PowerToys/src/modules/Hosts/HostsUILib/Helpers/VisualTreeUtils.cs

// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Media;

namespace HostsUILib.Helpers
{
    // Taken from https://github.com/microsoft/microsoft-ui-xaml/blob/main/test/MUXControlsTestApp/Utilities/VisualTreeUtils.cs
    // Original copyright header:
    // Copyright (c) Microsoft Corporation. All rights reserved.
    // Licensed under the MIT License. See LICENSE in the project root for license information.
    public static class VisualTreeUtils
    {
        public static T FindVisualChildByType<T>(this DependencyObject element)
            where T : DependencyObject
        {
            if (element == null)
            {
                return null;
            }

            if (element is T elementAsT)
            {
                return elementAsT;
            }

            int childrenCount = VisualTreeHelper.GetChildrenCount(element);
            for (int i = 0; i < childrenCount; i++)
            {
                var result = VisualTreeHelper.GetChild(element, i).FindVisualChildByType<T>();
                if (result != null)
                {
                    return result;
                }
            }

            return null;
        }

        public static FrameworkElement FindVisualChildByName(this DependencyObject element, string name)
        {
            if (element == null || string.IsNullOrWhiteSpace(name))
            {
                return null;
            }

            if (element is FrameworkElement elementAsFE && elementAsFE.Name == name)
            {
                return elementAsFE;
            }

            int childrenCount = VisualTreeHelper.GetChildrenCount(element);
            for (int i = 0; i < childrenCount; i++)
            {
                var result = VisualTreeHelper.GetChild(element, i).FindVisualChildByName(name);
                if (result != null)
                {
                    return result;
                }
            }

            return null;
        }
    }
}