Avalonia/tests/Avalonia.IntegrationTests.Appium/WindowTests.cs

using System;
using System.Linq;
using System.Runtime.InteropServices;
using Avalonia.Controls;
using OpenQA.Selenium.Appium;
using Xunit;
using Xunit.Sdk;

namespace Avalonia.IntegrationTests.Appium
{
    [Collection("Default")]
    public class WindowTests
    {
        private readonly AppiumDriver<AppiumWebElement> _session;

        public WindowTests(TestAppFixture fixture)
        {
            _session = fixture.Session;

            var tabs = _session.FindElementByAccessibilityId("MainTabs");
            var tab = tabs.FindElementByName("Window");
            tab.Click();
        }

        [Theory]
        [MemberData(nameof(StartupLocationData))]
        public void StartupLocation(string? size, ShowWindowMode mode, WindowStartupLocation location)
        {
            var mainWindowHandle = GetCurrentWindowHandleHack();

            try
            {
                var sizeTextBox = _session.FindElementByAccessibilityId("ShowWindowSize");
                var modeComboBox = _session.FindElementByAccessibilityId("ShowWindowMode");
                var locationComboBox = _session.FindElementByAccessibilityId("ShowWindowLocation");
                var showButton = _session.FindElementByAccessibilityId("ShowWindow");

                if (size is not null)
                    sizeTextBox.SendKeys(size);

                modeComboBox.Click();
                _session.FindElementByName(mode.ToString()).SendClick();

                locationComboBox.Click();
                _session.FindElementByName(location.ToString()).SendClick();

                showButton.Click();
                SwitchToNewWindowHack(oldWindowHandle: mainWindowHandle);

                var clientSize = Size.Parse(_session.FindElementByAccessibilityId("ClientSize").Text);
                var frameSize = Size.Parse(_session.FindElementByAccessibilityId("FrameSize").Text);
                var position = PixelPoint.Parse(_session.FindElementByAccessibilityId("Position").Text);
                var screenRect = PixelRect.Parse(_session.FindElementByAccessibilityId("ScreenRect").Text);
                var scaling = double.Parse(_session.FindElementByAccessibilityId("Scaling").Text);

                Assert.True(frameSize.Width >= clientSize.Width, "Expected frame width >= client width.");
                Assert.True(frameSize.Height > clientSize.Height, "Expected frame height > client height.");

                var frameRect = new PixelRect(position, PixelSize.FromSize(frameSize, scaling));

                switch (location)
                {
                    case WindowStartupLocation.CenterScreen:
                        {
                            var expected = screenRect.CenterRect(frameRect);
                            AssertCloseEnough(expected.Position, frameRect.Position);
                            break;
                        }
                }
            }
            finally
            {
                try
                {
                    var closeButton = _session.FindElementByAccessibilityId("CloseWindow");
                    closeButton.Click();
                    SwitchToMainWindowHack(mainWindowHandle);
                }
                catch { }
            }
        }
        
        public static TheoryData<string?, ShowWindowMode, WindowStartupLocation> StartupLocationData()
        {
            var sizes = new[] { null, "400,300" };
            var data = new TheoryData<string?, ShowWindowMode, WindowStartupLocation>();

            foreach (var size in sizes)
            {
                foreach (var mode in Enum.GetValues<ShowWindowMode>())
                {
                    foreach (var location in Enum.GetValues<WindowStartupLocation>())
                    {
                        if (!(location == WindowStartupLocation.CenterOwner && mode == ShowWindowMode.NonOwned))
                        {
                            data.Add(size, mode, location);
                        }
                    }
                }
            }

            return data;
        }

        private string? GetCurrentWindowHandleHack()
        {
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                // HACK: WinAppDriver only seems to switch to a newly opened window if the window has an owner,
                // otherwise the session remains targeting the previous window. Return the handle for the
                // current window so we know which window to switch to when another is opened.
                return _session.WindowHandles.Single();
            }

            return null;
        }

        private void SwitchToNewWindowHack(string? oldWindowHandle)
        {
            if (oldWindowHandle is not null)
            {
                var newWindowHandle = _session.WindowHandles.FirstOrDefault(x => x != oldWindowHandle);

                // HACK: Looks like WinAppDriver only adds window handles for non-owned windows, but luckily
                // non-owned windows is where we're having the problem, so if we find a window handle that
                // isn't the main window handle then switch to it.
                if (newWindowHandle is not null)
                    _session.SwitchTo().Window(newWindowHandle);
            }
        }

        private void SwitchToMainWindowHack(string? mainWindowHandle)
        {
            if (mainWindowHandle is not null)
                _session.SwitchTo().Window(mainWindowHandle);
        }

        private static void AssertCloseEnough(PixelPoint expected, PixelPoint actual)
        {
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                // On win32, accurate frame information cannot be obtained until a window is shown but
                // WindowStartupLocation needs to be calculated before the window is shown, meaning that
                // the position of a centered window can be off by a bit. From initial testing, looks
                // like this shouldn't be more than 10 pixels.
                if (Math.Abs(expected.X - actual.X) > 10)
                    throw new EqualException(expected, actual);
                if (Math.Abs(expected.Y - actual.Y) > 10)
                    throw new EqualException(expected, actual);
            }
            else
            {
                Assert.Equal(expected, actual);
            }
        }

        public enum ShowWindowMode
        {
            NonOwned,
            Owned,
            Modal
        }
    }
}