Datagrid: drag and drop row reordering

[mathijsmeulendijks]

Currently, the datagrid allows rows to be selected. I'd like to propose functionality to reorder the datagrid rows. This functionality has been proposed before in the archive: Reordering Datagrid rows (design spec) #1826. I think the suggestions in this request are useful for many Clarity users. I'd like to propose one change: when a datagrid is sorted by a certain field and the users starts reordering, the reorder action should either be blocked or the column sort should be removed. This behaviour should be configurable in code.

(image by gracesnoh)

Usecase

In our applications have lots of data that needs to be presented to the user, for this we use the datagrid. Mainly because of column selection and ordering functionality and the clean UI. Forms and detail views can easily be used for data modification.
However, clarity doesn't provide an option to put rows in a certain order in a simple way. Many applications require this, for example to determine the order items should be shown in other systems, or to set the execution order of process steps.