function _fnKey()

in uima-ducc-web/src/main/webapp/root/opensources/DataTables-1.10.1/extensions/KeyTable/js/dataTables.keyTable.js [643:823]
138 lines of code
35 McCabe index (conditional complexity)

	function _fnKey ( e )
	{
		/* If user or system has blocked KeyTable from doing anything, just ignore this event */
		if ( _that.block || !_bKeyCapture )
		{
			return true;
		}

		/* If a modifier key is pressed (exapct shift), ignore the event */
		if ( e.metaKey || e.altKey || e.ctrlKey )
		{
			return true;
		}
		var
			x, y,
			iTableWidth = _nBody.getElementsByTagName('tr')[0].getElementsByTagName('td').length,
			iTableHeight;

		/* Get table height and width - done here so as to be dynamic (if table is updated) */
		if ( _oDatatable )
		{
			/* 
			 * Locate the current node in the DataTable overriding the old positions - the reason for
			 * is is that there might have been some DataTables interaction between the last focus and
			 * now
			 */
			iTableHeight = _oDatatable.aiDisplay.length;

			var aDtPos = _fnFindDtCell( _nOldFocus );
			if ( aDtPos === null )
			{
				/* If the table has been updated such that the focused cell can't be seen - do nothing */
				return;
			}
			_iOldX = aDtPos[ 0 ];
			_iOldY = aDtPos[ 1 ];
		}
		else
		{
			iTableHeight = _nBody.getElementsByTagName('tr').length;
		}

		/* Capture shift+tab to match the left arrow key */
		var iKey = (e.keyCode == 9 && e.shiftKey) ? -1 : e.keyCode;

		switch( iKey )
		{
			case 13: /* return */
				e.preventDefault();
				e.stopPropagation();
				_fnEventFire( "action", _iOldX, _iOldY );
				return true;

			case 27: /* esc */
				if ( !_fnEventFire( "esc", _iOldX, _iOldY ) )
				{
					/* Only lose focus if there isn't an escape handler on the cell */
					_fnBlur();
					return;
				}
				x = _iOldX;
				y = _iOldY;
				break;

			case -1:
			case 37: /* left arrow */
				if ( _iOldX > 0 ) {
					x = _iOldX - 1;
					y = _iOldY;
				} else if ( _iOldY > 0 ) {
					x = iTableWidth-1;
					y = _iOldY - 1;
				} else {
					/* at start of table */
					if ( iKey == -1 && _bForm )
					{
						/* If we are in a form, return focus to the 'input' element such that tabbing will
						 * follow correctly in the browser
						 */
						_bInputFocused = true;
						_nInput.focus();

						/* This timeout is a little nasty - but IE appears to have some asyhnc behaviour for 
						 * focus
						 */
						setTimeout( function(){ _bInputFocused = false; }, 0 );
						_bKeyCapture = false;
						_fnBlur();
						return true;
					}
					else
					{
						return false;
					}
				}
				break;

			case 38: /* up arrow */
				if ( _iOldY > 0 ) {
					x = _iOldX;
					y = _iOldY - 1;
				} else {
					return false;
				}
				break;

			case 36: /* home */
				x = _iOldX;
				y = 0;
				break;

			case 33: /* page up */
				x = _iOldX;
				y = _iOldY - 10;
				if (y < 0) {
					y = 0;
				}
				break;

			case 9: /* tab */
			case 39: /* right arrow */
				if ( _iOldX < iTableWidth-1 ) {
					x = _iOldX + 1;
					y = _iOldY;
				} else if ( _iOldY < iTableHeight-1 ) {
					x = 0;
					y = _iOldY + 1;
				} else {
					/* at end of table */
					if ( iKey == 9 && _bForm )
					{
						/* If we are in a form, return focus to the 'input' element such that tabbing will
						 * follow correctly in the browser
						 */
						_bInputFocused = true;
						_nInput.focus();

						/* This timeout is a little nasty - but IE appears to have some asyhnc behaviour for 
						 * focus
						 */
						setTimeout( function(){ _bInputFocused = false; }, 0 );
						_bKeyCapture = false;
						_fnBlur();
						return true;
					}
					else
					{
						return false;
					}
				}
				break;

			case 40: /* down arrow */
				if ( _iOldY < iTableHeight-1 ) {
					x = _iOldX;
					y = _iOldY + 1;
				} else {
					return false;
				}
				break;

			case 35: /* end */
				x = _iOldX;
				y = iTableHeight-1;
				break;

			case 34: /* page down */
				x = _iOldX;
				y = _iOldY+10;
				if (y > iTableHeight-1) {
					y = iTableHeight-1;
				}
				break;

			default: /* Nothing we are interested in */
				return true;
		}

		_fnSetFocus( _fnCellFromCoords(x, y) );
		return false;
	}