Ted On Flex: DataGrid CellRenderer V2 Error

DataGrid CellRenderer V2 Error

DIGG IT! 7 Comments Published Wednesday, February 23, 2005 at 4:00 AM .

There is an error in the V2 DataGrid CellRenderer that makes using components within the dataGrid problematic. Here is the fix.&

In Class "mx.controls.gridclasses.DataGridRow" line 165:

cell._y = (__height-cell._height)/2;

Replace this line with:

if( cell.__height == undefined ){
cell._y = (__height-cell._height)/2;
}else{
cell._y = (__height-cell.__height)/2;
}

The problem was that the cell _y coordinate was based on _height not __height for components. If you added a ComboBox or NumericStepper into a Cell, they would resize incorrectly. The ComboBox would be ok until you opened it and then resized a column. Since the _height of the cell now contains the dropdown list, the _y of the cell is thrown off shooting the cell up aboout 50px. Using __height resolves the issue, but makes it essential to defined a getPreferredHeight function in your cell renderer class.

This makes writing cell renderers for DataGrid much easier allowing just about any component to be inserted, or better many controls in a form.

Cheers and Happy CellRenderering!

Ted ;)

7 Responses to “ DataGrid CellRenderer V2 Error ”

# Ted Patrick February 23, 2005 5:40 AM

If you wanted to get fancy here you could also add in pixel snapping for cell content using Math.round. Cheers, ted ;)
# Ted Patrick February 23, 2005 5:42 AM

Actually make that Math.floor since that is what is used for the drawing API calls in drawing the background.
# Anonymous February 23, 2005 9:40 AM

Yeah, we got this bug for the Flex release, AFAIK. Good catch.

nig
# Ted Patrick February 23, 2005 10:07 AM

Thanks Nigel. Cheers, Ted ;)
# Anonymous March 22, 2005 3:17 AM

Thanks, this bug was driving me up the wall :)
# Garry Schafer July 8, 2005 11:54 AM

Would this be the same as working with a listcomponent? I've got a list that has a cellrenderer with a loader component in it, and it starts off as halfway down the item; upon a rollover it fixes itself.
# Ted Patrick July 8, 2005 12:13 PM

Gary,

That sounds like the exact error.

Ted ;)