2e7fa83f67
This PR is to make preparations to make `CardTheme` conform to Flutter's conventions for component themes: * Added a `CardThemeData` class which defines overrides for the defaults for `Card` properties. * Added 2 `CardTheme` constructor parameters: `CardThemeData? data` and `Widget? child`. This is now the preferred way to configure a `CardTheme`: ```dart CardTheme( data: CardThemeData(color: xxx, elevation: xxx, ...), child: Card(...) ) ``` These two properties are made nullable to not break existing apps which has customized `ThemeData.cardTheme`. * Changed the type of theme defaults from `CardTheme` to `CardThemeData`. TODO: * Fix internal failures that may have breakages. * Change the type of `ThemeData.cardTheme` from `CardTheme` to `CardThemeData`. This may cause breaking changes, a migration guide will be created. Addresses the "theme normalization" sub project within https://github.com/flutter/flutter/issues/91772
Token Defaults Generator
Script that generates component theme data defaults based on token data.
Usage
Run this program from the root of the git repository:
dart dev/tools/gen_defaults/bin/gen_defaults.dart [-v]
This updates generated/used_tokens.csv and the various component theme files.
Templates
There is a template file for every component that needs defaults from
the token database. These templates are implemented as subclasses of
TokenTemplate. This base class provides some utilities and a structure
for adding a new block of generated code to the bottom of a given file.
Templates need to override the generate method to provide the generated
code block as a string.
See lib/fab_template.dart for an example that generates defaults for the
Floating Action Button.
Tokens
Tokens are stored in JSON files in data/, and are sourced from
an internal Google database.
template.dart should provide nearly all useful token resolvers
(e.g. color, shape, etc.). For special cases in which one shouldn't
be defined, use getToken to get the raw token value. The script, through
the various revolvers and getToken, validates tokens, keeps track of
which tokens are used, and generates generated/used_tokens.csv.