secondo/Algebras/SpatialLR/Dsplline2.java

//This file is part of SECONDO.

//Copyright (C) 2004, University in Hagen, Department of Computer Science,
//Database Systems for New Applications.

//SECONDO 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 2 of the License, or
//(at your option) any later version.

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//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 SECONDO; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

/*
8 Dsplline2

8.1 Overview

This file contains the implementation to add the new type ~Line2~ of the
~SpatialLRAlgebra~ to the ~HoeseViewer~.

*/

package  viewer.hoese.algebras;

import  java.awt.geom.*;
import  java.awt.*;
import  sj.lang.ListExpr;
import  java.util.*;
import  viewer.*;
import viewer.hoese.*;
import tools.Reporter;


/*
8.2 Class ~Dsplline2

*/
public class Dsplline2 extends DisplayGraph {
/*
The shape representing this line

*/
  GeneralPath GP;

/*
boolean flag indicating the defined state

*/
  boolean defined;

/*
The textual representation of this line2

*/
  String entry;


/*
returns true because this type is a line

*/
  public boolean isLineType(int num){
    return true;
  }

  public int numberOfShapes(){
     return 1;
  }

  public Shape getRenderObject(int num, AffineTransform at){
    if(num!=0){
      return null;
    } else{
        return GP;
    }
  }


/*
returns the string for the textual representation of this

*/
  public String toString(){
     if(err || !defined){
        return entry;
     }
     else{
        return entry + " ("+Cat.getName()+")";
     }

  }

/*
Creates an instance of ~GeneralPath~ form the ~ListExpr~.

*/
  public boolean ScanValue (ListExpr expr) {
    if(isUndefined(expr)){
       defined=false;
       GP=null;
       return false;
    }
    if (expr.listLength() != 2) {
        Reporter.writeError("Invalid line2 expression: 2 elements needed");
        err = true;
        return false;
    }

    defined=true;
    GP = new GeneralPath();
    ListExpr types = expr.first();
    ListExpr coords = expr.second();
    int offsetCoords = 0;
    double x1, x2, y1, y2 = 0;

    while(!types.isEmpty()) {
      if(LEUtils.readNumeric(types.first()) == 0) {
        x1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        y1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        GP.moveTo(x1,y1);
      } else if(LEUtils.readNumeric(types.first()) == 1) {
        x1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        y1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        GP.lineTo(x1,y1);
      } else if(LEUtils.readNumeric(types.first()) == 2) {
        x1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        y1 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        x2 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        y2 = LEUtils.readNumeric(coords.first());
        coords = coords.rest();
        GP.quadTo(x1,y1,x2,y2);
      } else if(LEUtils.readNumeric(types.first()) == 4) {
        GP.closePath();
      }
      types = types.rest();
    }
    return true;
  }

/*
Gets called by ~HoeseViewer~ to change a list expr to a java object.

*/
  public void init (String name, int nameWidth, int indent, ListExpr type, ListExpr value, QueryResult qr) {
    AttrName = extendString(name,nameWidth, indent);

    ScanValue(value);
    if (err) {
      Reporter.writeError("Error in ListExpr :parsing aborted");
      entry = AttrName + " : <error>";
      qr.addEntry(entry);
      GP=null;
      return;
    }
    else if(!defined){
      entry = AttrName+" : undefined";
      qr.addEntry(entry);
      return;
    }
    // normal case-> defined line
    entry = AttrName + " : line";
    defined=GP!=null;
    err=false;
    qr.addEntry(this);
  }

}