Pulling the AutoCompleteBox from the original GitHub Desktop for Windows

Author: StanleyGoldman

src/GitHub.UI/Controls/AutoCompleteBox/AutoCompleteBox.cs

@@ -0,0 +1,300 @@
+// (c) Copyright Microsoft Corporation.
+// This source is subject to the Microsoft Public License (Ms-PL).
+// Please see http://go.microsoft.com/fwlink/?LinkID=131993] for details.
+// All other rights reserved.
+
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Windows;
+using System.Windows.Automation;
+using System.Windows.Automation.Peers;
+using System.Windows.Automation.Provider;
+
+namespace GitHub.UI
+{
+    /// <summary>
+    /// Exposes AutoCompleteBox types to UI Automation.
+    /// </summary>
+    /// <QualityBand>Stable</QualityBand>
+    public sealed class AutoCompleteBoxAutomationPeer : FrameworkElementAutomationPeer, IValueProvider, IExpandCollapseProvider, ISelectionProvider
+    {
+        /// <summary>
+        /// The name reported as the core class name.
+        /// </summary>
+        private const string autoCompleteBoxClassNameCore = "AutoCompleteBox";
+
+        /// <summary>
+        /// Gets the AutoCompleteBox that owns this
+        /// AutoCompleteBoxAutomationPeer.
+        /// </summary>
+        private AutoCompleteBox OwnerAutoCompleteBox
+        {
+            get { return (AutoCompleteBox)Owner; }
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether the UI automation provider allows
+        /// more than one child element to be selected concurrently.
+        /// </summary>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        /// <value>True if multiple selection is allowed; otherwise, false.</value>
+        bool ISelectionProvider.CanSelectMultiple
+        {
+            get { return false; }
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether the UI automation provider
+        /// requires at least one child element to be selected.
+        /// </summary>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        /// <value>True if selection is required; otherwise, false.</value>
+        bool ISelectionProvider.IsSelectionRequired
+        {
+            get { return false; }
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the AutoCompleteBoxAutomationPeer
+        /// class.
+        /// </summary>
+        /// <param name="owner">
+        /// The AutoCompleteBox that is associated with this
+        /// AutoCompleteBoxAutomationPeer.
+        /// </param>
+        public AutoCompleteBoxAutomationPeer(AutoCompleteBox owner)
+            : base(owner)
+        {
+        }
+
+        /// <summary>
+        /// Gets the control type for the AutoCompleteBox that is associated
+        /// with this AutoCompleteBoxAutomationPeer. This method is called by
+        /// GetAutomationControlType.
+        /// </summary>
+        /// <returns>ComboBox AutomationControlType.</returns>
+        protected override AutomationControlType GetAutomationControlTypeCore()
+        {
+            return AutomationControlType.ComboBox;
+        }
+
+        /// <summary>
+        /// Gets the name of the AutoCompleteBox that is associated with this
+        /// AutoCompleteBoxAutomationPeer. This method is called by
+        /// GetClassName.
+        /// </summary>
+        /// <returns>The name AutoCompleteBox.</returns>
+        protected override string GetClassNameCore()
+        {
+            return autoCompleteBoxClassNameCore;
+        }
+
+        /// <summary>
+        /// Gets the control pattern for the AutoCompleteBox that is associated
+        /// with this AutoCompleteBoxAutomationPeer.
+        /// </summary>
+        /// <param name="patternInterface">The desired PatternInterface.</param>
+        /// <returns>The desired AutomationPeer or null.</returns>
+        public override object GetPattern(PatternInterface patternInterface)
+        {
+            object iface = null;
+            var owner = OwnerAutoCompleteBox;
+
+            if (patternInterface == PatternInterface.Value)
+            {
+                iface = this;
+            }
+            else if (patternInterface == PatternInterface.ExpandCollapse)
+            {
+                iface = this;
+            }
+            else if (owner.SelectionAdapter != null)
+            {
+                var peer = owner.SelectionAdapter.CreateAutomationPeer();
+                if (peer != null)
+                {
+                    iface = peer.GetPattern(patternInterface);
+                }
+            }
+
+            return iface ?? base.GetPattern(patternInterface);
+        }
+
+        /// <summary>
+        /// Blocking method that returns after the element has been expanded.
+        /// </summary>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        void IExpandCollapseProvider.Expand()
+        {
+            if (!IsEnabled())
+            {
+                throw new ElementNotEnabledException();
+            }
+
+            OwnerAutoCompleteBox.IsDropDownOpen = true;
+        }
+
+        /// <summary>
+        /// Blocking method that returns after the element has been collapsed.
+        /// </summary>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        void IExpandCollapseProvider.Collapse()
+        {
+            if (!IsEnabled())
+            {
+                throw new ElementNotEnabledException();
+            }
+
+            OwnerAutoCompleteBox.IsDropDownOpen = false;
+        }
+
+        /// <summary>
+        /// Gets an element's current Collapsed or Expanded state.
+        /// </summary>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        ExpandCollapseState IExpandCollapseProvider.ExpandCollapseState
+        {
+            get
+            {
+                return OwnerAutoCompleteBox.IsDropDownOpen ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed;
+            }
+        }
+
+        /// <summary>
+        /// Raises the ExpandCollapse automation event.
+        /// </summary>
+        /// <param name="oldValue">The old value.</param>
+        /// <param name="newValue">The new value.</param>
+        internal void RaiseExpandCollapseAutomationEvent(bool oldValue, bool newValue)
+        {
+            RaisePropertyChangedEvent(
+                ExpandCollapsePatternIdentifiers.ExpandCollapseStateProperty,
+                oldValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed,
+                newValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed);
+        }
+        
+        /// <summary>
+        /// Sets the value of a control.
+        /// </summary>
+        /// <param name="value">The value to set. The provider is responsible
+        /// for converting the value to the appropriate data type.</param>
+        void IValueProvider.SetValue(string value)
+        {
+            OwnerAutoCompleteBox.Text = value;
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether the value of a control is
+        /// read-only.
+        /// </summary>
+        /// <value>True if the value is read-only; false if it can be modified.</value>
+        bool IValueProvider.IsReadOnly
+        {
+            get
+            {
+                return !OwnerAutoCompleteBox.IsEnabled;
+            }
+        }
+
+        /// <summary>
+        /// Gets the value of the control.
+        /// </summary>
+        /// <value>The value of the control.</value>
+        string IValueProvider.Value
+        {
+            get
+            {
+                return OwnerAutoCompleteBox.Text ?? string.Empty;
+            }
+        }
+
+        /// <summary>
+        /// Gets the collection of child elements of the AutoCompleteBox that
+        /// are associated with this AutoCompleteBoxAutomationPeer. This method
+        /// is called by GetChildren.
+        /// </summary>
+        /// <returns>
+        /// A collection of automation peer elements, or an empty collection
+        /// if there are no child elements.
+        /// </returns>
+        [SuppressMessage("Microsoft.Design", "CA1002:DoNotExposeGenericLists", Justification = "Required by automation")]
+        protected override List<AutomationPeer> GetChildrenCore()
+        {
+            var children = new List<AutomationPeer>();
+            var owner = OwnerAutoCompleteBox;
+
+            // TextBox part.
+            var textBox = owner.TextBox;
+            if (textBox != null)
+            {
+                var peer = CreatePeerForElement(textBox.Control);
+                if (peer != null)
+                {
+                    children.Insert(0, peer);
+                }
+           }
+
+            // Include SelectionAdapter's children.
+            if (owner.SelectionAdapter != null)
+            {
+                var selectionAdapterPeer = owner.SelectionAdapter.CreateAutomationPeer();
+                if (selectionAdapterPeer != null)
+                {
+                    var listChildren = selectionAdapterPeer.GetChildren();
+                    if (listChildren != null)
+                    {
+                        children.AddRange(listChildren);
+                    }
+                }
+            }
+
+            return children;
+        }
+
+        /// <summary>
+        /// Retrieves a UI automation provider for each child element that is
+        /// selected.
+        /// </summary>
+        /// <returns>An array of UI automation providers.</returns>
+        /// <remarks>
+        /// This API supports the .NET Framework infrastructure and is not 
+        /// intended to be used directly from your code.
+        /// </remarks>
+        IRawElementProviderSimple[] ISelectionProvider.GetSelection()
+        {
+            if (OwnerAutoCompleteBox.SelectionAdapter != null)
+            {
+                var selectedItem = OwnerAutoCompleteBox.SelectionAdapter.SelectedItem;
+                if (selectedItem != null)
+                {
+                    var uie = selectedItem as UIElement;
+                    if (uie != null)
+                    {
+                        var peer = CreatePeerForElement(uie);
+                        if (peer != null)
+                        {
+                            return new[] { ProviderFromPeer(peer) };
+                        }
+                    }
+                }
+            }
+
+            return new IRawElementProviderSimple[] { };
+        }
+    }
+}

src/GitHub.UI/Controls/AutoCompleteBox/AutoCompleteBoxAutomationPeer.cs

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+using System.Collections.Generic;
+
+namespace GitHub.UI
+{
+    public class AutoCompleteResult
+    {
+        public static AutoCompleteResult Empty = new AutoCompleteResult(0, new AutoCompleteSuggestion[] {});
+
+        public AutoCompleteResult(int offset, IReadOnlyList<AutoCompleteSuggestion> suggestions)
+        {
+            Offset = offset;
+            Suggestions = suggestions;
+        }
+
+        public int Offset { get; private set; }
+        public IReadOnlyList<AutoCompleteSuggestion> Suggestions { get; private set; }
+    }
+}