some stuff

[GitHub/Stricted/SpeedportHybridControl.git] / SpeedportHybridControl.Implementations / PasswordHelper.cs

diff --git a/SpeedportHybridControl.Implementations/PasswordHelper.cs b/SpeedportHybridControl.Implementations/PasswordHelper.cs
index 87824915acc958391117722f806aae9fe2be8e6b..7b5e0aef6330fb8e507e46e9dde1bf375ba60fa0 100644 (file)
--- a/SpeedportHybridControl.Implementations/PasswordHelper.cs
+++ b/SpeedportHybridControl.Implementations/PasswordHelper.cs
@@ -5,79 +5,59 @@ using System.Text;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Data;
 
 namespace SpeedportHybridControl.Implementations {
-       public static class PasswordHelper {
-               public static readonly DependencyProperty PasswordProperty =
-                       DependencyProperty.RegisterAttached("Password",
-                       typeof(string), typeof(PasswordHelper),
-                       new FrameworkPropertyMetadata(string.Empty, OnPasswordPropertyChanged));
-
-               public static readonly DependencyProperty AttachProperty =
-                       DependencyProperty.RegisterAttached("Attach",
-                       typeof(bool), typeof(PasswordHelper), new PropertyMetadata(false, Attach));
-
-               private static readonly DependencyProperty IsUpdatingProperty =
-                  DependencyProperty.RegisterAttached("IsUpdating", typeof(bool),
-                  typeof(PasswordHelper));
-
-
-               public static void SetAttach (DependencyObject dp, bool value) {
-                       dp.SetValue(AttachProperty, value);
-               }
-
-               public static bool GetAttach (DependencyObject dp) {
-                       return (bool)dp.GetValue(AttachProperty);
-               }
 
-               public static string GetPassword (DependencyObject dp) {
-                       return (string)dp.GetValue(PasswordProperty);
-               }
-
-               public static void SetPassword (DependencyObject dp, string value) {
-                       dp.SetValue(PasswordProperty, value);
-               }
+       // see http://antonymale.co.uk/2015/08/binding-to-a-passwordbox-password-in-wpf
+       public static class PasswordHelper {
+               private static readonly DependencyProperty PasswordInitializedProperty =
+                       DependencyProperty.RegisterAttached("PasswordInitialized", typeof(bool), typeof(PasswordHelper), new PropertyMetadata(false));
 
-               private static bool GetIsUpdating (DependencyObject dp) {
-                       return (bool)dp.GetValue(IsUpdatingProperty);
-               }
+               private static readonly DependencyProperty SettingPasswordProperty =
+                       DependencyProperty.RegisterAttached("SettingPassword", typeof(bool), typeof(PasswordHelper), new PropertyMetadata(false));
 
-               private static void SetIsUpdating (DependencyObject dp, bool value) {
-                       dp.SetValue(IsUpdatingProperty, value);
+               public static string GetPassword (DependencyObject obj) {
+                       return (string)obj.GetValue(PasswordProperty);
                }
-
-               private static void OnPasswordPropertyChanged (DependencyObject sender,
-                       DependencyPropertyChangedEventArgs e) {
-                       PasswordBox passwordBox = sender as PasswordBox;
-                       passwordBox.PasswordChanged -= PasswordChanged;
-
-                       if (!(bool)GetIsUpdating(passwordBox)) {
-                               passwordBox.Password = (string)e.NewValue;
-                       }
-                       passwordBox.PasswordChanged += PasswordChanged;
+               public static void SetPassword (DependencyObject obj, string value) {
+                       obj.SetValue(PasswordProperty, value);
                }
-
-               private static void Attach (DependencyObject sender,
-                       DependencyPropertyChangedEventArgs e) {
-                       PasswordBox passwordBox = sender as PasswordBox;
-
+               // We play a trick here. If we set the initial value to something, it'll be set to something else when the binding kicks in,
+               // and HandleBoundPasswordChanged will be called, which allows us to set up our event subscription.
+               // If the binding sets us to a value which we already are, then this doesn't happen. Therefore start with a value that's
+               // definitely unique.
+               public static readonly DependencyProperty PasswordProperty =
+                       DependencyProperty.RegisterAttached("Password", typeof(string), typeof(PasswordHelper),
+                               new FrameworkPropertyMetadata(Guid.NewGuid().ToString(), HandleBoundPasswordChanged) {
+                                       BindsTwoWayByDefault = true,
+                                       DefaultUpdateSourceTrigger = UpdateSourceTrigger.LostFocus // Match the default on Binding
+                               });
+
+               private static void HandleBoundPasswordChanged (DependencyObject dp, DependencyPropertyChangedEventArgs e) {
+                       var passwordBox = dp as PasswordBox;
                        if (passwordBox == null)
                                return;
 
-                       if ((bool)e.OldValue) {
-                               passwordBox.PasswordChanged -= PasswordChanged;
-                       }
+                       // If we're being called because we set the value of the property we're bound to (from inside 
+                       // HandlePasswordChanged, then do nothing - we already have the latest value).
+                       if ((bool)passwordBox.GetValue(SettingPasswordProperty))
+                               return;
 
-                       if ((bool)e.NewValue) {
-                               passwordBox.PasswordChanged += PasswordChanged;
+                       // If this is the initial set (see the comment on PasswordProperty), set ourselves up
+                       if (!(bool)passwordBox.GetValue(PasswordInitializedProperty)) {
+                               passwordBox.SetValue(PasswordInitializedProperty, true);
+                               passwordBox.PasswordChanged += HandlePasswordChanged;
                        }
+
+                       passwordBox.Password = e.NewValue as string;
                }
 
-               private static void PasswordChanged (object sender, RoutedEventArgs e) {
-                       PasswordBox passwordBox = sender as PasswordBox;
-                       SetIsUpdating(passwordBox, true);
+               private static void HandlePasswordChanged (object sender, RoutedEventArgs e) {
+                       var passwordBox = (PasswordBox)sender;
+                       passwordBox.SetValue(SettingPasswordProperty, true);
                        SetPassword(passwordBox, passwordBox.Password);
-                       SetIsUpdating(passwordBox, false);
+                       passwordBox.SetValue(SettingPasswordProperty, false);
                }
        }
 }