Show access keys in menus.

Currently always shown, whether user pressed alt/f10 or not.

Perspex.Controls/Perspex.Controls.csproj

@@ -36,6 +36,7 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="Primitives\AccessText.cs" />
     <Compile Include="Border.cs" />
     <Compile Include="GlobalSuppressions.cs" />
     <Compile Include="MenuItem.cs" />

Perspex.Controls/Presenters/TextPresenter.cs

@@ -140,9 +140,9 @@ namespace Perspex.Controls.Presenters
             }
         }
 
-        protected override FormattedText CreateFormattedText()
+        protected override FormattedText CreateFormattedText(Size constraint)
         {
-            var result = base.CreateFormattedText();
+            var result = base.CreateFormattedText(constraint);
             var selectionStart = this.SelectionStart;
             var selectionEnd = this.SelectionEnd;
             var start = Math.Min(selectionStart, selectionEnd);

Perspex.Controls/Primitives/AccessText.cs

@@ -0,0 +1,85 @@
+// -----------------------------------------------------------------------
+// <copyright file="AccessText.cs" company="Steven Kirk">
+// Copyright 2015 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls.Primitives
+{
+    using Perspex.Media;
+
+    /// <summary>
+    /// A text block that displays a character prefixed with an underscore as an access key.
+    /// </summary>
+    public class AccessText : TextBlock
+    {
+        /// <summary>
+        /// Renders the <see cref="AccessText"/> to a drawing context.
+        /// </summary>
+        /// <param name="context">The drawing context.</param>
+        public override void Render(IDrawingContext context)
+        {
+            base.Render(context);
+
+            int underscore = this.Text?.IndexOf('_') ?? -1;
+
+            if (underscore != -1)
+            {
+                var rect = this.FormattedText.HitTestTextPosition(underscore);
+                var offset = new Vector(0, -0.5);
+                context.DrawLine(
+                    new Pen(this.Foreground, 1),
+                    rect.BottomLeft + offset,
+                    rect.BottomRight + offset);
+            }
+        }
+
+        /// <summary>
+        /// Creates the <see cref="FormattedText"/> used to render the text.
+        /// </summary>
+        /// <param name="constraint">The constraint of the text.</param>
+        /// <returns>A <see cref="FormattedText"/> object.</returns>
+        protected override FormattedText CreateFormattedText(Size constraint)
+        {
+            var result = new FormattedText(
+                this.StripAccessKey(this.Text),
+                this.FontFamily,
+                this.FontSize,
+                this.FontStyle,
+                this.TextAlignment,
+                this.FontWeight);
+            result.Constraint = constraint;
+            return result;
+        }
+
+        /// <summary>
+        /// Measures the control.
+        /// </summary>
+        /// <param name="availableSize">The available size for the control.</param>
+        /// <returns>The desired size.</returns>
+        protected override Size MeasureOverride(Size availableSize)
+        {
+            var result = base.MeasureOverride(availableSize);
+            return result.WithHeight(result.Height + 1);
+        }
+
+        /// <summary>
+        /// Returns a string with the first underscore stripped.
+        /// </summary>
+        /// <param name="text">The text.</param>
+        /// <returns>The text with the first underscore stripped.</returns>
+        private string StripAccessKey(string text)
+        {
+            var position = text.IndexOf('_');
+
+            if (position == -1)
+            {
+                return text;
+            }
+            else
+            {
+                return text.Substring(0, position) + text.Substring(position + 1);
+            }
+        }
+    }
+}

Perspex.Controls/TextBlock.cs

@@ -11,39 +11,78 @@ namespace Perspex.Controls
     using System.Reactive.Linq;
     using Perspex.Media;
 
+    /// <summary>
+    /// A control that displays a block of text.
+    /// </summary>
     public class TextBlock : Control
     {
+        /// <summary>
+        /// Defines the <see cref="Background"/> property.
+        /// </summary>
         public static readonly PerspexProperty<Brush> BackgroundProperty =
             Border.BackgroundProperty.AddOwner<TextBlock>();
 
+        /// <summary>
+        /// Defines the <see cref="FontFamily"/> property.
+        /// </summary>
         public static readonly PerspexProperty<string> FontFamilyProperty =
             PerspexProperty.RegisterAttached<TextBlock, Control, string>("FontFamily", inherits: true);
 
+        /// <summary>
+        /// Defines the <see cref="FontSize"/> property.
+        /// </summary>
         public static readonly PerspexProperty<double> FontSizeProperty =
             PerspexProperty.RegisterAttached<TextBlock, Control, double>("FontSize", inherits: true);
 
+        /// <summary>
+        /// Defines the <see cref="FontStyle"/> property.
+        /// </summary>
         public static readonly PerspexProperty<FontStyle> FontStyleProperty =
             PerspexProperty.RegisterAttached<TextBlock, Control, FontStyle>("FontStyle", inherits: true);
 
+        /// <summary>
+        /// Defines the <see cref="FontWeight"/> property.
+        /// </summary>
         public static readonly PerspexProperty<FontWeight> FontWeightProperty =
             PerspexProperty.RegisterAttached<TextBlock, Control, FontWeight>("FontWeight", inherits: true, defaultValue: FontWeight.Normal);
 
+        /// <summary>
+        /// Defines the <see cref="Foreground"/> property.
+        /// </summary>
         public static readonly PerspexProperty<Brush> ForegroundProperty =
             PerspexProperty.RegisterAttached<TextBlock, Control, Brush>("Foreground", new SolidColorBrush(0xff000000), inherits: true);
 
+        /// <summary>
+        /// Defines the <see cref="Text"/> property.
+        /// </summary>
         public static readonly PerspexProperty<string> TextProperty =
             PerspexProperty.Register<TextBlock, string>("Text");
 
-        public static readonly PerspexProperty<TextWrapping> TextWrappingProperty =
-            PerspexProperty.Register<TextBlock, TextWrapping>("TextWrapping");
-
+        /// <summary>
+        /// Defines the <see cref="TextAlignment"/> property.
+        /// </summary>
         public static readonly PerspexProperty<TextAlignment> TextAlignmentProperty =
             PerspexProperty.Register<TextBlock, TextAlignment>("TextAlignment");
 
+        /// <summary>
+        /// Defines the <see cref="TextWrapping"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<TextWrapping> TextWrappingProperty =
+            PerspexProperty.Register<TextBlock, TextWrapping>("TextWrapping");
+
+        /// <summary>
+        /// The formatted text used for rendering.
+        /// </summary>
         private FormattedText formattedText;
 
+        /// <summary>
+        /// Stores the last constraint passed to MeasureOverride.
+        /// </summary>
         private Size constraint;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TextBlock"/> class.
+        /// </summary>
         public TextBlock()
         {
             Observable.Merge(
@@ -57,73 +96,107 @@ namespace Perspex.Controls
                 });
         }
 
+        /// <summary>
+        /// Gets or sets a brush used to paint the control's background.
+        /// </summary>
         public Brush Background
         {
             get { return this.GetValue(BackgroundProperty); }
             set { this.SetValue(BackgroundProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the text.
+        /// </summary>
         public string Text
         {
             get { return this.GetValue(TextProperty); }
             set { this.SetValue(TextProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the font family.
+        /// </summary>
         public string FontFamily
         {
             get { return this.GetValue(FontFamilyProperty); }
             set { this.SetValue(FontFamilyProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the font size.
+        /// </summary>
         public double FontSize
         {
             get { return this.GetValue(FontSizeProperty); }
             set { this.SetValue(FontSizeProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the font style.
+        /// </summary>
         public FontStyle FontStyle
         {
             get { return this.GetValue(FontStyleProperty); }
             set { this.SetValue(FontStyleProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the font weight.
+        /// </summary>
         public FontWeight FontWeight
         {
             get { return this.GetValue(FontWeightProperty); }
             set { this.SetValue(FontWeightProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets a brush used to paint the text.
+        /// </summary>
         public Brush Foreground
         {
             get { return this.GetValue(ForegroundProperty); }
             set { this.SetValue(ForegroundProperty, value); }
         }
 
+        /// <summary>
+        /// Gets the <see cref="FormattedText"/> used to render the text.
+        /// </summary>
         public FormattedText FormattedText
         {
             get
             {
                 if (this.formattedText == null)
                 {
-                    this.formattedText = this.CreateFormattedText();
+                    this.formattedText = this.CreateFormattedText(this.constraint);
                 }
 
                 return this.formattedText;
             }
         }
 
+        /// <summary>
+        /// Gets or sets the control's text wrapping mode.
+        /// </summary>
         public TextWrapping TextWrapping
         {
             get { return this.GetValue(TextWrappingProperty); }
             set { this.SetValue(TextWrappingProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the text alignment.
+        /// </summary>
         public TextAlignment TextAlignment
         {
             get { return this.GetValue(TextAlignmentProperty); }
             set { this.SetValue(TextAlignmentProperty, value); }
         }
 
+        /// <summary>
+        /// Renders the <see cref="TextBlock"/> to a drawing context.
+        /// </summary>
+        /// <param name="context">The drawing context.</param>
         public override void Render(IDrawingContext context)
         {
             Brush background = this.Background;
@@ -137,7 +210,12 @@ namespace Perspex.Controls
             context.DrawText(this.Foreground,  new Point(), this.FormattedText);
         }
 
-        protected virtual FormattedText CreateFormattedText()
+        /// <summary>
+        /// Creates the <see cref="FormattedText"/> used to render the text.
+        /// </summary>
+        /// <param name="constraint">The constraint of the text.</param>
+        /// <returns>A <see cref="FormattedText"/> object.</returns>
+        protected virtual FormattedText CreateFormattedText(Size constraint)
         {
             var result = new FormattedText(
                 this.Text,
@@ -146,10 +224,13 @@ namespace Perspex.Controls
                 this.FontStyle,
                 this.TextAlignment,
                 this.FontWeight);
-            result.Constraint = this.constraint;
+            result.Constraint = constraint;
             return result;
         }
 
+        /// <summary>
+        /// Invalidates <see cref="FormattedText"/>.
+        /// </summary>
         protected void InvalidateFormattedText()
         {
             if (this.formattedText != null)
@@ -162,6 +243,11 @@ namespace Perspex.Controls
             this.InvalidateMeasure();
         }
 
+        /// <summary>
+        /// Measures the control.
+        /// </summary>
+        /// <param name="availableSize">The available size for the control.</param>
+        /// <returns>The desired size.</returns>
         protected override Size MeasureOverride(Size availableSize)
         {
             if (!string.IsNullOrEmpty(this.Text))

Perspex.Themes.Default/MenuItemStyle.cs

@@ -6,17 +6,21 @@
 
 namespace Perspex.Themes.Default
 {
+    using System.Linq;
     using Perspex.Controls;
     using Perspex.Controls.Presenters;
+    using Perspex.Controls.Primitives;
     using Perspex.Controls.Shapes;
     using Perspex.Input;
     using Perspex.Layout;
     using Perspex.Media;
     using Perspex.Styling;
-    using System.Linq;
 
     public class MenuItemStyle : Styles
     {
+        private static readonly DataTemplate AccessKeyDataTemplate =
+            new DataTemplate<string>(x => new AccessText { Text = x });
+
         public MenuItemStyle()
         {
             this.AddRange(new[]
@@ -79,6 +83,10 @@ namespace Perspex.Themes.Default
                     {
                         new ContentPresenter
                         {
+                            DataTemplates = new DataTemplates
+                            {
+                                AccessKeyDataTemplate,
+                            },
                             [~ContentPresenter.ContentProperty] = control[~MenuItem.HeaderProperty],
                             [~ContentPresenter.MarginProperty] = control[~MenuItem.PaddingProperty],
                             [Grid.ColumnProperty] = 1,
@@ -171,6 +179,10 @@ namespace Perspex.Themes.Default
                         },
                         new ContentPresenter
                         {
+                            DataTemplates = new DataTemplates
+                            {
+                                AccessKeyDataTemplate,
+                            },
                             VerticalAlignment = VerticalAlignment.Center,
                             [~ContentPresenter.ContentProperty] = control[~MenuItem.HeaderProperty],
                             [~ContentPresenter.MarginProperty] = control[~MenuItem.PaddingProperty],

TestApplication/Program.cs

@@ -144,12 +144,12 @@ namespace TestApplication
                             {
                                 new MenuItem
                                 {
-                                    Header = "File",
+                                    Header = "_File",
                                     Items = new[]
                                     {
                                         new MenuItem
                                         {
-                                            Header = "Open...",
+                                            Header = "_Open...",
                                             Icon = new Image
                                             {
                                                 Source = new Bitmap("github_icon.png"),
@@ -157,57 +157,57 @@ namespace TestApplication
                                         },
                                         new MenuItem
                                         {
-                                            Header = "Save",
+                                            Header = "_Save",
                                             Items = new[]
                                             {
                                                 new MenuItem
                                                 {
-                                                    Header = "Sub Item 1",
+                                                    Header = "Sub Item _1",
                                                 },
                                                 new MenuItem
                                                 {
-                                                    Header = "Sub Item 2",
+                                                    Header = "Sub Item _2",
                                                 },
                                             }
                                         },
                                         new MenuItem
                                         {
-                                            Header = "Save As",
+                                            Header = "Save _As",
                                             Items = new[]
                                             {
                                                 new MenuItem
                                                 {
-                                                    Header = "Sub Item 1",
+                                                    Header = "Sub Item _1",
                                                 },
                                                 new MenuItem
                                                 {
-                                                    Header = "Sub Item 2",
+                                                    Header = "Sub Item _2",
                                                 },
                                             }
                                         },
                                         new MenuItem
                                         {
-                                            Header = "Exit",
+                                            Header = "E_xit",
                                             Command = testCommand,
                                         },
                                     }
                                 },
                                 new MenuItem
                                 {
-                                    Header = "Edit",
+                                    Header = "_Edit",
                                     Items = new[]
                                     {
                                         new MenuItem
                                         {
-                                            Header = "Cut",
+                                            Header = "Cu_t",
                                         },
                                         new MenuItem
                                         {
-                                            Header = "Copy",
+                                            Header = "_Copy",
                                         },
                                         new MenuItem
                                         {
-                                            Header = "Paste",
+                                            Header = "_Paste",
                                         },
                                     }
                                 }