Customizing Bridges

// Custom obstacle provider which provides a node's outline
class MyNodeObstacleProvider extends BaseClass(IObstacleProvider) {
  // Create a specific instance for a node
  constructor(private node: INode) {
    super()
  }

  // IObstacleProvider implementation
  getObstacles(context: IRenderContext): GeneralPath | null {
    const style = this.node.style
    if (
      style.renderer
        .getVisibilityTestable(this.node, style)
        .isVisible(context, context.clip)
    ) {
      // only for nodes which are currently visible:
      // let the IShapeGeometry return the outline as GeneralPath
      const geometry = style.renderer.getShapeGeometry(this.node, style)
      const obstaclePath = geometry.getOutline()
      return obstaclePath
    }
    // not visible: return null
    return null
  }
}

// enable querying nodes on the obstacle provider
const provider = new GraphObstacleProvider()
provider.queryNodes = true
bridgeManager.addObstacleProvider(provider)

// add the custom obstacle provider
graph.decorator.nodes.obstacleProvider.addFactory(
  // if the current node is a group node ...
  (n) => graph.isGroupNode(n),
  // ... then return our custom obstacle provider
  (n) => new MyNodeObstacleProvider(n)
)