A data tip is a tooltip that shows for text in a datagrid column that does not fit. So, if you have a “Name” column in your datagrid, and the person’s name is “Pimp Double-G Booty-licious Birdman”, but the column is only 20 pixels wide, the text will clip. If showDataTips is true on the datagrid’s column, it’ll show a tooltip when you hover over that row. It only shows for cells where the text is too big.
Windows XP does this for example when the folder name is too small to fit into Explorer. You can hover your cursor over the folder, and it’ll show the full folder name.
The problem is, the DataGridRow class specifically does NOT implement dataTips if the DataGridColumn has a cellRenderer. The fix is to set the cellRenderer’s toolTip value in it’s setValue function.
I’m not sure how this is handled for itemRenderer’s in Flex 2, but I’m sure it’s similiar as is the fix if needed.