This example demonstrates the DataViews header selection feature, which allows the user to select entire sets of data based on the rows and groups.
When the allowHeaderSelect property is set to true, a selection icon is placed in the row header.
When the icon is clicked, that row is selected.
If that row is a group header, the group is selected.
If that row is the grid header (or if you select the header in the top left header cell), the entire grid is selected.