Added selection to TextBox.

Perspex.Controls/TextBox.cs

@@ -20,11 +20,18 @@ namespace Perspex.Controls
         public static readonly PerspexProperty<bool> AcceptsTabProperty =
             PerspexProperty.Register<TextBox, bool>("AcceptsTab");
 
+        public static readonly PerspexProperty<int> CaretIndexProperty =
+            PerspexProperty.Register<TextBox, int>("CaretIndex", coerce: CoerceCaretIndex);
+
+        public static readonly PerspexProperty<int> SelectionStartProperty =
+            PerspexProperty.Register<TextBox, int>("SelectionStart", coerce: CoerceCaretIndex);
+
+        public static readonly PerspexProperty<int> SelectionEndProperty =
+            PerspexProperty.Register<TextBox, int>("SelectionEnd", coerce: CoerceCaretIndex);
+
         public static readonly PerspexProperty<string> TextProperty =
             TextBlock.TextProperty.AddOwner<TextBox>();
 
-        private int caretIndex;
-
         private TextBoxView textBoxView;
 
         static TextBox()
@@ -54,23 +61,20 @@ namespace Perspex.Controls
 
         public int CaretIndex
         {
-            get
-            {
-                return this.caretIndex;
-            }
-
-            set
-            {
-                var text = this.Text ?? string.Empty;
+            get { return this.GetValue(CaretIndexProperty); }
+            set { this.SetValue(CaretIndexProperty, value); }
+        }
 
-                value = Math.Min(Math.Max(value, 0), text.Length);
+        public int SelectionStart
+        {
+            get { return this.GetValue(SelectionStartProperty); }
+            set { this.SetValue(SelectionStartProperty, value); }
+        }
 
-                if (this.caretIndex != value)
-                {
-                    this.caretIndex = value;
-                    this.textBoxView.CaretMoved();
-                }
-            }
+        public int SelectionEnd
+        {
+            get { return this.GetValue(SelectionEndProperty); }
+            set { this.SetValue(SelectionEndProperty, value); }
         }
 
         public string Text
@@ -95,33 +99,54 @@ namespace Perspex.Controls
             textContainer.Content = this.textBoxView = new TextBoxView(this);
         }
 
+        private static int CoerceCaretIndex(PerspexObject o, int value)
+        {
+            var text = o.GetValue(TextProperty);
+            var length = (text != null) ? text.Length : 0;
+            return Math.Max(0, Math.Min(length, value));
+        }
+
+        private void MoveHorizontal(int count, ModifierKeys modifiers)
+        {
+            if (modifiers == ModifierKeys.None)
+            {
+                this.CaretIndex += count;
+                this.SelectionStart = this.SelectionEnd = this.CaretIndex;
+            }
+            else if ((modifiers & ModifierKeys.Shift) == ModifierKeys.Shift)
+            {
+                this.SelectionEnd = (this.CaretIndex += count);
+            }
+        }
+
         private void OnKeyDown(object sender, KeyEventArgs e)
         {
             string text = this.Text ?? string.Empty;
+            var caretIndex = this.CaretIndex;
 
             switch (e.Key)
             {
                 case Key.Left:
-                    --this.CaretIndex;
+                    this.MoveHorizontal(-1, e.Device.Modifiers);
                     break;
 
                 case Key.Right:
-                    ++this.CaretIndex;
+                    this.MoveHorizontal(1, e.Device.Modifiers);
                     break;
 
                 case Key.Back:
-                    if (this.caretIndex > 0)
+                    if (this.CaretIndex > 0)
                     {
-                        this.Text = text.Substring(0, this.caretIndex - 1) + text.Substring(this.caretIndex);
+                        this.Text = text.Substring(0, caretIndex - 1) + text.Substring(caretIndex);
                         --this.CaretIndex;
                     }
 
                     break;
 
                 case Key.Delete:
-                    if (this.caretIndex < text.Length)
+                    if (caretIndex < text.Length)
                     {
-                        this.Text = text.Substring(0, this.caretIndex) + text.Substring(this.caretIndex + 1);
+                        this.Text = text.Substring(0, caretIndex) + text.Substring(caretIndex + 1);
                     }
 
                     break;
@@ -145,7 +170,7 @@ namespace Perspex.Controls
                 default:
                     if (!string.IsNullOrEmpty(e.Text))
                     {
-                        this.Text = text.Substring(0, this.caretIndex) + e.Text + text.Substring(this.caretIndex);
+                        this.Text = text.Substring(0, caretIndex) + e.Text + text.Substring(caretIndex);
                         ++this.CaretIndex;
                     }
 

Perspex.Controls/TextBoxView.cs

@@ -7,6 +7,7 @@
 namespace Perspex.Controls
 {
     using System;
+    using System.Reactive.Linq;
     using Perspex.Media;
     using Perspex.Threading;
 
@@ -25,6 +26,13 @@ namespace Perspex.Controls
             this.caretTimer.Tick += this.CaretTimerTick;
             this.parent = parent;
             this[!TextProperty] = parent[!TextProperty];
+
+            Observable.Merge(
+                this.parent.GetObservable(TextBox.SelectionStartProperty),
+                this.parent.GetObservable(TextBox.SelectionEndProperty))
+                .Subscribe(_ => this.InvalidateVisual());
+
+            parent.GetObservable(TextBox.CaretIndexProperty).Subscribe(_ => this.CaretMoved());
         }
 
         public int GetCaretIndex(Point point)
@@ -47,6 +55,23 @@ namespace Perspex.Controls
 
         public override void Render(IDrawingContext context)
         {
+            var selectionStart = this.parent.SelectionStart;
+            var selectionEnd = this.parent.SelectionEnd;
+
+            if (selectionStart != selectionEnd)
+            {
+                var start = Math.Min(selectionStart, selectionEnd);
+                var length = Math.Max(selectionStart, selectionEnd) - start;
+                var rects = this.FormattedText.HitTestTextRange(start, length);
+
+                var brush = new SolidColorBrush(0xff086f9e);
+
+                foreach (var rect in rects)
+                {
+                    context.FillRectange(brush, rect);
+                }
+            }
+
             base.Render(context);
 
             if (this.parent.IsFocused)

Perspex.SceneGraph/Media/FormattedText.cs

@@ -79,7 +79,7 @@ namespace Perspex.Media
             return this.PlatformImpl.HitTestTextPosition(index);
         }
 
-        public IEnumerable<Rect> HitTestTextRange(int index, int length, Point origin)
+        public IEnumerable<Rect> HitTestTextRange(int index, int length, Point origin = default(Point))
         {
             return this.PlatformImpl.HitTestTextRange(index, length, origin);
         }
@@ -89,4 +89,4 @@ namespace Perspex.Media
             return this.PlatformImpl.Measure();
         }
     }
-}
+} 

Windows/Perspex.Win32/Input/WindowsKeyboardDevice.cs

@@ -28,26 +28,22 @@ namespace Perspex.Win32.Input
             {
                 ModifierKeys result = 0;
 
-                if (this.GetKeyStates(Key.LeftAlt) == KeyStates.Down ||
-                    this.GetKeyStates(Key.RightAlt) == KeyStates.Down)
+                if (this.IsDown(Key.LeftAlt) || this.IsDown(Key.RightAlt))
                 {
                     result |= ModifierKeys.Alt;
                 }
 
-                if (this.GetKeyStates(Key.LeftCtrl) == KeyStates.Down ||
-                    this.GetKeyStates(Key.RightCtrl) == KeyStates.Down)
+                if (this.IsDown(Key.LeftCtrl) || this.IsDown(Key.RightCtrl))
                 {
                     result |= ModifierKeys.Control;
                 }
 
-                if (this.GetKeyStates(Key.LeftShift) == KeyStates.Down ||
-                    this.GetKeyStates(Key.RightShift) == KeyStates.Down)
+                if (this.IsDown(Key.LeftShift) || this.IsDown(Key.RightShift))
                 {
                     result |= ModifierKeys.Shift;
                 }
 
-                if (this.GetKeyStates(Key.LWin) == KeyStates.Down ||
-                    this.GetKeyStates(Key.RWin) == KeyStates.Down)
+                if (this.IsDown(Key.LWin) || this.IsDown(Key.RWin))
                 {
                     result |= ModifierKeys.Windows;
                 }
@@ -79,6 +75,11 @@ namespace Perspex.Win32.Input
             UnmanagedMethods.GetKeyboardState(this.keyStates);
         }
 
+        private bool IsDown(Key key)
+        {
+            return (this.GetKeyStates(key) & KeyStates.Down) != 0;
+        }
+
         private KeyStates GetKeyStates(Key key)
         {
             int vk = KeyInterop.VirtualKeyFromKey(key);