Sketcher Ticket #3793 - Reference Constraints toggle to driving on edit

[hatari]

If it really is a feature, I would be very curious about its benefit..

This behaviour is indeed a bit confusing. You can label the blue reference constraints with the right click menu in the constraints list in the panel.

Thanks a lot, Chris, this workaround is very helpful!

[bejant]

I think this behavior came about because at first it wasn't possible to edit a blue Constraint at all; the user first had to change it to a regular (driving, red) Constraint and then change the numerical value. After blue Constraints were introduced there was a discussion to the effect that when someone wanted to edit the numerical value of a blue Constraint, the user therefore wanted that Constraint to be a driving (red) Constraint. So, as a time-saver, editing the number value of a blue Constraint caused that Constraint to become a driving (red) Constraint.

I think the bug is that editing the Name of a blue Constraint, so that it can be used in a Spreadsheet / Expression, also changes the Constraint to red. Instead, a blue Constraint should only become red if the Length / Angle field is edited.

This recollection is all from memory; I think Abdullah or maybe Normand will be able to provide more input.

[abdullah]

I think the bug is that editing the Name of a blue Constraint, so that it can be used in a Spreadsheet / Expression, also changes the Constraint to red. Instead, a blue Constraint should only become red if the Length / Angle field is edited.

This recollection is all from memory; I think Abdullah or maybe Normand will be able to provide more input.

Your memory is perfect.

There is a very stubborn user that never names reference constraints and wants this behaviour of changing to driving. That user is me .

It should be possible to implement something as you describe. I see that there is from time to time a user complaining about this behaviour. So I think we should do something for v0.19. Do we have a ticket?

[chrisb]

Do we have a ticket?

Yes: issue #3793.

[bejant]

Your memory is perfect.

Maybe that time, but not always!

[openBrain]

Just submitted PR 3201 to solve this.

Basically it adds a checkbox in the dimension edition dialog that shows/determines if the created/edited constraint is driving or driven (aka reference) one :

driving.png (11.39 KiB) Viewed 1487 times

The new behavior is :

• If the value is changed, the constraint is automatically switched to driving
• If the constraint is set as driven, the value is reset to current one
• Constraint name can be freely edited without tampering the constraint driving/driven state (that was the main point)
• No live update, everything is updated when dialog is accepted (same as currently)
• When a driven (reference) constraint is created, the dialog isn't opened (same as currently). I had a doubt on that because probably someone that set a driven constraint want to name it so it can be reused. However this isn't a big deal to double-click on it to edit its name

EDIT : saw a small issue. When editing a driven constraint, then making it driving with the checkbox, it's not possible to enter an expression (works with a value). To enter an expression it is a 2 step process, first making it driving, then entering expression. Will have a look at this on tomorrow.

[triplus]

We had a long discussion in the past and the term Reference was selected, user facing, not driving. Please update the term in PR. Using more terms in the GUI and in the documentation only adds to the confusion.

P.S. As for the term constrain vs. dimension. This one is a bit tricky one. Notably not all are happy with the terminology Reference constraints, but the solution is not easy. For that to make sense, using the term constraint and dimension separately, we would basically need to split them apart, have double the amount of commands, dialogs, two toolbars, and move away from the toggle approach. As in toggle mode, people perceive them too much as constraints. But then again if in general people would like to move away from using terminology Reference (constraint), to using something like the Dimension. Therefore for such checkbox to have a label Dimension. I am OK with that. But then the term needs to be used consistently elsewhere too.

[chrisb]

Just submitted PR 3201 to solve this.

Thanks for the PR, I think it's still a bit cumbersome, but its the best we can do. Easy to handle, and rather easy to explain.

(Now I have to check my tutorial again.)

[openBrain]

We had a long discussion in the past and the term Reference was selected, user facing, not driving. Please update the term in PR. Using more terms in the GUI and in the documentation only adds to the confusion.

'Reference' in FreeCAD stands for 'driven', not 'driving'. No need to write a book, just tell me what is FC terminology for 'driving' and I'll update.

[openBrain]

Thanks for the PR, I think it's still a bit cumbersome, but its the best we can do. Easy to handle, and rather easy to explain.

Could you give some more details about what you think is cumbersome and could be improved?