theme_util_flutter.dart

import 'package:flutter/material.dart';

enum CLThemeConstants {
  LIGHT_RED,
  LIGHT_BLUE,
  LIGHT_GRAY,
  DARK_ORANGE,
  DARK_GREEN,
  DARK_BROWN
}

class CLThemeItemsDto {
  CLThemeItemsDto(this.sThemeName, this.sThemeNameId, this.themeColors,
      this.isSelectedTheme, this.themeBuilder);

  final String sThemeName;
  final CLThemeConstants sThemeNameId;
  final LinearGradient themeColors;
  final bool isSelectedTheme;
  final _ThemeColor themeBuilder;
}

class _CLThemeListOption {
  _CLThemeListOption() {
//  for  setting Default Theme in case
    _themeData = _appLightThemeBuilder(_ThemeColorDarkGreen());
  }

  ThemeData _themeData;

  CLThemeConstants currentTheme;

  ThemeData buildThemeData(CLThemeConstants themeConstants) {
    if (currentTheme == null || currentTheme.index != themeConstants.index) {
      switch (themeConstants) {
        case CLThemeConstants.LIGHT_RED:
          _themeData = _appLightThemeBuilder(_ThemeColorLightRed());
          break;
        case CLThemeConstants.LIGHT_BLUE:
          _themeData = _appLightThemeBuilder(_ThemeColorLightBlue());
          break;
        case CLThemeConstants.LIGHT_GRAY:
          _themeData = _appLightThemeBuilder(_ThemeColorLightGray());
          break;
        case CLThemeConstants.DARK_ORANGE:
          _themeData = _appDarkThemeBuilder(_ThemeColorDarkOrange());
          break;
        case CLThemeConstants.DARK_GREEN:
          _themeData = _appDarkThemeBuilder(_ThemeColorDarkGreen());
          break;
        case CLThemeConstants.DARK_BROWN:
          _themeData = _appDarkThemeBuilder(_ThemeColorDarkBrown());
          break;
        default:
          _themeData = _appLightThemeBuilder(_ThemeColorLightRed());
      }
    }

    currentTheme = themeConstants;
    return _themeData;
  }

  ThemeData _appLightThemeBuilder(_ThemeColor baseTheme) {
    Color primaryColor = baseTheme._primaryColor;
    Color secondaryColor = baseTheme._primaryColorDark;
    final ColorScheme colorScheme = const ColorScheme.light().copyWith(
      primary: primaryColor,
      secondary: secondaryColor,
    );
    final ThemeData base = ThemeData.light();
    return base.copyWith(
      colorScheme: colorScheme,
      primaryColor: primaryColor,
      buttonColor: primaryColor,
      indicatorColor: Colors.white,
      splashColor: Colors.white24,
      splashFactory: InkRipple.splashFactory,
      accentColor: secondaryColor,
      canvasColor: Colors.white,
      scaffoldBackgroundColor: Colors.white,
      backgroundColor: Colors.white,
      errorColor: const Color(0xFFB00020),
      buttonTheme: ButtonThemeData(
        colorScheme: colorScheme,
        textTheme: ButtonTextTheme.primary,
      ),
      textTheme: _buildTextTheme(base.textTheme),
      primaryTextTheme: _buildTextTheme(base.primaryTextTheme),
      accentTextTheme: _buildTextTheme(base.accentTextTheme),
    );
  }

  ThemeData _appDarkThemeBuilder(_ThemeColor baseTheme) {
    Color primaryColor = baseTheme._primaryColor;
    Color secondaryColor = baseTheme._primaryColorDark;
    final ThemeData base = ThemeData.dark();
    final ColorScheme colorScheme = const ColorScheme.dark().copyWith(
      primary: primaryColor,
      secondary: secondaryColor,
    );
    return base.copyWith(
      primaryColor: primaryColor,
      buttonColor: primaryColor,
      indicatorColor: Colors.white,
      accentColor: secondaryColor,
      canvasColor: const Color(0xFF202124),
      scaffoldBackgroundColor: const Color(0xFF202124),
      backgroundColor: const Color(0xFF202124),
      errorColor: const Color(0xFFB00020),
      buttonTheme: ButtonThemeData(
        colorScheme: colorScheme,
        textTheme: ButtonTextTheme.primary,
      ),
      textTheme: _buildTextTheme(base.textTheme),
      primaryTextTheme: _buildTextTheme(base.primaryTextTheme),
      accentTextTheme: _buildTextTheme(base.accentTextTheme),
    );
  }

  TextTheme _buildTextTheme(TextTheme base) {
    return base.copyWith(
      title: base.title.copyWith(
        fontFamily: 'GoogleSans',
      ),
    );
  }

  openThemePickerDialog(BuildContext context) {
    _themeList = getThemeList();

    double dialogWidth = MediaQuery.of(context).size.width;
    bool isSelectedTheme;
    return showDialog(
        context: context,
        builder: (BuildContext builderContext) {
          return AlertDialog(
            shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.all(Radius.circular(10.0))),
            contentPadding:
                EdgeInsets.only(top: 10.0, right: 10, left: 10, bottom: 10),
            content: Container(
              width: dialogWidth * 0.6 > 300 ? dialogWidth * 0.6 : dialogWidth,
              child: new GridView.builder(
                itemCount: _themeList.length,
                shrinkWrap: true,
                gridDelegate: new SliverGridDelegateWithFixedCrossAxisCount(
                    crossAxisCount: 5),
                itemBuilder: (BuildContext itemContext, int index) {
                  if (index == selectedTheme) {
                    isSelectedTheme = true;
                  } else
                    isSelectedTheme = false;
                  return InkWell(
                    onTap: () => changeTheme(itemContext, index),
                    child: Card(
                      elevation: 5,
                      shape: CircleBorder(),
                      child: Container(
                        alignment: Alignment.center,
                        decoration: ShapeDecoration(
                            shape: CircleBorder(),
                            gradient: _themeList[index].themeColors),
                        child: isSelectedTheme
                            ? Icon(
                                Icons.done,
                                color: Colors.white,
                              )
                            : null,
                      ),
                    ),
                  );
                },
              ),
            ),
          );
        });
  }

  changeTheme(BuildContext context, int selIndex) {
    selectedTheme = selIndex;
    Navigator.pop(context, _themeList[selIndex]);
  }

  List<CLThemeItemsDto> getThemeList() {
    return [
      CLThemeItemsDto(
          'Light Red',
          CLThemeConstants.LIGHT_RED,
          LinearGradient(
            colors: [Colors.red, Colors.blue],
          ),
          false,
          _ThemeColorDarkGreen()),
      CLThemeItemsDto(
          'Light Blue ',
          CLThemeConstants.LIGHT_BLUE,
          LinearGradient(colors: [Colors.blue, Colors.green]),
          false,
          _ThemeColorDarkGreen()),
      CLThemeItemsDto(
          'Light Black gray',
          CLThemeConstants.LIGHT_GRAY,
          LinearGradient(colors: [Colors.black, Colors.grey]),
          false,
          _ThemeColorDarkGreen()),
      CLThemeItemsDto(
          'Dark Orange Blue',
          CLThemeConstants.DARK_ORANGE,
          LinearGradient(
              colors: [Colors.deepOrangeAccent, Colors.orangeAccent]),
          false,
          _ThemeColorDarkGreen()),
      CLThemeItemsDto(
          'Dark Green ',
          CLThemeConstants.DARK_GREEN,
          LinearGradient(colors: [Colors.green, Colors.lightGreen]),
          false,
          _ThemeColorDarkGreen()),
      CLThemeItemsDto(
          'Dark brown',
          CLThemeConstants.DARK_BROWN,
          LinearGradient(colors: [Colors.brown, Colors.amber]),
          false,
          _ThemeColorDarkGreen())
    ];
  }
}

//class _ThemeColorLightBlue implements _ThemeColor {
//  Color _toolBarColor = Colors.blue;
//}

class _ThemeColorLightRed implements _ThemeColor {
  @override
  Color _primaryColor = Colors.red;

  @override
  Color _primaryColorDark = Colors.blue;

  @override
  Color _primaryColorLight = Color(0xffff686b);

  @override
  Color _toolBarColor = Color(0xffff686b);
}

class _ThemeColorLightBlue implements _ThemeColor {
  @override
  Color _primaryColor = Colors.blueAccent;

  @override
  Color _primaryColorDark = Colors.lightGreen;

  @override
  Color _primaryColorLight = Color(0xffff686b);

  @override
  Color _toolBarColor = Color(0xffff686b);
}

class _ThemeColorLightGray implements _ThemeColor {
  @override
  Color _toolBarColor = Colors.black;

  @override
  Color _primaryColor = Colors.grey;

  @override
  Color _primaryColorDark = Color(0xffff686b);

  @override
  Color _primaryColorLight = Color(0xffff686b);
}

class _ThemeColorDarkOrange implements _ThemeColor {
  @override
  Color _toolBarColor = Colors.orange;

  @override
  Color _primaryColor = Colors.deepOrangeAccent;

  @override
  Color _primaryColorDark = Color(0xffff686b);

  @override
  Color _primaryColorLight = Color(0xffff686b);
}

class _ThemeColorDarkGreen implements _ThemeColor {
  @override
  Color _primaryColor = Colors.green;

  @override
  Color _primaryColorDark = Colors.lightGreen;

  @override
  Color _primaryColorLight = Color(0xffff686b);

  @override
  Color _toolBarColor = Color(0xffff686b);
}

class _ThemeColorDarkBrown implements _ThemeColor {
  @override
  Color _primaryColor = Colors.brown;

  @override
  Color _primaryColorDark = Colors.yellowAccent;

  @override
  Color _primaryColorLight = Color(0xffff686b);

  @override
  Color _toolBarColor = Color(0xffff686b);
}

// AppColors.blue[500]
class AppColors {
  AppColors._(); // this basically makes it so you can instantiate this class

  static const int _deepPurplePrimaryValue = 0xFF673AB7;
  static const MaterialColor green = MaterialColor(
    _deepPurplePrimaryValue,
    <int, Color>{
      50: Color(0x25df7d35),
      100: Color(0x40df7d35),
      200: Color(0x70df7d35),
      300: Color(0xa5df7d35),
      400: Color(0xbFdf7d35),
      500: Color(0xc0df7d35),
      600: Color(0xd0df7d35),
      700: Color(0xe0df7d35),
      800: Color(0xF0df7d35),
      900: Color(0xFFdf7d35),
    },
  );
}

List<CLThemeItemsDto> _themeList;
int selectedTheme = 0;

abstract class _ThemeColor {
  Color _toolBarColor;

//  Color _brightness;
  Color _primaryColor;

//  Color _primaryColorBrightness;
  Color _primaryColorLight;
  Color _primaryColorDark;

//  Color _canvasColor;
//  Color _accentColor;

//  Color _accentColorBrightness;
//  Color _scaffoldBackgroundColor;
//  Color _bottomAppBarColor;
//  Color _cardColor;
//  Color _dividerColor;
//  Color _highlightColor;
//  Color _splashColor;
//
//  Color _splashFactory;
//  Color _selectedRowColor;
//  Color _unselectedWidgetColor;
//  Color _disabledColor;
//  Color _buttonColor;
//  Color _secondaryHeaderColor;
//  Color _textSelectionColor;
//  Color _cursorColor;
//  Color _textSelectionHandleColor;
//  Color _backgroundColor;
//  Color _dialogBackgroundColor;
//  Color _indicatorColor;
//  Color _hintColor;
//  Color _errorColor;
//  Color _toggleableActiveColor;
//
//  ButtonThemeData _buttonTheme();

//  Color _textTheme();

//  Color _primaryTextTheme();

//  Color _accentTextTheme();

//  Color _inputDecorationTheme();

//  Color _iconTheme();

//  Color _primaryIconTheme();

//  Color _accentIconTheme();

//  Color _sliderTheme();

//  Color _tabBarTheme();

//  Color _cardTheme();

//  Color _chipTheme();

//  Color _platform;
//  Color _materialTapTargetSize;

//  Color _pageTransitionsTheme();

//  Color _appBarTheme();

//  Color _bottomAppBarTheme();

//  Color _colorScheme;

//  Color _dialogTheme();

//  Color _typography;
//  Color _cupertinoOverrideThem;

//  Color changeAlpha(Color color, int alpha);
}

_CLThemeListOption themeController = _CLThemeListOption();