Sort a multilinear equation on its coefficients?

Questions
,
1

What’s the easy way to display a multilinear equation as sorted on its coefficients? For instance, display

7 + 3x[1] - 2x[2] + x[3]

as

7 - 2x[2] + x[3] + 3x[1]

I’m now converting the equation into a list of {coefficient, variable} pairs, sorting on the first component, and then constructing the desired display. It’s easy enough but I’m hoping there’s an easier way.

Thanks.

2

This almost does it:

SortBy[7 + 3 x[1] - 2 x[2] + x[3] /. 
  Plus -> Inactive[Plus], # /. x[_] -> 1 &]
3

This is great, Gianluca. Thanks.