PR#2559: expose link and navigation actions

[realthunder]

https://github.com/FreeCAD/FreeCAD/pull/2559

There are also various small fixes. I have made a user oriented video to introduce the Link feature.

phpBB [video]

[chrisb]

Thanks for this very important video. I think this should be moved to the Tutorials and videos forum, do you agree?

[Kunda1]

great job, no small effort as well ! Thank you for your contributions, realthunder!

[vocx]

The video is good but don't forget the written documentation.

For example, I created the Std LinkMake page. The other accessible command is Std_LinkMakeGroup, which apparently has several modes of operation.

Some of the link and expression commands are also accessible from the tree view, the property editor, and 3D view, so the basic documentation should be available, in order to link to it as necessary.

[realthunder]

The video is good but don't forget the written documentation.

For example, I created the Std LinkMake page. The other accessible command is Std_LinkMakeGroup, which apparently has several modes of operation.

I am thinking of removing Link group commands in the future and integrate some of its features into App::Part. That's why I didn't mention it in the video. I'll complete that page once everything is settled.

[vocx]

I am thinking of removing Link group commands in the future and integrate some of its features into App::Part.

Understood. If I recall from the big Assembly3 thread, the LinkGroup would sort of become an alternative to App::Part because of disagreements with Ickby's implementation of App::Part. However, I also got the impression that well, the LinkGroup functionality could still be merged into App::Part to avoid having a competing object. Is this correct?

[realthunder]

Understood. If I recall from the big Assembly3 thread, the LinkGroup would sort of become an alternative to App::Part because of disagreements with Ickby's implementation of App::Part. However, I also got the impression that well, the LinkGroup functionality could still be merged into App::Part to avoid having a competing object. Is this correct?

Yes, that's true.