DocumentLayers

We've got the most important part of layers implemented now; a group can be turned into a layer by setting its inkscape:groupmode attribute to "layer" (it defaults to "group").

For now, all this does is permit the objects in a group to be directly selected, rather than selecting the group itself (i.e. by clicking or rubber-banding). To fulfill all the expectations for layers, there are still some things we need to take into account:

• There needs to be a notion of a "current layer", where e.g. the drawing tools and paste operate.

• • At present, this "current layer" is always the root SVG element.

• • The current layer should probably be determined by the most recent object selected -- the object's first layer ancestor (or the object itself, if it is a layer) becomes the current layer until another object is selected. Deselection should probably not alter the current layer.

• • We need to handle the case where the current layer is removed from the document (either directly, or because one of its ancestors was removed) or stops being a layer (due to an inkscape:groupmode change).

• • To find a new layer to become the current, we need to walk up the (pre-removal) hierarchy to find a layer, as if the parent of the removed/unlayered object had been selected.

• We need a layer dialog -- an ObjectTree window (operating on SVG objects) similar to the XMLEditor (which operates on XML nodes) should fulfill this requirement.

• • What behavior should result from selecting a layer in the ObjectTree or XMLEditor? Should that actually select all of the layer's children, or should the layer (temporarily) behave like a group in terms of dragging/rotation/whatever?

I personally lean towards the latter, though I think the former is what many apps with layers do. I think it depends on how much we think layers should break with their fundamental group-nature. -- MenTaLguY

The main venefit from layers is being able to toggle visibility and editability of a layer. That's what layer palettes in most apps focus on, and what we must provide. As for selecting all objects within a layer, that may be useful too, but is of secondary importance IMHO. --bb

• • Similarly, if a group's descendents are directly selected, should that group temporarily behave like a layer? Yes, options and dragging/copying should feel the same as if they were layers. Also de ObjectTree should reflect each action inmediatly.

• The schema should be something like this:

MasterDocument Document Layers Page RightPage LeftPage Groups Objects

From another point of view we can reflect the schema like this: ObjectProperties LocalProperties (shape, color, etc) GroupProperties (Group/s the Object belongs to) LayerProperties PageProperties DocumentProperties

Styles, in both views are floating above everything as a PropertiesGroup that affects the Elements the user decide to assign to that Style. The mechanism could be as simple as CSS.

---

Adobe seems to export their layers as simple groups with id's

Adobe Developer Knowledgebase document #50557

---

One of the nice things about illustrator is that it automaticly creates sublayers [[1]]