Allow reorder of layers via drag (grab handles?)

[jimkring]

As a LabVIEW user, I want a quick way to reorder my layers.

Current Situation
Right now, I have to select layers by clicking on them, and then use the up/down arrows. This is a bit cumbersome and not obvious that it's even a possibility (i.e. it's not very "discoverable").

Possible Solution

Add some grab handles (visible for the selected layers? or, visible all the time?) to indicate that the layers can be re-positioned.

[svelderrainruiz]

@gregr-ni please let us know if you have any objections on attempting to implement this.

[gregr-ni]

Seems reasonable. The graphics shown in the image seem a bit large but that may have been just for illustration. Will the grab handle be always visible or only show up on hover?

[j-medland]

This is a promising idea so we will move it to a discussion to hammer out some technical details before opening for contribution