Merge pull request #101 from atc-net/bugfix/VisualTreeHelperEx-GetChild

feat: Fix bug in GetChild method and add FindChild and FindParent

Author: davidkallesen

src/Atc.Wpf/Helpers/VisualTreeHelperEx.cs

@@ -1,37 +1,81 @@
-#pragma warning disable CS0162 // Unreachable code detected
 namespace Atc.Wpf.Helpers;
 
+/// <summary>
+/// Provides extended methods for working with the visual tree in WPF applications.
+/// </summary>
 [SuppressMessage("Naming", "CA1711:Identifiers should not have incorrect suffix", Justification = "OK.")]
 public static class VisualTreeHelperEx
 {
-    public static T? GetParent<T>(DependencyObject child)
+    /// <summary>
+    /// Finds and returns the first parent object of the specified type T in the visual tree.
+    /// </summary>
+    /// <typeparam name="T">The type of the parent to find.</typeparam>
+    /// <param name="control">The starting dependency object to search up from.</param>
+    /// <returns>The first parent object of type T found in the visual tree, or null if no such parent exists.</returns>
+    public static T? GetParent<T>(
+        DependencyObject control)
         where T : DependencyObject
-    {
-        var parent = VisualTreeHelper.GetParent(child);
+        => FindParent<T>(control);
+
+    /// <summary>
+    /// Searches for and returns the first child object of the specified type T within the visual tree.
+    /// </summary>
+    /// <typeparam name="T">The type of the child to find.</typeparam>
+    /// <param name="control">The parent dependency object to search down from.</param>
+    /// <returns>The first child of type T found within the visual tree, or null if no such child exists.</returns>
+    public static T? GetChild<T>(
+        DependencyObject control)
+        where T : DependencyObject
+        => FindChild<T>(control);
 
-        return parent switch
+    /// <summary>
+    /// Recursively finds the first parent of the specified type T in the visual tree.
+    /// </summary>
+    /// <typeparam name="T">The type of the parent to find.</typeparam>
+    /// <param name="control">The starting point dependency object to search up from.</param>
+    /// <returns>The first parent object of type T in the visual tree, or null if no such parent is found.</returns>
+    public static T? FindParent<T>(
+        DependencyObject control)
+        where T : DependencyObject
+    {
+        var parent = VisualTreeHelper.GetParent(control);
+        while (parent is not null)
         {
-            null => null,
-            T tParent => tParent,
-            _ => GetParent<T>(parent),
-        };
+            if (parent is T tParent)
+            {
+                return tParent;
+            }
+
+            parent = VisualTreeHelper.GetParent(parent);
+        }
+
+        return null;
     }
 
-    [SuppressMessage("Major Bug", "S1751:Loops with at most one iteration should be refactored", Justification = "OK.")]
-    public static T? GetChild<T>(DependencyObject control)
+    /// <summary>
+    /// Recursively searches for and returns the first child of the specified type T within the visual tree.
+    /// </summary>
+    /// <typeparam name="T">The type of the child to find.</typeparam>
+    /// <param name="control">The parent dependency object to search down from.</param>
+    /// <returns>The first child of type T, or null if no such child is found.</returns>
+    public static T? FindChild<T>(
+        DependencyObject control)
         where T : DependencyObject
     {
         var childNumber = VisualTreeHelper.GetChildrenCount(control);
         for (var i = 0; i < childNumber; i++)
         {
             var child = VisualTreeHelper.GetChild(control, i);
+            if (child is T tChild)
+            {
+                return tChild;
+            }
 
-            return child switch
+            var result = FindChild<T>(child);
+            if (result is not null)
             {
-                null => null,
-                T tChild => tChild,
-                _ => GetChild<T>(child),
-            };
+                return result;
+            }
         }
 
         return null;