content: import 'dart:collection';
  
  import 'dart:ui';
  
  import 'package:flutter/material.dart';
  
  const String COLOR_PRIMARY        = "ColorPrimary";
  const String COLOR_SECONDARY      = "ColorSecondary";
  const String COLOR_CANVAS         = "ColorCanvas";
  const String COLOR_TEXT           = "ColorText";
  
  const String STYLE_NORMAL         = "StyleNormal";
  const String STYLE_NORMAL_BOLD    = "StyleNormalBold";
  const String STYLE_TITLE          = "StyleTitle";
  
  class ThemeManager {
    //<editor-fold desc="Singleton Setup">
    static final ThemeManager _instance = new ThemeManager._internal();
    factory ThemeManager() {
      return _instance;
    }
    ThemeManager._internal(){
      _initialize();
    }
    //</editor-fold>
  
    Map _colors = LinkedHashMap<String, Object>();
    Map _styles = LinkedHashMap<String, TextStyle>();
  
    getColor(String name) {
      return _colors[name];
    }
  
    getStyle(String name) {
      return _styles[name];
    }
  
    _initialize(){
      _colors.putIfAbsent(COLOR_PRIMARY,      () => Colors.lightBlue);
      _colors.putIfAbsent(COLOR_SECONDARY,    () => Colors.purple[50]);
      _colors.putIfAbsent(COLOR_CANVAS,       () => Colors.purple[50]);
      _colors.putIfAbsent(COLOR_TEXT,         () => Colors.white);
  
      _styles.putIfAbsent(STYLE_NORMAL,       () => TextStyle(fontSize: 22.0, color: Colors.black));
      _styles.putIfAbsent(STYLE_NORMAL_BOLD,  () => TextStyle(fontSize: 20.0, color: Colors.black, fontWeight: FontWeight.bold));
      _styles.putIfAbsent(STYLE_TITLE,        () => TextStyle(fontSize: 30.0, color: Colors.black, fontWeight: FontWeight.bold));
    }
  }