Implement Object Query Cache

[IssueSyncBot]

Original issue opened by:

marlenaklein-msft

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Overview

In MRTK3 implement a generic component object cache. This would be a generic class with a type parameter T. The generic class should be capable is searching for type T, and cache the first found instance of T. T must derive from the Unity Component base class.

Class definition

using UnityEngine;

namespace Microsoft.MixedReality.Toolkit
{
   static class ComponentCache<T> where T : Componet
   {
        private static T cache = null;

        public static T FindFirstInstance()
        {
             _ = TryFindFirstInstance(out T result);
             return result;
        }

        public static bool TryFindFirstInstance(out T result)
        {
            if (cache == null)
            {
               cache = Object.FindFirstObjectByType<T>();
            }

            result  = cache;
            return result  != null;
        }
   }
}

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ISSUE MIGRATION

Issue migrated from: microsoft/MixedRealityToolkit-Unity#11682

[IssueSyncBot]

Original comment by:

marlenaklein-msft

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Closed with #11686.