default width and body height
+    }
+
+    public HouseShape(int width, int height) {
+        this.width = width;
+        this.height = height;
+    }
+
+    @Override
+    public int getWidth() {
+        return width;
+    }
+
+    @Override
+    public int getHeight() {
+        // Total height = body height + roof height (approx 0.5 * width)
+        return height + (int) (width * 0.5);
+    }
+
+    @Override
+    public void draw(Graphics2D g2) {
+        // Drawing relative to (0,0) - top-left of bounding box.
+
+        // Body
+        double bodyY = width * 0.5; // Start body below roof peak
+        Rectangle2D.Double body = new Rectangle2D.Double(0, bodyY, width, height);
+
+        // Roof (triangle using Path2D)
+        Path2D.Double roof = new Path2D.Double();
+        roof.moveTo(0, bodyY);            // Bottom-left corner of roof
+        roof.lineTo(width / 2.0, 0);      // Peak of roof
+        roof.lineTo(width, bodyY);        // Bottom-right corner of roof
+        // No need to close path for drawing outline
+
+        // Door (small rectangle)
+        double doorWidth = width * 0.25;
+        double doorHeight = height * 0.5;
+        double doorX = (width - doorWidth) / 2.0; // Centered horizontally
+        double doorY = bodyY + height - doorHeight; // At the bottom of the body
+        Rectangle2D.Double door = new Rectangle2D.Double(doorX, doorY, doorWidth, doorHeight);
+
+        // Window (small square rectangle)
+        double windowSize = width * 0.2;
+        double windowX = width * 0.15; // Positioned left of center
+        double windowY = bodyY + height * 0.2; // Positioned near top of body
+        Rectangle2D.Double window = new Rectangle2D.Double(windowX, windowY, windowSize, windowSize);
+
+
+        // Draw parts
+        g2.draw(body);
+        g2.draw(roof);
+        g2.draw(door);
+        g2.draw(window);
+    }
+}

hw4/src/ShapeDisplayer.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.geom.AffineTransform;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ShapeDisplayer extends JFrame {
+
+    private static final int ICON_WIDTH = 50;
+    private static final int ICON_HEIGHT = 50;
+
+    private final DrawingPanel drawingPanel;
+    private CompositeShape currentShape = null; // The shape currently selected
+
+    private final JButton carButton;
+    private final JButton snowmanButton;
+    private final JButton houseButton;
+    private final ShapeIcon carIcon;
+    private final ShapeIcon snowmanIcon;
+    private final ShapeIcon houseIcon;
+
+    // Helper class to store drawn shapes and their positions
+    private static class PlacedShape {
+        final CompositeShape shape;
+        final Point position; // Top-left corner where the shape should be drawn
+
+        PlacedShape(CompositeShape shape, Point position) {
+            this.shape = shape;
+            this.position = position;
+        }
+    }
+
+    // Custom JPanel for drawing
+    private class DrawingPanel extends JPanel {
+        private final List<PlacedShape> drawnShapes = new ArrayList<>();
+
+        public DrawingPanel() {
+            setBackground(Color.WHITE);
+            setPreferredSize(new Dimension(600, 400)); // Set preferred size
+
+            addMouseListener(new MouseAdapter() {
+                @Override
+                public void mousePressed(MouseEvent e) {
+                    if (currentShape != null) {
+                        // Create a *new instance* for drawing, if shapes had state.
+                        // For these stateless shapes, reusing is fine, but creating
+                        // new instances is conceptually safer if shapes could change.
+                        // Example: drawnShapes.add(new PlacedShape(createNewShapeInstance(currentShape), e.getPoint()));
+
+                        // Simpler approach for current stateless shapes:
+                        drawnShapes.add(new PlacedShape(currentShape, e.getPoint()));
+                        repaint(); // Trigger redraw
+                    }
+                }
+            });
+        }
+
+        public void setCurrentShape(CompositeShape shape) {
+            currentShape = shape;
+        }
+
+        @Override
+        protected void paintComponent(Graphics g) {
+            super.paintComponent(g);
+            Graphics2D g2 = (Graphics2D) g.create(); // Work on a copy
+
+            // Enable antialiasing for smoother graphics
+            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+
+
+            // Draw all the placed shapes
+            for (PlacedShape ps : drawnShapes) {
+                // Save the current transform state
+                AffineTransform savedTransform = g2.getTransform();
+
+                // Translate to the position where the mouse was clicked
+                g2.translate(ps.position.x, ps.position.y);
+
+                // Draw the shape (its draw method assumes drawing at 0,0)
+                ps.shape.draw(g2);
+
+                // Restore the original transform for the next shape
+                g2.setTransform(savedTransform);
+            }
+
+            g2.dispose(); // Clean up the graphics copy
+        }
+    }
+
+
+    public ShapeDisplayer() {
+        super("Shape Displayer"); // Frame title
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        // --- Create Shapes ---
+        CompositeShape car = new CarShape();
+        CompositeShape snowman = new SnowmanShape();
+        CompositeShape house = new HouseShape(); // Your custom shape
+
+        // --- Create Icons ---
+        carIcon = new ShapeIcon(car, ICON_WIDTH, ICON_HEIGHT);
+        snowmanIcon = new ShapeIcon(snowman, ICON_WIDTH, ICON_HEIGHT);
+        houseIcon = new ShapeIcon(house, ICON_WIDTH, ICON_HEIGHT);
+
+        // --- Create Buttons ---
+        carButton = new JButton(carIcon);
+        snowmanButton = new JButton(snowmanIcon);
+        houseButton = new JButton(houseIcon);
+
+        // Configure buttons (remove text, set margins if needed)
+        carButton.setMargin(new Insets(2, 2, 2, 2));
+        snowmanButton.setMargin(new Insets(2, 2, 2, 2));
+        houseButton.setMargin(new Insets(2, 2, 2, 2));
+
+        // --- Create Panels ---
+        drawingPanel = new DrawingPanel();
+        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT)); // Align buttons left
+        buttonPanel.add(carButton);
+        buttonPanel.add(snowmanButton);
+        buttonPanel.add(houseButton);
+
+        // --- Layout ---
+        setLayout(new BorderLayout());
+        add(buttonPanel, BorderLayout.NORTH);
+        add(drawingPanel, BorderLayout.CENTER);
+
+        // --- Add Action Listeners ---
+        carButton.addActionListener(e -> selectShape(car, carIcon));
+        snowmanButton.addActionListener(e -> selectShape(snowman, snowmanIcon));
+        houseButton.addActionListener(e -> selectShape(house, houseIcon));
+
+
+        // Initially, no shape is selected
+        deselectAllIcons();
+
+        pack(); // Size the frame based on components
+        setLocationRelativeTo(null); // Center on screen
+    }
+
+    // Method to handle shape selection
+    private void selectShape(CompositeShape shape, ShapeIcon icon) {
+        drawingPanel.setCurrentShape(shape);
+        deselectAllIcons(); // Clear previous selection outline
+        icon.setOutline(true); // Set outline on the selected icon
+        // Force repaint of the button containing the icon
+        if (icon == carIcon) carButton.repaint();
+        else if (icon == snowmanIcon) snowmanButton.repaint();
+        else if (icon == houseIcon) houseButton.repaint();
+
+        // Optional: Add a border to the button itself for clearer selection
+        // resetBorders(); // Reset borders on all buttons
+        // if (icon == carIcon) carButton.setBorder(BorderFactory.createLineBorder(Color.BLACK, 2));
+        // else if (icon == snowManIcon) snowManButton.setBorder(BorderFactory.createLineBorder(Color.BLACK, 2));
+        // else if (icon == houseIcon) houseButton.setBorder(BorderFactory.createLineBorder(Color.BLACK, 2));
+
+    }
+
+    // Method to remove outline from all icons
+    private void deselectAllIcons() {
+        carIcon.setOutline(false);
+        snowmanIcon.setOutline(false);
+        houseIcon.setOutline(false);
+        // Repaint all buttons to remove outlines
+        carButton.repaint();
+        snowmanButton.repaint();
+        houseButton.repaint();
+    }
+
+    // Optional: Helper to reset button borders
+    // private void resetBorders() {
+    //     Border defaultBorder = UIManager.getBorder("Button.border");
+    //     carButton.setBorder(defaultBorder);
+    //     snowManButton.setBorder(defaultBorder);
+    //     houseButton.setBorder(defaultBorder);
+    // }
+
+
+    public static void main(String[] args) {
+        // Run the GUI creation on the Event Dispatch Thread (EDT)
+        SwingUtilities.invokeLater(() -> {
+            ShapeDisplayer displayer = new ShapeDisplayer();
+            displayer.setVisible(true);
+        });
+    }
+}

hw4/src/ShapeIcon.java

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+import javax.swing.Icon;
+import java.awt.Component;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.geom.AffineTransform;
+
+/**
+ * An icon that draws a CompositeShape.
+ */
+public class ShapeIcon implements Icon {
+    private final CompositeShape shape;
+    private final int width;
+    private final int height;
+    private boolean outline = false; // Flag to indicate if the icon should be outlined
+
+    /**
+     * Constructs a ShapeIcon.
+     * @param shape the shape to draw
+     * @param width the desired width of the icon
+     * @param height the desired height of the icon
+     */
+    public ShapeIcon(CompositeShape shape, int width, int height) {
+        this.shape = shape;
+        this.width = width;
+        this.height = height;
+    }
+
+    /**
+     * Sets whether this icon should draw an outline (e.g., when selected).
+     * @param outline true to draw outline, false otherwise.
+     */
+    public void setOutline(boolean outline) {
+        this.outline = outline;
+    }
+
+    @Override
+    public int getIconWidth() {
+        return width;
+    }
+
+    @Override
+    public int getIconHeight() {
+        return height;
+    }
+
+    @Override
+    public void paintIcon(Component c, Graphics g, int x, int y) {
+        Graphics2D g2 = (Graphics2D) g.create(); // Work on a copy
+
+        // Enable antialiasing for smoother graphics
+        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+
+        // Translate to the icon's drawing position
+        g2.translate(x, y);
+
+        double shapeWidth = shape.getWidth();
+        double shapeHeight = shape.getHeight();
+
+        // Calculate scaling factor to fit shape within icon bounds
+        double scaleX = (shapeWidth == 0) ? 1 : (double) width / shapeWidth;
+        double scaleY = (shapeHeight == 0) ? 1 : (double) height / shapeHeight;
+        double scale = Math.min(scaleX, scaleY) * 0.8; // Use 80% of space for padding
+
+        // Calculate translation to center the scaled shape
+        double dx = (width - shapeWidth * scale) / 2.0;
+        double dy = (height - shapeHeight * scale) / 2.0;
+
+        // Apply centering translation and scaling
+        AffineTransform originalTransform = g2.getTransform();
+        g2.translate(dx, dy);
+        g2.scale(scale, scale);
+
+        // Draw the shape
+        shape.draw(g2);
+
+        // Restore original transform before drawing outline (if any)
+        g2.setTransform(originalTransform);
+
+        // Draw outline if selected
+        if (outline) {
+            // Simple rectangle outline around the icon area
+            g2.setColor(java.awt.Color.GRAY);
+            g2.drawRect(0, 0, width - 1, height - 1);
+            g2.drawRect(1, 1, width - 3, height - 3); // Inner outline
+        }
+
+        g2.dispose(); // Clean up the graphics copy
+    }
+}

hw4/src/SnowmanShape.java

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+import java.awt.Graphics2D;
+import java.awt.geom.Ellipse2D;
+
+/**
+ * A snowman shape composed of three circles.
+ */
+public class SnowmanShape implements CompositeShape {
+    private final int width; // Base diameter of the bottom circle
+
+    public SnowmanShape() {
+        this(40); // Default width
+    }
+
+    public SnowmanShape(int width) {
+        this.width = width;
+    }
+
+    @Override
+    public int getWidth() {
+        return width;
+    }
+
+    @Override
+    public int getHeight() {
+        // Total height is approx sum of diameters: w + 0.75w + 0.5w
+        return (int) (width + width * 0.75 + width * 0.5);
+    }
+
+    @Override
+    public void draw(Graphics2D g2) {
+        // All drawing relative to (0,0) which represents the top-left
+        // of the bounding box for the *icon*. The actual drawing will be centered.
+
+        // Calculate diameters
+        double bottomDiameter = width;
+        double middleDiameter = width * 0.75;
+        double topDiameter = width * 0.5;
+
+        // Calculate positions (y-coordinates are offset from the top)
+        double bottomY = topDiameter + middleDiameter;
+        double middleY = topDiameter;
+        double topY = 0;
+
+        // Center horizontally (x-coordinates)
+        double bottomX = (width - bottomDiameter) / 2.0;
+        double middleX = (width - middleDiameter) / 2.0;
+        double topX = (width - topDiameter) / 2.0;
+
+
+        // Create circles
+        Ellipse2D.Double bottomCircle = new Ellipse2D.Double(bottomX, bottomY, bottomDiameter, bottomDiameter);
+        Ellipse2D.Double middleCircle = new Ellipse2D.Double(middleX, middleY, middleDiameter, middleDiameter);
+        Ellipse2D.Double topCircle = new Ellipse2D.Double(topX, topY, topDiameter, topDiameter);
+
+        // Draw circles
+        g2.draw(bottomCircle);
+        g2.draw(middleCircle);
+        g2.draw(topCircle);
+    }
+}

midterm2/.gitignore

@@ -0,0 +1,29 @@
+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

midterm2/.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

midterm2/.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,6 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="Eslint" enabled="true" level="WARNING" enabled_by_default="true" />
+  </profile>
+</component>

midterm2/.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="openjdk-22" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

midterm2/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/midterm2.iml" filepath="$PROJECT_DIR$/midterm2.iml" />
+    </modules>
+  </component>
+</project>

midterm2/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

midterm2/midterm2.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

midterm2/src/BarFrame.java

@@ -0,0 +1,96 @@
+import java.awt.*;
+import java.awt.event.*;
+import java.awt.geom.*;
+import javax.swing.*;
+import javax.swing.event.*;
+import java.util.*;
+
+/**
+ * A class that implements an Observer object that displays a barchart view of
+ * a data model.
+ */
+public class BarFrame extends JFrame implements ChangeListener {
+    /**
+     * Constructs a BarFrame object
+     *
+     * @param dataModel the data that is displayed in the barchart
+     */
+    public BarFrame(DataModel dataModel) {
+        this.dataModel = dataModel;
+        a = dataModel.getData();
+
+        setLocation(0, 200);
+        setLayout(new BorderLayout());
+
+        JLabel barLabel = new JLabel();
+        barLabel.setIcon(new BarIcon());
+        barLabel.addMouseListener(new MouseAdapter() {
+            @Override
+            public void mousePressed(MouseEvent e) {
+                int mouseX = e.getX();
+                int mouseY = e.getY();
+
+                double max = a.stream().max(Double::compare).orElse(1.0);
+                double barHeight = ICON_HEIGHT / (double) a.size();
+
+                // Find the nearest bar to the mouse click
+                int index = (int) (mouseY / barHeight);
+                if (index >= 0 && index < a.size()) {
+                    double newValue = max * mouseX / ICON_WIDTH;
+                    dataModel.update(index, newValue);
+                }
+            }
+        });
+
+        add(barLabel);
+
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        pack();
+        setVisible(true);
+    }
+
+    /**
+     * Called when the data in the model is changed.
+     *
+     * @param e the event representing the change
+     */
+    public void stateChanged(ChangeEvent e) {
+        a = dataModel.getData();
+        repaint();
+    }
+
+    private class BarIcon implements Icon {
+        public int getIconWidth() {
+            return ICON_WIDTH;
+        }
+
+        public int getIconHeight() {
+            return ICON_HEIGHT;
+        }
+
+        public void paintIcon(Component c, Graphics g, int x, int y) {
+            Graphics2D g2 = (Graphics2D) g;
+
+            g2.setColor(Color.red);
+
+            double max = a.stream().max(Double::compare).orElse(1.0);
+            double barHeight = getIconHeight() / (double) a.size();
+
+            int i = 0;
+            for (Double value : a) {
+                double barLength = getIconWidth() * value / max;
+
+                Rectangle2D.Double rectangle = new Rectangle2D.Double(
+                        0, barHeight * i, barLength, barHeight);
+                i++;
+                g2.fill(rectangle);
+            }
+        }
+    }
+
+    private ArrayList<Double> a;
+    private DataModel dataModel;
+
+    private static final int ICON_WIDTH = 200;
+    private static final int ICON_HEIGHT = 200;
+}

midterm2/src/DataModel.java

@@ -0,0 +1,51 @@
+import java.util.ArrayList;
+import javax.swing.event.*;
+
+/**
+ * A Subject class for the observer pattern.
+ */
+public class DataModel {
+    /**
+     * Constructs a DataModel object
+     *
+     * @param d the data to model
+     */
+    public DataModel(ArrayList<Double> d) {
+        data = d;
+        listeners = new ArrayList<ChangeListener>();
+    }
+
+    /**
+     * Constructs a DataModel object
+     *
+     * @return the data in an ArrayList
+     */
+    public ArrayList<Double> getData() {
+        return (ArrayList<Double>) (data.clone());
+    }
+
+    /**
+     * Attach a listener to the Model
+     *
+     * @param c the listener
+     */
+    public void attach(ChangeListener c) {
+        listeners.add(c);
+    }
+
+    /**
+     * Change the data in the model at a particular location
+     *
+     * @param location the index of the field to change
+     * @param value    the new value
+     */
+    public void update(int location, double value) {
+        data.set(location, new Double(value));
+        for (ChangeListener l : listeners) {
+            l.stateChanged(new ChangeEvent(this));
+        }
+    }
+
+    ArrayList<Double> data;
+    ArrayList<ChangeListener> listeners;
+}

midterm2/src/Main.java

@@ -0,0 +1,14 @@
+/**
+ * Write a program that contains two frames, one with a column of text fields
+ * containing numbers, and another that draws a bar graph showing the values of
+ * the numbers. When the user edits one of the numbers, the graph should be
+ * redrawn. Use the observer pattern. Store the data in a model. Attach the graph
+ * view as a listener. When a number is updated, the number view should update the
+ * model, and the model should tell the graph view that a change has occured. As a
+ * result, the graph view should repaint itself.
+ */
+public class Main {
+    public static void main(String[] args) {
+
+    }
+}

midterm2/src/ObserverTester.java

@@ -0,0 +1,29 @@
+import java.util.ArrayList;
+
+/**
+ * A class for testing an implementation of the Observer pattern.
+ */
+public class ObserverTester {
+    /**
+     * Creates a DataModel and attaches barchart and textfield listeners
+     *
+     * @param args unused
+     */
+    public static void main(String[] args) {
+        ArrayList<Double> data = new ArrayList<Double>();
+
+        data.add(33.0);
+        data.add(44.0);
+        data.add(22.0);
+        data.add(22.0);
+
+        DataModel model = new DataModel(data);
+
+        TextFrame frame = new TextFrame(model);
+
+        BarFrame barFrame = new BarFrame(model);
+
+        model.attach(frame);
+        model.attach(barFrame);
+    }
+}

midterm2/src/TextFrame.java

@@ -0,0 +1,76 @@
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import java.util.ArrayList;
+
+/**
+ * A class for displaying the model as a column of textfields in a frame.
+ */
+public class TextFrame extends JFrame implements ChangeListener {
+    /**
+     * Constructs a JFrame that contains the textfields containing the data
+     * in the model.
+     *
+     * @param d the model to display
+     */
+    public TextFrame(DataModel d) {
+        dataModel = d;
+
+        final Container contentPane = this.getContentPane();
+        setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
+
+        ArrayList<Double> a = dataModel.getData();
+        fieldList = new JTextField[a.size()];
+
+        // A listener for action events in the text fields
+        ActionListener l = new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                // Figure out which field generated the event
+                JTextField c = (JTextField) e.getSource();
+                int i = 0;
+                int count = fieldList.length;
+                while (i < count && fieldList[i] != c)
+                    i++;
+
+                String text = c.getText().trim();
+
+                try {
+                    double value = Double.parseDouble(text);
+                    dataModel.update(i, value);
+                } catch (Exception exc) {
+                    c.setText("Error.  No update");
+                }
+            }
+        };
+
+        final int FIELD_WIDTH = 11;
+        for (int i = 0; i < a.size(); i++) {
+            JTextField textField = new JTextField(a.get(i).toString(), FIELD_WIDTH);
+            textField.addActionListener(l);
+            add(textField);
+            fieldList[i] = textField;
+        }
+
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        pack();
+        setVisible(true);
+    }
+
+    /**
+     * Called when the data in the model is changed.
+     *
+     * @param e the event representing the change
+     */
+    @Override
+    public void stateChanged(ChangeEvent e) {
+        ArrayList<Double> a = dataModel.getData();
+        for (int i = 0; i < a.size(); i++) {
+            fieldList[i].setText(a.get(i).toString());
+        }
+    }
+
+    DataModel dataModel;
+    JTextField[] fieldList;
+}