AdvancedDataGridEventReason  - AS3 Flex

Specifies that the user cancelled editing and that they do not want to save the edited data. Even if you call the preventDefault() method from within your event listener for the itemEditEnd event, Flex still calls the destroyItemEditor() editor to close the editor.

Specifies that the user moved focus to a new column in the same row. Within an event listener, you can let the focus change occur, or prevent it. For example, your event listener might check that the user entered a valid value for the item currently being edited. If not, you can prevent the user from moving to a new item by calling the preventDefault() method. In this case, the item editor remains open, and the user continues to edit the current item. If you call the preventDefault() method and also call the destroyItemEditor() method, you block the move to the new item, but the item editor closes.

Specifies that the user moved focus to a new row. You handle this reason much like you handle NEW_COLUMN.

Specifies that the list control lost focus, was scrolled, or is somehow in a state where editing is not allowed. Even if you call the preventDefault() method from within your event listener for the itemEditEnd event, Flex still calls the destroyItemEditor() editor to close the editor.