id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
12872	Allow hierarchical layers	michael2402	team	"Currently, JOSM uses one global layer list.

There are many layers that depend on other layers (validator results, audio tracks along GPX, ...).

I suggest to split the layers in different types:
- Main layers that represent a single data type. Those are the OSM layers, GPX tracks, background imagery, ...
- Sublayers that depend on one of those layers

[[Image(layers-sublayers.png​)]]

Only main layers can be active layers.

I would suggest the following sublayers:
- Validator results as single sublayer of OSM layers
- Audio layer as sublayer of GPX layer

I want to render the sub layers independendly from the parent layer and directly above the parent layer. The visibility setting is independent for the parent/child layer (we can e.g. add an interit checkbox there).

The problems I see:
- Merging of e.g. audio layers from different tracks will not be possible any more (does anyone use this)
- You cannot sort the sublayers to be on top of other main layers. This won't be a problem for the validator, since the active edit layer is always drawn on top.
- The audio playback assumes there can be an active audio layer (although I probably need to rewrite part of this to make the PlayHeadMarker a temporary layer)

This is only a rough draft so feel free to provide feedback and state if this is a desired feature or if it reduces usability."	enhancement	new	major		Core			hierarchical layer	Don-vip bastiK stoecker