I have a cell in a column that is editable by the insertion of text. The user is able to add the text manually once they've doubled clicked the cell. What is the best cursor to display on:hover to let the user know this area is editable?
To answer your question directly - there isn't any conventional cursor to denote a double click.
There are quite a few gestures that has no innate 'affordance': double-click or even a swipe, for example. In these cases, you can:
- Hope the users come across these by mistake. This may sound daft, but when no action is obvious people start trying random things (psychology has it, user testing can demonstrate it and also computer games).
- Teach users somehow that the action is possible (and there are many ways to do this).
Perhaps important to say that these sort of 'hidden' gestures mostly fall into what I call 'celluloid interactions' - a single exposure is highly likely to be retain the knowledge; not further learning required. The hamburger menu may come to mind here.
So in your case, you shall be fine only teaching users once (say a dismissible message or a super-quick tour), as opposed to tooltips etc.
The cursor for text looks similar to those found on Noun Project. The css is:
cursor:text. See the reference on W3Schools for info. Once the cursor changes to text, it will be obvious that you can (single) click to edit.
There is no cursor that indicates double-click; you will have to explain that with instructions, a label, a tooltip, an icon, or a goofy image like this.