[with patch, positive review] Do not automatically evaluate interact cells in notebook

[kcrisman]

Current behavior is that @interact cells automatically evaluate upon opening a worksheet. This can cause problems if (for instance) the cell depends on other cells which are not automatically evaluated, and also can take a long time if there are lots of them.

Since other cells do not auto-evaluate, and since this functionality still is easily available by putting #auto in the cell, this ticket calls for the current behavior to be changed.

[jason]

I second that this should be changed.

[mhansen]

I've also added this as a test case to the notebook test suite.

[was]

I think to solve this trac ticket, it is necessary that:

1. Output of interact cells should be completely empty when a worksheet is open.

2. @interact needs to work with #auto (or %auto?) because I have a project with a student that involves making a bunch of interacts that are all %hideall'd, so one sees *only* the controls.

[was]

Just to emphasize, the patch above mysteriously doesn't work with #auto...

[mhansen]

I've posted a patch which does not enqueue interact cells at startup and deletes their output so that users don't think that they're running.

I've also made a ticket to fix the auto-evaluation at  http://trac.sagemath.org/sage_trac/ticket/5020 . I think this is a separate issue, and I'm looking into it.

[mhampton]

This seems to solve the problem, and the auto-launch problem of #4947. My setup seems to have some issues with #auto cells, so I can't test the compatibility of this patch with that, but that is addressed in other ways by #5020.

[mabshoff]

Merged in Sage 3.3.alpha0