ExpansionTile : expandedAlignment not accepts AlignmentDirectional to support rtl language

the expandedAlignment defined as Alignment , not as AlignmentGeometry even if _buildBody returns Align widget which accepts alignment property as AlignmentGeometry

Fixing ExpansionTile expandedAlignment not Accepts AlignmentGeometry f…

What about using AlignmentGeometry.resolve with rtl to get the alignment and pass it into expandedAlignment?

@victorsanni

@victorsanni we can do that with one trade-off , The .resolve() method is not context-aware on its own. so this shifts the burden of finding the text direction from the Framework to the developer , so the developer forced to perform a lookup first to find out if the app is currently LTR or RTL.

by using the Automatic Lookup (i.e expandedAlignment: AlignmentDirectional. ) , we writing clean and simple without creating a boilerplate or doing manual look up .

find examples below

manual look up

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter ExpansionTile Test',
      localizationsDelegates: const [
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
      ],
      locale: Locale('ar'),

      supportedLocales: const [Locale('en', 'US'), Locale('ar', 'IQ')],
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  const MyHomePage({super.key});

  @override
  Widget build(BuildContext context) {
    // 1- we need lookup the framework and get the current TextDirection first
    final TextDirection currentDirection = Directionality.of(context);
    // 2- pass the TextDirection to the resolve method
    final Alignment resolvedAlignment = AlignmentDirectional.centerStart
        .resolve(currentDirection);
    return Scaffold(
      body: Center(
        child: ExpansionTile(
          title: Text('data'),
          expandedAlignment: resolvedAlignment,
          children: [Text('data')],
        ),
      ),
    );
  }
}

automatic look up

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter ExpansionTile Test',
      localizationsDelegates: const [
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
      ],
      locale: Locale('ar'),

      supportedLocales: const [Locale('en', 'US'), Locale('ar', 'IQ')],
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  const MyHomePage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ExpansionTile(
          title: Text('data'),
          // the Framwork handles the lookup automatically
          expandedAlignment: AlignmentDirectional.centerStart,
          children: [Text('data')],
        ),
      ),
    );
  }
}

To confirm, are you suggesting a new property that takes into account text direction? Should it replace the current one? (from triage)

@dkwingsmt

@dkwingsmt thanks for your review

We are not introducing a new property. Instead, we are generalizing the existing expandedAlignment property by changing its type from Alignment to AlignmentGeometry.

Since AlignmentGeometry is the base class for both, this change is non-breaking:

Backward Compatible: Alignment inherits from AlignmentGeometry, so existing code remains valid.
New Feature: AlignmentDirectional also inherits from AlignmentGeometry, allowing us to support RTL layouts naturally.

Fixing ExpansionTile expandedAlignment not Accepts AlignmentGeometry f…

Fixing ExpansionTile expandedAlignment not Accepts AlignmentGeometry … (

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ExpansionTile : expandedAlignment not accepts AlignmentDirectional to support rtl language #180813

manual look up

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ExpansionTile : expandedAlignment not accepts AlignmentDirectional to support rtl language #180813

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victorsanni commented on Jan 12, 2026

devnoaman commented on Jan 13, 2026

manual look up

automatic look up

dkwingsmt commented on Jan 14, 2026

devnoaman commented on Jan 15, 2026

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