import java.awt.*;
import java.io.Serializable;
import java.awt.geom.*;
public abstract class Element implements Serializable{
public Element(Point position, Color color) {
this.position = new Point(position);
this.color = color;
}
// Returns the color of the element
public Color getColor() {
return color;
}
// Returns the position of the element
public Point getPosition() {
return position;
}
// Returns the bounding rectangle enclosing an element boundary
public java.awt.Rectangle getBounds() {
return bounds;
}
// Create a new element
public static Element createElement(int type, Color color, Point start, Point end) {
int LINE = 101;
int RECTANGLE = 102;
int CIRCLE = 103;
int CURVE = 104;
// Initial conditions
switch(type) {
case 101:
return new Element.Line(start, end, color);
case 102:
return new Rectangle(start, end, color);
case 103:
// return new Circle(start, end, color);
case 104:
// return new Curve(start, end, color);
default:
assert false; // We should never get to here
}
return null;
}
// Nested class defining a line
public static class Line extends Element {
public Line(Point start, Point end, Color color) {
super(start, color);
line = new Line2D.Double(origin.x, origin.y, end.x - position.x, end.y - position.y);
bounds = new java.awt.Rectangle(
Math.min(start.x ,end.x), Math.min(start.y, end.y),
Math.abs(start.x - end.x)+1, Math.abs(start.y - end.y)+1);
}
// Change the end point for the line
public void modify(Point start, Point last) {
line.x2 = last.x - position.x;
line.y2 = last.y - position.y;
bounds = new java.awt.Rectangle(
Math.min(start.x ,last.x), Math.min(start.y, last.y),
Math.abs(start.x - last.x)+1, Math.abs(start.y - last.y)+1);
}
// Display the line
public void draw(Graphics2D g2D) {
g2D.setPaint(color); // Set the line color
g2D.translate(position.x, position.y); // Move context origin
g2D.draw(line); // Draw the line
g2D.translate(-position.x, -position.y); // Move context origin back
}
private Line2D.Double line;
private final static long serialVersionUID = 1001L;
}
// Nested class defining a rectangle
public static class Rectangle extends Element {
public Rectangle(Point start, Point end, Color color) {
super(new Point(Math.min(start.x, end.x), Math.min(start.y, end.y)), color);
rectangle = new Rectangle2D.Double(
origin.x, origin.y, // Top-left corner
Math.abs(start.x - end.x), Math.abs(start.y - end.y)); // Width & height
bounds = new java.awt.Rectangle(
Math.min(start.x ,end.x), Math.min(start.y, end.y),
Math.abs(start.x - end.x)+1, Math.abs(start.y - end.y)+1);
}
// Display the rectangle
public void draw(Graphics2D g2D) {
g2D.setPaint(color); // Set the rectangle color
g2D.translate(position.x, position.y); // Move context origin
g2D.draw(rectangle); // Draw the rectangle
g2D.translate(-position.x, -position.y); // Move context origin back
}
// Method to redefine the rectangle
public void modify(Point start, Point last) {
bounds.x = position.x = Math.min(start.x, last.x);
bounds.y = position.y = Math.min(start.y, last.y);
rectangle.width = Math.abs(start.x - last.x);
rectangle.height = Math.abs(start.y - last.y);
bounds.width = (int)rectangle.width +1;
bounds.height = (int)rectangle.height + 1;
}
private Rectangle2D.Double rectangle;
private final static long serialVersionUID = 1001L;
}
// Abstract Element class methods
public abstract void draw(Graphics2D g2D);
public abstract void modify(Point start, Point last);
// Element class fields
protected Point position; // Position of a shape
protected Color color; // Color of a shape
protected java.awt.Rectangle bounds; // Bounding rectangle
protected static final Point origin = new Point(); // Origin for elements
private final static long serialVersionUID = 1001L;
}