This is the third topic in a series discussing the essential features that make up the Visio application.
Essential Feature: Connectors
The fundamental drawing type in Visio is the flowchart - a collection of boxes connected together by lines. When Visio was first introduced, drawing programs mostly worked with geometric primitives. Boxes and connectors were just sets of lines, with no intelligent behavior. If you wanted to move a box to a new location, you also had to redraw the connecting line to make it reach the box again.
To avoid the tediousness of fixing up drawings, Visio introduced a pair of diagramming innovations: connectors and glue. A connector is a one-dimensional shape consisting of line segments. Each endpoint is attached to a two-dimensional shape (the box) using glue. When the box is moved to a new location, the connector stays attached and stretches as needed to maintain the connectivity between boxes. Visio chooses the route the connector will take between its endpoints.
Connectors have intelligent routing behavior. They will avoid other shapes on the page where possible. They will even show line jumps (or line breaks) where they cross over each other. When you do choose to override Visio, you can easily control the connector path using green handles found on the shape.
The default connector in Visio is the Dynamic Connector, which is the shape created by the Connector Tool. However, any 1-D shape can be used as a connector. You can turn an ordinary line into a connector by changing the ObjType cell in the Shapesheet from 0 to 2. You can also make your own connector master shape. If you name your master "Dynamic Connector", Visio will use it when you draw with the Connector Tool.
There are some other interesting behaviors when using the Connector Tool in conjunction with masters in the Shapes window. Try this: Select an existing shape on the page. Then switch to the Connector Tool and drag a master shape out onto the page. Not only is the shape added, a connector is created and glued between the existing shape and the new shape. You can also make Visio use a different connector shape with the Connector Tool. Switch to the Connector Tool, then select a 1-D master in the Shapes window. Now draw a connector on the page. Visio uses the selected master instead of the Dynamic Connector.
The Dynamic Connector is itself a master. It's built into Visio. The first time you draw with the Connector Tool, Visio looks for a master named "Dynamic Connector" in the Document Stencil. If no master is found, Visio puts a copy of its built-in Dynamic Connector master in the Document Stencil (File > Shapes > Show Document Stencil). You can edit this master to change the appearance of all connectors in the diagram.
There's a lot more that can be said about connectors and also glue, but those are the basics. Connectors streamline the diagramming process by maintaining their connections with shapes and managing their routing automatically.