Feature Proposal: Gray out/lock constraint toolbar buttons that are invalid for the current selection. Update locked/unlocked status of constraint toolbar buttons each time selection changes to allow only valid constraints to be clicked on/applied.

[python50]

Hi, I'm a new user. I am writing a series of bug reports and feature proposals as I learn how to use Assembly3. The goal of doing this is to capture where I experienced "sharp corners" in the user experience and bugs. Hopefully, some of these issues will help in identifying ways that the workbench could potentially be made more user friendly and easier to learn.

The first thing that stood out to me within the first 5 minutes of using this workbench was that learning which constraints could be used in what context was slightly more difficult than I expected. The tooltips help - they are a good start. I noticed that the constraint buttons get greyed out if nothing is selected - making it impossible to "do an incorrect" action in that situation - this is excellent. However, as soon as anything is selected all the constraint buttons get unlocked - even though most of them would not work with the current selection.

As a new user, the "context sensitivity" of the constraint buttons (watching them lock and unlock in respond to my current selection) created the expectation (in my mind) that the constraint buttons would only "unlock" when the selection was appropriate to use them. The way it is currently implemented, this isn't really the case (but the current implementation it is much better than nothing at all !).

The proposed feature would aid new users in learning what operations are valid. I have made a graphic with embedded text to demonstrate the proposal.

I'd be willing to assist in whatever way possible if this feature would be useful.

Edit: Despite the screenshots being taken in the FreeCAD master daily release I have verified this behavior is the same with this repo's latest (2020.1230) daily release.

[ceremcem]

+1 for (more) grayed out buttons.