/*----------------------------------------------------------------------------\

|                                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 = 5;

	this._extent = 1;



	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;

};