Make some TextBox/Block properties direct.

src/Perspex.Base/DirectProperty.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using System;
+using Perspex.Data;
 
 namespace Perspex
 {
@@ -44,11 +45,13 @@ namespace Perspex
         /// <param name="source">The property to copy.</param>
         /// <param name="getter">Gets the current value of the property.</param>
         /// <param name="setter">Sets the value of the property. May be null.</param>
+        /// <param name="metadata">Optional overridden metadata.</param>
         private DirectProperty(
             PerspexProperty<TValue> source,
             Func<TOwner, TValue> getter,
-            Action<TOwner, TValue> setter)
-            : base(source, typeof(TOwner))
+            Action<TOwner, TValue> setter,
+            PropertyMetadata metadata)
+            : base(source, typeof(TOwner), metadata)
         {
             Contract.Requires<ArgumentNullException>(getter != null);
 
@@ -76,16 +79,25 @@ namespace Perspex
         /// Registers the direct property on another type.
         /// </summary>
         /// <typeparam name="TNewOwner">The type of the additional owner.</typeparam>
+        /// <param name="getter">Gets the current value of the property.</param>
+        /// <param name="setter">Sets the value of the property.</param>
+        /// <param name="unsetValue">
+        /// The value to use when the property is set to <see cref="PerspexProperty.UnsetValue"/>
+        /// </param>
+        /// <param name="defaultBindingMode">The default binding mode for the property.</param>
         /// <returns>The property.</returns>
         public DirectProperty<TNewOwner, TValue> AddOwner<TNewOwner>(
             Func<TNewOwner, TValue> getter,
-            Action<TNewOwner, TValue> setter = null)
+            Action<TNewOwner, TValue> setter = null,
+            TValue unsetValue = default(TValue),
+            BindingMode defaultBindingMode = BindingMode.OneWay)
                 where TNewOwner : PerspexObject
         {
             var result = new DirectProperty<TNewOwner, TValue>(
                 this,
                 getter,
-                setter);
+                setter,
+                new DirectPropertyMetadata<TValue>(unsetValue, defaultBindingMode));
 
             PerspexPropertyRegistry.Instance.Register(typeof(TNewOwner), result);
             return result;

src/Perspex.Base/PerspexProperty.cs

@@ -71,7 +71,11 @@ namespace Perspex
         /// </summary>
         /// <param name="source">The direct property to copy.</param>
         /// <param name="ownerType">The new owner type.</param>
-        protected PerspexProperty(PerspexProperty source, Type ownerType)
+        /// <param name="metadata">Optional overridden metadata.</param>
+        protected PerspexProperty(
+            PerspexProperty source, 
+            Type ownerType, 
+            PropertyMetadata metadata)
         {
             Contract.Requires<ArgumentNullException>(source != null);
             Contract.Requires<ArgumentNullException>(ownerType != null);
@@ -86,6 +90,11 @@ namespace Perspex
             Notifying = source.Notifying;
             Id = source.Id;
             _defaultMetadata = source._defaultMetadata;
+
+            if (metadata != null)
+            {
+                _metadata.Add(ownerType, metadata);
+            }
         }
 
         /// <summary>

src/Perspex.Base/PerspexProperty`1.cs

@@ -32,8 +32,12 @@ namespace Perspex
         /// </summary>
         /// <param name="source">The property to copy.</param>
         /// <param name="ownerType">The new owner type.</param>
-        protected PerspexProperty(PerspexProperty source, Type ownerType)
-            : base(source, ownerType)
+        /// <param name="metadata">Optional overridden metadata.</param>
+        protected PerspexProperty(
+            PerspexProperty source, 
+            Type ownerType, 
+            PropertyMetadata metadata)
+            : base(source, ownerType, metadata)
         {
         }
     }

src/Perspex.Base/StyledPropertyBase.cs

@@ -46,7 +46,7 @@ namespace Perspex
         /// <param name="source">The property to add the owner to.</param>
         /// <param name="ownerType">The type of the class that registers the property.</param>
         protected StyledPropertyBase(StyledPropertyBase<TValue> source, Type ownerType)
-            : base(source, ownerType)
+            : base(source, ownerType, null)
         {
             _inherits = source.Inherits;
         }

src/Perspex.Controls/Presenters/TextPresenter.cs

@@ -12,24 +12,28 @@ namespace Perspex.Controls.Presenters
 {
     public class TextPresenter : TextBlock
     {
-        public static readonly StyledProperty<int> CaretIndexProperty =
-            TextBox.CaretIndexProperty.AddOwner<TextPresenter>();
+        public static readonly DirectProperty<TextPresenter, int> CaretIndexProperty =
+            TextBox.CaretIndexProperty.AddOwner<TextPresenter>(
+                o => o.CaretIndex,
+                (o, v) => o.CaretIndex = v);
 
-        public static readonly StyledProperty<int> SelectionStartProperty =
-            TextBox.SelectionStartProperty.AddOwner<TextPresenter>();
+        public static readonly DirectProperty<TextPresenter, int> SelectionStartProperty =
+            TextBox.SelectionStartProperty.AddOwner<TextPresenter>(
+                o => o.SelectionStart,
+                (o, v) => o.SelectionStart = v);
 
-        public static readonly StyledProperty<int> SelectionEndProperty =
-            TextBox.SelectionEndProperty.AddOwner<TextPresenter>();
+        public static readonly DirectProperty<TextPresenter, int> SelectionEndProperty =
+            TextBox.SelectionEndProperty.AddOwner<TextPresenter>(
+                o => o.SelectionEnd,
+                (o, v) => o.SelectionEnd = v);
 
         private readonly DispatcherTimer _caretTimer;
+        private int _caretIndex;
+        private int _selectionStart;
+        private int _selectionEnd;
         private bool _caretBlink;
         private IBrush _highlightBrush;
 
-        static TextPresenter()
-        {
-            CaretIndexProperty.OverrideValidation<TextPresenter>((o, v) => v);
-        }
-
         public TextPresenter()
         {
             _caretTimer = new DispatcherTimer();
@@ -47,20 +51,44 @@ namespace Perspex.Controls.Presenters
 
         public int CaretIndex
         {
-            get { return GetValue(CaretIndexProperty); }
-            set { SetValue(CaretIndexProperty, value); }
+            get
+            {
+                return _caretIndex;
+            }
+
+            set
+            {
+                value = CoerceCaretIndex(value);
+                SetAndRaise(CaretIndexProperty, ref _caretIndex, value);
+            }
         }
 
         public int SelectionStart
         {
-            get { return GetValue(SelectionStartProperty); }
-            set { SetValue(SelectionStartProperty, value); }
+            get
+            {
+                return _selectionStart;
+            }
+
+            set
+            {
+                value = CoerceCaretIndex(value);
+                SetAndRaise(SelectionStartProperty, ref _selectionStart, value);
+            }
         }
 
         public int SelectionEnd
         {
-            get { return GetValue(SelectionEndProperty); }
-            set { SetValue(SelectionEndProperty, value); }
+            get
+            {
+                return _selectionEnd;
+            }
+
+            set
+            {
+                value = CoerceCaretIndex(value);
+                SetAndRaise(SelectionEndProperty, ref _selectionEnd, value);
+            }
         }
 
         public int GetCaretIndex(Point point)
@@ -206,6 +234,13 @@ namespace Perspex.Controls.Presenters
             }
         }
 
+        private int CoerceCaretIndex(int value)
+        {
+            var text = Text;
+            var length = text?.Length ?? 0;
+            return Math.Max(0, Math.Min(length, value));
+        }
+
         private void CaretTimerTick(object sender, EventArgs e)
         {
             _caretBlink = !_caretBlink;

src/Perspex.Controls/TextBlock.cs

@@ -72,8 +72,11 @@ namespace Perspex.Controls
         /// <summary>
         /// Defines the <see cref="Text"/> property.
         /// </summary>
-        public static readonly StyledProperty<string> TextProperty =
-            PerspexProperty.Register<TextBlock, string>(nameof(Text));
+        public static readonly DirectProperty<TextBlock, string> TextProperty =
+            PerspexProperty.RegisterDirect<TextBlock, string>(
+                nameof(Text),
+                o => o.Text,
+                (o, v) => o.Text = v);
 
         /// <summary>
         /// Defines the <see cref="TextAlignment"/> property.
@@ -87,14 +90,8 @@ namespace Perspex.Controls
         public static readonly StyledProperty<TextWrapping> TextWrappingProperty =
             PerspexProperty.Register<TextBlock, TextWrapping>(nameof(TextWrapping));
 
-        /// <summary>
-        /// The formatted text used for rendering.
-        /// </summary>
+        private string _text;
         private FormattedText _formattedText;
-
-        /// <summary>
-        /// Stores the last constraint passed to MeasureOverride.
-        /// </summary>
         private Size _constraint;
 
         /// <summary>
@@ -140,8 +137,8 @@ namespace Perspex.Controls
         [Content]
         public string Text
         {
-            get { return GetValue(TextProperty); }
-            set { SetValue(TextProperty, value); }
+            get { return _text; }
+            set { SetAndRaise(TextProperty, ref _text, value); }
         }
 
         /// <summary>

src/Perspex.Controls/TextBox.cs

@@ -29,18 +29,29 @@ namespace Perspex.Controls
         public static readonly DirectProperty<TextBox, bool> CanScrollHorizontallyProperty =
             PerspexProperty.RegisterDirect<TextBox, bool>("CanScrollHorizontally", o => o.CanScrollHorizontally);
 
-        // TODO: Should CaretIndex, SelectionStart/End and Text be direct properties?
-        public static readonly StyledProperty<int> CaretIndexProperty =
-            PerspexProperty.Register<TextBox, int>("CaretIndex", validate: ValidateCaretIndex);
-
-        public static readonly StyledProperty<int> SelectionStartProperty =
-            PerspexProperty.Register<TextBox, int>("SelectionStart", validate: ValidateCaretIndex);
-
-        public static readonly StyledProperty<int> SelectionEndProperty =
-            PerspexProperty.Register<TextBox, int>("SelectionEnd", validate: ValidateCaretIndex);
-
-        public static readonly StyledProperty<string> TextProperty =
-            TextBlock.TextProperty.AddOwner<TextBox>();
+        public static readonly DirectProperty<TextBox, int> CaretIndexProperty =
+            PerspexProperty.RegisterDirect<TextBox, int>(
+                nameof(CaretIndex),
+                o => o.CaretIndex,
+                (o, v) => o.CaretIndex = v);
+
+        public static readonly DirectProperty<TextBox, int> SelectionStartProperty =
+            PerspexProperty.RegisterDirect<TextBox, int>(
+                nameof(SelectionStart),
+                o => o.SelectionStart,
+                (o, v) => o.SelectionStart = v);
+
+        public static readonly DirectProperty<TextBox, int> SelectionEndProperty =
+            PerspexProperty.RegisterDirect<TextBox, int>(
+                nameof(SelectionEnd),
+                o => o.SelectionEnd,
+                (o, v) => o.SelectionEnd = v);
+
+        public static readonly DirectProperty<TextBox, string> TextProperty =
+            TextBlock.TextProperty.AddOwner<TextBox>(
+                o => o.Text,
+                (o, v) => o.Text = v,
+                defaultBindingMode: BindingMode.TwoWay);
 
         public static readonly StyledProperty<TextAlignment> TextAlignmentProperty =
             TextBlock.TextAlignmentProperty.AddOwner<TextBox>();
@@ -71,6 +82,10 @@ namespace Perspex.Controls
             public bool Equals(UndoRedoState other) => ReferenceEquals(Text, other.Text) || Equals(Text, other.Text);
         }
 
+        private string _text;
+        private int _caretIndex;
+        private int _selectionStart;
+        private int _selectionEnd;
         private bool _canScrollHorizontally;
         private TextPresenter _presenter;
         private UndoRedoHelper<UndoRedoState> _undoRedoHelper;
@@ -78,7 +93,6 @@ namespace Perspex.Controls
         static TextBox()
         {
             FocusableProperty.OverrideDefaultValue(typeof(TextBox), true);
-            TextProperty.OverrideMetadata<TextBox>(new StyledPropertyMetadata<string>(defaultBindingMode: BindingMode.TwoWay));
         }
 
         public TextBox()
@@ -117,10 +131,15 @@ namespace Perspex.Controls
 
         public int CaretIndex
         {
-            get { return GetValue(CaretIndexProperty); }
+            get
+            {
+                return _caretIndex;
+            }
+
             set
             {
-                SetValue(CaretIndexProperty, value);
+                value = CoerceCaretIndex(value);
+                SetAndRaise(CaretIndexProperty, ref _caretIndex, value);
                 if (_undoRedoHelper.IsLastState && _undoRedoHelper.LastState.Text == Text)
                     _undoRedoHelper.UpdateLastState();
             }
@@ -128,21 +147,37 @@ namespace Perspex.Controls
 
         public int SelectionStart
         {
-            get { return GetValue(SelectionStartProperty); }
-            set { SetValue(SelectionStartProperty, value); }
+            get
+            {
+                return _selectionStart;
+            }
+
+            set
+            {
+                value = CoerceCaretIndex(value);
+                SetAndRaise(SelectionStartProperty, ref _selectionStart, value);
+            }
         }
 
         public int SelectionEnd
         {
-            get { return GetValue(SelectionEndProperty); }
-            set { SetValue(SelectionEndProperty, value); }
+            get
+            {
+                return _selectionEnd;
+            }
+
+            set
+            {
+                value = CoerceCaretIndex(value);
+                SetAndRaise(SelectionEndProperty, ref _selectionEnd, value);
+            }
         }
 
         [Content]
         public string Text
         {
-            get { return GetValue(TextProperty); }
-            set { SetValue(TextProperty, value); }
+            get { return _text; }
+            set { SetAndRaise(TextProperty, ref _text, value); }
         }
 
         public TextAlignment TextAlignment
@@ -426,9 +461,9 @@ namespace Perspex.Controls
             }
         }
 
-        private static int ValidateCaretIndex(PerspexObject o, int value)
+        private int CoerceCaretIndex(int value)
         {
-            var text = o.GetValue(TextProperty);
+            var text = Text;
             var length = text?.Length ?? 0;
             return Math.Max(0, Math.Min(length, value));
         }