/**
 * $Id: mxGeometry.java,v 1.30 2009/11/24 12:00:29 gaudenz Exp $
 * Copyright (c) 2007, Gaudenz Alder
 */
package com.mxgraph.model;

import java.util.ArrayList;
import java.util.List;

import com.mxgraph.util.mxPoint;
import com.mxgraph.util.mxRectangle;

/**
 * Represents the geometry of a cell. For vertices, the geometry consists
 * of the x- and y-location, as well as the width and height. For edges,
 * the geometry either defines the source- and target-terminal, or it
 * defines the respective terminal points.
 * 
 * For edges, if the geometry is relative (default), then the x-coordinate
 * is used to describe the distance from the center of the edge from -1 to 1
 * with 0 being the center of the edge and the default value, and the
 * y-coordinate is used to describe the absolute, orthogonal distance in
 * pixels from that point. In addition, the offset is used as an absolute
 * offset vector from the resulting point. 
 */
public class mxGeometry extends mxRectangle
{

	/**
	 * 
	 */
	private static final long serialVersionUID = 2649828026610336589L;

	/**
	 * Global switch to translate the points in translate. Default is true.
	 */
	public static transient boolean TRANSLATE_CONTROL_POINTS = true;

	/**
	 * Stores alternate values for x, y, width and height in a rectangle.
	 * Default is null.
	 */
	protected mxRectangle alternateBounds;

	/**
	 * Defines the source- and target-point of the edge. This is used if the
	 * corresponding edge does not have a source vertex. Otherwise it is
	 * ignored. Default is null.
	 */
	protected mxPoint sourcePoint, targetPoint;

	/**
	 * List of mxPoints which specifies the control points along the edge.
	 * These points are the intermediate points on the edge, for the endpoints
	 * use targetPoint and sourcePoint or set the terminals of the edge to
	 * a non-null value. Default is null.
	 */
	protected List<mxPoint> points;

	/**
	 * Holds the offset of the label for edges. This is the absolute vector
	 * between the center of the edge and the top, left point of the label.
	 * Default is null.
	 */
	protected mxPoint offset;

	/**
	 * Specifies if the coordinates in the geometry are to be interpreted as
	 * relative coordinates. Default is false. This is used to mark a geometry
	 * with an x- and y-coordinate that is used to describe an edge label
	 * position, or a relative location with respect to a parent cell's
	 * width and height.
	 */
	protected boolean relative = false;

	/**
	 * Constructs a new geometry at (0, 0) with the width and height set to 0.
	 */
	public mxGeometry()
	{
		this(0, 0, 0, 0);
	}

	/**
	 * Constructs a geometry using the given parameters.
	 * 
	 * @param x X-coordinate of the new geometry.
	 * @param y Y-coordinate of the new geometry.
	 * @param width Width of the new geometry.
	 * @param height Height of the new geometry.
	 */
	public mxGeometry(double x, double y, double width, double height)
	{
		super(x, y, width, height);
	}

	/**
	 * Returns the alternate bounds.
	 */
	public mxRectangle getAlternateBounds()
	{
		return alternateBounds;
	}

	/**
	 * Sets the alternate bounds to the given rectangle.
	 * 
	 * @param rect Rectangle to be used for the alternate bounds.
	 */
	public void setAlternateBounds(mxRectangle rect)
	{
		alternateBounds = rect;
	}

	/**
	 * Returns the source point.
	 * 
	 * @return Returns the source point.
	 */
	public mxPoint getSourcePoint()
	{
		return sourcePoint;
	}

	/**
	 * Sets the source point.
	 * 
	 * @param sourcePoint Source point to be used.
	 */
	public void setSourcePoint(mxPoint sourcePoint)
	{
		this.sourcePoint = sourcePoint;
	}

	/**
	 * Returns the target point.
	 * 
	 * @return Returns the target point.
	 */
	public mxPoint getTargetPoint()
	{
		return targetPoint;
	}

	/**
	 * Sets the target point.
	 * 
	 * @param targetPoint Target point to be used.
	 */
	public void setTargetPoint(mxPoint targetPoint)
	{
		this.targetPoint = targetPoint;
	}

	/**
	 * Returns the list of control points.
	 */
	public List<mxPoint> getPoints()
	{
		return points;
	}

	/**
	 * Sets the list of control points to the given list.
	 * 
	 * @param value List that contains the new control points.
	 */
	public void setPoints(List<mxPoint> value)
	{
		points = value;
	}

	/**
	 * Returns the offset.
	 */
	public mxPoint getOffset()
	{
		return offset;
	}

	/**
	 * Sets the offset to the given point.
	 * 
	 * @param offset Point to be used for the offset.
	 */
	public void setOffset(mxPoint offset)
	{
		this.offset = offset;
	}

	/**
	 * Returns true of the geometry is relative.
	 */
	public boolean isRelative()
	{
		return relative;
	}

	/**
	 * Sets the relative state of the geometry.
	 * 
	 * @param value Boolean value to be used as the new relative state.
	 */
	public void setRelative(boolean value)
	{
		relative = value;
	}

	/**
	 * Swaps the x, y, width and height with the values stored in
	 * alternateBounds and puts the previous values into alternateBounds as
	 * a rectangle. This operation is carried-out in-place, that is, using the
	 * existing geometry instance. If this operation is called during a graph
	 * model transactional change, then the geometry should be cloned before
	 * calling this method and setting the geometry of the cell using
	 * mxGraphModel.setGeometry.
	 */
	public void swap()
	{
		if (alternateBounds != null)
		{
			mxRectangle old = new mxRectangle(getX(), getY(), getWidth(),
					getHeight());

			x = alternateBounds.getX();
			y = alternateBounds.getY();
			width = alternateBounds.getWidth();
			height = alternateBounds.getHeight();

			alternateBounds = old;
		}
	}

	/**
	 * Returns the point representing the source or target point of this edge.
	 * This is only used if the edge has no source or target vertex.
	 * 
	 * @param isSource Boolean that specifies if the source or target point
	 * should be returned.
	 * @return Returns the source or target point.
	 */
	public mxPoint getTerminalPoint(boolean isSource)
	{
		return (isSource) ? sourcePoint : targetPoint;
	}

	/**
	 * Sets the sourcePoint or targetPoint to the given point and returns the
	 * new point.
	 * 
	 * @param point Point to be used as the new source or target point.
	 * @param isSource Boolean that specifies if the source or target point
	 * should be set.
	 * @return Returns the new point.
	 */
	public mxPoint setTerminalPoint(mxPoint point, boolean isSource)
	{
		if (isSource)
		{
			sourcePoint = point;
		}
		else
		{
			targetPoint = point;
		}

		return point;
	}

	/**
	 * Translates the geometry by the specified amount. That is, x and y of the
	 * geometry, the sourcePoint, targetPoint and all elements of points are
	 * translated by the given amount. X and y are only translated if the
	 * geometry is not relative. If TRANSLATE_CONTROL_POINTS is false, then
	 * are not modified by this function.
	 * 
	 * @param dx Integer that specifies the x-coordinate of the translation.
	 * @param dy Integer that specifies the y-coordinate of the translation.
	 */
	public void translate(double dx, double dy)
	{
		// Translates the geometry
		if (!isRelative())
		{
			x += dx;
			y += dy;
		}

		// Translates the source point
		if (sourcePoint != null)
		{
			sourcePoint.setX(sourcePoint.getX() + dx);
			sourcePoint.setY(sourcePoint.getY() + dy);
		}

		// Translates the target point
		if (targetPoint != null)
		{
			targetPoint.setX(targetPoint.getX() + dx);
			targetPoint.setY(targetPoint.getY() + dy);
		}

		// Translate the control points
		if (TRANSLATE_CONTROL_POINTS && points != null)
		{
			int count = points.size();

			for (int i = 0; i < count; i++)
			{
				mxPoint pt = (mxPoint) points.get(i);

				pt.setX(pt.getX() + dx);
				pt.setY(pt.getY() + dy);
			}
		}
	}

	/**
	 * Returns a clone of the cell.
	 */
	public Object clone()
	{
		mxGeometry clone = (mxGeometry) super.clone();

		clone.setX(getX());
		clone.setY(getY());
		clone.setWidth(getWidth());
		clone.setHeight(getHeight());
		clone.setRelative(isRelative());

		List<mxPoint> pts = getPoints();

		if (pts != null)
		{
			clone.points = new ArrayList<mxPoint>(pts.size());

			for (int i = 0; i < pts.size(); i++)
			{
				clone.points.add((mxPoint) pts.get(i).clone());
			}
		}

		mxPoint tp = getTargetPoint();

		if (tp != null)
		{
			clone.setTargetPoint((mxPoint) tp.clone());
		}

		mxPoint sp = getSourcePoint();

		if (sp != null)
		{
			setSourcePoint((mxPoint) sp.clone());
		}

		mxPoint off = getOffset();

		if (off != null)
		{
			clone.setOffset((mxPoint) off.clone());
		}

		mxRectangle alt = getAlternateBounds();

		if (alt != null)
		{
			setAlternateBounds((mxRectangle) alt.clone());
		}

		return clone;
	}

}
