generateTheme method

void generateTheme(
  1. ThemeManagerData themeData
)

Make sure ThemesManager exist in the widget tree and your are in the correct BuildContext.

builder: (context, child) {
  ...
  ThemeManager.of(context).generateTheme(
    ThemeManagerData(
        key: <themeKey>,
        data: <ThemeData>,
    )
  );
  return child;
},

Implementation

void generateTheme(
  ThemeManagerData themeData,
) {
  _themes[themeData.key] = themeData;
}