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.
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(); }
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