96e02c61dc
fixes [`PopupMenuItem` adds redundant padding when using `ListItem`](https://github.com/flutter/flutter/issues/128553) ### Description - Fixed redundant `ListTile` padding when using `CheckedPopupMenuItem` or `PopupMenuItem` with the `ListTile` child for complex popup menu items as suggested in the docs. - Updated default horizontal padding for popup menu items. ### Code sample <details> <summary>expand to view the code sample</summary> ```dart import 'package:flutter/material.dart'; /// Flutter code sample for [PopupMenuButton]. // This is the type used by the popup menu below. enum SampleItem { itemOne, itemTwo, itemThree } void main() => runApp(const PopupMenuApp()); class PopupMenuApp extends StatelessWidget { const PopupMenuApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( theme: ThemeData(useMaterial3: true), home: const PopupMenuExample(), ); } } class PopupMenuExample extends StatefulWidget { const PopupMenuExample({super.key}); @override State<PopupMenuExample> createState() => _PopupMenuExampleState(); } class _PopupMenuExampleState extends State<PopupMenuExample> { SampleItem? selectedMenu; @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: const Text('PopupMenuButton')), body: Center( child: SizedBox( width: 150, height: 100, child: Align( alignment: Alignment.topLeft, child: PopupMenuButton<SampleItem>( initialValue: selectedMenu, // Callback that sets the selected popup menu item. onSelected: (SampleItem item) { setState(() { selectedMenu = item; }); }, itemBuilder: (BuildContext context) => <PopupMenuEntry<SampleItem>>[ const PopupMenuItem<SampleItem>( value: SampleItem.itemOne, child: Text('PopupMenuItem'), ), const CheckedPopupMenuItem<SampleItem>( checked: true, value: SampleItem.itemTwo, child: Text('CheckedPopupMenuItem'), ), const PopupMenuItem<SampleItem>( value: SampleItem.itemOne, child: ListTile( leading: Icon(Icons.cloud), title: Text('ListTile'), contentPadding: EdgeInsets.zero, trailing: Icon(Icons.arrow_right_rounded), ), ), ], ), ), ), ), ); } } ``` </details> ### Before  - Default horizontal padding is the same as M2 (16.0), while the specs use a smaller value (12.0) - `ListTile` nested by default in `CheckedPopupMenuItem` has redundant padding - `PopupMenuItem` using `ListTile` as a child for complex menu items contains redundant padding.  ### After - Default horizontal padding is updated for Material 3. - `PopupMenuItem` & `CheckedPopupMenuItem` override `ListTile` padding (similar to how `ExpansionTile` overrides `ListTile` text and icon color. 
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.