Class: Scroller

Methods

fnMeasure( [bRedraw:bool] ):void

Calculate and store information about how many rows are to be displayed in the scrolling viewport, based on current dimensions in the browser's rendering. This can be particularly useful if the table is initially drawn in a hidden element - for example in a tab.

Parameters:

	Name	Type	Attributes	Default	Description
1	bRedraw	bool	Optional	true	Redraw the table automatically after the recalculation, with the new dimentions forming the basis for the draw.

Example:

   $(document).ready(function() {
     // Make the example container hidden to throw off the browser's sizing
     document.getElementById('container').style.display = "none";
     var oTable = $('#example').dataTable( {
       "sScrollY": "200px",
       "sAjaxSource": "media/dataset/large.txt",
       "sDom": "frtiS",
       "bDeferRender": true,
       "fnInitComplete": function (o) {
         // Immediately scroll to row 1000
         o.oScroller.fnScrollToRow( 1000 );
       }
     } );
     
     setTimeout( function () {
       // Make the example container visible and recalculate the scroller sizes
       document.getElementById('container').style.display = "block";
       oTable.fnSettings().oScroller.fnMeasure();
     }, 3000 );

fnPixelsToRow( iPixels:int ):int

Calculate the row number that will be found at the given pixel position (y-scroll)

Parameters:

	Name	Type	Attributes	Default	Description
1	iPixels	int			Offset from top to caluclate the row number of

Returns:

Row index

Example:

   $(document).ready(function() {
     $('#example').dataTable( {
       "sScrollY": "200px",
       "sAjaxSource": "media/dataset/large.txt",
       "sDom": "frtiS",
       "bDeferRender": true,
       "fnInitComplete": function (o) {
         // Find what row number is at 500px
         alert( o.oScroller.fnPixelsToRow( 500 ) );
       }
     } );
   } );

fnRowToPixels( iRow:int ):int

Calculate the pixel position from the top of the scrolling container for a given row

Parameters:

	Name	Type	Attributes	Default	Description
1	iRow	int			Row number to calculate the position of

Returns:

Pixels

Example:

   $(document).ready(function() {
     $('#example').dataTable( {
       "sScrollY": "200px",
       "sAjaxSource": "media/dataset/large.txt",
       "sDom": "frtiS",
       "bDeferRender": true,
       "fnInitComplete": function (o) {
         // Find where row 25 is
         alert( o.oScroller.fnRowToPixels( 25 ) );
       }
     } );
   } );

fnScrollToRow( iRow:int, [bAnimate:bool] ):void

Calculate the row number that will be found at the given pixel position (y-scroll)

Parameters:

	Name	Type	Attributes	Default	Description
1	iRow	int			Row index to scroll to
2	bAnimate	bool	Optional	true	Animate the transision or not

Example:

   $(document).ready(function() {
     $('#example').dataTable( {
       "sScrollY": "200px",
       "sAjaxSource": "media/dataset/large.txt",
       "sDom": "frtiS",
       "bDeferRender": true,
       "fnInitComplete": function (o) {
         // Immediately scroll to row 1000
         o.oScroller.fnScrollToRow( 1000 );
       }
     } );
     
     // Sometime later on use the following to scroll to row 500...
         var oSettings = $('#example').dataTable().fnSettings();
     oSettings.oScroller.fnScrollToRow( 500 );
   } );

<private> _fnCalcRowHeight( ):void

Automatic calculation of table row height. This is just a little tricky here as using initialisation DataTables has tale the table out of the document, so we need to create a new table and insert it into the document, calculate the row height and then whip the table out.

<private> _fnConstruct( ):void

Initialisation for Scroller

<private> _fnDrawCallback( ):void

Draw callback function which is fired when the DataTable is redrawn. The main function of this method is to position the drawn table correctly the scrolling container for the rows that is displays as a result of the scrolling position.

<private> _fnInfo( ):void

Update any information elements that are controlled by the DataTable based on the scrolling viewport and what rows are visible in it. This function basically acts in the same way as _fnUpdateInfo in DataTables, and effectively replaces that function.

<private> _fnScroll( ):void

Scrolling function - fired whenever the scrolling position is changed. This method needs to use the stored values to see if the table should be redrawn as we are moving towards the end of the information that is currently drawn or not. If needed, then it will redraw the table based on the new position.