In SQL Developer version 4 (Early Adopter), the default display for a Scheduler Chain has changed significantly.
In version 3.2, the display is of the Chain beginning and end, connected by a mesh of steps (displayed as square icons) connected by rules (displayed as lines). It visually resembles a web or fishing net. This is very useful for seeing the flow of the chain and dependencies for each step.
In version 4, the display is of a steps (displayed as green sprocket icons) in a single line. The rules appear to be woven into a single blue line connecting the sprocket icons. This is a significant reduction in utility. One can no longer see the relationships among steps.
The new icons are fine, but please restore the web effect for the rules.