content: import 'package:flutter/material.dart';
  
  class AppbarThemeExtensions extends ThemeExtension<AppbarThemeExtensions> {
    final Color iconColor;
    final Color appBarGradientStartColor;
    final Color appBarGradientEndColor;
    final Color
        searchBarFillColor; // fill color for search bar in home page appbar
  
    AppbarThemeExtensions({
      required this.iconColor,
      required this.appBarGradientStartColor,
      required this.appBarGradientEndColor,
      required this.searchBarFillColor,
    });
  
    @override
    ThemeExtension<AppbarThemeExtensions> copyWith({
      Color? iconColor,
      Color? appBarGradientStartColor,
      Color? appBarGradientEndColor,
      Color? searchBarFillColor,
    }) {
      return AppbarThemeExtensions(
        iconColor: iconColor ?? this.iconColor,
        appBarGradientStartColor:
            appBarGradientStartColor ?? this.appBarGradientStartColor,
        appBarGradientEndColor:
            appBarGradientEndColor ?? this.appBarGradientEndColor,
        searchBarFillColor: this.searchBarFillColor,
      );
    }
  
    @override
    ThemeExtension<AppbarThemeExtensions> lerp(
      covariant AppbarThemeExtensions? other,
      double t,
    ) {
      return AppbarThemeExtensions(
        iconColor: Color.lerp(iconColor, other?.iconColor, t)!,
        appBarGradientStartColor: Color.lerp(
            appBarGradientStartColor, other?.appBarGradientStartColor, t)!,
        appBarGradientEndColor:
            Color.lerp(appBarGradientEndColor, other?.appBarGradientEndColor, t)!,
        searchBarFillColor:
            Color.lerp(searchBarFillColor, other?.searchBarFillColor, t)!,
      );
    }
  }
  