CupertinoThemeData.brightness 现可为空
Summary
CupertinoThemeData.brightness is now nullable.
Context
CupertinoThemeData.brightness is now used to
override MediaQuery.platformBrightness for Cupertino widgets.
Before this change, the CupertinoThemeData.brightness
getter returned Brightness.light when it was set to null.
Description of change
Previously CupertinoThemeData.brightness
was implemented as a getter:
Brightness get brightness => _brightness ?? Brightness.light;
final Brightness _brightness;
It is now a stored property:
final Brightness brightness;
Migration guide
Generally CupertinoThemeData.brightness
is rarely useful outside of the Flutter framework.
To retrieve the brightness for Cupertino widgets,
now use CupertinoTheme.brightnessOf instead.
With this change, it is now possible to override
CupertinoThemeData.brightness in a CupertinoThemeData
subclass to change the brightness override. For example:
class AwaysDarkCupertinoThemeData extends CupertinoThemeData {
Brightness brightness => Brightness.dark;
}
When a CupertinoTheme uses the above CupertinoThemeData,
dark mode is enabled for all its Cupertino descendants
that are affected by this CupertinoTheme.
Timeline
Landed in version: 1.16.3
In stable release: 1.17
References
Design doc:
API documentation:
Relevant issue:
Relevant PR: