Vertex.java

/*
 * Author:  Chris Seguin
 *
 * This software has been developed under the copyleft
 * rules of the GNU General Public License.  Please
 * consult the GNU General Public License for more
 * details about use and distribution of this software.
 */
package org.acm.seguin.uml.line;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.io.PrintWriter;

/**
 *  Vertex
 *
 *@author     Chris Seguin
 *@created    July 28, 1999
 */
public class Vertex {
	private Point point;
	private boolean selected;
	private boolean activated;
	private boolean rescaled;
	private double scale;
	private Point computed;
	private static double near = 3.0;
	private static int vertexSizeHalf = 2;
	private static int vertexSize = 5;


	/**
	 *  Constructor for the Vertex object
	 *
	 *@param  init  Description of Parameter
	 */
	public Vertex(Point init) {
		point = init;
		computed = new Point();
		activated = false;
		selected = false;
		rescaled = true;
		scale = 1.0;
	}


	/**
	 *  Checks if the point is selected
	 *
	 *@return    true if the point is selected
	 */
	public boolean isSelected() {
		return selected;
	}


	/**
	 *  Checks if this vertex is the active vertex
	 *
	 *@return    true if it is
	 */
	public boolean isActive() {
		return activated;
	}


	/**
	 *  Paints the object
	 *
	 *@param  g  The graphics context
	 */
	public void paint(Graphics g) {
		if (activated) {
			g.setColor(Color.magenta);
			g.fillOval((int) (getX() - Vertex.vertexSizeHalf),
					(int) (getY() - Vertex.vertexSizeHalf),
					Vertex.vertexSize, Vertex.vertexSize);
		}
		else if (selected) {
			g.setColor(Color.black);
			g.fillOval((int) (getX() - Vertex.vertexSizeHalf),
					(int) (getY() - Vertex.vertexSizeHalf),
					Vertex.vertexSize, Vertex.vertexSize);
		}
		else {
			//  Don't paint it
			//g.setColor(Color.black);
			//g.drawOval((int) point.getX(), (int) point.getY(), 1, 1);
		}
	}


	/**
	 *  Determines if it is hit by a point
	 *
	 *@param  p  The point
	 *@return    true if this point hits this vertex
	 */
	public boolean hit(Point p) {
		double diffX = getX() - p.getX();
		double diffY = getY() - p.getY();

		double dist = Math.sqrt(diffX * diffX + diffY * diffY);

		return (dist < Vertex.near);
	}


	/**
	 *  Moves the vertex to p
	 *
	 *@param  p  the destination of the move
	 */
	public void move(Point p) {
		point.x = (int) (p.x / scale);
		point.y = (int) (p.y / scale);
		rescaled = true;
	}


	/**
	 *  Save the vertex
	 *
	 *@param  output  the output stream
	 */
	public void save(PrintWriter output) {
		output.print("(" + point.x + "," + point.y + ")");
	}


	/**
	 *  Shifts the point by a certain amount
	 *
	 *@param  x  the amount in the x coordinate
	 *@param  y  the amount in the y coordinate
	 */
	public void shift(int x, int y) {
		point.x += x;
		point.y += y;
		rescaled = true;
	}


	/**
	 *  Scales the vertex
	 *
	 *@param  value  the scaling factor
	 */
	public void scale(double value) {
		if (Math.abs(value - scale) > 0.001) {
			rescaled = true;
			scale = value;
		}
	}


	/**
	 *  Gets the X attribute of the Vertex object
	 *
	 *@return    The X value
	 */
	protected int getX() {
		if (rescaled) {
			computed.x = (int) (point.x * scale);
			computed.y = (int) (point.y * scale);
			rescaled = false;
		}
		return computed.x;
	}


	/**
	 *  Gets the Y attribute of the Vertex object
	 *
	 *@return    The Y value
	 */
	protected int getY() {
		if (rescaled) {
			computed.x = (int) (point.x * scale);
			computed.y = (int) (point.y * scale);
			rescaled = false;
		}
		return computed.y;
	}


	/**
	 *  Gets the scaled point
	 *
	 *@return    the scaled point
	 */
	protected Point getPoint() {
		if (rescaled) {
			computed.x = (int) (point.x * scale);
			computed.y = (int) (point.y * scale);
			rescaled = false;
		}
		return computed;
	}


	/**
	 *  Selects the point
	 *
	 *@param  way  true if the point is selected
	 */
	protected void select(boolean way) {
		selected = way;
		if (!selected) {
			activated = false;
		}
	}


	/**
	 *  Sets whether this is the active vertex
	 *
	 *@param  way  true if this vertex is active
	 */
	protected void active(boolean way) {
		activated = way;
		if (activated) {
			selected = true;
		}
	}


	/**
	 *  Sets the Near attribute of the Vertex class
	 *
	 *@param  value  The new Near value
	 */
	public static void setNear(double value) {
		near = value;
	}


	/**
	 *  Sets the VertexSize attribute of the Vertex class
	 *
	 *@param  value  The new VertexSize value
	 */
	public static void setVertexSize(int value) {
		vertexSizeHalf = value / 2;
		vertexSize = value;
	}
}