/// <summary>
    /// draws a check box to toggle persist state ON / OFF for a
    /// component. will be disabled if the 'Default' state has
    /// been overridden
    /// </summary>
    public static void PersistToggle(vp_AIComponentPersister persister)
    {
        bool oldPersistState = persister.Component.Persist;

        GUI.color = Color.white;
        if (persister.Component.DefaultState.TextAsset != null)
        {
            persister.Component.Persist = false;
            GUI.color = m_ColorTransparentWhite;
        }

        persister.Component.Persist = vp_EditorGUIUtility.SmallToggle("Persist Play Mode Changes", persister.Component.Persist);
        if (persister.Component.DefaultState.TextAsset != null && persister.Component.Persist == true)
        {
            string s = "Can't Persist Play Mode Changes when the 'Default' state has been overridden with a text file preset.";
            if (!Application.isPlaying)
            {
                s += "\n\nClick 'Unlock' to reenable inspector changes to this component.";
            }
            vp_MessageBox.Create(vp_MessageBox.Mode.OK, "Locked", s);
            persister.Component.Persist = false;
        }

        if (oldPersistState != persister.Component.Persist)
        {
            persister.Persist();
        }
        GUI.color = Color.white;
    }
    /// <summary>
    /// draws a field allowing the user to create, reorganize,
    /// name, assign presets to and delete states on a component
    /// </summary>
    public static bool StateFoldout(bool foldout, vp_AIComponent component, List <vp_AIState> stateList, vp_AIComponentPersister persister = null)
    {
        bool before = foldout;

        foldout = EditorGUILayout.Foldout(foldout,
                                          (foldout && !Application.isPlaying) ? "State             Preset" : "States"
                                          );

        if (foldout != before)
        {
            m_ShowBlockListFor = null;
            component.RefreshDefaultState();
        }

        if (foldout)
        {
            if (m_ShowBlockListFor != null)
            {
                if (!stateList.Contains(m_ShowBlockListFor))
                {
                    foldout = false;
                }
            }
        }

        if (foldout)
        {
            for (int v = 0; v < stateList.Count; v++)
            {
                vp_AIState s = stateList[v];
                if (!Application.isPlaying)
                {
                    vp_AIPresetEditorGUIUtility.StateField(s, stateList, component);
                    if ((m_ShowBlockListFor != null) && m_ShowBlockListFor == s)
                    {
                        StateBlockList(component, s);
                    }
                }
                else
                {
                    vp_AIPresetEditorGUIUtility.RunTimeStateField(component, s, stateList);
                }
            }

            GUILayout.BeginHorizontal();
            if (!Application.isPlaying)
            {
                if (GUILayout.Button("Add State", GUILayout.MinWidth(90), GUILayout.MaxWidth(90)))
                {
                    m_ShowBlockListFor = null;
                    string newStateName = "Untitled";
                    int    n            = 1;
                    while (GetStateId(component, newStateName) != -1)
                    {
                        n++;
                        newStateName = newStateName.Substring(0, 8) + (n < 10?"0":"") + n.ToString();
                    }

                    stateList.Add(new vp_AIState(component.GetType().Name, newStateName, ""));
                    component.RefreshDefaultState();
                    EditorUtility.SetDirty(component);
                }
            }
            else
            {
                GUI.color = Color.clear;
                GUILayout.Button("", GUILayout.MinWidth(36), GUILayout.MaxWidth(36));
                GUI.color = Color.white;
            }
            if (!Application.isPlaying)
            {
                GUILayout.EndHorizontal();
            }
            if (persister != null)
            {
                vp_AIPresetEditorGUIUtility.PersistToggle(persister);
            }
            if (Application.isPlaying)
            {
                GUILayout.EndHorizontal();
            }

            vp_EditorGUIUtility.Separator();
        }

        return(foldout);
    }