Merge pull request #11523 from AvaloniaUI/feature/peer-from-element

Added ControlAutomationPeer.FromElement.

src/Avalonia.Controls/Automation/Peers/ControlAutomationPeer.cs

@@ -31,11 +31,31 @@ namespace Avalonia.Automation.Peers
             return CreatePeerForElement(element);
         }
 
+        /// <summary>
+        /// Gets the <see cref="AutomationPeer"/> for a <see cref="Control"/>, creating it if
+        /// necessary.
+        /// </summary>
+        /// <param name="element">The control.</param>
+        /// <returns>The automation peer.</returns>
+        /// <remarks>
+        /// Despite the name (which comes from the analogous WPF API), this method does not create
+        /// a new peer if one already exists: instead it returns the existing peer.
+        /// </remarks>
         public static AutomationPeer CreatePeerForElement(Control element)
         {
             return element.GetOrCreateAutomationPeer();
         }
 
+        /// <summary>
+        /// Gets an existing <see cref="AutomationPeer"/> for a <see cref="Control"/>.
+        /// </summary>
+        /// <param name="element">The control.</param>
+        /// <returns>The automation peer if already created; otherwise null.</returns>
+        /// <remarks>
+        /// To ensure that a peer is created, use <see cref="CreatePeerForElement(Control)"/>.
+        /// </remarks>
+        public static AutomationPeer? FromElement(Control element) => element.GetAutomationPeer();
+
         protected override void BringIntoViewCore() => Owner.BringIntoView();
 
         protected override IReadOnlyList<AutomationPeer> GetOrCreateChildrenCore()

src/Avalonia.Controls/Control.cs

@@ -440,6 +440,12 @@ namespace Avalonia.Controls
             return new NoneAutomationPeer(this);
         }
 
+        internal AutomationPeer? GetAutomationPeer()
+        {
+            VerifyAccess();
+            return _automationPeer;
+        }
+
         internal AutomationPeer GetOrCreateAutomationPeer()
         {
             VerifyAccess();