SIPSorcery.LoginControl.LoginTextBox_KeyUp C# (CSharp) Method

        private void LoginTextBox_KeyUp(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {
                Login();
            }
            else if(e.Key == Key.A && m_usernameTextBox.Text.IsNullOrBlank())
            {
                if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control && (Keyboard.Modifiers & ModifierKeys.Alt) == ModifierKeys.Alt)
                {
                    m_impersonateCanvas.Visibility = (m_impersonateCanvas.Visibility == System.Windows.Visibility.Collapsed) ? System.Windows.Visibility.Visible : System.Windows.Visibility.Collapsed;
                }
            }
        }