PrView now broken

[butler]

In all the cleanup PrView which worked relatively well in version 3.1 alpha just before code camp, is now very broken:

Discovered as I was trying to add the Help button to this panel (have this and Invariant left to finish documentation redesign). Have decided not to confuse the issue by adding that now and would like to see this fixed first.

Used test data 1000A_sphere_dsm.xml for most all of my testing (NOTE: the DMAX is very large on this .. and in fact the name is WRONG it is 1000nm!!). Main issues

1. Buttons do not update value (regularization constant and number of terms). It does seem to take the number typed in manually. Error reported in sasview log is:

   2015-03-22 10:57:56,072 ERROR InversionControl._on_accept_alpha: String or Unicode type required
   2015-03-22 10:58:40,540 ERROR InversionControl._on_accept_nterms: String or Unicode type required
   

2. The number of terms is NOT being evaluated. Suggested value is always the defaule of 10. Error reported in console is given below. In the alpha release, once I put in a Dmax of 20,000 (2 microns diameter) it suggests 25 and clicking on the button properly puts that value into the parameter box.

   	Could not estimate number of terms
   

3. The "explore box" is broken.
   1. You can put some numbers in but quickly some boxes become inaccessible such as "number of points" and may even get stuck in max or min and not allow chaning any other value … including the drop down.
   2. The alpha version behaves very well and even deals elegantly with putting a SMALLER number in the max by simply inverting the plot scale.