public override void OnGUI()
    {
        base.OnGUI();

        GUILayout.BeginHorizontal();

        mTrueTypeFont = (Font)EditorGUILayout.ObjectField(mTrueTypeFont, typeof(Font), false, GUILayout.Width(140f));

        GUILayout.Label("font used by the labels");
        GUILayout.EndHorizontal();
        NGraphUtils.DrawSeparator();

        GameObject go = NGraphUtils.SelectedRoot <Canvas>();

        if (ShouldCreate(go, go != null && mTrueTypeFont != null))
        {
            UIUnityGraph pGraph = CreateGraphGo <UIUnityGraph>(go);
            pGraph.AxisLabelDynamicFont = mTrueTypeFont;
        }
    }