/*

Copyright (c) 2003-2012, CKSource - Frederico Knabben. All rights reserved.

For licensing, see LICENSE.html or http://ckeditor.com/license

*/



(function()

{

	var meta =

	{

		editorFocus : false,

		modes : { wysiwyg:1, source:1 }

	};



	var blurCommand =

		{

			exec : function( editor )

			{

				editor.container.focusNext( true, editor.tabIndex );

			}

		};



	var blurBackCommand =

		{

			exec : function( editor )

			{

				editor.container.focusPrevious( true, editor.tabIndex );

			}

		};



	function selectNextCellCommand( backward )

	{

		return {

			editorFocus : false,

			canUndo : false,

			modes : { wysiwyg : 1 },

			exec : function( editor )

			{

				if ( editor.focusManager.hasFocus )

				{

					var sel = editor.getSelection(),

						ancestor = sel.getCommonAncestor(),

						cell;



					if ( ( cell = ( ancestor.getAscendant( 'td', true ) || ancestor.getAscendant( 'th', true ) ) ) )

					{

						var resultRange = new CKEDITOR.dom.range( editor.document ),

								next = CKEDITOR.tools.tryThese( function()

								{

									var row = cell.getParent(),

											next = row.$.cells[ cell.$.cellIndex + ( backward ? - 1 : 1 ) ];



									// Invalid any empty value.

									next.parentNode.parentNode;

									return next;

								},

								function()

								{

									var row = cell.getParent(),

											table = row.getAscendant( 'table' ),

											nextRow = table.$.rows[ row.$.rowIndex + ( backward ? - 1 : 1 ) ];



									return nextRow.cells[ backward? nextRow.cells.length -1 : 0 ];

								});



						// Clone one more row at the end of table and select the first newly established cell.

						if ( ! ( next || backward ) )

						{

							var table = cell.getAscendant( 'table' ).$,

									cells = cell.getParent().$.cells;



							var newRow = new CKEDITOR.dom.element( table.insertRow( -1 ), editor.document );



							for ( var i = 0, count = cells.length ; i < count; i++ )

							{

								var newCell = newRow.append( new CKEDITOR.dom.element(

										cells[ i ], editor.document ).clone( false, false ) );

								!CKEDITOR.env.ie && newCell.appendBogus();

							}



							resultRange.moveToElementEditStart( newRow );

						}

						else if ( next )

						{

							next = new CKEDITOR.dom.element( next );

							resultRange.moveToElementEditStart( next );

							// Avoid selecting empty block makes the cursor blind.

							if ( !( resultRange.checkStartOfBlock() && resultRange.checkEndOfBlock() ) )

								resultRange.selectNodeContents( next );

						}

						else

							return true;



						resultRange.select( true );

						return true;

					}

				}

				return false;

			}

		};

	}



	CKEDITOR.plugins.add( 'tab',

	{

		requires : [ 'keystrokes' ],



		init : function( editor )

		{

			var tabTools = editor.config.enableTabKeyTools !== false,

				tabSpaces = editor.config.tabSpaces || 0,

				tabText = '';



			while ( tabSpaces-- )

				tabText += '\xa0';



			if ( tabText )

			{

				editor.on( 'key', function( ev )

					{

						if ( ev.data.keyCode == 9 )	// TAB

						{

							editor.insertHtml( tabText );

							ev.cancel();

						}

					});

			}



			if ( tabTools )

			{

				editor.on( 'key', function( ev )

				{

					if ( ev.data.keyCode == 9 && editor.execCommand( 'selectNextCell' ) ||	// TAB

							ev.data.keyCode == ( CKEDITOR.SHIFT + 9 ) && editor.execCommand( 'selectPreviousCell' ) )	// SHIFT+TAB

						ev.cancel();

				});

			}



			if ( CKEDITOR.env.webkit || CKEDITOR.env.gecko )

			{

				editor.on( 'key', function( ev )

					{

						var keyCode = ev.data.keyCode;



						if ( keyCode == 9 && !tabText )				// TAB

						{

							ev.cancel();

							editor.execCommand( 'blur' );

						}



						if ( keyCode == ( CKEDITOR.SHIFT + 9 ) )	// SHIFT+TAB

						{

							editor.execCommand( 'blurBack' );

							ev.cancel();

						}

					});

			}



			editor.addCommand( 'blur', CKEDITOR.tools.extend( blurCommand, meta ) );

			editor.addCommand( 'blurBack', CKEDITOR.tools.extend( blurBackCommand, meta ) );

			editor.addCommand( 'selectNextCell', selectNextCellCommand() );

			editor.addCommand( 'selectPreviousCell', selectNextCellCommand( true ) );

		}

	});

})();



/**

 * Moves the UI focus to the element following this element in the tabindex

 * order.

 * @example

 * var element = CKEDITOR.document.getById( 'example' );

 * element.focusNext();

 */

CKEDITOR.dom.element.prototype.focusNext = function( ignoreChildren, indexToUse )

{

	var $ = this.$,

		curTabIndex = ( indexToUse === undefined ? this.getTabIndex() : indexToUse ),

		passedCurrent, enteredCurrent,

		elected, electedTabIndex,

		element, elementTabIndex;



	if ( curTabIndex <= 0 )

	{

		// If this element has tabindex <= 0 then we must simply look for any

		// element following it containing tabindex=0.



		element = this.getNextSourceNode( ignoreChildren, CKEDITOR.NODE_ELEMENT );



		while ( element )

		{

			if ( element.isVisible() && element.getTabIndex() === 0 )

			{

				elected = element;

				break;

			}



			element = element.getNextSourceNode( false, CKEDITOR.NODE_ELEMENT );

		}

	}

	else

	{

		// If this element has tabindex > 0 then we must look for:

		//		1. An element following this element with the same tabindex.

		//		2. The first element in source other with the lowest tabindex

		//		   that is higher than this element tabindex.

		//		3. The first element with tabindex=0.



		element = this.getDocument().getBody().getFirst();



		while ( ( element = element.getNextSourceNode( false, CKEDITOR.NODE_ELEMENT ) ) )

		{

			if ( !passedCurrent )

			{

				if ( !enteredCurrent && element.equals( this ) )

				{

					enteredCurrent = true;



					// Ignore this element, if required.

					if ( ignoreChildren )

					{

						if ( !( element = element.getNextSourceNode( true, CKEDITOR.NODE_ELEMENT ) ) )

							break;

						passedCurrent = 1;

					}

				}

				else if ( enteredCurrent && !this.contains( element ) )

					passedCurrent = 1;

			}



			if ( !element.isVisible() || ( elementTabIndex = element.getTabIndex() ) < 0 )

				continue;



			if ( passedCurrent && elementTabIndex == curTabIndex )

			{

				elected = element;

				break;

			}



			if ( elementTabIndex > curTabIndex && ( !elected || !electedTabIndex || elementTabIndex < electedTabIndex ) )

			{

				elected = element;

				electedTabIndex = elementTabIndex;

			}

			else if ( !elected && elementTabIndex === 0 )

			{

				elected = element;

				electedTabIndex = elementTabIndex;

			}

		}

	}



	if ( elected )

		elected.focus();

};



/**

 * Moves the UI focus to the element before this element in the tabindex order.

 * @example

 * var element = CKEDITOR.document.getById( 'example' );

 * element.focusPrevious();

 */

CKEDITOR.dom.element.prototype.focusPrevious = function( ignoreChildren, indexToUse )

{

	var $ = this.$,

		curTabIndex = ( indexToUse === undefined ? this.getTabIndex() : indexToUse ),

		passedCurrent, enteredCurrent,

		elected,

		electedTabIndex = 0,

		elementTabIndex;



	var element = this.getDocument().getBody().getLast();



	while ( ( element = element.getPreviousSourceNode( false, CKEDITOR.NODE_ELEMENT ) ) )

	{

		if ( !passedCurrent )

		{

			if ( !enteredCurrent && element.equals( this ) )

			{

				enteredCurrent = true;



				// Ignore this element, if required.

				if ( ignoreChildren )

				{

					if ( !( element = element.getPreviousSourceNode( true, CKEDITOR.NODE_ELEMENT ) ) )

						break;

					passedCurrent = 1;

				}

			}

			else if ( enteredCurrent && !this.contains( element ) )

				passedCurrent = 1;

		}



		if ( !element.isVisible() || ( elementTabIndex = element.getTabIndex() ) < 0 )

			continue;



		if ( curTabIndex <= 0 )

		{

			// If this element has tabindex <= 0 then we must look for:

			//		1. An element before this one containing tabindex=0.

			//		2. The last element with the highest tabindex.



			if ( passedCurrent && elementTabIndex === 0 )

			{

				elected = element;

				break;

			}



			if ( elementTabIndex > electedTabIndex )

			{

				elected = element;

				electedTabIndex = elementTabIndex;

			}

		}

		else

		{

			// If this element has tabindex > 0 we must look for:

			//		1. An element preceeding this one, with the same tabindex.

			//		2. The last element in source other with the highest tabindex

			//		   that is lower than this element tabindex.



			if ( passedCurrent && elementTabIndex == curTabIndex )

			{

				elected = element;

				break;

			}



			if ( elementTabIndex < curTabIndex && ( !elected || elementTabIndex > electedTabIndex ) )

			{

				elected = element;

				electedTabIndex = elementTabIndex;

			}

		}

	}



	if ( elected )

		elected.focus();

};



/**

 * Intructs the editor to add a number of spaces (&amp;nbsp;) to the text when

 * hitting the TAB key. If set to zero, the TAB key will be used to move the

 * cursor focus to the next element in the page, out of the editor focus.

 * @name CKEDITOR.config.tabSpaces

 * @type Number

 * @default 0

 * @example

 * config.tabSpaces = 4;

 */



/**

 * Allow context-sensitive tab key behaviors, including the following scenarios:

 * <h5>When selection is anchored inside <b>table cells</b>:</h5>

 * <ul>

 * 		<li>If TAB is pressed, select the contents of the "next" cell. If in the last cell in the table, add a new row to it and focus its first cell.</li>

 * 		<li>If SHIFT+TAB is pressed, select the contents of the "previous" cell. Do nothing when it's in the first cell.</li>

 * </ul>

 * @name CKEDITOR.config.enableTabKeyTools

 * @type Boolean

 * @default true

 * @example

 * config.enableTabKeyTools = false;

 */



// If the TAB key is not supposed to be enabled for navigation, the following

// settings could be used alternatively:

// config.keystrokes.push(

//	[ CKEDITOR.ALT + 38 /*Arrow Up*/, 'selectPreviousCell' ],

//	[ CKEDITOR.ALT + 40 /*Arrow Down*/, 'selectNextCell' ]

// );

