Workflow designer in Java

I need UI for graphically design workflows for defining software execution processes. At least 3 different types of will be required: Event received, method execution and conditional if/else (we could use different shapes or each type of node, for example, an ellipse, a rectangle and a diamond respectively). All nodes should have at least a label it would be good if we can add more specific things to each type of node. Links between nodes should be directed arrows. Event received and method execution nodes should only have one outbound connection while the conditional if/else nodes should allow only two possible outbound connections (TRUE/FALSE). All nodes can receive any number of inbound connections from other nodes except for event received which are always the beginning of a given workflow. It should be possible to add new types of nodes with different shapes, colors, etc. The idea is having a canvas that uses, for example, Jgraphx java library or similar which already do all the hard work of managing the nodes, connection, etc and have many example project to start from. We would also need a toolbox with buttons for each type of node and also connections so that we can add new nodes and connections to our workflow easily. That way we would be able to add new nodes, connect them and also remove nodes and connections if needed. Each node should have its own label, but we should also be able to add other labels anywhere on the canvas. From a programmer point of view, this UI should be a class/component and raise events when we click on a node or connection. We should also be able to check the list of nodes and all their properties so that we can save the whole workflow to a file and reload it anytime we need it. On a second phase I will need to add configuration forms for each of these nodes and also a tree view of all the workflows created, but for now what I want is just the graphical part related to the workflow design. When programming in Java I usually work with Eclipse so if possible I prefer that you also use that for this project.