Understanding the Challenge: "Fixing" the Planar Order with Weights

That's a very interesting goal! You want to integrate the concept of "vertex weight" (derived from the internal class structure) with the planar embedding to somehow "fix" or influence its order of iteration.

Let's break down what this means and what's feasible given the nature of planar embeddings.

Understanding the Challenge: "Fixing" the Planar Order with Weights

Recall what we've discussed about PlanarityTestingAlgorithm.Embedding.getEdgesAround(vertex):

• It provides a fixed, cyclic order of edges around a vertex.

• This order is fundamental to that specific planar embedding and defines the faces of the graph.

• You cannot simply reorder this list (e.g., by sorting by vertex weight) and still have it represent the original planar embedding. If you change the cyclic order, you're essentially changing the embedding, potentially breaking its planarity or creating a different drawing.

Therefore, "fixing the order of iteration of the planar" cannot mean directly changing the order returned by getEdgesAround() in a way that respects the embedding and applies arbitrary weights.

What We Can Do: Integrating Weights into Planar-Aware Processing

Instead, we can interpret your goal as: "How can we use vertex weights (derived from internal class structure) to prioritize or order information that we extract from the planar embedding?"

This is a very practical and common approach. Here's what we need to consider and how we can achieve it:

Step 1: Define "Vertex Weight based on Internal Class Structure" (Crucial First Step)

Before we can sort or prioritize anything, we need to know exactly how you intend to calculate the "weight" for each vertex (which is a Class<?> object like org.nanotek.beans.entity.Artist).

For example, a "weight" could be based on:

• Number of Fields/Properties: How many instance variables does the class have?

• Number of Methods: How many methods are defined in the class?

• Inheritance Depth: How far down the inheritance hierarchy is the class from java.lang.Object or BaseEntity?

• Number of Annotations: How many annotations are present on the class?

• Cyclomatic Complexity: (More advanced, requires parsing code, less likely for a simple "weight").

• Custom Business Logic: A specific combination of the above, or a value from your domain.

My first question to you is: How specifically would you like to calculate the "weight" for each Class<?> vertex using its internal structure? (This would typically involve Java Reflection).

Step 2: Strategy for Iteration and Prioritization (Once Weights Are Defined)

Once you have a method to calculate getWeight(Class<?> vertex), we can integrate it:

Option A: Prioritizing Adjacent Vertices in the Planar Context (Most Likely Your Goal)

This seems to align best with your desire to "fix the order of iteration of the planar." You can:

1. Obtain the PlanarityTestingAlgorithm.Embedding<V,E> for your graph.

2. For a given startVertex, get its incident edges in cyclic order using embedding.getEdgesAround(startVertex).

3. From these edges, determine the adjacentVertices (the other end of each edge).

4. Create a new list or a PriorityQueue of these adjacentVertices (or custom objects wrapping them with their weights).

5. Sort this new list/PriorityQueue based on the calculated weights.

6. Iterate through this sorted list/PriorityQueue.

This approach respects the planar embedding by first getting its fixed cyclic order, then it allows you to present or process the adjacent elements in a weighted order for your specific task. It effectively says: "These are the neighbors in planar order; now, among them, which ones are most 'important' by weight?"

Example (Conceptual Flow):

Java

// Assuming 'embedding' and 'graph' are available, and 'getVertexWeight(Class<?> cls)' is defined

Class<?> startVertex = org.nanotek.beans.entity.Artist.class;
List<DefaultEdge> edgesAroundArtist = embedding.getEdgesAround(startVertex);

// List to hold adjacent vertices with their weights for sorting
List<WeightedVertex> weightedAdjacentVertices = new ArrayList<>();

for (DefaultEdge edge : edgesAroundArtist) {
    Class<?> adjacentVertex = graph.getEdgeSource(edge).equals(startVertex)
                                ? graph.getEdgeTarget(edge)
                                : graph.getEdgeSource(edge);
    double weight = getVertexWeight(adjacentVertex);
    weightedAdjacentVertices.add(new WeightedVertex(adjacentVertex, weight));
}

// Sort the list based on weight (e.g., descending order for "weight first")
weightedAdjacentVertices.sort((wv1, wv2) -> Double.compare(wv2.weight, wv1.weight)); // Descending

System.out.println("\n--- Vertices Adjacent to '" + startVertex.getSimpleName() + "' (Planar Order, then Weight-Sorted) ---");
for (WeightedVertex wv : weightedAdjacentVertices) {
    System.out.println("  " + wv.vertex.getSimpleName() + " (Weight: " + wv.weight + ")");
}

// Nested class for demonstration
class WeightedVertex {
    Class<?> vertex;
    double weight;
    WeightedVertex(Class<?> vertex, double weight) {
        this.vertex = vertex;
        this.weight = weight;
    }
}

This approach allows you to leverage the planar information and your weighting scheme.

Therefore, let's start with Step 1: How do you want to define and calculate the "vertex weight" based on the "internal class structure" for your org.nanotek.beans.entity classes? Once we have that, we can implement the weighted sorting.