/**********************************************
    * Copyright (C) 2011 Lukas Laag
    * This file is part of svgreal.
    * 
    * svgreal is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * svgreal is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with svgreal.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.svg.edit.client.command.path;
  
  import java.util.List;
  
  import org.vectomatic.dom.svg.OMSVGDocument;
  import org.vectomatic.dom.svg.OMSVGGElement;
  import org.vectomatic.dom.svg.OMSVGPathSeg;
  import org.vectomatic.dom.svg.OMSVGPoint;
  import org.vectomatic.dom.svg.OMSVGRectElement;
  import org.vectomatic.svg.edit.client.command.path.IPathRepOwner.VertexState;
  
  import com.google.gwt.dom.client.Element;
  
  /**
   * Base class to path segment representation
   * @author laaglu
   */
  public abstract class SVGSegRep {
  	/**
  	 * The owner of this segment
  	 */
  	protected IPathRepOwner owner;
  	/**
  	 * The previous segment in the path
  	 */
  	protected SVGSegRep previous;
  	/**
  	 * The next segment in the path
  	 */
  	protected SVGSegRep next;
  	/**
  	 * The group where SVG elements representing tangents
  	 * to this segment are nested
  	 */
  	protected OMSVGGElement tangents;
  	/**
  	 * The endpoint of the segment
  	 */
  	protected OMSVGRectElement vertex;
  
  	public SVGSegRep(IPathRepOwner owner) {
  		this.owner = owner;
  		OMSVGDocument document = (OMSVGDocument) owner.getSvg().getOwnerDocument();
  		tangents = document.createSVGGElement();
  		vertex = document.createSVGRectElement();
  	}
  
  	public OMSVGGElement getTangents() {
  		return tangents;
  	}
  
  	public OMSVGRectElement getVertex() {
  		return vertex;
  	}
  
  	public abstract OMSVGPathSeg getElement();
  	public abstract float getX();
  	public abstract float getY();
  	public abstract void setX(float x);
  	public abstract void setY(float y);
  	public float getX1() {
  		return 0;
  	}
  	public float getY1() {
  		return 0;
  	}
  	public float getX2() {
  		return 0;
  	}
  	public float getY2() {
  		return 0;
  	}
  	public Element getCp1() {
  		return null;
  	}
  	public void setCp1(OMSVGPoint p, float hs) {
  	}
  	public Element getCp2() {
  		return null;
  	}
  	public void setCp2(OMSVGPoint p, float hs) {
  	}
 	/**
 	 * Updates the vertex, control points and tangents defining the segment
 	 * @param delta
 	 * The translation to apply
 	 * @param target
 	 * The vertex, control point or tangeant to update. null means the segment endpoint vertex
 	 * @param hs
 	 * The control point size
 	 * @param isCtrlKeyDown
 	 * True if the control key is pressed (spline will interpret this to preserve
 	 * the angle between tangents when a tangent control point is dragged)
 	 */
 	public abstract void processMouseMove(OMSVGPoint delta, Element target, float hs, boolean isCtrlKeyDown);
 	public void updateStart(OMSVGPoint delta, float hs) {
 	}
 	public abstract void updateEnd(OMSVGPoint delta, float hs);
 	public abstract void update(float hs);
 
 	public VertexState getState() {
 		return VertexState.read(vertex);
 	}
 	
 	public void setState(VertexState state) {
 		state.write(vertex);
 	}
 	
 	public SVGSegRep getPreviousSplineSeg() {
 		SVGSegRep splineSeg = null;
 		List<SVGSegRep> segments = owner.getSegments();
 		splineSeg = previous;
 		return (splineSeg instanceof SVGCubicSegRep || splineSeg instanceof SVGQuadraticSegRep) ? splineSeg : null;
 	}
 
 	public SVGSegRep getNextSplineSeg() {
 		SVGSegRep splineSeg = null;
 		splineSeg = next;
 		return (splineSeg instanceof SVGCubicSegRep || splineSeg instanceof SVGQuadraticSegRep) ? splineSeg : null;
 	}
 	
 	public void setNext(SVGSegRep seg) {
 		next = seg;
 	}
 	public void setPrevious(SVGSegRep seg) {
 		previous = seg;
 	}
 
 }