Add initialEmail parameter and update onSignInComplete

Added an optional initialEmail to pass in a saved email address so that the email field is already populated.

Passed in the email to the onSignInComplete() callback, so that the email can be used inside (eg. for saving to sharedPreferences)

Also, added a focus node for the password field to move the focus to it if the initialEmail is non-empty.

Author: salarshad

lib/src/components/supa_email_auth.dart

@@ -179,7 +179,7 @@ class SupaEmailAuth extends StatefulWidget {
   final String? Function(String?)? passwordValidator;
 
   /// Callback for the user to complete a sign in.
-  final void Function(AuthResponse response) onSignInComplete;
+  final void Function(AuthResponse response, String email) onSignInComplete;
 
   /// Callback for the user to complete a signUp.
   ///
@@ -217,12 +217,15 @@ class SupaEmailAuth extends StatefulWidget {
   final Widget? prefixIconEmail;
   final Widget? prefixIconPassword;
 
+  final String? initialEmail;
+
   /// Whether the confirm password field should be displayed
   final bool showConfirmPasswordField;
 
   /// {@macro supa_email_auth}
   const SupaEmailAuth({
     super.key,
+    this.initialEmail = "",
     this.autofocus = true,
     this.redirectTo,
     this.resetPasswordRedirectTo,
@@ -248,7 +251,7 @@ class SupaEmailAuth extends StatefulWidget {
 
 class _SupaEmailAuthState extends State<SupaEmailAuth> {
   final _formKey = GlobalKey<FormState>();
-  final _emailController = TextEditingController();
+  late final TextEditingController _emailController;
   final _passwordController = TextEditingController();
   final _confirmPasswordController = TextEditingController();
   late bool _isSigningIn;
@@ -261,10 +264,12 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
 
   /// Focus node for email field
   final FocusNode _emailFocusNode = FocusNode();
+  final FocusNode _passwordFocusNode = FocusNode();
 
   @override
   void initState() {
     super.initState();
+    _emailController = TextEditingController(text: widget.initialEmail);
     _isSigningIn = widget.isInitiallySigningIn;
     _metadataControllers = Map.fromEntries((widget.metadataFields ?? []).map(
       (metadataField) => MapEntry(
@@ -274,13 +279,33 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
             : TextEditingController(),
       ),
     ));
+
+    // Request focus on password field if email is pre-filled and not recovering password
+    if (widget.initialEmail != null && widget.initialEmail!.isNotEmpty && !_isRecoveringPassword) {
+      // It's important to request focus after the first frame has been built.
+      // WidgetsBinding.instance.addPostFrameCallback ensures that.
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (mounted) {
+          FocusScope.of(context).requestFocus(_passwordFocusNode);
+        }
+      });
+    } else if (widget.autofocus && !_isRecoveringPassword) {
+      // Default autofocus behavior if no initial email or recovering password
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (mounted) {
+          FocusScope.of(context).requestFocus(_emailFocusNode);
+        }
+      });
+    }
   }
 
   @override
   void dispose() {
     _emailController.dispose();
     _passwordController.dispose();
     _confirmPasswordController.dispose();
+    _emailFocusNode.dispose();
+    _passwordFocusNode.dispose();
     for (final controller in _metadataControllers.values) {
       if (controller is TextEditingController) {
         controller.dispose();
@@ -333,6 +358,7 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
                     ? [AutofillHints.password]
                     : [AutofillHints.newPassword],
                 autovalidateMode: AutovalidateMode.onUserInteraction,
+                focusNode: _passwordFocusNode,
                 textInputAction: widget.metadataFields != null && !_isSigningIn
                     ? TextInputAction.next
                     : TextInputAction.done,
@@ -468,7 +494,7 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
                         height: 16,
                         width: 16,
                         child: CircularProgressIndicator(
-                          color: Theme.of(context).colorScheme.onPrimary,
+                          color: Theme.of(context).colorScheme.surface,
                           strokeWidth: 1.5,
                         ),
                       )
@@ -539,7 +565,7 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
           email: _emailController.text.trim(),
           password: _passwordController.text.trim(),
         );
-        widget.onSignInComplete.call(response);
+        widget.onSignInComplete.call(response, _emailController.text.trim());
       } else {
         final user = supabase.auth.currentUser;
         late final AuthResponse response;
@@ -607,9 +633,7 @@ class _SupaEmailAuthState extends State<SupaEmailAuth> {
       // FIX use_build_context_synchronously
       if (!mounted) return;
       context.showSnackBar(widget.localization.passwordResetSent);
-      setState(() {
-        _isRecoveringPassword = false;
-      });
+      
     } on AuthException catch (error) {
       widget.onError?.call(error);
     } catch (error) {