useTextTheme property

Determines if Material-3 TextTheme and Typography is used.

When opting in on using the sub-theming, this flag controls if the TextTheme will use the new Material-3 Typography.material2021 as specified in the Material-3 Design Guide.

If not defined, and ThemeData.useMaterial3 is true, then it defaults to true. If not defined and ThemeData.useMaterial3 is false, then it defaults to false.

This toggle works as an override toggle for using Typography.material2021 in Material-2 mode and for using Typography.material2018 in Material-3 mode.

When using FlexColorScheme and ThemeData.useMaterial3 is false and sub themes are not used, then default typography is Typography.material2018. Note that if FlexColorScheme is not used at all, and your ThemeData has ThemeData.useMaterial3 false, then Flutter defaults to using very old poor Typography.material2014. In such cases consider defining your typography manually to Typography.material2018 or why not even Typography.material2021.

FlexColorScheme fully supports using any custom TextTheme and fonts, just like ThemeData. You apply and use them just as you would with ThemeData. This text theme is just a custom predefined TextTheme.

If you specify a custom typography to FlexColorScheme or FlexThemeData, this property has no impact on used typography.

This property was originally used in FlexColorScheme to opt-in on using a custom text theme defined internally by FlexColorScheme to look like the typography and text theme used in Material-3, before such a text theme and typography existed in Flutter. When Flutter started providing M3 text theme and typography, this property was converted into toggle to opt in and out of using the text theme. Typically, you do not want to opt-out of it, but in M2 mode you may want to opt-in and set it to true.