Click item in grid and some action should happen

I'm trying to make ability to edit items(cell开发者_Python百科s) by clicking them in Grid. I want to have possibility to click ex. ITEM1 and some action should takes place. I know that I can use renderer, but it returns only string.

Any idea how to do this?

Why not use the built in ExtJS Cell Editing Grid?

http://dev.sencha.com/deploy/ext-4.0.0/examples/grid/cell-editing.html

Or you can edit the entire row at once:

http://dev.sencha.com/deploy/ext-4.0.0/examples/grid/row-editing.html