Unity: display mesh info for selected object

MeshInfo.cs

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(MeshFilter))]
public class MeshInfo : Editor {
  protected MeshFilter meshFilter;
  protected Mesh mesh;
  protected Vector3[] lines;

  public void OnEnable() {
    meshFilter = target as MeshFilter;
    if (meshFilter != null)
      {
        mesh = meshFilter.sharedMesh;
        Recalculate();
      }
    else
      {
        mesh = null;
        lines = new Vector3[0];
      }
  }

  public void OnSceneGUI() {
    if (mesh == null) {
      return;
    }

    if (MeshInfoSettings.changed)
      {
        Recalculate();
        MeshInfoSettings.changed = false;
      }

    if (MeshInfoSettings.showMeshDebugInfo)
      {
        Transform transform = meshFilter.transform;
        Handles.zTest = UnityEngine.Rendering.CompareFunction.LessEqual;
        Handles.matrix = meshFilter.transform.localToWorldMatrix;
        Handles.color = Color.yellow;
        Handles.DrawLines(lines);
        string info = "";
        info += "Indices:\t" + mesh.GetIndexCount(0) + "\n";
        info += "Vertices:\t" + mesh.vertexCount + "\n";
        info += "Triangles:\t" + mesh.triangles.Length + "\n";
        info += "Normals:\t" + mesh.normals.Length;
        GUIStyle style = new GUIStyle();
        style.padding = new RectOffset(8, 0, 8, 0);
        style.normal.textColor = Color.black;
        style.normal.background = Texture2D.whiteTexture;
        Handles.Label(transform.position, info, style);
      }
  }

  protected void Recalculate() {
    if (mesh != null)
      {
        lines = new Vector3[mesh.vertexCount * 2];
        for (int i = 0; i < mesh.vertexCount; i++)
          {
            lines[i * 2] = mesh.vertices[i];
            lines[i * 2 + 1] = mesh.vertices[i] + mesh.normals[i] * MeshInfoSettings.vertexNormalLength;
          }
      }
  }
}

public class MeshInfoSettings : EditorWindow
{
  static public bool changed;
  static public bool showMeshDebugInfo;
  static public float vertexNormalLength = 0.1f;

  [MenuItem("GameObject/Mesh Info")]
  static void InitWindow()
  {
    EditorWindow.GetWindow(typeof(MeshInfoSettings));
  }

  public void OnEnable()
  {
    titleContent = new GUIContent("Mesh Info");
  }

  public void OnGUI() {
    EditorGUILayout.Space();
    showMeshDebugInfo = EditorGUILayout.Toggle("Show Mesh Debug Info", showMeshDebugInfo);
    if (vertexNormalLength != (vertexNormalLength = EditorGUILayout.FloatField("Vertex Normal Length", vertexNormalLength)))
      changed = true;
  }
}