[PythonCAD] layers

[Chris Somerlot]

My 2 cents:

> Layers nested under layers seems awkward, and there doesn't appear to be a way
> to create more than one top-level layer.  Maybe your analogy for top-level
> layers is the same as the one that autocad uses for model/layout tabs.  If I
> could have multiple top-level layers, would I be able to see them
> simultaneously?

I don't know. Layer management under autocad and microstation has
always seemed awkward to me, and I see pythoncad as having improved on
the process. I like the advantage to nested layers: one layer contains
all the data on say topography, with nested layers for labels and
contours. All the nested layers can be turned on or off thru the
parent layer.

The toplevel layer is present in any drawing, whether it is implicit
or explicit. I think in proper cad etiquette nothing is drawn on that
layer, and in throw-away drawings its more of a place holder, like the
"0" layer in autocad.

> 
> Also, the differentiation in color of the active layer could get unsettling at
> higher drawing densities.  If I had just drawn a yellow line on layer '300'
> and then changed to layer 'concrete' and wanted to snap to that yellow line,
> it is not yellow anymore.  That could get confusing if it is between 10 other
> lines.

I'll admit this took some getting used to. But again, this streamlines
layer management for me. 90% of the time I'll open up one of my
autocad drawings and just start drawing things without paying
attention to layers, then go back and change all the layer properties

> Possibly, the inactive layer coloring should be done with some sort of mask
> using the background color (if the background is black, whites turn grey, etc
> (object color minus background color?))  But, even at that, there should be a
> way to toggle it on and off.  It is good to be able to highlight the active
> layer, or individual inactive layers, but I mostly don't care what layer
> things are on while drawing (there's some mental record-keeping and sometimes
> it just plain doesn't matter.)  That said, turning off layers to find what is
> what can be a real pain too.

Yeah, this would be good. Sometimes I differentiate between layers by
setting them to different colors.

-Chris-