Filtering Designer's widget box via QDesignerWidgetBoxInterface

[altendky]

I have several custom widgets I have been using in Designer and that could be used by users of my application without having to write any code. Most of the widgets listed in Designer's widget box need code behind them to be useful and I would like to hide those. I have attempted to write the widget box's configuration to a file, load that and remove a few example items, write that to a file, then load that second file back into the widget box... load() returns true but I see no change in the widget box.

Code: https://github.com/altendky/st/commit/27a48439273ccfbfafd572e477c92ad55df8606f
Designer output: https://gist.github.com/altendky/490c7f7d14377e50fa7bb266612de24d

Any obvious errors? Thoughts on something else to try? Thanks for your time.

Cheers,
-kyle