In an earlier article, a couple of what I like to call Scrollers were created — it's those last two guys on the end...

These two tools were really easy to create — what they do is Increment and Decrement the Active Level one at a time. As we'll see, there are a number of these Scrollers we can create. First, some background on the technology that makes it possible.

What's really important about these Scroller tools is that they make use of some pretty Back-to-Basics MicroStation stuff. First off, all these tools really do is send a Key-In down the pike to MicroStation (now just where Down the Pike actually is, is another discussion altogether — maybe we'll get there one 'O these days.) So anyhow, a Key-in is sent. However, if you poke around (like in the Key-In Browser, or cmdlist.h) you won't find what makes these tools tick.

As you may have heard me carry on about before, knowing how these MicroStation key-ins work, and where to find them, are just about the must useful things that can be learned about this Monster. But if we were to go on a quest for key-ins to turn Levels On or Off, what we might find would look sorta like this...

 Active Level 16

 Set Levels On 63

 Set Levels Off 1-63

 Lv=16

 On=63

 Of=1-63

Using these guys assume you figure out to plug in the Level(s) we are interested in messing with. If you are a Really Old Dog, you'll remember the IGDS-style On= and Of= versions of the first three entries (and yes, they still work in MicroStation!)

As a quick aside here, we need to remember that beside specifying individual Levels, we can also talk about a list or range of Levels (or other things) to turn On/Off; if we use the correct syntax...

 a single Level on — Set Level On 16 or on=16 or lv=16

 a single Level off — Set Level Off 16 or of=16

 a list of Levels — Set Levels On 10,25,26,30,40
 or of=10,25,26,30,40  (Case, by the way, doesn't
 matter for key-ins — ON is the same as On or on!)

 a range of Levels — Set Level On 20-30 or on=1-63

That last range example (on=1-63) is one I use all the time — its Partner-in-Crime of=1-63 is equally useful for turning 'em all off (well, at least until you get carried away in V8!)

Anyhow, getting back to our discussion here — the point is, if we poked around, although we'd find ways to activate, and turn a Level on/off, we wouldn't find a way to increment one. To, say, move from Level 10 to Level 11, which is just what these tools do! So what, you may ask, are the Key-ins for those two? They're pretty easy, but none-the-less, also pretty much undocumented...

 Up — LV=+1

 and Down — LV=-1

They look like regular key-ins, but the addition of those Plus and Minus Signs make a big difference — if we happen to be on Level 10, and send the LV=+1 key-in, we end up on Level 11 pretty quickly. Put these kind of key-ins behind a copuple of Icons, and, you have some pretty powerful stuff working for you.

And it's not just the Levels we can work with here...

I've got Level, Weight, Linecode, and Color scrollin' here — the key-ins are: lv=+1, wt=+1, lc=+1, co=+1, and lv=-1, wt=-1, lc=-1, co=-1. And bear in mind, that these guys can scroll by other numbers, like lv=+5 'fer instance.

And it's not just these guys that can be Scrolled — how about ky=+1 (keypoint snap), or ti=+1 (Tag increment), or ft=+1 (Font), to name a few.