textLayout/src/flashx/textLayout/container/ColumnState.as - flex-tlf - Git at Google

 ////////////////////////////////////////////////////////////////////////////////
 //
 //  Licensed to the Apache Software Foundation (ASF) under one or more
 //  contributor license agreements.  See the NOTICE file distributed with
 //  this work for additional information regarding copyright ownership.
 //  The ASF licenses this file to You 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.
 //
 ////////////////////////////////////////////////////////////////////////////////
 package flashx.textLayout.container
 {
 	import flash.geom.Rectangle;

 	import flashx.textLayout.debug.assert;
 	import flashx.textLayout.elements.TableDataCellElement;
 	import flashx.textLayout.formats.BlockProgression;
 	import flashx.textLayout.formats.Direction;
 	import flashx.textLayout.formats.FormatValue;
 	import flashx.textLayout.formats.ITextLayoutFormat;
 	import flashx.textLayout.formats.LineBreak;
 	import flashx.textLayout.tlf_internal;
 	import flashx.textLayout.utils.Twips;

 	use namespace tlf_internal;

 	/**
 	 * The ColumnState class calculates the sizes and locations of columns using
 	 * the width of the container and the container attributes. You can create instances of this class
 	 * independently to calculate column values, or you can get the column values that
 	 * were used for the text after the container has been composed or updated (redrawn).
 	 *
 	 * @playerversion Flash 10
 	 * @playerversion AIR 1.5
 	 * @langversion 3.0
 	 *
 	 * @see ContainerController
 	 */

 	public class ColumnState
 	{
 		// input information
 		private var _inputsChanged:Boolean;
 		private var _blockProgression:String;
 		private var _columnDirection:String;
 		private var _paddingTop:Number;
 		private var _paddingBottom:Number;
 		private var _paddingLeft:Number;
 		private var _paddingRight:Number;
 		private var _compositionWidth:Number;
 		private var _compositionHeight:Number;
 		private var _forceSingleColumn:Boolean;

 		private var _inputColumnWidth:Object;
 		private var _inputColumnGap:Number;
 		private var _inputColumnCount:Object

 		// Generated column information
 		private var _columnWidth:Number;
 		private var _columnCount:int;
 		private var _columnGap:Number;
 		private var _inset:Number;

 		// and the array of columns
 		private var _columnArray:Array;
 		private var _tableCellArray:Array;
 		private var _singleColumn:Rectangle;

 		/**
 		 * Constructor function - creates a ColumnState object.
 		 *
 		 * If the values of <code>controller.compositionWidth</code> and <code>controller.compositionHeight</code> equal
 		 * <code>NaN</code> (not a number), the constructor measures the container's contents to determine the actual
 		 * composition width and height that feed into ColumnState.
 		 *
 		 * Use the constants defined by the <code>flashx.textLayout.formats.BlockProgression</code> class to
 		 * specify the value of the <code>blockProgression</code> parameter. Use the constants defined by
 		 * <code>flashx.textLayout.formats.Direction</code> to specify the value of the <code>columnDirection</code>
 		 * parameter.
 		 *
 		 * @param blockProgression The direction of lines for the textflow, either BlockProgression.TB (top-to-bottom) or
 		 * 		BlockProgression.RL (right-to-left).
 		 * @param columnDirection The direction of column layout for the text flow, either Direction.RTL (right-to-left) or
 		 * 		Direction.LTR (left-to-right).
 		 * @param controller A ContainerController instance whose attributes are used to calculate the column values.
 		 * @param compositionWidth The horizontal extent, in pixels, allowed for text inside the container.
 		 * @param compositionHeight The vertical extent, in pixels, allowed for text inside the container.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 		 * @langversion 3.0
 		 *
 		 * @see flashx.textLayout.formats.BlockProgression BlockProgression
 		 * @see flashx.textLayout.formats.Direction Direction
 	 	 */

 		public function ColumnState(blockProgression:String, columnDirection:String, controller:ContainerController, compositionWidth:Number, compositionHeight:Number)
 		{
 			_inputsChanged = true;
 			_columnCount = 0;

 			if (blockProgression != null)		// if values are legit, recalculate now. They might not be, if this is called from a containerController constructor.
 			{
 				updateInputs(blockProgression, columnDirection, controller, compositionWidth, compositionHeight);
 				computeColumns();
 			}
 		}

 		/**
 		 * The width of columns, in pixels, in the container.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 	 	 * @langversion 3.0
 	 	 */

 		public function get columnWidth():Number
 		{ return _columnWidth; }

 		/**
 		 * The number of columns in the container.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 	 	 * @langversion 3.0
 	 	 */

 		public function get columnCount():int
 		{ return _columnCount; }

 		/**
 		 * The number of cells in the container.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 		 * @langversion 3.0
 		 */

 		public function get cellCount():int
 		{
 			if ( _tableCellArray )
 				return _tableCellArray.length;
 			return -1;
 		}

 		/**
 		 * The amount of space, in pixels, left between columns in the container.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 	 	 * @langversion 3.0
 	 	 */

 		public function get columnGap():Number
 		{ return _columnGap; }

 		/**
 		 * Returns the area that a column takes within the container. Allows you to access the area for a
 		 * specific column.
 		 *
 		 * @param index The relative position of the column among all columns in the container, with the first
 		 * 	column at position 0.
 		 *
 		 * @return The area of the specified column.
 		 *
 		 * @playerversion Flash 10
 		 * @playerversion AIR 1.5
 		 * @langversion 3.0
 		 */

 		public function getColumnAt(index:int):Rectangle
 		{
 			return _columnCount == 1 ? _singleColumn : _columnArray[index];
 		}

 		public function getCellAt(index:int):TableDataCellElement
 		{
 			return _tableCellArray[index];
 		}

 		public function pushTableCell(cell:TableDataCellElement):void
 		{
 			if ( _tableCellArray == null )
 				_tableCellArray = new Array();
 			_tableCellArray.push(cell);
 		}

 		public function clearCellList():void
 		{
 			_tableCellArray = null;
 		}

 		/** Recalculate actual column settings based on attributes and width
 		 * from the container. Call this after either the attributes or the
 		 * width has been changed to get the new values.
 		 *
 		 * @param newBlockProgression block progression for the textflow
 		 * @param newColumnDirection column layout direction for the textflow
 		 * @param containerAttr		Formatting attributes from the container
 		 * @param containerWidth		Width of the container
 		 * @return Boolean			true if the actual column settings have changed
 		 * @private
 		 */
 		tlf_internal function updateInputs(newBlockProgression:String, newColumnDirection:String, controller:ContainerController, newCompositionWidth:Number, newCompositionHeight:Number ):void
 		{
 			var newPaddingTop:Number = controller.getTotalPaddingTop();
 			var newPaddingBottom:Number = controller.getTotalPaddingBottom();
 			var newPaddingLeft:Number = controller.getTotalPaddingLeft();
 			var newPaddingRight:Number = controller.getTotalPaddingRight();

 			var containerAttr:ITextLayoutFormat = controller.computedFormat;

 			var newColumnWidth:Object = containerAttr.columnWidth;
 			var newColumnGap:Number = containerAttr.columnGap;
 			var newColumnCount:Object = containerAttr.columnCount;

 			var newForceSingleColumn:Boolean = ((containerAttr.columnCount == FormatValue.AUTO && (containerAttr.columnWidth == FormatValue.AUTO || Number(containerAttr.columnWidth) == 0)) ||
 				controller.rootElement.computedFormat.lineBreak == LineBreak.EXPLICIT) || isNaN(newBlockProgression == BlockProgression.RL ? newCompositionHeight : newCompositionWidth);

 			if (_inputsChanged == false)
 				_inputsChanged = newCompositionWidth != _compositionHeight || newCompositionHeight != _compositionHeight
 				|| _paddingTop != newPaddingTop || _paddingBottom != newPaddingBottom || _paddingLeft != newPaddingLeft || _paddingRight != newPaddingRight
 				|| _blockProgression != _blockProgression || _columnDirection != newColumnDirection || _forceSingleColumn != newForceSingleColumn
 				|| _inputColumnWidth != newColumnWidth || _inputColumnGap != newColumnGap || _inputColumnCount != newColumnCount;

 			if (_inputsChanged)
 			{
 				_blockProgression = newBlockProgression;
 				_columnDirection = newColumnDirection;
 				_paddingTop = newPaddingTop;
 				_paddingBottom = newPaddingBottom;
 				_paddingLeft = newPaddingLeft;
 				_paddingRight = newPaddingRight;
 				_compositionWidth = newCompositionWidth;
 				_compositionHeight = newCompositionHeight;
 				_forceSingleColumn = newForceSingleColumn;

 				_inputColumnWidth = newColumnWidth;
 				_inputColumnGap = newColumnGap;
 				_inputColumnCount = newColumnCount;
 			}
 		}

 		/** Compute the actual columns based on the input values @private */
 		tlf_internal function computeColumns():void
 		{
 			if (!_inputsChanged)
 				return;

 			// Recalculate all the column settings. Returns true if settings have changed as a result.
 			// See http://www.w3.org/TR/2005/WD-css3-multicol-20051215/#the-number
 			var newColumnGap:Number;
 			var newColumnCount:int;
 			var newColumnWidth:Number;

 			// calculate the width to divy the columns up among
 			var totalColumnWidth:Number = _blockProgression == BlockProgression.RL ? _compositionHeight : _compositionWidth;
 			// inset to use
 			var newColumnInset:Number   = _blockProgression == BlockProgression.RL ? _paddingTop + _paddingBottom : _paddingLeft + _paddingRight;

 			totalColumnWidth = (totalColumnWidth > newColumnInset && !isNaN(totalColumnWidth)) ? totalColumnWidth - newColumnInset : 0;

 			// columnCount is auto && columnWidth is auto || 0 --> one column
 			if (_forceSingleColumn)
 			{
 				// This case deviates from the spec.  Spec is no columns.
 				// TextLayout does either one auto full width column or a zero width column
 				newColumnCount = 1;
 				newColumnWidth = totalColumnWidth;
 				newColumnGap = 0;
 			}
 			else
 			{
 				newColumnGap   = _inputColumnGap;

 				if (_inputColumnWidth == FormatValue.AUTO)		// auto
 				{
 					newColumnCount = Number(_inputColumnCount);
 					// Column width is not specified, we'll use columnCount and columnGap to figure it out
 					if ((newColumnCount-1)*newColumnGap < totalColumnWidth)
 					{
 						newColumnWidth = (totalColumnWidth - (newColumnCount-1)*newColumnGap) / newColumnCount;
 					}
 					else if (newColumnGap > totalColumnWidth)
 					{
 						newColumnCount = 1;
 						newColumnWidth = totalColumnWidth;
 						newColumnGap = 0;
 					}
 					else
 					{
 						newColumnCount = Math.floor(totalColumnWidth/newColumnGap);
 						newColumnWidth = (totalColumnWidth-(newColumnCount-1)*newColumnGap)/newColumnCount;
 						// newColumnGap = newColumnCount == 1 ? 0 : (totalColumnWidth - newColumnWidth*newColumnCount) / (newColumnCount-1);
 					}
 				}
 				else if (_inputColumnCount == FormatValue.AUTO)	// auto
 				{
 					newColumnWidth = Number(_inputColumnWidth);
 					if (newColumnWidth >= totalColumnWidth)
 					{
 						newColumnCount = 1;
 						newColumnWidth = totalColumnWidth;
 						newColumnGap   = 0;
 					}
 					else
 					{
 						newColumnCount = Math.floor((totalColumnWidth+newColumnGap)/(newColumnWidth+newColumnGap));
 						newColumnWidth = ((totalColumnWidth+newColumnGap)/newColumnCount) - newColumnGap;
 					}
 				}
 				else
 				{
 					newColumnCount = Number(_inputColumnCount);
 					newColumnWidth = Number(_inputColumnWidth);
 					if (newColumnCount*newColumnWidth+(newColumnCount-1)*newColumnGap <= totalColumnWidth)
 					{
 						// done
 					}
 					else if (newColumnWidth >= totalColumnWidth)
 					{
 						newColumnCount = 1;
 						newColumnGap = 0;
 						// use newColumnWidth
 					}
 					else
 					{
 						newColumnCount = Math.floor( (totalColumnWidth+newColumnGap) / (newColumnWidth+newColumnGap) );
 						newColumnWidth = ((totalColumnWidth+newColumnGap) / newColumnCount) - newColumnGap;
 					}
 				}
 			}

 			_columnWidth = newColumnWidth;
 			_columnCount = newColumnCount;
 			_columnGap = newColumnGap;
 			_inset = newColumnInset;

 			// setup these values for each case
 			var xPos:Number;
 			var yPos:Number;
 			var delX:Number;
 			var delY:Number;
 			var colH:Number;
 			var colW:Number;

 			// scratch vars
 			var insetHeight:Number;

 			// TODO: USE DIRECTION!!!
 			if (_blockProgression == BlockProgression.TB)
 			{
 				if (_columnDirection == Direction.LTR)
 				{
 					xPos = _paddingLeft;
 					delX = _columnWidth + _columnGap;
 					colW = _columnWidth;
 				}
 				else
 				{
 					CONFIG::debug { assert(_columnDirection == Direction.RTL,"bad columndirection in ColumnState.computeColumns"); }
 					xPos = isNaN(_compositionWidth) ? _paddingLeft : _compositionWidth-_paddingRight-_columnWidth;
 					delX = -(_columnWidth + _columnGap);
 					colW = _columnWidth;
 				}
 				yPos = _paddingTop;
 				delY = 0;
 				insetHeight = _paddingTop + _paddingBottom;
 				colH = (_compositionHeight > insetHeight && !isNaN(_compositionHeight)) ? (_compositionHeight - insetHeight) : 0;
 			}
 			else if (_blockProgression == BlockProgression.RL)
 			{
 				xPos = isNaN(_compositionWidth) ? -_paddingRight : _paddingLeft -_compositionWidth;
 				yPos = _paddingTop;
 				delX = 0;
 				delY = _columnWidth + _columnGap;
 				insetHeight = _paddingLeft + _paddingRight;
 				colW = (_compositionWidth > insetHeight) ? (_compositionWidth - insetHeight) : 0;
 				colH = _columnWidth;
 			}

 			// make colW and colH just off zero so that we don't get empties
 			if (colW == 0)
 			{
 				colW = Twips.ONE_TWIP;	// MINIMUM VALUE OF ONE TWIP
 				if (_blockProgression == BlockProgression.RL)
 					xPos -= colW;
 			}
 			if (colH == 0)
 				colH = Twips.ONE_TWIP;	// MINIMUM VALUE OF ONE TWIP

 			if (_columnCount == 1)
 			{
 				_singleColumn = new Rectangle(xPos, yPos, colW, colH);
 				_columnArray = null;
 			}
 			else if (_columnCount == 0)
 			{
 				_singleColumn = null;
 				_columnArray = null;
 			}
 			else
 			{
 				if (_columnArray)
 					_columnArray.splice(0);
 				else
 					_columnArray = new Array();
 				for (var i:int = 0; i < _columnCount; ++i)
 				{
 					_columnArray.push(new Rectangle(xPos, yPos, colW, colH));
 					xPos += delX;
 					yPos += delY;
 				}
 			}
 		}
 	}


 } // end package
	////////////////////////////////////////////////////////////////////////////////
	//
	// Licensed to the Apache Software Foundation (ASF) under one or more
	// contributor license agreements. See the NOTICE file distributed with
	// this work for additional information regarding copyright ownership.
	// The ASF licenses this file to You 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.
	//
	////////////////////////////////////////////////////////////////////////////////
	package flashx.textLayout.container
	{
	import flash.geom.Rectangle;

	import flashx.textLayout.debug.assert;
	import flashx.textLayout.elements.TableDataCellElement;
	import flashx.textLayout.formats.BlockProgression;
	import flashx.textLayout.formats.Direction;
	import flashx.textLayout.formats.FormatValue;
	import flashx.textLayout.formats.ITextLayoutFormat;
	import flashx.textLayout.formats.LineBreak;
	import flashx.textLayout.tlf_internal;
	import flashx.textLayout.utils.Twips;

	use namespace tlf_internal;

	/**
	* The ColumnState class calculates the sizes and locations of columns using
	* the width of the container and the container attributes. You can create instances of this class
	* independently to calculate column values, or you can get the column values that
	* were used for the text after the container has been composed or updated (redrawn).
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*
	* @see ContainerController
	*/

	public class ColumnState
	{
	// input information
	private var _inputsChanged:Boolean;
	private var _blockProgression:String;
	private var _columnDirection:String;
	private var _paddingTop:Number;
	private var _paddingBottom:Number;
	private var _paddingLeft:Number;
	private var _paddingRight:Number;
	private var _compositionWidth:Number;
	private var _compositionHeight:Number;
	private var _forceSingleColumn:Boolean;

	private var _inputColumnWidth:Object;
	private var _inputColumnGap:Number;
	private var _inputColumnCount:Object

	// Generated column information
	private var _columnWidth:Number;
	private var _columnCount:int;
	private var _columnGap:Number;
	private var _inset:Number;

	// and the array of columns
	private var _columnArray:Array;
	private var _tableCellArray:Array;
	private var _singleColumn:Rectangle;

	/**
	* Constructor function - creates a ColumnState object.
	*
	* If the values of <code>controller.compositionWidth</code> and <code>controller.compositionHeight</code> equal
	* <code>NaN</code> (not a number), the constructor measures the container's contents to determine the actual
	* composition width and height that feed into ColumnState.
	*
	* Use the constants defined by the <code>flashx.textLayout.formats.BlockProgression</code> class to
	* specify the value of the <code>blockProgression</code> parameter. Use the constants defined by
	* <code>flashx.textLayout.formats.Direction</code> to specify the value of the <code>columnDirection</code>
	* parameter.
	*
	* @param blockProgression The direction of lines for the textflow, either BlockProgression.TB (top-to-bottom) or
	* BlockProgression.RL (right-to-left).
	* @param columnDirection The direction of column layout for the text flow, either Direction.RTL (right-to-left) or
	* Direction.LTR (left-to-right).
	* @param controller A ContainerController instance whose attributes are used to calculate the column values.
	* @param compositionWidth The horizontal extent, in pixels, allowed for text inside the container.
	* @param compositionHeight The vertical extent, in pixels, allowed for text inside the container.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*
	* @see flashx.textLayout.formats.BlockProgression BlockProgression
	* @see flashx.textLayout.formats.Direction Direction
	*/

	public function ColumnState(blockProgression:String, columnDirection:String, controller:ContainerController, compositionWidth:Number, compositionHeight:Number)
	{
	_inputsChanged = true;
	_columnCount = 0;

	if (blockProgression != null) // if values are legit, recalculate now. They might not be, if this is called from a containerController constructor.
	{
	updateInputs(blockProgression, columnDirection, controller, compositionWidth, compositionHeight);
	computeColumns();
	}
	}

	/**
	* The width of columns, in pixels, in the container.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*/

	public function get columnWidth():Number
	{ return _columnWidth; }

	/**
	* The number of columns in the container.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*/

	public function get columnCount():int
	{ return _columnCount; }

	/**
	* The number of cells in the container.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*/

	public function get cellCount():int
	{
	if ( _tableCellArray )
	return _tableCellArray.length;
	return -1;
	}

	/**
	* The amount of space, in pixels, left between columns in the container.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*/

	public function get columnGap():Number
	{ return _columnGap; }

	/**
	* Returns the area that a column takes within the container. Allows you to access the area for a
	* specific column.
	*
	* @param index The relative position of the column among all columns in the container, with the first
	* column at position 0.
	*
	* @return The area of the specified column.
	*
	* @playerversion Flash 10
	* @playerversion AIR 1.5
	* @langversion 3.0
	*/

	public function getColumnAt(index:int):Rectangle
	{
	return _columnCount == 1 ? _singleColumn : _columnArray[index];
	}

	public function getCellAt(index:int):TableDataCellElement
	{
	return _tableCellArray[index];
	}

	public function pushTableCell(cell:TableDataCellElement):void
	{
	if ( _tableCellArray == null )
	_tableCellArray = new Array();
	_tableCellArray.push(cell);
	}

	public function clearCellList():void
	{
	_tableCellArray = null;
	}

	/** Recalculate actual column settings based on attributes and width
	* from the container. Call this after either the attributes or the
	* width has been changed to get the new values.
	*
	* @param newBlockProgression block progression for the textflow
	* @param newColumnDirection column layout direction for the textflow
	* @param containerAttr Formatting attributes from the container
	* @param containerWidth Width of the container
	* @return Boolean true if the actual column settings have changed
	* @private
	*/
	tlf_internal function updateInputs(newBlockProgression:String, newColumnDirection:String, controller:ContainerController, newCompositionWidth:Number, newCompositionHeight:Number ):void
	{
	var newPaddingTop:Number = controller.getTotalPaddingTop();
	var newPaddingBottom:Number = controller.getTotalPaddingBottom();
	var newPaddingLeft:Number = controller.getTotalPaddingLeft();
	var newPaddingRight:Number = controller.getTotalPaddingRight();

	var containerAttr:ITextLayoutFormat = controller.computedFormat;

	var newColumnWidth:Object = containerAttr.columnWidth;
	var newColumnGap:Number = containerAttr.columnGap;
	var newColumnCount:Object = containerAttr.columnCount;

	var newForceSingleColumn:Boolean = ((containerAttr.columnCount == FormatValue.AUTO && (containerAttr.columnWidth == FormatValue.AUTO \|\| Number(containerAttr.columnWidth) == 0)) \|\|
	controller.rootElement.computedFormat.lineBreak == LineBreak.EXPLICIT) \|\| isNaN(newBlockProgression == BlockProgression.RL ? newCompositionHeight : newCompositionWidth);

	if (_inputsChanged == false)
	_inputsChanged = newCompositionWidth != _compositionHeight \|\| newCompositionHeight != _compositionHeight
	\|\| _paddingTop != newPaddingTop \|\| _paddingBottom != newPaddingBottom \|\| _paddingLeft != newPaddingLeft \|\| _paddingRight != newPaddingRight
	\|\| _blockProgression != _blockProgression \|\| _columnDirection != newColumnDirection \|\| _forceSingleColumn != newForceSingleColumn
	\|\| _inputColumnWidth != newColumnWidth \|\| _inputColumnGap != newColumnGap \|\| _inputColumnCount != newColumnCount;

	if (_inputsChanged)
	{
	_blockProgression = newBlockProgression;
	_columnDirection = newColumnDirection;
	_paddingTop = newPaddingTop;
	_paddingBottom = newPaddingBottom;
	_paddingLeft = newPaddingLeft;
	_paddingRight = newPaddingRight;
	_compositionWidth = newCompositionWidth;
	_compositionHeight = newCompositionHeight;
	_forceSingleColumn = newForceSingleColumn;

	_inputColumnWidth = newColumnWidth;
	_inputColumnGap = newColumnGap;
	_inputColumnCount = newColumnCount;
	}
	}

	/** Compute the actual columns based on the input values @private */
	tlf_internal function computeColumns():void
	{
	if (!_inputsChanged)
	return;

	// Recalculate all the column settings. Returns true if settings have changed as a result.
	// See http://www.w3.org/TR/2005/WD-css3-multicol-20051215/#the-number
	var newColumnGap:Number;
	var newColumnCount:int;
	var newColumnWidth:Number;

	// calculate the width to divy the columns up among
	var totalColumnWidth:Number = _blockProgression == BlockProgression.RL ? _compositionHeight : _compositionWidth;
	// inset to use
	var newColumnInset:Number = _blockProgression == BlockProgression.RL ? _paddingTop + _paddingBottom : _paddingLeft + _paddingRight;

	totalColumnWidth = (totalColumnWidth > newColumnInset && !isNaN(totalColumnWidth)) ? totalColumnWidth - newColumnInset : 0;

	// columnCount is auto && columnWidth is auto \|\| 0 --> one column
	if (_forceSingleColumn)
	{
	// This case deviates from the spec. Spec is no columns.
	// TextLayout does either one auto full width column or a zero width column
	newColumnCount = 1;
	newColumnWidth = totalColumnWidth;
	newColumnGap = 0;
	}
	else
	{
	newColumnGap = _inputColumnGap;

	if (_inputColumnWidth == FormatValue.AUTO) // auto
	{
	newColumnCount = Number(_inputColumnCount);
	// Column width is not specified, we'll use columnCount and columnGap to figure it out
	if ((newColumnCount-1)*newColumnGap < totalColumnWidth)
	{
	newColumnWidth = (totalColumnWidth - (newColumnCount-1)*newColumnGap) / newColumnCount;
	}
	else if (newColumnGap > totalColumnWidth)
	{
	newColumnCount = 1;
	newColumnWidth = totalColumnWidth;
	newColumnGap = 0;
	}
	else
	{
	newColumnCount = Math.floor(totalColumnWidth/newColumnGap);
	newColumnWidth = (totalColumnWidth-(newColumnCount-1)*newColumnGap)/newColumnCount;
	// newColumnGap = newColumnCount == 1 ? 0 : (totalColumnWidth - newColumnWidth*newColumnCount) / (newColumnCount-1);
	}
	}
	else if (_inputColumnCount == FormatValue.AUTO) // auto
	{
	newColumnWidth = Number(_inputColumnWidth);
	if (newColumnWidth >= totalColumnWidth)
	{
	newColumnCount = 1;
	newColumnWidth = totalColumnWidth;
	newColumnGap = 0;
	}
	else
	{
	newColumnCount = Math.floor((totalColumnWidth+newColumnGap)/(newColumnWidth+newColumnGap));
	newColumnWidth = ((totalColumnWidth+newColumnGap)/newColumnCount) - newColumnGap;
	}
	}
	else
	{
	newColumnCount = Number(_inputColumnCount);
	newColumnWidth = Number(_inputColumnWidth);
	if (newColumnCountnewColumnWidth+(newColumnCount-1)newColumnGap <= totalColumnWidth)
	{
	// done
	}
	else if (newColumnWidth >= totalColumnWidth)
	{
	newColumnCount = 1;
	newColumnGap = 0;
	// use newColumnWidth
	}
	else
	{
	newColumnCount = Math.floor( (totalColumnWidth+newColumnGap) / (newColumnWidth+newColumnGap) );
	newColumnWidth = ((totalColumnWidth+newColumnGap) / newColumnCount) - newColumnGap;
	}
	}
	}

	_columnWidth = newColumnWidth;
	_columnCount = newColumnCount;
	_columnGap = newColumnGap;
	_inset = newColumnInset;

	// setup these values for each case
	var xPos:Number;
	var yPos:Number;
	var delX:Number;
	var delY:Number;
	var colH:Number;
	var colW:Number;

	// scratch vars
	var insetHeight:Number;

	// TODO: USE DIRECTION!!!
	if (_blockProgression == BlockProgression.TB)
	{
	if (_columnDirection == Direction.LTR)
	{
	xPos = _paddingLeft;
	delX = _columnWidth + _columnGap;
	colW = _columnWidth;
	}
	else
	{
	CONFIG::debug { assert(_columnDirection == Direction.RTL,"bad columndirection in ColumnState.computeColumns"); }
	xPos = isNaN(_compositionWidth) ? _paddingLeft : _compositionWidth-_paddingRight-_columnWidth;
	delX = -(_columnWidth + _columnGap);
	colW = _columnWidth;
	}
	yPos = _paddingTop;
	delY = 0;
	insetHeight = _paddingTop + _paddingBottom;
	colH = (_compositionHeight > insetHeight && !isNaN(_compositionHeight)) ? (_compositionHeight - insetHeight) : 0;
	}
	else if (_blockProgression == BlockProgression.RL)
	{
	xPos = isNaN(_compositionWidth) ? -_paddingRight : _paddingLeft -_compositionWidth;
	yPos = _paddingTop;
	delX = 0;
	delY = _columnWidth + _columnGap;
	insetHeight = _paddingLeft + _paddingRight;
	colW = (_compositionWidth > insetHeight) ? (_compositionWidth - insetHeight) : 0;
	colH = _columnWidth;
	}

	// make colW and colH just off zero so that we don't get empties
	if (colW == 0)
	{
	colW = Twips.ONE_TWIP; // MINIMUM VALUE OF ONE TWIP
	if (_blockProgression == BlockProgression.RL)
	xPos -= colW;
	}
	if (colH == 0)
	colH = Twips.ONE_TWIP; // MINIMUM VALUE OF ONE TWIP

	if (_columnCount == 1)
	{
	_singleColumn = new Rectangle(xPos, yPos, colW, colH);
	_columnArray = null;
	}
	else if (_columnCount == 0)
	{
	_singleColumn = null;
	_columnArray = null;
	}
	else
	{
	if (_columnArray)
	_columnArray.splice(0);
	else
	_columnArray = new Array();
	for (var i:int = 0; i < _columnCount; ++i)
	{
	_columnArray.push(new Rectangle(xPos, yPos, colW, colH));
	xPos += delX;
	yPos += delY;
	}
	}
	}
	}


	} // end package