Fixes #4374 - Nukes all (?) legacy Driver and Application stuff; revamps tests (#4376)

Tests/UnitTestsParallelizable/Views/AllViewsDrawTests.cs

@@ -0,0 +1,57 @@
+#nullable enable
+using UnitTests;
+using Xunit.Abstractions;
+
+namespace UnitTests_Parallelizable.ViewsTests;
+
+public class AllViewsDrawTests (ITestOutputHelper output) : TestsAllViews
+{
+    [Theory]
+    [MemberData (nameof (AllViewTypes))]
+    public void AllViews_Draw_Does_Not_Layout (Type viewType)
+    {
+        IDriver driver = CreateFakeDriver ();
+
+        View? view = CreateInstanceIfNotGeneric (viewType);
+
+        if (view is null)
+        {
+            output.WriteLine ($"Ignoring {viewType} - It's a Generic");
+
+            return;
+        }
+
+        output.WriteLine ($"Testing {viewType}");
+
+        if (view is IDesignable designable)
+        {
+            designable.EnableForDesign ();
+        }
+
+        var drawCompleteCount = 0;
+        view.DrawComplete += (s, e) => drawCompleteCount++;
+
+        var layoutStartedCount = 0;
+        view.SubViewLayout += (s, e) => layoutStartedCount++;
+
+        var layoutCompleteCount = 0;
+        view.SubViewsLaidOut += (s, e) => layoutCompleteCount++;
+
+        view.SetNeedsLayout ();
+        view.Layout ();
+
+        Assert.Equal (0, drawCompleteCount);
+        Assert.Equal (1, layoutStartedCount);
+        Assert.Equal (1, layoutCompleteCount);
+
+        if (view.Visible)
+        {
+            view.SetNeedsDraw ();
+            view.Draw ();
+
+            Assert.Equal (1, drawCompleteCount);
+            Assert.Equal (1, layoutStartedCount);
+            Assert.Equal (1, layoutCompleteCount);
+        }
+    }
+}