Shouldn't this be exposed in Data tab?
Maybe, yeah. I'm not sure if this is implemented for all DocumentObjects, or just App::FeaturePython, or Part::FeaturePython, that is, those with 2D and 3D shapes.
But you can't change the width in 0.18, either. Because there is only one column in 0.18 tree. I added another column for general purpose description or whatever. If auto sizing is not enabled, then it is possible to obscure the object names in the tree which will be more disturbing.
You can edit the description directly in the tree, just like object labels.
Yes, but there is no need for that because when renaming you don't need more space. But now, renaming needs more space for the formula icon that will be displayed behind the name.
It allows the user to name the object with expression, but yeah, it should be considered as a power feature. I shall hide it by default.
Yes, it's easy to add.Anyway, enabling to change the column width is just a Qt UI setting, And I think it should be enabled, independent of the formula editor icon.
OK, but document this please. By the way, where do I find info like about this feature?
It's an extension to the FC expression engine. Previously it can only bind to numerical property. Now it can bind to all. I have modified the PR thread for a temporary document of all the expression enhancement.
On MacOS I can edit the names with return key. And luckily the same works for the description ! This new possibility is highly welcome here, as I don't have to describe things in the label, as I do now. Tiny imbalance: The description should go at least up to the right end. There is no need to have something beyond.
Click the description field of an object, and press F2. I'll modify the rename action for that too.