Avalonia/tests/Avalonia.Benchmarks/Themes/ThemeBenchmark.cs

using System;
using System.Runtime.CompilerServices;
using Avalonia.Controls;
using Avalonia.Markup.Xaml.Styling;
using Avalonia.Platform;
using Avalonia.Styling;
using Avalonia.Themes.Fluent;
using Avalonia.Themes.Simple;
using Avalonia.UnitTests;

using BenchmarkDotNet.Attributes;

namespace Avalonia.Benchmarks.Themes
{
    [MemoryDiagnoser]
    public class ThemeBenchmark : IDisposable
    {
        private IDisposable _app;
        private readonly FluentTheme _reusableFluentTheme = new FluentTheme();
        private readonly SimpleTheme _reusableSimpleTheme = new SimpleTheme();

        public ThemeBenchmark()
        {
            AssetLoader.RegisterResUriParsers();

            _app = UnitTestApplication.Start(TestServices.StyledWindow.With(theme: () => null));
            // Add empty style to override it later
            UnitTestApplication.Current.Styles.Add(new Style());
        }

        [Benchmark]
        [MethodImpl(MethodImplOptions.NoInlining)]
        public bool InitFluentTheme()
        {
            UnitTestApplication.Current.Styles[0] = new FluentTheme();
            return ((IResourceHost)UnitTestApplication.Current).TryGetResource("SystemAccentColor", out _);
        }

        [Benchmark]
        [MethodImpl(MethodImplOptions.NoInlining)]
        public bool InitSimpleTheme()
        {
            UnitTestApplication.Current.Styles[0] = new SimpleTheme();
            return ((IResourceHost)UnitTestApplication.Current).TryGetResource("ThemeAccentColor", out _);
        }
        
        [Benchmark]
        [Arguments(typeof(Button))]
        [Arguments(typeof(TextBox))]
        [Arguments(typeof(DatePicker))]
        public object FindFluentControlTheme(Type type)
        {
            _reusableFluentTheme.TryGetResource(type, ThemeVariant.Default, out var theme);
            return theme;
        }

        [Benchmark]
        [Arguments(typeof(Button))]
        [Arguments(typeof(TextBox))]
        [Arguments(typeof(DatePicker))]
        public object FindSimpleControlTheme(Type type)
        {
            _reusableSimpleTheme.TryGetResource(type, ThemeVariant.Default, out var theme);
            return theme;
        }

        public void Dispose()
        {
            _app.Dispose();
        }
    }
}