Added a right-click context menu to tree items that has a "save selected branch as a scene" button

[lonevox]

Also changed the readme to explain what the button does.

[Zylann]

I think I'd do this with a right-click contextual menu for consistency with the editor's scene tree. A standalone button looks too "disconnected" from the use case and is not always valid to click if nothing is/can be selected.

Also several things:

• Like Save Branch as Scene, there must be a file dialog to choose where to save it. Hardcoding a tscn is not friendly and offers no feedback.
• Your code changes the owner of editor nodes but does not clean it up. Ideally this plugin should not modify stuff unless the action is clearly meant to do that, and saving a branch isn't.
• The owner stuff should probably not be in Util, it's not something generic enough, it's tied to a particular use case.
• _selected_node is unnecessary since the selected node can already be obtained anytime with _get_node_from_view
• Which version of Godot did you use? There are lots of properties saved for the button you added, and I recall Godot is no longer supposed to save them if they are left to the defaults

[lonevox]

A right click menu was what I had in mind too, but admittedly a button was the fastest implementation. Same with the file dialog, which will be very easy to add in. You make a very good point that the nodes are modified and then not reverted. That should be easy to change too. I'll make sure to move the other methods out of Util.

As for my Godot version, I was using 3.0.6, as it is the version listed on the Godot asset library for this plugin. I wasn't sure if this plugin worked on 3.2.3 but I just tried it out and it seems fine. I'll change the scene in 3.2.3 so the unnecessary lines are removed.

[Zylann]

was using 3.0.6, as it is the version listed on the Godot asset library for this plugin

The assetlib is probably not clear but this actually means it can be used from 3.0.6 onwards, it is not tied uniquely to that version.

[lonevox]

I've changed it so it works as you described. Would this be fit to merge?

[Zylann]

Thank!