Question

JAVA problem:

Upgrade and extend the previous programs Draw.java and DrawCanvas.java used in the class to maintain a list of shapes drawn as follows:

1. Replace and upgrade all the AWT components used in the programs to the corresponding Swing components, including Frame, Button, Label, Choice, and Panel.
2. Add a JList to the left of the canvas to record and display the list of shapes that have been drawn on the canvas. Each entry in the list should contain the name of the shape and its x and y coordinates. When the drawing of a new shape is completed, it should be added to the end of the list.
3. Add two buttons of type JButton, one labeled “Remove Shape” and the other “Clear All”, below the list of shapes. Complete the programs so that a shape can be removed from the display list by selecting the shape first and then clicking on the remove button. The clear all button is used to remove all the shapes in the list.

The codes below:

Draw.java

//------------------------------------------------------------

// Import Core Java packages
import java.awt.*;
import java.awt.event.*;

public class Draw extends Frame implements ActionListener, ItemListener {

   // Initial Frame size
   static final int WIDTH = 400;                // frame width
   static final int HEIGHT = 300;               // frame height

    // Color choices
    static final String COLOR_NAMES[] = {"None", "Red", "Blue", "Green"};
    static final Color COLORS[] = {null, Color.red, Color.blue, Color.green};

    // Button control
    Button circle;
    Button roundRec;
    Button threeDRec;

    // Color choice box
    Choice colorChoice;

    // the canvas
    DrawCanvas canvas;

    /**
     * Constructor
     */
   public Draw() {
        super("Java Draw");
        setLayout(new BorderLayout());

        // create panel for controls
        Panel topPanel = new Panel(new GridLayout(2, 1));
        add(topPanel, BorderLayout.NORTH);

        // create button control
        Panel buttonPanel = new Panel(new FlowLayout(FlowLayout.LEFT));
        topPanel.add(buttonPanel);

        circle = new Button("Circle");
        buttonPanel.add(circle);
        roundRec = new Button("Rounded Rectangle");
        buttonPanel.add(roundRec);
        threeDRec = new Button("3D Rectangle");
        buttonPanel.add(threeDRec);

        // add button listener
        circle.addActionListener(this);
        roundRec.addActionListener(this);
        threeDRec.addActionListener(this);

        // create panel for color choices
        Panel colorPanel = new Panel(new FlowLayout(FlowLayout.LEFT));
        topPanel.add(colorPanel);
        Label label = new Label("Filled Color:");
        colorPanel.add(label);
        colorChoice = new Choice();
        for(int i=0; i<COLOR_NAMES.length; i++) {
            colorChoice.add(COLOR_NAMES[i]);
        }
        colorPanel.add(colorChoice);
        colorChoice.addItemListener(this);

        // create the canvas
        canvas = new DrawCanvas();
        add(canvas, BorderLayout.CENTER);
   } // end of constructor

    /**
     * Implementing ActionListener
     */
    public void actionPerformed(ActionEvent event) {
        if(event.getSource() == circle) { // circle button
            canvas.setShape(DrawCanvas.CIRCLE);
        }
        else if(event.getSource() == roundRec) { // rounded rectangle button
            canvas.setShape(DrawCanvas.ROUNDED_RECTANGLE);
        }
        else if(event.getSource() == threeDRec) { // 3D rectangle button
            canvas.setShape(DrawCanvas.RECTANGLE_3D);
        }
    }

    /**
     * Implementing ItemListener
     */
    public void itemStateChanged(ItemEvent event) {
        Color color = COLORS[colorChoice.getSelectedIndex()];
        canvas.setFilledColor(color);
    }

    /**
     * the main method
     */
    public static void main(String[] argv) {
        // Create a frame
        Draw frame = new Draw();
        frame.setSize(WIDTH, HEIGHT);
        frame.setLocation(150, 100);

        // add window closing listener
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent event) {
                System.exit(0);
            }
        });

        // Show the frame
        frame.setVisible(true);
    }
}

//-----------end of draw.java

DrawCanvas.java

//----------------------------------------

// Import Core Java packages
import java.awt.*;
import java.awt.event.*;

public class DrawCanvas extends Canvas implements MouseListener,
                                                  MouseMotionListener {

    // Constants for shapes
    public static final int CIRCLE = 1;
    public static final int ROUNDED_RECTANGLE = 2;
    public static final int RECTANGLE_3D = 3;

    // Coordinates of points to draw
    private int x1, y1, x2, y2;

    // shape to draw
    private int shape = CIRCLE;
    /**
     * Method to set the shape
     */
    public void setShape(int shape) {
        this.shape = shape;
    }

    // filled color
    private Color filledColor = null;
    /**
     * Method to set filled color
     */
    public void setFilledColor(Color color) {
        filledColor = color;
    }

    /**
     * Constructor
     */
   public DrawCanvas() {
        addMouseListener(this);
        addMouseMotionListener(this);
   } // end of constructor

    /**
     * painting the component
     */
    public void paint(Graphics g) {

        // the drawing area
        int x, y, width, height;

        // determine the upper-left corner of bounding rectangle
        x = Math.min(x1, x2);
        y = Math.min(y1, y2);

        // determine the width and height of bounding rectangle
        width = Math.abs(x1 - x2);
        height = Math.abs(y1 - y2);

        if(filledColor != null)
            g.setColor(filledColor);
        switch (shape) {
            case ROUNDED_RECTANGLE :
                if(filledColor == null)
                    g.drawRoundRect(x, y, width, height, width/4, height/4);
                else
                    g.fillRoundRect(x, y, width, height, width/4, height/4);
                break;
            case CIRCLE :
                int diameter = Math.max(width, height);
                if(filledColor == null)
                    g.drawOval(x, y, diameter, diameter);
                else
                    g.fillOval(x, y, diameter, diameter);
                break;
            case RECTANGLE_3D :
                if(filledColor == null)
                    g.draw3DRect(x, y, width, height, true);
                else
                    g.fill3DRect(x, y, width, height, true);
                break;
        }
    }

    /**
     * Implementing MouseListener
     */
    public void mousePressed(MouseEvent event) {
        x1 = event.getX();
        y1 = event.getY();
    }

    public void mouseReleased(MouseEvent event) {
        x2 = event.getX();
        y2 = event.getY();
        repaint();
    }

    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}

    /**
     * Implementing MouseMotionListener
     */
    public void mouseDragged(MouseEvent event) {
        x2 = event.getX();
        y2 = event.getY();
        repaint();
    }

    public void mouseMoved(MouseEvent e) {}
}

Answer 1

Code:

import java.awt.*;

import java.awt.event.*;

import java.awt.geom.*;

import java.util.ArrayList;

import javax.swing.*;

public class ListOfShapes {

  

}

class Draw extends JFrame implements ActionListener, ItemListener {

    static final ArrayList<ShapeClass> listOfShapes = new ArrayList<>();

  

    static final int FINALWIDTH = 500;               

    static final int FINALHEIGHT = 400;

    static final String COLORNAMESARR[] = {"None", "Red", "Blue", "Green"};

    static final Color COLORSARR[] = {null, Color.red, Color.blue, Color.green};

    JButton circleButton;

    JButton roundRectangleButton;

    JButton ThreeDRectangleButton;

    JComboBox<String> chooseColor;

    JList<String> jShapeList;

    JScrollPane jScrollbar2;

  

    DrawCanvas userCanvas;

    public Draw() {

            super("Java Draw");

        setLayout(new BorderLayout());

        JPanel topBar = new JPanel(new GridLayout(2, 1));

        add(topBar, BorderLayout.NORTH);

        JPanel buttonBar = new JPanel(new FlowLayout(FlowLayout.LEFT));

        topBar.add(buttonBar);

        circleButton = new JButton("Circle");

        buttonBar.add(circleButton);

        roundRectangleButton = new JButton("Rounded Rectangle");

        buttonBar.add(roundRectangleButton);

        ThreeDRectangleButton = new JButton("3D Rectangle");

        buttonBar.add(ThreeDRectangleButton);

        circleButton.addActionListener(this);

        roundRectangleButton.addActionListener(this);

        ThreeDRectangleButton.addActionListener(this);

        JPanel colorPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));

        topBar.add(colorPanel);

        JLabel label = new JLabel("Filled Color:");

        colorPanel.add(label);

        chooseColor = new JComboBox();

              

        for(int i=0; i<COLORNAMESARR.length; i++) {

            chooseColor.addItem(COLORNAMESARR[i]);

        }

        colorPanel.add(chooseColor);

        chooseColor.addItemListener(this);

      

        JPanel listPanel = getListPanel();

        add(listPanel, BorderLayout.WEST);

        userCanvas = new DrawCanvas();

        add(userCanvas, BorderLayout.CENTER);

    }

    @Override

    public void actionPerformed(ActionEvent event) {

        if(event.getSource() == circleButton) {

            userCanvas.setShape(DrawCanvas.CIRCLE);

        }

        else if(event.getSource() == roundRectangleButton) {

            userCanvas.setShape(DrawCanvas.ROUNDED_RECTANGLE);

        }

        else if(event.getSource() == ThreeDRectangleButton) {

            userCanvas.setShape(DrawCanvas.RECTANGLE_3D);

        } else if(event.getActionCommand().equals("Delete Shape")) {

            String name = jShapeList.getSelectedValue();

            if(name == null) {

                JOptionPane.showMessageDialog(null, "Please select any one shape and try again", "Error", JOptionPane.ERROR_MESSAGE);

                return;

            }

            System.out.println(listOfShapes);

            for(int i = 0; i < listOfShapes.size();i++) {

                if(listOfShapes.get(i).toString().equals(name)) {

                    listOfShapes.remove(i);

                    break;

                }

            }

            updateShapeList();

            System.out.println(listOfShapes);

            userCanvas.repaint();

        }

    }

   

    @Override

    public void itemStateChanged(ItemEvent event) {

        Color color = COLORSARR[chooseColor.getSelectedIndex()];

        userCanvas.setFilledColor(color);

    }

   

    public static void main(String[] argv) {

        Draw userFrame = new Draw();

        userFrame.setSize(FINALWIDTH, FINALHEIGHT);

        userFrame.setLocation(150, 100);

        userFrame.addWindowListener(new WindowAdapter() {

            @Override

            public void windowClosing(WindowEvent event) {

                System.exit(0);

            }

        });

        userFrame.setVisible(true);

    }

    private JPanel getListPanel() {

        JPanel p = new JPanel(new GridLayout(2,1));

        p.setSize(100, 300);

        jScrollbar2 = new JScrollPane();

        jShapeList = new JList<>();

      

        updateShapeList();

        jScrollbar2.setViewportView(jShapeList);

      

        p.add(jScrollbar2);

      

        JButton deleteShape = new JButton("Delete Shape");

        deleteShape.addActionListener(this);

      

        p.add(deleteShape);

      

        return p;

    }

    public void updateShapeList() {

        jShapeList.setModel(new javax.swing.AbstractListModel<String>() {

            String[] shapenames = getMenuNames();

            private String[] getMenuNames(){

                int i = 0;

                String[] names = new String[listOfShapes.size()+1];

                for(ShapeClass m : listOfShapes) {

                    names[i++] = m.toString();

                }

                return names;

            }

            @Override

            public int getSize() {

                return shapenames.length;

            }

            @Override

            public String getElementAt(int i) { return shapenames[i]; }

        });

    }

  

    class DrawCanvas extends Canvas implements MouseListener,

                                                  MouseMotionListener {

    public static final int CIRCLE = 1;

    public static final int ROUNDED_RECTANGLE = 2;

    public static final int RECTANGLE_3D = 3;

        private int x1, y1, x2, y2;

        private int shape = CIRCLE;

        private final int PAINTTRUE = 0;

        private final int PAINTFALSE = 1;

      private int paintChoice = PAINTFALSE;

        public void setShape(int shape) {

            this.shape = shape;

        }

        private Color filledColor = null;

        public void setFilledColor(Color color) {

            filledColor = color;

                                }

        public DrawCanvas() {

            addMouseListener(this);

            addMouseMotionListener(this);

        }

        @Override

        public void paint(Graphics g) {

            int x, y, width, height;

            x = Math.min(x1, x2);

            y = Math.min(y1, y2);

            width = Math.abs(x1 - x2);

            height = Math.abs(y1 - y2);

                                               

            Shape currentShape = new Line2D.Double(x1, y1, x2, y2);

            switch (shape) {

            case ROUNDED_RECTANGLE :

                currentShape = new RoundRectangle2D.Double(x, y, width, height, width/4, height/4);

                break;

            case CIRCLE :

                int diameter = Math.max(width, height);

                currentShape = new Ellipse2D.Double(x,y, diameter, diameter);

                break;

            case RECTANGLE_3D :

                currentShape = new Rectangle2D.Double(x, y, width, height);

                break;

            }

          

            if(paintChoice == PAINTTRUE){

                ShapeClass sh = new ShapeClass(currentShape,filledColor, shape);

                Draw.listOfShapes.add(sh);

            }

          

            Graphics2D graphics = (Graphics2D) g;

            for (ShapeClass s : Draw.listOfShapes) {

                System.out.println("Shape : fill :"+s.fill);

                if(s.fill != null)

                    g.setColor(s.fill);

                else

                    g.setColor(Color.BLACK);

                if(s.fill != null)

                    graphics.fill(s.shape);

                else

                    graphics.draw(s.shape);

            }

            updateShapeList();

            setPaintOrRepaint(PAINTFALSE);

        }

        @Override

        public void mousePressed(MouseEvent event) {

            x1 = event.getX();

            y1 = event.getY();

        }

        @Override

        public void mouseReleased(MouseEvent event) {

            x2 = event.getX();

            y2 = event.getY();

            setPaintOrRepaint(PAINTTRUE);

            repaint();

        }

        @Override

        public void mouseClicked(MouseEvent e) {}

        @Override

        public void mouseEntered(MouseEvent e) {}

        @Override

        public void mouseExited(MouseEvent e) {}

      

        @Override

        public void mouseDragged(MouseEvent event) {

            x2 = event.getX();

            y2 = event.getY();

        }

        @Override

        public void mouseMoved(MouseEvent e) {}

        private void setPaintOrRepaint(int option) {

            paintChoice = option;

        }

    }

  

}

class ShapeClass {

    Shape shape;

    Color fill;

    String shapeName;

    ShapeClass(Shape shape, Color filledColor, int shapeName) {

        this.shape = shape;

        this.fill = filledColor;

        this.shapeName = getName(shapeName);

      

    }

    private String getName(int shapeName) {

        switch(shapeName) {

            case 1: return "Circle";

            case 2: return "Round Rectangle";

            case 3: return "Rectangle 3D";

            default: return "NoshapeName";

        }

    }

  

    @Override

    public String toString() {

        return shapeName+"("+shape.getBounds().x+","+shape.getBounds().y+", "+(fill==null?"No Color":fill.toString())+")";

    }

}

Output: