Question

Java Programming

.zip or .jar with 4 files: Shape.java, Square.java, TSquare.java, Triangle.java

In this homework, you will build the below hierarchy:

Overview:

You will implement the supplier code: Shape, Square, TSquare, and Triangle, which will be used by the Homework7Main program. This program will use the DrawingPanel to draw these objects onto a canvas.

Specification:

You will take advantage of inheritance with using a super class, Shape.java. (below) Shape is an abstract class, which means it can be extended, but not instantiated. We will talk more about abstract classes this week.

Notice in Shape that there is only 1 dimension: size, and coordinates for one point. The coordinates represent the point in the top left corner of the shape. Most shapes can be defined with just these 3 pieces of information.

First, there's some work to do in the parent class, Shape:

Implement the isInShape() method. Return true if the coordinates lie within the bounding box of Shape

Implement moveCenterTo(), which moves the center of the bounding box of the Shape to those coordinates.

Next, implement the subclasses Square, TSquare, and Triangle, Each of these shapes use the value size to determine the square bounding box.

Be smart with inheritance. Do not introduce new instance variables unless they are needed. Do not implement methods unnecessarily.

Override isInShape(). This method should be accurate for the specific shape, don't just rely on a point lying on the bounding box. Does Square need to override isInShape()?

Each subclass will need to implement the method, drawMe(), to draw the figure on the provided Graphics space.

For the TSquare shape, the width parameter determines the width of the horizontal and vertical blocks of the 'T'. Check out the label on the diagram above. You will need to draw multiple rectangles to create the T shape.

For the Triangle, you will use the fillPolygon method in Graphics, and supply it with the three points of the triangle

Expected Output of Homework7Main program below:

[true, false, true, false, true, false] [true, false, true, false, true, false] [true, false, true, false, true, true, false]

Homework7Main.java:

import java.awt.*;
import java.util.Arrays;

public class Homework7Main {

    public static void main(String[] args) {

        DrawingPanel canvas = new DrawingPanel(500, 500);
        Graphics g = canvas.getGraphics();

        /**
         * Group 1:
         */

        Shape[] shapes = { new Square(10, 10, Color.BLACK, 20),
              new TSquare(30, 200, new Color( 0, 255, 180 ), 50, 10),
              new Triangle(400, 10, Color.BLUE, 40)};

        shapes[0].drawMe(g);
        shapes[1].drawMe(g);
        shapes[2].drawMe(g);

        boolean[] a = {shapes[0].isInShape(15, 15),
                shapes[0].isInShape(31, 20),
                shapes[1].isInShape(70, 205),
                shapes[1].isInShape(30, 215),
                shapes[2].isInShape( 410, 30),
                shapes[2].isInShape(430, 20)};

        System.out.println(Arrays.toString(a));


        /**
         * Group 2:
         */

        Square s = new Square(100, 100, Color.YELLOW, 40);
        TSquare t = new TSquare(300, 150, Color.GRAY, 75, 30);
        Triangle rt = new Triangle(375, 300, Color.CYAN, 17);

        s.drawMe(g);
        t.drawMe(g);
        rt.drawMe(g);

        boolean[] b = {s.isInShape(100, 139),
                       s.isInShape(140, 140),
                       t.isInShape(374, 150),
                       t.isInShape(370, 220),
                       rt.isInShape( 375, 300),
                       rt.isInShape(390, 305)};

        System.out.println(Arrays.toString(b));


        /**
         * Group 3:
         */

        s.setColor(new Color(35, 45, 90));
        s.setPosition(275, 250);
        t.setColor(new Color(0, 255, 90));
        t.setPosition(200, 380);
        t.setSize(50);
        t.setWidth(5);
        rt.setColor(Color.MAGENTA);
        rt.setSize(50);
        rt.moveCenterTo(350, 473);

        s.drawMe(g);
        t.drawMe(g);
        rt.drawMe(g);

        boolean[] c = {s.isInShape(275, 250),
                       s.isInShape(274, 250),
                       t.isInShape(210, 380),
                       t.isInShape(200, 385),
                       rt.isInShape( 350, 473),
                       rt.isInShape(340, 490),
                       rt.isInShape(328, 450)};

        System.out.println(Arrays.toString(c));
    }
}

Shape.java:

import java.awt.*;

/**
 * Shape is an abstract class. This means that it
 * can be extended, but not instantiated. 
 * 
 * This means that new Shape(..) is impossible. 
 * 
 * Child clases will inherit all of the methods
 * and properties below. Child classes will also
 * need to implement the abstract method below. 
 * 
 * Child class headers will look like this:
 * 
 * public class ChildClass extends Shape {
 */
public abstract class Shape{

    /**
     * x and y represent the top, left corner
     * of the bounding box of the shape
     */
    private int x, y;
    private Color color;
    private int size;


    public Shape (int x, int y, Color color, int size){
        this.x = x;
        this.y = y;
        this.color = color;
        this.size = size;
    }

    public int getX(){
        return x;
    }

    public int getY(){
        return y;
    }

    public Color getColor() {
        return color;
    }

    public void setColor (Color color){
        this.color = color;
    }

    public void setPosition (int x, int y){
        this.x = x;
        this.y = y;
    }
    
    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    /**
     * This method will return true if the the
     * x and y arguments are within both the 
     * bounding box and the shape itself.
     * @param x
     * @param y
     */
    public boolean isInShape(int x, int y) {
        //Implement this method
        return false;
    }

    /**
     * This will set the center of the bounding box
     * to the x and y parameter. 
     * 
     * Example: A square of height 10 that uses this
     * method to move its center to (5, 5) will have 
     * its top left corner at (0,0)
     * 
     * @param x
     * @param y
     */
    public void moveCenterTo(int x, int y){
        //Implement this method
    }

    /**
     * This method is abstract, which means
     * that there is no implementation in this 
     * class. However - the child classes will
     * implement this method. 
     * 
     * The method header in child classes will 
     * look like this:
     * 
     * public void drawMe(Graphics g) {
     *     //...
     * }
     */
    public abstract void drawMe(Graphics g);

}

abstract Shape TSquare Triangle Square DrawingPanel Homework7Main LI Drawing Panel File View Help

Answer 1

Shape.java :

import java.awt.*;

/**
* Shape is an abstract class. This means that it
* can be extended, but not instantiated.
*
* This means that new Shape(..) is impossible.
*
* Child clases will inherit all of the methods
* and properties below. Child classes will also
* need to implement the abstract method below.
*
* Child class headers will look like this:
*
* public class ChildClass extends Shape {
*/
public abstract class Shape{

    /**
     * x and y represent the top, left corner
     * of the bounding box of the shape
     */
    private int x, y;
    private Color color;
    private int size;

    public Shape (int x, int y, Color color, int size){
        this.x = x;
        this.y = y;
        this.color = color;
        this.size = size;
    }

    public int getX(){
        return x;
    }

    public int getY(){
        return y;
    }

    public Color getColor() {
        return color;
    }

    public void setColor (Color color){
        this.color = color;
    }

    public void setPosition (int x, int y){
        this.x = x;
        this.y = y;
    }
  
    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    /**
     * This method will return true if the the
     * x and y arguments are within both the
     * bounding box and the shape itself.
     * @param x
     * @param y
     */
    public boolean isInShape(int x, int y) {
       if((size+this.x-1)<x || this.x>x){
           return false;
       }
       if((size+this.y-1)<y || this.y>y){
           return false;
       }
        return true;
    }

    /**
     * This will set the center of the bounding box
     * to the x and y parameter.
     *
     * Example: A square of height 10 that uses this
     * method to move its center to (5, 5) will have
     * its top left corner at (0,0)
     *
     * @param x
     * @param y
     */
    public void moveCenterTo(int x, int y){
        this.x = x - (size/2);
        this.y = y - (size/2);
    }

    /**
     * This method is abstract, which means
     * that there is no implementation in this
     * class. However - the child classes will
     * implement this method.
     *
     * The method header in child classes will
     * look like this:
     *
     * public void drawMe(Graphics g) {
     *     //...
     * }
     */
    public abstract void drawMe(Graphics g);

}

Square.java:

import java.awt.Color;
import java.awt.Graphics;

public class Square extends Shape {

   public Square(int x, int y, Color color, int size) {
       super(x, y, color, size);
   }

   public void drawMe(Graphics g) {
       g.setColor(getColor());
       g.fillRect(getX(), getY(), getSize(), getSize());
   }
  
   //Square does not need to override isInShape().

}

TSquare.java:

import java.awt.Color;
import java.awt.Graphics;

public class TSquare extends Shape {
   private int width;
  
   public TSquare(int i, int j, Color color, int k, int l) {
       super(i, j, color, k);
       this.width = l;
   }

   public void drawMe(Graphics g) {
       g.setColor(getColor());
       g.fillRect(getX(), getY(), getSize(), width);
       g.fillRect((getX()+(getSize()/2)-(width/2)), getY(), width, getSize());
      
   }

   public void setWidth(int i) {
       width = i;
   }
  
   public boolean isInShape(int x, int y) {
       if((getSize()+getX()-1)<x || getX()>x){
           return false;
       }
       if((getSize()+getY()-1)<y || getY()>y){
           return false;
       }
       if((getX()+(getSize()/2)-(width/2))>x && (width+getY()-1)<y){
           return false;
       }
       if((getX()+(getSize()/2)+(width/2))<x && (width+getY()-1)<y){
           return false;
       }
        return true;
    }

}

Triangle.java:

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Polygon;

public class Triangle extends Shape {

   public Triangle(int x, int y, Color color, int size) {
       super(x, y, color, size);
   }

   public void drawMe(Graphics g) {
       g.setColor(getColor());
       Polygon poly = new Polygon();
       poly.addPoint(getX(), getY());
       poly.addPoint(getX(), (getY()+getSize()));
       poly.addPoint((getX()+getSize()), (getY()+getSize()));
       g.fillPolygon(poly);
   }
  
   public boolean isInShape(int x, int y) {
       if((getSize()+getX()-1)<x || getX()>x){
           return false;
       }
       if((getSize()+getY()-1)<y || getY()>y){
           return false;
       }
       if((getX()+(y-getY()))<x){
           return false;
       }
        return true;
    }

}