[Win] Add windows basic autocomplete support

3 files changed, 192 insertions, 36 deletions

diff --git a/Xamarin.PropertyEditing.Windows/EntryPopup.cs b/Xamarin.PropertyEditing.Windows/EntryPopup.cs
index fbc3a05..08db76b 100644
--- a/Xamarin.PropertyEditing.Windows/EntryPopup.cs
+++ b/Xamarin.PropertyEditing.Windows/EntryPopup.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Windows;
-using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
 using System.Windows.Input;
 
@@ -9,6 +8,20 @@ namespace Xamarin.PropertyEditing.Windows
 	internal class EntryPopup
 		: Popup
     {
+		static EntryPopup ()
+		{
+			// Autocomplete is a popup in a popup and when you go to click the other popup, this one might close
+			// so we need to hack around this otherwise uncontrollable behavior (StaysOpen has no effect).
+			var existing = IsOpenProperty.GetMetadata (typeof(Popup));
+			PropertyChangedCallback callback = (o,e) => {
+				if ((bool) e.NewValue || ((EntryPopup) o).CanClose ()) {
+					existing.PropertyChangedCallback (o, e);
+				}
+			};
+
+			IsOpenProperty.OverrideMetadata(typeof(EntryPopup), new FrameworkPropertyMetadata (existing.DefaultValue, callback, existing.CoerceValueCallback));
+		}
+
 		public static readonly DependencyProperty ContentTemplateProperty = DependencyProperty.Register (
 			nameof(ContentTemplate), typeof(DataTemplate), typeof(EntryPopup), new PropertyMetadata ((s,e) => ((EntryPopup)s).UpdateContentTemplate()));
 
@@ -18,6 +31,15 @@ namespace Xamarin.PropertyEditing.Windows
 			set { SetValue (ContentTemplateProperty, value); }
 		}
 
+		public static readonly DependencyProperty ValueProperty = DependencyProperty.Register (
+		    "Value", typeof(string), typeof(EntryPopup), new PropertyMetadata (default(string)));
+
+		public string Value
+		{
+		    get { return (string) GetValue (ValueProperty); }
+		    set { SetValue (ValueProperty, value); }
+		}
+
 		public override void OnApplyTemplate ()
 		{
 			base.OnApplyTemplate ();
@@ -33,15 +55,20 @@ namespace Xamarin.PropertyEditing.Windows
 		protected override void OnClosed (EventArgs e)
 		{
 			if (!this.closingFromEscape) {
-				this.textBox.GetBindingExpression (TextBox.TextProperty)?.UpdateSource();
+				GetBindingExpression (ValueProperty)?.UpdateSource ();
 			} else
 				this.closingFromEscape = false;
 
 			base.OnClosed (e);
 		}
 
-		protected override void OnPreviewKeyDown (KeyEventArgs e)
+		protected override void OnKeyDown (KeyEventArgs e)
 		{
+			base.OnKeyDown (e);
+
+			if (e.Handled)
+				return;
+
 			if (e.Key == Key.Escape) {
 				this.closingFromEscape = true;
 				IsOpen = false;
@@ -50,22 +77,25 @@ namespace Xamarin.PropertyEditing.Windows
 				IsOpen = false;
 				e.Handled = true;
 			}
-
-			base.OnPreviewKeyDown (e);
 		}
 
-		private TextBox textBox;
+		private TextBoxEx textBox;
 		private bool closingFromEscape;
 
+		private bool CanClose ()
+		{
+			return this.textBox.CanCloseParent ();
+		}
+
 		private void UpdateContentTemplate()
 		{
 			Child = ContentTemplate?.LoadContent() as UIElement;
 			if (Child == null)
 				return;
 
-			this.textBox = ((FrameworkElement)Child)?.FindName ("entry") as TextBox;
+			this.textBox = ((FrameworkElement)Child)?.FindName ("entry") as TextBoxEx;
 			if (this.textBox == null)
-				throw new InvalidOperationException ("Need an entry TextBox for EntryPopup");
+				throw new InvalidOperationException ("Need an entry TextBoxEx for EntryPopup");
 		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.PropertyEditing.Windows/TextBoxEx.cs b/Xamarin.PropertyEditing.Windows/TextBoxEx.cs
index 295ea32..74863fe 100644
--- a/Xamarin.PropertyEditing.Windows/TextBoxEx.cs
+++ b/Xamarin.PropertyEditing.Windows/TextBoxEx.cs
@@ -1,19 +1,19 @@
 using System;
+using System.Collections;
 using System.ComponentModel;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
 using System.Windows.Input;
 
 namespace Xamarin.PropertyEditing.Windows
 {
 	[TemplatePart (Name ="PART_Clear", Type = typeof (Button))]
+	[TemplatePart (Name = "PART_CompletePopup", Type = typeof (Popup))]
+	[TemplatePart (Name = "PART_CompleteList", Type = typeof (ListBox))]
 	internal class TextBoxEx
 		: TextBox
 	{
-		public TextBoxEx()
-		{
-			PreviewKeyDown += OnPreviewKeyDown;
-		}
 
 		public static readonly DependencyProperty HintProperty = DependencyProperty.Register (
 			"Hint", typeof(object), typeof(TextBoxEx), new PropertyMetadata (default(object)));
@@ -42,6 +42,15 @@ namespace Xamarin.PropertyEditing.Windows
 			set { SetValue (FocusSelectsAllProperty, value); }
 		}
 
+		public static readonly DependencyProperty EnableClearProperty = DependencyProperty.Register (
+			"EnableClear", typeof(bool), typeof(TextBoxEx), new PropertyMetadata (true));
+
+		public bool EnableClear
+		{
+			get { return (bool) GetValue (EnableClearProperty); }
+			set { SetValue (EnableClearProperty, value); }
+		}
+
 		public static readonly DependencyProperty ShowClearButtonProperty = DependencyProperty.Register (
 			"ShowClearButton", typeof(bool), typeof(TextBoxEx), new PropertyMetadata (default(bool)));
 
@@ -60,6 +69,15 @@ namespace Xamarin.PropertyEditing.Windows
 			set { SetValue (ClearButtonStyleProperty, value); }
 		}
 
+		public static readonly DependencyProperty EnableSubmitProperty = DependencyProperty.Register (
+			"EnableSubmit", typeof(bool), typeof(TextBoxEx), new PropertyMetadata (true));
+
+		public bool EnableSubmit
+		{
+			get { return (bool) GetValue (EnableSubmitProperty); }
+			set { SetValue (EnableSubmitProperty, value); }
+		}
+
 		public static readonly DependencyProperty SubmitButtonStyleProperty = DependencyProperty.Register (
 			"SubmitButtonStyle", typeof(Style), typeof(TextBoxEx), new PropertyMetadata (default(Style)));
 
@@ -69,6 +87,24 @@ namespace Xamarin.PropertyEditing.Windows
 			set { SetValue (SubmitButtonStyleProperty, value); }
 		}
 
+		public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register (
+			"ItemsSource", typeof (IEnumerable), typeof (TextBoxEx), new PropertyMetadata (default (IEnumerable)));
+
+		public IEnumerable ItemsSource
+		{
+			get { return (IEnumerable)GetValue (ItemsSourceProperty); }
+			set { SetValue (ItemsSourceProperty, value); }
+		}
+
+		public static readonly DependencyProperty ItemTemplateProperty = DependencyProperty.Register (
+			"ItemTemplate", typeof (DataTemplate), typeof (TextBoxEx), new PropertyMetadata (default (DataTemplate)));
+
+		public DataTemplate ItemTemplate
+		{
+			get { return (DataTemplate)GetValue (ItemTemplateProperty); }
+			set { SetValue (ItemTemplateProperty, value); }
+		}
+
 		public override void OnApplyTemplate ()
 		{
 			base.OnApplyTemplate ();
@@ -81,6 +117,14 @@ namespace Xamarin.PropertyEditing.Windows
 				return;
 			}
 
+			this.popup = (Popup)GetTemplateChild ("PART_CompletePopup");
+			this.list = (ListBox)GetTemplateChild ("PART_CompleteList");
+			if (this.popup == null || this.list == null)
+				throw new InvalidOperationException ("PART_CompletePopup and PART_CompleteList must be present");
+
+			this.list.ItemContainerGenerator.ItemsChanged += OnItemsChanged;
+			this.list.PreviewMouseLeftButtonDown += OnListMouseDown;
+
 			clear.Click += (sender, e) => {
 				Clear();
 			};
@@ -114,8 +158,14 @@ namespace Xamarin.PropertyEditing.Windows
 
 		protected override void OnLostKeyboardFocus (KeyboardFocusChangedEventArgs e)
 		{
+			if (this.defocusFromList)
+				return;
+
 			base.OnLostKeyboardFocus (e);
-			OnSubmit();
+			this.popup.IsOpen = false;
+
+			if (EnableSubmit)
+				OnSubmit ();
 		}
 
 		protected virtual void OnSubmit()
@@ -124,6 +174,64 @@ namespace Xamarin.PropertyEditing.Windows
 			expression?.UpdateSource ();
 		}
 
+		protected override void OnPreviewKeyDown (KeyEventArgs e)
+		{
+			e.Handled = true;
+			if (e.Key == Key.Down) {
+				if (this.list.SelectedIndex == -1 || this.list.SelectedIndex + 1 == this.list.Items.Count)
+					this.list.SelectedIndex = 0;
+				else
+					this.list.SelectedIndex++;
+
+				this.list.ScrollIntoView (this.list.SelectedItem);
+			} else if (e.Key == Key.Up) {
+				if (this.list.SelectedIndex == -1 || this.list.SelectedIndex == 0)
+					this.list.SelectedIndex = this.list.Items.Count - 1;
+				else
+					this.list.SelectedIndex--;
+
+				this.list.ScrollIntoView (this.list.SelectedItem);
+			} else if (e.Key == Key.Enter || e.Key == Key.Tab) {
+				if (this.list.SelectedValue != null) {
+					SelectCompleteItem (this.list.SelectedItem);
+				} else if (!this.popup.IsOpen) {
+					if (EnableSubmit)
+						OnSubmit ();
+					else
+						e.Handled = false;
+				}
+			} else if (e.Key == Key.Escape) {
+				if (this.popup.IsOpen)
+					this.popup.IsOpen = false;
+				else if (EnableClear)
+					Clear ();
+				else
+					e.Handled = false;
+			} else {
+				e.Handled = false;
+			}
+
+			base.OnPreviewKeyDown (e);
+		}
+
+		protected internal bool CanCloseParent ()
+		{
+			bool can = !this.defocusFromList;
+			this.defocusFromList = false;
+			return can;
+		}
+
+		private bool defocusFromList;
+		private Popup popup;
+		private ListBox list;
+
+		private void SelectCompleteItem (object item)
+		{
+			Text = item.ToString ();
+			CaretIndex = Text.Length;
+			this.popup.IsOpen = false;
+		}
+
 		private void FocusSelect()
 		{
 			if (!FocusSelectsAll)
@@ -133,13 +241,27 @@ namespace Xamarin.PropertyEditing.Windows
 				SelectAll ();
 		}
 
-		private void OnPreviewKeyDown (object sender, System.Windows.Input.KeyEventArgs e)
+		private void OnItemsChanged (object sender, ItemsChangedEventArgs e)
 		{
-			if (e.Key == Key.Enter) {
-				OnSubmit();
-			} else if (e.Key == Key.Escape) {
-				Clear();
-			}
+			if (!HasEffectiveKeyboardFocus)
+				return;
+
+			this.popup.IsOpen = (this.list.Items.Count > 0);
+			if (this.list.SelectedIndex == -1)
+				this.list.SelectedIndex = 0;
+		}
+
+		private void OnListMouseDown (object sender, MouseButtonEventArgs e)
+		{
+			Point pos = e.GetPosition (this.list);
+			var element = this.list.InputHitTest (pos) as FrameworkElement;
+			var item = element?.FindParentOrSelf<ListBoxItem> ();
+			if (item == null)
+				return;
+
+			SelectCompleteItem (item.DataContext);
+			this.defocusFromList = true;
+			e.Handled = true;
 		}
 	}
 }
diff --git a/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml b/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
index 0772b60..75b5b92 100644
--- a/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
+++ b/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
@@ -497,7 +497,8 @@
 	<Style x:Key="CustomExpressionPopup" TargetType="local:EntryPopup">
 		<Setter Property="Placement" Value="Bottom" />
 		<Setter Property="Width" Value="400" />
-		<Setter Property="StaysOpen" Value="False" />
+		<Setter Property="StaysOpen" Value="True" />
+		<Setter Property="Value" Value="{Binding CustomExpression,Mode=TwoWay,UpdateSourceTrigger=Explicit}" />
 		<Setter Property="ContentTemplate">
 			<Setter.Value>
 				<DataTemplate>
@@ -509,7 +510,7 @@
 							</Grid.RowDefinitions>
 
 							<TextBlock Name="label" Grid.Row="0" Margin="5,5,0,5" FontWeight="Bold" Text="{x:Static prop:Resources.CustomExpression}" />
-							<local:TextBoxEx x:Name="entry" Grid.Row="1" Margin="5,0,5,5" AutomationProperties.LabeledBy="{Binding Mode=OneTime,ElementName=label}" FocusSelectsAll="True" Text="{Binding CustomExpression,Mode=TwoWay,UpdateSourceTrigger=Explicit}" />
+							<local:TextBoxEx x:Name="entry" Grid.Row="1" Margin="5,0,5,5" AutomationProperties.LabeledBy="{Binding Mode=OneTime,ElementName=label}" FocusSelectsAll="True" EnableClear="False" EnableSubmit="False" Text="{Binding PreviewCustomExpression,Mode=OneWayToSource,UpdateSourceTrigger=PropertyChanged}" ItemsSource="{Binding AutocompleteItems}" />
 						</Grid>
 					</Border>
 				</DataTemplate>
@@ -1631,8 +1632,6 @@
 	<Style TargetType="ListBoxItem">
 		<Setter Property="SnapsToDevicePixels" Value="True"/>
 		<Setter Property="Padding" Value="4,1"/>
-		<Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
-		<Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
 		<Setter Property="Foreground" Value="{DynamicResource ListItemForegroundBrush}" />
 		<Setter Property="Background" Value="Transparent"/>
 		<Setter Property="BorderBrush" Value="Transparent"/>
@@ -1942,21 +1941,26 @@
 		<Setter Property="Template">
 			<Setter.Value>
 				<ControlTemplate TargetType="{x:Type local:TextBoxEx}">
-					<Border x:Name="border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="True">
-						<Grid>
-							<Grid.ColumnDefinitions>
-								<ColumnDefinition Width="*" />
-								<ColumnDefinition Width="Auto" />
-							</Grid.ColumnDefinitions>
+					<Grid>
+						<Border x:Name="border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="True">
+							<Grid>
+								<Grid.ColumnDefinitions>
+									<ColumnDefinition Width="*" />
+									<ColumnDefinition Width="Auto" />
+								</Grid.ColumnDefinitions>
 
-							<ContentPresenter Grid.Column="0" Name="hintContent" Margin="2,0,2,0" Visibility="Collapsed" ContentSource="Hint" />
-							<ScrollViewer x:Name="PART_ContentHost" Grid.Column="0" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
+								<ContentPresenter Grid.Column="0" Name="hintContent" Margin="2,0,2,0" Visibility="Collapsed" ContentSource="Hint" />
+								<ScrollViewer x:Name="PART_ContentHost" Grid.Column="0" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
 
-							<Button Name="PART_Clear" Grid.Column="1" Style="{TemplateBinding ClearButtonStyle}" Visibility="{TemplateBinding ShowClearButton,Converter={StaticResource BoolToVisibilityConverter}}" />
-							<Button Name="PART_Submit" Grid.Column="1" Style="{TemplateBinding SubmitButtonStyle}" Visibility="Collapsed" />
-						</Grid>
-					</Border>
-					<ControlTemplate.Triggers>
+								<Button Name="PART_Clear" Grid.Column="1" Style="{TemplateBinding ClearButtonStyle}" Visibility="{TemplateBinding ShowClearButton,Converter={StaticResource BoolToVisibilityConverter}}" />
+								<Button Name="PART_Submit" Grid.Column="1" Style="{TemplateBinding SubmitButtonStyle}" Visibility="Collapsed" />
+							</Grid>
+						</Border>
+						<Popup Name="PART_CompletePopup" Placement="Bottom" StaysOpen="True" Focusable="False" Width="{Binding ElementName=border,Path=ActualWidth}">
+							<ListBox Name="PART_CompleteList" Focusable="False" MaxHeight="200" ItemsSource="{TemplateBinding ItemsSource}" ItemTemplate="{TemplateBinding ItemTemplate}" />
+						</Popup>
+					</Grid>
+						<ControlTemplate.Triggers>
 						<Trigger Property="IsEnabled" Value="false">
 							<Setter Property="Opacity" TargetName="border" Value="0.56"/>
 						</Trigger>