/*----------------------------------------------------------------------------\
|                                Range Class                                  |
|-----------------------------------------------------------------------------|
|                         Created by Erik Arvidsson                           |
|                  (http://webfx.eae.net/contact.html#erik)                   |
|                      For WebFX (http://webfx.eae.net/)                      |
|-----------------------------------------------------------------------------|
| Used to  model the data  used  when working  with  sliders,  scrollbars and |
| progress bars.  Based  on  the  ideas of  the javax.swing.BoundedRangeModel |
| interface  defined  by  Sun  for  Java;   http://java.sun.com/products/jfc/ |
| swingdoc-api-1.0.3/com/sun/java/swing/BoundedRangeModel.html                |
|-----------------------------------------------------------------------------|
|                Copyright (c) 2002, 2005, 2006 Erik Arvidsson                |
|-----------------------------------------------------------------------------|
| Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0                |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| 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.                                                          |
|-----------------------------------------------------------------------------|
| 2002-10-14 | Original version released                                      |
| 2005-10-27 | Use Math.round instead of Math.floor                           |
| 2006-05-28 | Changed license to Apache Software License 2.0.                |
|-----------------------------------------------------------------------------|
| Created 2002-10-14 | All changes are in the log above. | Updated 2006-05-28 |
\----------------------------------------------------------------------------*/


function Range() 
{
	this._value = 0;
	this._minimum = 0;
	this._maximum = 100;
	this._extent = 0;

	this._isChanging = false;
}

Range.prototype.setValue = function (value) 
	{
		value = Math.round(parseFloat(value));

		if (isNaN(value)) 
			return;

		if (this._value != value) 
		{
			if (value + this._extent > this._maximum)
				this._value = this._maximum - this._extent;
			else if (value < this._minimum)
				this._value = this._minimum;
			else
				this._value = value;

			if (!this._isChanging && typeof this.onchange == "function")
			 	this.onchange();
		}
	};

Range.prototype.getValue = function () 
	{
		return this._value;
	};

Range.prototype.setExtent = function (extent) 
	{
		if (this._extent != extent) 
		{
			if (extent < 0)
				this._extent = 0;
			else if (this._value + extent > this._maximum)
				this._extent = this._maximum - this._value;
			else
				this._extent = extent;

			if (!this._isChanging && typeof this.onchange == "function")
				this.onchange();
		}
	};

Range.prototype.getExtent = function () 
	{
		return this._extent;
	};

Range.prototype.setMinimum = function (minimum) 
	{
		if (this._minimum != minimum) 
		{
			var oldIsChanging = this._isChanging;
			this._isChanging = true;

			this._minimum = minimum;

			if (minimum > this._value)
				this.setValue(minimum);

			if (minimum > this._maximum) 
			{
				this._extent = 0;
				this.setMaximum(minimum);
				this.setValue(minimum)
			}
		
			if (minimum + this._extent > this._maximum)
				this._extent = this._maximum - this._minimum;

			this._isChanging = oldIsChanging;
		
			if (!this._isChanging && typeof this.onchange == "function")
				this.onchange();
		}
	};

Range.prototype.getMinimum = function () 
	{
		return this._minimum;
	};

Range.prototype.setMaximum = function (maximum) 
	{
		if (this._maximum != maximum) 
		{
			var oldIsChanging = this._isChanging;
			this._isChanging = true;

			this._maximum = maximum;

			if (maximum < this._value)
				this.setValue(maximum - this._extent);

			if (maximum < this._minimum) 
			{
				this._extent = 0;
				this.setMinimum(maximum);
				this.setValue(this._maximum);
			}
	
			if (maximum < this._minimum + this._extent)
				this._extent = this._maximum - this._minimum;

			if (maximum < this._value + this._extent)
				this._extent = this._maximum - this._value;

			this._isChanging = oldIsChanging;

			if (!this._isChanging && typeof this.onchange == "function")
				this.onchange();
		}
	};

Range.prototype.getMaximum = function () 
	{
		return this._maximum;
	};