refactor(ui): refactor platform specific widget styling (#8333)

packages/flutterfire_ui/lib/src/auth/widgets/delete_account_button.dart

@@ -1,10 +1,11 @@
+import 'package:flutter/material.dart';
 import 'package:firebase_auth/firebase_auth.dart'
     show FirebaseAuth, FirebaseAuthException;
 import 'package:flutter/cupertino.dart';
 import 'package:flutterfire_ui/auth.dart';
 import 'package:flutterfire_ui/i10n.dart';
 import '../widgets/internal/loading_button.dart';
-import 'package:flutter/material.dart';
+import '../widgets/internal/universal_button.dart';
 
 typedef DeleteFailedCallback = void Function(Exception exception);
 typedef SignInRequiredCallback = Future<bool> Function();
@@ -13,12 +14,14 @@ class DeleteAccountButton extends StatefulWidget {
   final FirebaseAuth? auth;
   final SignInRequiredCallback? onSignInRequired;
   final DeleteFailedCallback? onDeleteFailed;
+  final ButtonVariant? variant;
 
   const DeleteAccountButton({
     Key? key,
     this.auth,
     this.onSignInRequired,
     this.onDeleteFailed,
+    this.variant,
   }) : super(key: key);
 
   @override
@@ -67,6 +70,7 @@ class _DeleteAccountButtonState extends State<DeleteAccountButton> {
       icon: isCupertino ? CupertinoIcons.delete : Icons.delete,
       label: l.deleteAccount,
       onTap: _deleteAccount,
+      variant: widget.variant,
     );
   }
 }

packages/flutterfire_ui/lib/src/auth/widgets/internal/loading_button.dart

@@ -1,21 +1,15 @@
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
 import 'package:flutterfire_ui/auth.dart';
 
-class LoadingButton extends StatelessWidget {
-  final bool isLoading;
-  final String label;
-  final IconData? icon;
-  final Color? color;
-  final VoidCallback onTap;
+import 'universal_button.dart';
 
-  const LoadingButton({
+class _LoadingButtonContent extends StatelessWidget {
+  final String label;
+  final bool isLoading;
+  const _LoadingButtonContent({
     Key? key,
     required this.label,
-    required this.onTap,
-    this.isLoading = false,
-    this.icon,
-    this.color,
+    required this.isLoading,
   }) : super(key: key);
 
   @override
@@ -31,59 +25,38 @@ class LoadingButton extends StatelessWidget {
       );
     }
 
-    ButtonStyle? style;
-
-    if (color != null) {
-      style = ButtonStyle(
-        foregroundColor: MaterialStateColor.resolveWith(
-          (states) => color!,
-        ),
-        overlayColor: MaterialStateColor.resolveWith(
-          (states) => color!.withAlpha(20),
-        ),
-      );
-    }
-
-    if (isCupertino) {
-      if (icon != null) {
-        child = Row(
-          mainAxisSize: MainAxisSize.min,
-          children: <Widget>[
-            Icon(icon, size: 20),
-            const SizedBox(width: 8),
-            child,
-          ],
-        );
-      }
+    return child;
+  }
+}
 
-      final button = CupertinoButton.filled(
-        onPressed: onTap,
-        child: child,
-      );
+class LoadingButton extends StatelessWidget {
+  final bool isLoading;
+  final String label;
+  final IconData? icon;
+  final Color? color;
+  final VoidCallback onTap;
+  final ButtonVariant? variant;
 
-      return color != null
-          ? CupertinoTheme(
-              data: CupertinoTheme.of(context).copyWith(
-                primaryColor: color,
-              ),
-              child: button,
-            )
-          : button;
-    }
+  const LoadingButton({
+    Key? key,
+    required this.label,
+    required this.onTap,
+    this.isLoading = false,
+    this.icon,
+    this.color,
+    this.variant = ButtonVariant.text,
+  }) : super(key: key);
 
-    if (icon != null) {
-      return OutlinedButton.icon(
-        onPressed: onTap,
-        icon: Icon(icon),
-        label: child,
-        style: style,
-      );
-    }
+  @override
+  Widget build(BuildContext context) {
+    final content = _LoadingButtonContent(label: label, isLoading: isLoading);
 
-    return OutlinedButton(
+    return UniversalButton(
+      color: color,
+      icon: icon,
       onPressed: onTap,
-      style: style,
-      child: child,
+      variant: variant,
+      child: content,
     );
   }
 }

packages/flutterfire_ui/lib/src/auth/widgets/internal/platform_widget.dart

@@ -6,14 +6,27 @@ abstract class PlatformWidget extends StatelessWidget {
   Widget buildCupertino(BuildContext context);
   Widget buildMaterial(BuildContext context);
 
+  Widget? buildWrapper(BuildContext context, Widget child) {
+    return null;
+  }
+
   @override
   Widget build(BuildContext context) {
     final isCupertino = CupertinoUserInterfaceLevel.maybeOf(context) != null;
+    late Widget child;
 
     if (isCupertino) {
-      return buildCupertino(context);
+      child = buildCupertino(context);
+    } else {
+      child = buildMaterial(context);
+    }
+
+    final wrapper = buildWrapper(context, child);
+
+    if (wrapper == null) {
+      return child;
     } else {
-      return buildMaterial(context);
+      return wrapper;
     }
   }
 }

packages/flutterfire_ui/lib/src/auth/widgets/internal/subtitle.dart

@@ -1,20 +1,24 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+import 'platform_widget.dart';
 
-class Subtitle extends StatelessWidget {
+class Subtitle extends PlatformWidget {
   final String text;
   const Subtitle({Key? key, required this.text}) : super(key: key);
 
   @override
-  Widget build(BuildContext context) {
-    final isCupertino = CupertinoUserInterfaceLevel.maybeOf(context) != null;
-    final titleStyle = isCupertino
-        ? CupertinoTheme.of(context).textTheme.navTitleTextStyle
-        : Theme.of(context).textTheme.subtitle1;
+  Widget buildCupertino(BuildContext context) {
+    return Text(
+      text,
+      style: CupertinoTheme.of(context).textTheme.navTitleTextStyle,
+    );
+  }
 
+  @override
+  Widget buildMaterial(BuildContext context) {
     return Text(
       text,
-      style: titleStyle,
+      style: Theme.of(context).textTheme.subtitle1,
     );
   }
 }

packages/flutterfire_ui/lib/src/auth/widgets/internal/universal_button.dart

@@ -6,78 +6,144 @@ import 'platform_widget.dart';
 enum ButtonVariant {
   text,
   filled,
+  outlined,
 }
 
 class UniversalButton extends PlatformWidget {
   final VoidCallback? onPressed;
-  final String text;
+  final String? text;
+  final Widget? child;
   final IconData? icon;
   final TextDirection? direction;
-  final ButtonVariant variant;
+  final ButtonVariant? variant;
+  final Color? color;
 
   const UniversalButton({
     Key? key,
-    required this.text,
+    this.text,
+    this.child,
     this.onPressed,
     this.icon,
-    this.direction,
-    this.variant = ButtonVariant.filled,
-  }) : super(key: key);
+    this.direction = TextDirection.ltr,
+    this.variant,
+    this.color,
+  })  : assert(text != null || child != null),
+        super(key: key);
+
+  ButtonVariant get _variant {
+    return variant ?? ButtonVariant.filled;
+  }
 
   @override
   Widget buildCupertino(BuildContext context) {
+    late Widget button;
+
     final child = Row(
       textDirection: direction,
       mainAxisAlignment: MainAxisAlignment.center,
       children: [
-        Text(text),
-        if (icon != null) ...[const SizedBox(width: 8), Icon(icon, size: 20)],
+        if (icon != null) ...[
+          if (direction == TextDirection.rtl) const SizedBox(width: 8),
+          Icon(icon, size: 20),
+          if (direction == TextDirection.ltr) const SizedBox(width: 8),
+        ],
+        this.child ?? Text(text!),
       ],
     );
 
-    if (variant == ButtonVariant.text) {
-      return CupertinoButton(
+    if (_variant == ButtonVariant.text || _variant == ButtonVariant.outlined) {
+      button = CupertinoButton(
         padding: EdgeInsets.zero,
         onPressed: onPressed,
         child: child,
       );
     } else {
-      return CupertinoButton.filled(
+      button = CupertinoButton.filled(
         onPressed: onPressed,
         child: child,
       );
     }
+
+    if (color != null) {
+      return CupertinoTheme(
+        data: CupertinoTheme.of(context).copyWith(primaryColor: color),
+        child: button,
+      );
+    } else {
+      return button;
+    }
   }
 
   @override
   Widget buildMaterial(BuildContext context) {
-    final child = Text(text);
+    final child = this.child ?? Text(text!);
+
+    ButtonStyle? style;
+
+    if (color != null) {
+      MaterialStateColor? foregroundColor;
+      MaterialStateColor? backgroundColor;
 
-    if (icon != null) {
       if (variant == ButtonVariant.text) {
-        return TextButton.icon(
-          icon: Icon(icon),
-          onPressed: onPressed,
-          label: child,
-        );
+        foregroundColor = MaterialStateColor.resolveWith((_) => color!);
       } else {
-        return ElevatedButton.icon(
-          icon: Icon(icon),
-          onPressed: onPressed,
-          label: child,
-        );
+        backgroundColor = MaterialStateColor.resolveWith((_) => color!);
       }
-    } else {
-      if (variant == ButtonVariant.text) {
-        return TextButton(
-          onPressed: onPressed,
-          child: child,
-        );
-      } else {}
-      return ElevatedButton(
-        onPressed: onPressed,
-        child: child,
+
+      style = ButtonStyle(
+        foregroundColor: foregroundColor,
+        backgroundColor: backgroundColor,
+        overlayColor: MaterialStateColor.resolveWith(
+          (states) => color!.withAlpha(20),
+        ),
       );
     }
+
+    if (icon != null) {
+      switch (_variant) {
+        case ButtonVariant.text:
+          return TextButton.icon(
+            icon: Icon(icon),
+            onPressed: onPressed,
+            label: child,
+            style: style,
+          );
+        case ButtonVariant.filled:
+          return ElevatedButton.icon(
+            onPressed: onPressed,
+            icon: Icon(icon),
+            label: child,
+            style: style,
+          );
+        case ButtonVariant.outlined:
+          return OutlinedButton.icon(
+            onPressed: onPressed,
+            icon: Icon(icon),
+            label: child,
+            style: style,
+          );
+      }
+    } else {
+      switch (_variant) {
+        case ButtonVariant.text:
+          return TextButton(
+            onPressed: onPressed,
+            style: style,
+            child: child,
+          );
+        case ButtonVariant.filled:
+          return ElevatedButton(
+            onPressed: onPressed,
+            style: style,
+            child: child,
+          );
+        case ButtonVariant.outlined:
+          return OutlinedButton(
+            onPressed: onPressed,
+            style: style,
+            child: child,
+          );
+      }
+    }
   }
 }