Normal shades are pretty well defined, open/close are readily apparent just by looking at a window. Position is also defined, 99/100 is fully open, 0 is fully closed.
But what about a TDBU shade, with two separate bars. The bottom bar is pretty easy and should probably mirror any other shade.
But what about the top bar? What does open mean as the bar at position 100 (aka at the top) could mean either fully open or fully closed depending on what the bottom bar is doing. Similarly, the top bar at position 0 (the bottom) means the window is fully open, which is opposite of a normal window shade.
So what should open and close mean for the top bar of a TDBU shade? Should open bring the bar to position 99 or to position 0? And what should the top bar report for open/closed - should it update its value based on the position of the bottom bar to reflect what is actually happening physically?
I suppose this is more of a thought experiment more than anything, as I’m not writing any drivers. But as I’ve got a handful of motorized TDBU shades, I’ve somewhat struggled with implementation due to the unique nature of these shades.
