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GridIterator

Kind of class:	class
Inherits from:	Point
Implements:	Iterator
Version:	1.0
Author:	Francis Bourre
Classpath:	com.bourre.structures.GridIterator
File last modified:	Wednesday, 31 October 2007, 07:35:30

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/*
 * Copyright the original author or authors.
 * 
 * Licensed under the MOZILLA PUBLIC LICENSE, Version 1.1 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.mozilla.org/MPL/MPL-1.1.html
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
/**
 * {@code GridIterator} iterates over an {@link AbstractGrid} data structure.
 * 
 * <p>Example
 * <code>
 *   var g : NGrid : NGrid = new NGrid(2,2);
 *   var myIterator : Iterator = new GridIterator( g );
 *   
 *   while( myIterator.hasNext() ) {
 *     var e : Number = myIterator.next();
 *   }
 * </code>
 * 
 * @author Francis Bourre
 * @version 1.0
 */
 
import com.bourre.data.iterator.Iterator;
import com.bourre.log.PixlibStringifier;
import com.bourre.structures.AbstractGrid;
import com.bourre.structures.Point;

class com.bourre.structures.GridIterator 
    extends Point
    implements Iterator
{
    //-------------------------------------------------------------------------
    // Private properties
    //-------------------------------------------------------------------------
    
    private var _g:AbstractGrid;
    private var _n:Number;
    private var _l:Number;
    
    
    //-------------------------------------------------------------------------
    // Public API
    //-------------------------------------------------------------------------
    
    /**
     * Usage : <em>var i:GridIterator = new GridIterator(myGrid);</em>
     * @param g                 target Grid for the iterator.
     */
    
    /**
     * Constructs a new {@code GridIterator} instance to iterate 
     * over passed-in {@link AbstractGrid} data structure.
     * 
     * <p>Example
     * <code>
     *   var g : NGrid : NGrid = new NGrid(2,2);
     *   var myIterator : Iterator = new GridIterator( g );
     * </code>
     * 
     * @param g an {@link AbstractGrid} instance.
     */
    public function GridIterator(g:AbstractGrid)
    {
        super(undefined, undefined);
        _g = g;
        _n = -1;
        _l = _g.getArea() - 1;
    }
    
    /**
     * Indicates if the next iterator position exists.
     * 
     * <p>Example
     * <code>
     *   var g : NGrid : NGrid = new NGrid(2,2);
     *   var myIterator : Iterator = new GridIterator( g );
     *   
     *   while( myIterator.hasNext() ) {
     *     //
     *   }
     * </code>
     * 
     * @return {@code true} if next position exist, either {@code false}
     */
    public function hasNext() : Boolean 
    {
        return _n < _l; 
    }

    /**
     * Increments iterator position and returns next object value.
     * 
     * <p>Example
     * <code>
     *   var g : NGrid : NGrid = new NGrid(2,2);
     *   var myIterator : Iterator = new GridIterator( g );
     *   
     *   while( myIterator.hasNext() ) {
     *     var e : Number = myIterator.next();
     *   }
     * </code>
     * 
     * @return Grid element (relaxed type for Grid polymorphism)
     */
    public function next()
    {
        reset(_g.getCoordinates(++_n));
        return  _g.getVal(this);
    }
    
    /**
     * Returns current iterator position in grid structure.
     * 
     * <p>Example
     * <code>
     *   var g : NGrid : NGrid = new NGrid(2,2);
     *   var myIterator : Iterator = new GridIterator( g );
     *   
     *   while( myIterator.hasNext() ) {
     *     var e : Number = myIterator.next();
     *     PixlibDebug.INFO( "Iterator index = " + myIterator.getIndex() );
     *   }
     * </code>

     * @return {@code Number} index
     */
    public function getIndex() : Number 
    { 
        return _n; 
    }
    
    /**
     * Returns the string representation of this instance.
     * @return the string representation of this instance
     */
    public function toString() : String 
    {
        return PixlibStringifier.stringify( this );
    }
}

GridIterator iterates over an AbstractGrid data structure.

Example

var g : NGrid : NGrid = new NGrid(2,2);
var myIterator : Iterator = new GridIterator( g );

while( myIterator.hasNext() ) {
  var e : Number = myIterator.next();
}

Summary

Constructor

GridIterator

Instance properties

Instance properties inherited from Point

x y

Class methods

Class methods inherited from Point

absNew getDistance minusNew negNew plusNew

Instance methods

hasNext
next
getIndex
toString

Instance methods inherited from Point

abs clone compare equals getCrossProduct getDirection getDotProduct getLength getProjectionLength init minus neg normalize plus project reset scalarMultiply toString

Constructor

GridIterator

function GridIterator (

g:AbstractGrid)

Usage : var i:GridIterator = new GridIterator(myGrid);

Parameters:

target Grid for the iterator.

Instance methods

getIndex

function getIndex (

) : Number

Returns current iterator position in grid structure.

Example

var g : NGrid : NGrid = new NGrid(2,2);
var myIterator : Iterator = new GridIterator( g );

while( myIterator.hasNext() ) {
  var e : Number = myIterator.next();
  PixlibDebug.INFO( "Iterator index = " + myIterator.getIndex() );
}

Returns:

Number index

Specified by:

com.bourre.data.iterator.Iterator.getIndex

hasNext

function hasNext (

) : Boolean

Indicates if the next iterator position exists.

Example

var g : NGrid : NGrid = new NGrid(2,2);
var myIterator : Iterator = new GridIterator( g );

while( myIterator.hasNext() ) {
  //
}

Returns:

true if next position exist, either false

Specified by:

com.bourre.data.iterator.Iterator.hasNext

function next (

)

Increments iterator position and returns next object value.

Example

var g : NGrid : NGrid = new NGrid(2,2);
var myIterator : Iterator = new GridIterator( g );

while( myIterator.hasNext() ) {
  var e : Number = myIterator.next();
}

Returns:

Grid element (relaxed type for Grid polymorphism)

Specified by:

com.bourre.data.iterator.Iterator.next

toString

function toString (

) : String

Returns the string representation of this instance.

Returns:

the string representation of this instance

Overrides:

Point.toString