TextSelectionTheme migration

Summary

The ThemeData properties that controlled the look of selected text in Material widgets have been moved into their own TextSelectionTheme. These properties include cursorColor, textSelectionColor, and textSelectionHandleColor. The defaults for these properties have also been changed to match the Material Design specification.

Context

As part of the larger Material Theme Updates, we have introduced a new Text Selection Theme used to specify the properties of selected text in TextField and SelectableText widgets. These replace several top-level properties of ThemeData and update their default values to match the Material Design specification. This document describes how applications can migrate to this new API.

Migration guide

If you are currently using the following properties of ThemeData, you need to update them to use the new equivalent properties on ThemeData.textSelectionTheme:

Code before migration:

ThemeData(
  cursorColor: Colors.red,
  textSelectionColor: Colors.green,
  textSelectionHandleColor: Colors.blue,
)

Code after migration:

ThemeData(
  textSelectionTheme: TextSelectionThemeData(
    cursorColor: Colors.red,
    selectionColor: Colors.green,
    selectionHandleColor: Colors.blue,
  )
)

Default changes

If you weren’t using these properties explicitly, but depended on the previous default colors used for text selection you can add a new field to your ThemeData for your app to return to the old defaults as shown:

// Old defaults for a light theme
ThemeData(
  textSelectionTheme: TextSelectionThemeData(
    cursorColor: const Color.fromRGBO(66, 133, 244, 1.0),
    selectionColor: const Color(0xff90caf9),
    selectionHandleColor: const Color(0xff64b5f6),
  )
)

// Old defaults for a dark theme
ThemeData(
  textSelectionTheme: TextSelectionThemeData(
    cursorColor: const Color.fromRGBO(66, 133, 244, 1.0),
    selectionColor: const Color(0xff64ffda),
    selectionHandleColor: const Color(0xff1de9b6),
  )
)

If you are fine with the new defaults, but have failing golden file tests, you can update your master golden files using the following command:

$ flutter test --update-goldens

Timeline

Landed in version: 1.23.0-4.0.pre
In stable release: 2.0.0

References

API documentation:

• TextSelectionThemeData
• ThemeData

Relevant PRs:

• PR 62014: TextSelectionTheme support