[OpenLayers-Users] Toggling vector layers?

[Jeff Dege]

I've a problem where I need to be able to toggle a vector layer on and
off.

I'd originally thought about adding and removing a vector layer, but the
panel edit controls need to have the layer existing when they are
constructed, and there's no method for removing controls from a panel,
so I thought I'd try just hiding the vector layer, using 

First issue was that I didn't want the vector layer to display in the
layer switcher when it was hidden, I needed to set
layer.displayInLayerSwitcher = false.  But if I later made the layer
visible and set layer.displayInLayerSwitcher = true, the layer would
still not display in the layer switcher.  Tracing through the code
resulted in my adding calling a changelayer event after setting
layer.displayInLayerSwitcher = true, after which the layer switcher
displayed the layer.

But drawing didn't work.  If I clicked on the polygon control, I could
draw a polygon, but when I double-clicked on the last point to close it
out, the scratch polygon would disappear, and the vector layer would be
blank.

The problem seems to be that Vector.drawn is false - it's only set to
true when moveTo() has been called, and because its visibility was
false, moveTo() has never been called on it.

Which leads me to conclude that there's more to toggling a layer on and
off than just changing its visibility flag.

How should I be approaching this?