email_password_sign_in_screen.dart

  // 他の関数など...

  void _updateFormType(EmailPasswordSignInFormType formType) {
    model.updateFormType(formType);
    _emailController.clear();
    _passwordController.clear();
  }
  
  Widget _buildContent() {
    return FocusScope(
      node: _node,
      child: Form(
        onChanged: () => model.updateWith(
            email: _emailController.text, password: _passwordController.text),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            const SizedBox(height: 8.0),
            _buildEmailField(),
            if (model.formType != EmailPasswordSignInFormType.forgotPassword) ...<Widget>[
              const SizedBox(height: 8.0),
              _buildPasswordField(),
            ],
            const SizedBox(height: 8.0),
            FormSubmitButton(
              key: const Key('primary-button'),
              text: model.primaryButtonText,
              initialLoading: model.isLoading,
              onPressed: model.isLoading ? null : _submit,
            ),
            const SizedBox(height: 8.0),
            TextButton(
              key: const Key('secondary-button'),
              child: Text(model.secondaryButtonText),
              onPressed: model.isLoading
                  ? null
                  : () => _updateFormType(model.secondaryActionFormType),
            ),
            if (model.formType == EmailPasswordSignInFormType.signIn)
              TextButton(
                key: const Key('tertiary-button'),
                child: const Text(
                    EmailPasswordSignInStrings.forgotPasswordQuestion),
                onPressed: model.isLoading
                    ? null
                    : () => _updateFormType(
                    EmailPasswordSignInFormType.forgotPassword),
              ),
          ],
        ),
      ),
    );
  }