Flying Logic Blog » Tip

Tip: Easy Zooming Using the Scroll Wheel

Robert McNally — Sat, 19 Jan 2008 12:10:18 +0000

If you have a mouse with a scroll wheel, you’ve probably already discovered that Flying Logic will scroll the document window up or down depending on which way you turn it. But did you know that by holding down the Option (Mac) or Alt (Windows) key and turning the scroll wheel, you can zoom in or out of large documents without moving back the the zoom slider?

This feature is even more useful when you understand that when zooming, Flying Logic does its best to keep your current selection visible. So if you want to quickly zoom in on part of the diagram that your mouse is near, just select any element you want to make sure stays visible, then hold down the modifier key and use the scroll wheel.

Quick and easy!

A Flying Logic Glossary

Robert McNally — Fri, 26 Oct 2007 00:17:22 +0000

I have added a glossary of important Flying Logic terminology to the Flying Logic Wiki, and many of the definitions are illustrated. Feel free to add your own refinements and contributions, or ask questions about the definitions in their discussion pages.

Don’t forget that an enormous amount of useful information is also in the Flying Logic User’s Guide and Thinking with Flying Logic.

Tip: Removing a Junctor

Robert McNally — Wed, 03 Oct 2007 19:57:58 +0000

A user wrote and asked:

I’m evaluating Flying Logic Pro on a Mac. I found that an edge with a negate or complement operator in it can’t easily have the operator removed. Selecting the operator and hitting Delete removes the operator and the edges connected to it. It should just remove the operator and unify the input and output edges. This should happen for any operator with one input edge and one output edge. I also think it should happen when an entity with one input and one output is deleted.

Part of the problem here is that when an edge is deleted, large-scale rearrangement may occur on the graph, making the previous state obscure to the user. I expect that it would be common to remove unary operators and want the connection to remain.

The situation described is like this:

If the junctor or either of the two edges is selected and then deleted, the two entities will end up unconnected. This is because edges must always be connected at both ends, and junctors must always have at least one incoming edge and one outgoing edge.

It turns out there is a very easy way to remove the junctor and keep the entities connected. To do this, we use the “redirect” gesture, which is used to redirect the head or tail of an edge to a different entity or junctor. Redirect is initiated by clicking and dragging right at the end of an edge, and is signified by a special arrow with a circular head.

By redirecting the head of the arrow before the junctor to the entity after the junctor…

The junctor and the second arrow are removed, while the redirected arrow remains.

You could just as easily redirect the tail of the second edge to the leftmost entity. Since edges can have different weights, this method gives you choice over which edge will remain after the junctor is removed.