Monday 19 December 2016

Chapter 13 Exercise 7, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

13.7 (The Colorable interface)
Design an interface named Colorable with a void method named howToColor().
Every class of a colorable object must imple- ment the Colorable interface.
Design a class named Square that extends GeometricObject and implements Colorable.
Implement howToColor to display the message Color all four sides.
Draw a UML diagram that involves Colorable, Square, and GeometricObject.
Write a test program that creates an array of five GeometricObjects.
For each object in the array, display its area and invoke its howToColor method
if it is colorable.

import javafx.scene.shape.Rectangle;

public class MyRectangle2D extends GeometricObject {

    private static final int X = 0;
    private static final int Y = 1;

    public double centerX;
    public double centerY;

    public double width;
    public double height;

    public MyRectangle2D(double centerX, double centerY, double width, double height) {
        this.centerX = centerX;
        this.centerY = centerY;
        this.width = width;
        this.height = height;
    }

    public MyRectangle2D(MyPoint centerPoint, double width, double height) {
        this(centerPoint.x, centerPoint.y, width, height);
    }

    public MyRectangle2D(Rectangle rectangle) {
        this(rectangle.getX(), rectangle.getY(), rectangle.getWidth(), rectangle.getHeight());
    }

    public MyRectangle2D() {
        this(0, 0, 1, 1);
    }

    public MyPoint getCenterP() {
        return new MyPoint(centerX, centerY);
    }
    public MyPoint getP1() {
        return new MyPoint(centerX - width / 2, centerY + height / 2);
    }

    public MyPoint getP2() {
        return new MyPoint(centerX + width / 2, centerY + height / 2);
    }

    public MyPoint getP3() {
        return new MyPoint(centerX - width / 2, centerY - height / 2);
    }

    public MyPoint getP4() {
        return new MyPoint(centerX + width / 2, centerY - height / 2);
    }

    public double getCenterX() {
        return centerX;
    }

    public void setCenterX(double centerX) {
        this.centerX = centerX;
    }

    public double getCenterY() {
        return centerY;
    }

    public void setCenterY(double centerY) {
        this.centerY = centerY;
    }

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }

    /** returns the perimeter of the rectangle. **/
    @Override
    public double getPerimeter() {

        return width * 2 + height * 2;
    }

    /** returns the area of the rectangle **/
    @Override
    public double getArea() {
        return width * height;
    }

    public boolean contains(double x, double y) {

        // Get max X & Y
        double maxX = getMax(getP1().x, getP2().x, getP3().x, getP4().x);
        double maxY = getMax(getP1().y, getP2().y, getP3().y, getP4().y);
        // Get min X & Y
        double minX = getMin(getP1().x, getP2().x, getP3().x, getP4().x);
        double minY = getMin(getP1().y, getP2().y, getP3().y, getP4().y);

        if (x < minX || x > maxX || y < minY || y > maxY)  return false;

        return true;

    }

    public boolean contains(MyRectangle2D r2) {
        double xDistance = (r2.centerX > centerX) ? r2.centerX - centerX : centerX - r2.centerX;
        double yDistance = (r2.centerY > centerY) ? r2.centerY - centerY : centerY - r2.centerY;

        // if the r2 is inside this rectangle
        // this is only valid if the rectangles are parallel
        return (xDistance <= (width - r2.width) / 2 && yDistance <= (height - r2.height) / 2);

    }

    public boolean overlaps(MyRectangle2D r2) {
        // subtract from the highest number
        double xDistance = (r2.centerX > centerX) ? r2.centerX - centerX : centerX - r2.centerX;
        double yDistance = (r2.centerY > centerY) ? r2.centerY - centerY : centerY - r2.centerY;

        // if the r2 overlaps this rectangle
        // this is only valid if the rectangles are parallel
        return (xDistance <= (width + r2.width) / 2 && yDistance <= (height + r2.height) / 2);

    }

    public static boolean r1OverLapsR2(Rectangle r1, Rectangle r2) {
        return r1.intersects(r2.getBoundsInLocal()) || r2.intersects(r1.getBoundsInLocal());
    }

    public javafx.scene.shape.Rectangle getRectangle() {
        return new Rectangle(centerX, centerY, width, height);
    }
    public boolean contains(MyPoint[] points) {

        for (MyPoint p : points) {
            if (!contains(p)) return false;
        }
        return true;
    }

    public boolean contains(MyPoint point) {
        return contains(point.x, point.y);
    }

    public static MyRectangle2D getRectangle(double[][] points) {

        // find leftLowestPoint

        // find rightMostPoint

        // find the center from highest and lowest point

        // x distance = width

        // y distance = height
        MyPoint[] myPoints = new MyPoint[points.length];
        for (int i = 0; i < points.length; i++) {
            myPoints[i] = new MyPoint(points[i][0], points[i][1]);
        }

        return getRectangle(myPoints);
    }

    public static MyRectangle2D getRectangle(MyPoint[] points) {

        MyPoint leftMost = getLeftMostPoint(points);
        MyPoint rightMost = getRighMostPoint(points);
        double width = Math.abs(rightMost.x - leftMost.x);

        MyPoint highest = getHighestPoint(points);
        MyPoint lowest = getLowestPoint(points);
        double height = Math.abs(highest.y - lowest.y);

        double centerX = highest.getCenterPoint(lowest).x;
        double centerY = leftMost.getCenterPoint(rightMost).y;

        return new MyRectangle2D(centerX, centerY, width, height);
    }

    private static MyPoint getLeftMostPoint(MyPoint[] points) {

        MyPoint leftMost = points[0];
        for (int i = 0; i < points.length; i++) {
            if (leftMost.x > points[i].x) {
                leftMost = points[i];
            }
        }
        return leftMost;
    }

    private static MyPoint getRighMostPoint(MyPoint[] points) {

        MyPoint rightMost = points[0];
        for (int i = 0; i < points.length; i++) {
            if (rightMost.x < points[i].x) {
                rightMost = points[i];
            }
        }
        return rightMost;
    }

    private static MyPoint getHighestPoint(MyPoint[] points) {

        MyPoint highest = points[0];
        for (int i = 0; i < points.length; i++) {
            if (highest.y < points[i].y) {
                highest = points[i];
            }
        }
        return highest;
    }

    private static MyPoint getLowestPoint(MyPoint[] points) {

        MyPoint lowest = points[0];
        for (int i = 0; i < points.length; i++) {
            if (lowest.y > points[i].y) {
                lowest = points[i];
            }
        }
        return lowest;
    }

    private double getMax(double... n) {
        double max = n[0];
        for (int i = 1; i < n.length; i++) {
            if (max < n[i]) {
                max = n[i];
            }
        }
        return max;
    }
    private double getMin(double... n) {
        double min = n[0];
        for (int i = 1; i < n.length; i++) {
            if (min > n[i]) {
                min = n[i];
            }
        }
        return min;
    }

    @Override
    public String toString() {
        return "MyRectangle2D{" +
                "centerX=" + centerX +
                ", centerY=" + centerY +
                ", width=" + width +
                ", height=" + height +
                '}';
    }
}

public abstract class GeometricObject implements Comparable<GeometricObject> {
    private String color = "white";
    private boolean filled;
    private java.util.Date dateCreated;

    /** Construct a default geometric object */
    protected GeometricObject() {
        dateCreated = new java.util.Date();
    }

    /** Construct a geometric object with color and filled value */
    protected GeometricObject(String color, boolean filled) {
        dateCreated = new java.util.Date();
        this.color = color;
        this.filled = filled;
    }

    /** Return color */
    public String getColor() {
        return color;
    }

    /** Set a new color */
    public void setColor(String color) {
        this.color = color;
    }

    /** Return filled. Since filled is boolean,
     *  the get method is named isFilled */
    public boolean isFilled() {
        return filled;
    }

    /** Set a new filled */
    public void setFilled(boolean filled) {
        this.filled = filled;
    }

    /** Get dateCreated */
    public java.util.Date getDateCreated() {
        return dateCreated;
    }

    /** Return a string representation of this object */
    @Override
    public String toString() {
        return "created on " + dateCreated + "\ncolor: " + color +
                " and filled: " + filled;
    }

    @Override
    public int compareTo(GeometricObject o) {
        if (getArea() > o.getArea())
            return 1;
        else if (getArea() < o.getArea())
            return -1;
        else
            return 0;
    }

    public static GeometricObject max(GeometricObject o1, GeometricObject o2) {
        return (o1.compareTo(o2) >= 0) ? o1 : o2;
    }

    public static double sumArea(GeometricObject[] a) {
        double sum = 0;
        for (GeometricObject o : a) {
            sum += o.getArea();
        }
        return sum;
    }
    /** Abstract method getArea */
    public abstract double getArea();

    /** Abstract method getPerimeter */
    public abstract double getPerimeter();
}

import javafx.scene.shape.Circle;

public class Circle2D  extends GeometricObject {

    private double x;
    private double y;
    private double radius;

    public Circle2D(Circle c) {
        this(c.getCenterX(), c.getCenterY(), c.getRadius());
    }
    public Circle2D(double x, double y, double radius) {
        this.x = x;
        this.y = y;
        this.radius = radius;
    }

    public Circle2D() {
        this(0, 0, 1);
    }

    public double getX() {
        return x;
    }

    public void setX(double x) {
        this.x = x;
    }

    public double getY() {
        return y;
    }

    public void setY(double y) {
        this.y = y;
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }

    @Override
    public double getArea() {
        return radius * radius * Math.PI;
    }

    @Override
    public double getPerimeter() {

        return 2 * radius * Math.PI;

    }



    public boolean contains(Circle2D circle2D) {
        double distance = getPoint().distance(circle2D.x, circle2D.y);

        if (distance <= Math.abs(this.radius - circle2D.radius)) {
            return true;
        } else {
            return false;
        }
    }

    public static boolean c1ContainsC2(Circle c1, Circle c2) {
        Circle2D cir1 = new Circle2D(c1);
        Circle2D cir2 =new Circle2D(c2);

        return cir1.contains(cir2);
    }

    public static boolean c1OverlapsC2(Circle c1, Circle c2) {
        Circle2D cir1 = new Circle2D(c1);
        Circle2D cir2 =new Circle2D(c2);

        if (cir1.contains(cir2) || cir2.contains(cir1)) return false;

        return cir1.overlaps(cir2);
    }

    public boolean overlaps(Circle2D circle2D) {
        double distance = getPoint().distance(circle2D.x, circle2D.y);

        if (distance  <= this.radius + circle2D.radius)
            return true;
        else
            return false;

    }

    private MyPoint getPoint() {
        return new MyPoint(this.x, this.y);
    }

    @Override
    public String toString() {
        return "Circle2D{" +
                "x=" + x +
                ", y=" + y +
                ", radius=" + radius +
                '}';
    }

    public boolean contains(double x, double y) {

        double distance = getPoint().distance(x, y);

        if (distance <= radius) return true;
        else return false;
    }
}

public class Exercise_07 {

    public static void main(String[] args) {

        GeometricObject[] geoShapes = new GeometricObject[5];
        geoShapes[0] = new MyRectangle2D();
        geoShapes[1] = new Circle2D();
        geoShapes[2] = new Square();
        geoShapes[3] = new MyRectangle2D(0, 0, 10, 5);
        geoShapes[4] = new Square(0,0,25);

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

            System.out.println("shape #" + (i + 1) + " area = " + geoShapes[i].getArea());
            if (geoShapes[i] instanceof Colorable) {
                System.out.println("How to color: "+((Colorable)geoShapes[i]).howToColor());
            }
        }

    }

}

class Square extends GeometricObject implements Colorable {

    private double x;
    private double y;
    private double side;

    Square() {
        this(0,0,10);
    }

    Square(double x, double y, double side) {
        this.x = x;
        this.y = y;
        this.side = side;
    }

    @Override
    public double getArea() {
        return side * side;
    }

    @Override
    public double getPerimeter() {
        return side * 4;
    }

    @Override
    public String howToColor() {
        return "Color all four sides.";
    }

    public double getX() {
        return x;
    }

    public void setX(double x) {
        this.x = x;
    }

    public double getY() {
        return y;
    }

    public void setY(double y) {
        this.y = y;
    }

    public double getSide() {
        return side;
    }

    public void setSide(double side) {
        this.side = side;
    }
}

interface Colorable {

    String howToColor();
}

1 comment :

  1. thank u man this is one of the best blogs i have ever seen

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