This comes down to 2 main things; the TypeConverter and Editor (of the
UITypeEditor sub-type). Both are easy to write, and can be associated
either with an entire type, or specificed on a property-by-property
basis.
The TypeConverter is responsible for object -> string and string ->
object, for suggesting sub-properties (and allowing reconstruction via
sub-properties for immutable types), and for listing simple drop-down
variations.
The EditorAttribute simply assigns an editor of a listed type, and
UITypeEditor is the one that matters.
The UITypeEditor is responsible for custom drop-downs (like the "dock"
window), painting modal pop-ups (like collection editors) and preview
panels (like colors, images, etc).
Google TypeConverter and UITypeEditor for more.
Marc
