Merge pull request #11495 from AvaloniaUI/refactor/remove-presenter-interfaces

Remove presenter interfaces
3 years ago · b2b908c6e8
25 changed files with 77 additions and 133 deletions
--- a/src/Avalonia.Controls/ContentControl.cs
+++ b/src/Avalonia.Controls/ContentControl.cs
@ -13,7 +13,7 @@ namespace Avalonia.Controls
    /// <summary>
    /// Displays <see cref="Content"/> according to an <see cref="IDataTemplate"/>.
    /// </summary>
-    [TemplatePart("PART_ContentPresenter", typeof(IContentPresenter))]
+    [TemplatePart("PART_ContentPresenter", typeof(ContentPresenter))]
    public class ContentControl : TemplatedControl, IContentControl, IContentPresenterHost
    {
        /// <summary>
@ -68,7 +68,7 @@ namespace Avalonia.Controls
        /// <summary>
        /// Gets the presenter from the control's template.
        /// </summary>
-        public IContentPresenter? Presenter
+        public ContentPresenter? Presenter
        {
            get;
            private set;
@ -96,16 +96,16 @@ namespace Avalonia.Controls
        IAvaloniaList<ILogical> IContentPresenterHost.LogicalChildren => LogicalChildren;

        /// <inheritdoc/>
-        bool IContentPresenterHost.RegisterContentPresenter(IContentPresenter presenter)
+        bool IContentPresenterHost.RegisterContentPresenter(ContentPresenter presenter)
        {
            return RegisterContentPresenter(presenter);
        }

        /// <summary>
-        /// Called when an <see cref="IContentPresenter"/> is registered with the control.
+        /// Called when an <see cref="ContentPresenter"/> is registered with the control.
        /// </summary>
        /// <param name="presenter">The presenter.</param>
-        protected virtual bool RegisterContentPresenter(IContentPresenter presenter)
+        protected virtual bool RegisterContentPresenter(ContentPresenter presenter)
        {
            if (presenter.Name == "PART_ContentPresenter")
            {
--- a/src/Avalonia.Controls/Presenters/ContentPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/ContentPresenter.cs
@ -17,7 +17,7 @@ namespace Avalonia.Controls.Presenters
    /// Presents a single item of data inside a <see cref="TemplatedControl"/> template.
    /// </summary>
    [PseudoClasses(":empty")]
-    public class ContentPresenter : Control, IContentPresenter
+    public class ContentPresenter : Control
    {
        /// <summary>
        /// Defines the <see cref="Background"/> property.
--- a/src/Avalonia.Controls/Presenters/IContentPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/IContentPresenter.cs
@ -1,23 +0,0 @@
-using Avalonia.Controls.Primitives;
-using Avalonia.Metadata;
-
-namespace Avalonia.Controls.Presenters
-{
-    /// <summary>
-    /// Interface for controls that present a single item of data inside a
-    /// <see cref="TemplatedControl"/> template.
-    /// </summary>
-    [NotClientImplementable]
-    public interface IContentPresenter : IPresenter
-    {
-        /// <summary>
-        /// Gets the control displayed by the presenter.
-        /// </summary>
-        Control? Child { get; }
-
-        /// <summary>
-        /// Gets or sets the content to be displayed by the presenter.
-        /// </summary>
-        object? Content { get; set; }
-    }
-}
--- a/src/Avalonia.Controls/Presenters/IContentPresenterHost.cs
+++ b/src/Avalonia.Controls/Presenters/IContentPresenterHost.cs
@ -22,13 +22,13 @@ namespace Avalonia.Controls.Presenters
        IAvaloniaList<ILogical> LogicalChildren { get; }

        /// <summary>
-        /// Registers an <see cref="IContentPresenter"/> with a host control.
+        /// Registers an <see cref="ContentPresenter"/> with a host control.
        /// </summary>
        /// <param name="presenter">The content presenter.</param>
        /// <returns>
        /// True if the content presenter should add its child to the logical children of the
        /// host; otherwise false.
        /// </returns>
-        bool RegisterContentPresenter(IContentPresenter presenter);
+        bool RegisterContentPresenter(ContentPresenter presenter);
    }
 }
--- a/src/Avalonia.Controls/Presenters/IPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/IPresenter.cs
@ -1,20 +0,0 @@
-using Avalonia.Controls.Primitives;
-using Avalonia.Metadata;
-
-namespace Avalonia.Controls.Presenters
-{
-    /// <summary>
-    /// Interface for presenters such as <see cref="ContentPresenter"/> and
-    /// <see cref="ItemsPresenter"/>.
-    /// </summary>
-    /// <remarks>
-    /// A presenter is the gateway between a templated control and its content. When
-    /// a control which implements <see cref="IPresenter"/> is found in the template
-    /// of a <see cref="TemplatedControl"/> then that signals that the visual child
-    /// of the presenter is not a part of the template.
-    /// </remarks>
-    [NotClientImplementable]
-    public interface IPresenter : INamed
-    {
-    }
-}
--- a/src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs
@ -13,7 +13,7 @@ namespace Avalonia.Controls.Presenters
    /// <summary>
    /// Presents a scrolling view of content inside a <see cref="ScrollViewer"/>.
    /// </summary>
-    public class ScrollContentPresenter : ContentPresenter, IPresenter, IScrollable, IScrollAnchorProvider
+    public class ScrollContentPresenter : ContentPresenter, IScrollable, IScrollAnchorProvider
    {
        private const double EdgeDetectionTolerance = 0.1;

--- a/src/Avalonia.Controls/Primitives/HeaderedContentControl.cs
+++ b/src/Avalonia.Controls/Primitives/HeaderedContentControl.cs
@ -41,7 +41,7 @@ namespace Avalonia.Controls.Primitives
        /// <summary>
        /// Gets the header presenter from the control's template.
        /// </summary>
-        public IContentPresenter? HeaderPresenter
+        public ContentPresenter? HeaderPresenter
        {
            get;
            private set;
@ -57,7 +57,7 @@ namespace Avalonia.Controls.Primitives
        }

        /// <inheritdoc/>
-        protected override bool RegisterContentPresenter(IContentPresenter presenter)
+        protected override bool RegisterContentPresenter(ContentPresenter presenter)
        {
            var result = base.RegisterContentPresenter(presenter);

--- a/src/Avalonia.Controls/Primitives/HeaderedItemsControl.cs
+++ b/src/Avalonia.Controls/Primitives/HeaderedItemsControl.cs
@ -56,7 +56,7 @@ namespace Avalonia.Controls.Primitives
        /// <summary>
        /// Gets the header presenter from the control's template.
        /// </summary>
-        public IContentPresenter? HeaderPresenter
+        public ContentPresenter? HeaderPresenter
        {
            get;
            private set;
@ -77,16 +77,16 @@ namespace Avalonia.Controls.Primitives
        }

        /// <inheritdoc/>
-        bool IContentPresenterHost.RegisterContentPresenter(IContentPresenter presenter)
+        bool IContentPresenterHost.RegisterContentPresenter(ContentPresenter presenter)
        {
            return RegisterContentPresenter(presenter);
        }

        /// <summary>
-        /// Called when an <see cref="IContentPresenter"/> is registered with the control.
+        /// Called when an <see cref="ContentPresenter"/> is registered with the control.
        /// </summary>
        /// <param name="presenter">The presenter.</param>
-        protected virtual bool RegisterContentPresenter(IContentPresenter presenter)
+        protected virtual bool RegisterContentPresenter(ContentPresenter presenter)
        {
            if (presenter.Name == "PART_HeaderPresenter")
            {
--- a/src/Avalonia.Controls/Primitives/HeaderedSelectingItemsControl.cs
+++ b/src/Avalonia.Controls/Primitives/HeaderedSelectingItemsControl.cs
@ -56,7 +56,7 @@ namespace Avalonia.Controls.Primitives
        /// <summary>
        /// Gets the header presenter from the control's template.
        /// </summary>
-        public IContentPresenter? HeaderPresenter
+        public ContentPresenter? HeaderPresenter
        {
            get;
            private set;
@ -66,7 +66,7 @@ namespace Avalonia.Controls.Primitives
        IAvaloniaList<ILogical> IContentPresenterHost.LogicalChildren => LogicalChildren;

        /// <inheritdoc/>
-        bool IContentPresenterHost.RegisterContentPresenter(IContentPresenter presenter)
+        bool IContentPresenterHost.RegisterContentPresenter(ContentPresenter presenter)
        {
            return RegisterContentPresenter(presenter);
        }
@ -83,10 +83,10 @@ namespace Avalonia.Controls.Primitives
        }

        /// <summary>
-        /// Called when an <see cref="IContentPresenter"/> is registered with the control.
+        /// Called when an <see cref="ContentPresenter"/> is registered with the control.
        /// </summary>
        /// <param name="presenter">The presenter.</param>
-        protected virtual bool RegisterContentPresenter(IContentPresenter presenter)
+        protected virtual bool RegisterContentPresenter(ContentPresenter presenter)
        {
            if (presenter.Name == "PART_HeaderPresenter")
            {
--- a/src/Avalonia.Controls/Primitives/IPopupHost.cs
+++ b/src/Avalonia.Controls/Primitives/IPopupHost.cs
@ -52,7 +52,7 @@ namespace Avalonia.Controls.Primitives
        /// <summary>
        /// Gets the presenter from the control's template.
        /// </summary>
-        IContentPresenter? Presenter { get; }
+        ContentPresenter? Presenter { get; }

        /// <summary>
        /// Gets or sets whether the popup appears on top of all other windows.
--- a/src/Avalonia.Controls/ScrollViewer.cs
+++ b/src/Avalonia.Controls/ScrollViewer.cs
@ -644,7 +644,7 @@ namespace Avalonia.Controls
            (Presenter as IScrollAnchorProvider)?.UnregisterAnchorCandidate(element);
        }

-        protected override bool RegisterContentPresenter(IContentPresenter presenter)
+        protected override bool RegisterContentPresenter(ContentPresenter presenter)
        {
            _childSubscription?.Dispose();
            _childSubscription = null;
--- a/src/Avalonia.Controls/SplitView/SplitView.cs
+++ b/src/Avalonia.Controls/SplitView/SplitView.cs
@ -279,7 +279,7 @@ namespace Avalonia.Controls
            remove => RemoveHandler(PaneOpeningEvent, value);
        }

-        protected override bool RegisterContentPresenter(IContentPresenter presenter)
+        protected override bool RegisterContentPresenter(ContentPresenter presenter)
        {
            var result = base.RegisterContentPresenter(presenter);

--- a/src/Avalonia.Controls/TabControl.cs
+++ b/src/Avalonia.Controls/TabControl.cs
@ -140,13 +140,13 @@ namespace Avalonia.Controls

        internal ItemsPresenter? ItemsPresenterPart { get; private set; }

-        internal IContentPresenter? ContentPart { get; private set; }
+        internal ContentPresenter? ContentPart { get; private set; }

        /// <inheritdoc/>
        IAvaloniaList<ILogical> IContentPresenterHost.LogicalChildren => LogicalChildren;

        /// <inheritdoc/>
-        bool IContentPresenterHost.RegisterContentPresenter(IContentPresenter presenter)
+        bool IContentPresenterHost.RegisterContentPresenter(ContentPresenter presenter)
        {
            return RegisterContentPresenter(presenter);
        }
@ -210,10 +210,10 @@ namespace Avalonia.Controls
        }

        /// <summary>
-        /// Called when an <see cref="IContentPresenter"/> is registered with the control.
+        /// Called when an <see cref="ContentPresenter"/> is registered with the control.
        /// </summary>
        /// <param name="presenter">The presenter.</param>
-        protected virtual bool RegisterContentPresenter(IContentPresenter presenter)
+        protected virtual bool RegisterContentPresenter(ContentPresenter presenter)
        {
            if (presenter.Name == "PART_SelectedContentHost")
            {
--- a/src/Avalonia.Controls/ToggleSwitch.cs
+++ b/src/Avalonia.Controls/ToggleSwitch.cs
@ -86,13 +86,13 @@ namespace Avalonia.Controls
            set { SetValue(OffContentProperty, value); }
        }

-        public IContentPresenter? OffContentPresenter
+        public ContentPresenter? OffContentPresenter
        {
            get;
            private set;
        }

-        public IContentPresenter? OnContentPresenter
+        public ContentPresenter? OnContentPresenter
        {
            get;
            private set;
@ -142,7 +142,7 @@ namespace Avalonia.Controls
            }
        }

-        protected override bool RegisterContentPresenter(IContentPresenter presenter)
+        protected override bool RegisterContentPresenter(ContentPresenter presenter)
        {
            var result = base.RegisterContentPresenter(presenter);

--- a/src/Avalonia.Controls/TransitioningContentControl.cs
+++ b/src/Avalonia.Controls/TransitioningContentControl.cs
@ -71,7 +71,7 @@ public class TransitioningContentControl : ContentControl
        return result;
    }

-    protected override bool RegisterContentPresenter(IContentPresenter presenter)
+    protected override bool RegisterContentPresenter(ContentPresenter presenter)
    {
        if (!base.RegisterContentPresenter(presenter) &&
            presenter is ContentPresenter p &&
--- a/tests/Avalonia.Controls.UnitTests/ContentControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContentControlTests.cs
@ -24,9 +24,9 @@ namespace Avalonia.Controls.UnitTests
            target.Content = "Foo";
            target.Template = GetTemplate();
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

-            var child = ((Visual)target).VisualChildren.Single();
+            var child = target.VisualChildren.Single();
            Assert.IsType<Border>(child);
            child = child.VisualChildren.Single();
            Assert.IsType<ContentPresenter>(child);
@ -55,7 +55,7 @@ namespace Avalonia.Controls.UnitTests
            root.Child = target;

            target.ApplyTemplate();
-            ((Control)target.Presenter).ApplyTemplate();
+            target.Presenter.ApplyTemplate();

            foreach (Control child in target.GetTemplateChildren())
                Assert.Equal("foo", child.Tag);
@ -70,7 +70,7 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = child;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            var contentPresenter = child.GetVisualParent<ContentPresenter>();
            Assert.Equal(target, contentPresenter.TemplatedParent);
@ -85,7 +85,7 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = child;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.Null(child.TemplatedParent);
        }
@ -117,7 +117,7 @@ namespace Avalonia.Controls.UnitTests
            var child = new Control();
            target.Content = child;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.Equal(child.Parent, target);
            Assert.Equal(child.GetLogicalParent(), target);
@ -135,7 +135,7 @@ namespace Avalonia.Controls.UnitTests

            target.Content = "Foo";
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            var child = target.Presenter.Child;

@ -152,7 +152,7 @@ namespace Avalonia.Controls.UnitTests

            target.Content = "Foo";
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            var child = target.Presenter.Child;

@ -192,7 +192,7 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = child;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.True(called);
        }
@ -207,12 +207,12 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = child;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;

            target.Content = null;
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.True(called);
        }
@ -228,12 +228,12 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = child1;
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;

            target.Content = child2;
-            ((Control)target.Presenter).ApplyTemplate();
+            target.Presenter.ApplyTemplate();

            Assert.True(called);
        }
@ -245,13 +245,13 @@ namespace Avalonia.Controls.UnitTests

            target.Template = GetTemplate();
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            target.Content = "Foo";
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();
            Assert.Equal("Foo", ((TextBlock)target.Presenter.Child).Text);
            target.Content = "Bar";
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();
            Assert.Equal("Bar", ((TextBlock)target.Presenter.Child).Text);
        }

@ -263,7 +263,7 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = "Foo";
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.Equal("Foo", target.Presenter.Child.DataContext);
        }
@ -276,7 +276,7 @@ namespace Avalonia.Controls.UnitTests
            target.Template = GetTemplate();
            target.Content = new TextBlock();
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            Assert.Null(target.Presenter.Child.DataContext);
        }
--- a/tests/Avalonia.Controls.UnitTests/HeaderedItemsControlTests
+++ b/tests/Avalonia.Controls.UnitTests/HeaderedItemsControlTests
@ -34,7 +34,7 @@ namespace Avalonia.Controls.UnitTests

            target.Header = "Foo";
            target.ApplyTemplate();
-            ((ContentPresenter)target.HeaderPresenter).UpdateChild();
+            target.HeaderPresenter.UpdateChild();

            var child = target.HeaderPresenter.Child;

--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs
@ -305,7 +305,7 @@ namespace Avalonia.Controls.UnitTests
            scrollViewer.ApplyTemplate();

            // Then make the ScrollViewer create its child.
-            ((ContentPresenter)scrollViewer.Presenter).UpdateChild();
+            scrollViewer.Presenter.UpdateChild();

            // Now the ItemsPresenter should be reigstered, so apply its template.
            target.Presenter.ApplyTemplate();
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs
@ -391,7 +391,7 @@ namespace Avalonia.Controls.UnitTests.Presenters

            templatedParent.ApplyTemplate();

-            return ((ContentPresenter)templatedParent.Presenter, templatedParent);
+            return (templatedParent.Presenter, templatedParent);
        }

        private class TestContentControl : ContentControl, IContentPresenterHost
--- a/tests/Avalonia.Controls.UnitTests/TabControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TabControlTests.cs
@ -272,28 +272,28 @@ namespace Avalonia.Controls.UnitTests

            ApplyTemplate(target);

-            ((ContentPresenter)target.ContentPart).UpdateChild();
+            target.ContentPart.UpdateChild();
            var dataContext = ((TextBlock)target.ContentPart.Child).DataContext;
            Assert.Equal(items[0], dataContext);

            target.SelectedIndex = 1;
-            ((ContentPresenter)target.ContentPart).UpdateChild();
+            target.ContentPart.UpdateChild();
            dataContext = ((Button)target.ContentPart.Child).DataContext;
            Assert.Equal(items[1], dataContext);

            target.SelectedIndex = 2;
-            ((ContentPresenter)target.ContentPart).UpdateChild();
+            target.ContentPart.UpdateChild();
            dataContext = ((TextBlock)target.ContentPart.Child).DataContext;
            Assert.Equal("Base", dataContext);

            target.SelectedIndex = 3;
-            ((ContentPresenter)target.ContentPart).UpdateChild();
+            target.ContentPart.UpdateChild();
            dataContext = ((TextBlock)target.ContentPart.Child).DataContext;
            Assert.Equal("Qux", dataContext);

            target.SelectedIndex = 4;
-            ((ContentPresenter)target.ContentPart).UpdateChild();
-            dataContext = ((Control)target.ContentPart).DataContext;
+            target.ContentPart.UpdateChild();
+            dataContext = target.ContentPart.DataContext;
            Assert.Equal("Base", dataContext);
        }

@ -367,7 +367,7 @@ namespace Avalonia.Controls.UnitTests
            var root = new TestRoot(target);

            ApplyTemplate(target);
-            ((ContentPresenter)target.ContentPart).UpdateChild();
+            target.ContentPart.UpdateChild();

            var content = Assert.IsType<TextBlock>(target.ContentPart.Child);
            Assert.Equal("bar", content.Tag);
@ -608,7 +608,7 @@ namespace Avalonia.Controls.UnitTests

                tabItem.ApplyTemplate();

-                ((ContentPresenter)tabItem.Presenter).UpdateChild();
+                tabItem.Presenter.UpdateChild();
            }

            target.ContentPart.ApplyTemplate();
--- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
@ -472,7 +472,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.Equal(dataContext.StringProperty, ((TextBlock)target.Presenter.Child).Text);
            }
@ -694,7 +694,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.Equal(dataContext.StringProperty, ((TextBlock)target.Presenter.Child).Text);
            }
@ -727,7 +727,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.Equal(dataContext.StringProperty, ((TextBlock)target.Presenter.Child).Text);
            }
@ -760,7 +760,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.Equal(dataContext.StringProperty, ((TextBlock)target.Presenter.Child).Text);
            }
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlTemplateTests.cs
@ -74,7 +74,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal(Brushes.Red, presenter.Background);

                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
@ -108,7 +108,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal(Brushes.Red, presenter.Background);

                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
@ -139,7 +139,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal(Dock.Top, DockPanel.GetDock(presenter));

                var diagnostic = presenter.GetDiagnostic(DockPanel.DockProperty);
@ -173,7 +173,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal(Brushes.Red, presenter.Background);

                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
@ -207,7 +207,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal(Brushes.Red, presenter.Background);

                var diagnostic = presenter.GetDiagnostic(Button.BackgroundProperty);
@ -238,7 +238,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                window.ApplyTemplate();
                button.ApplyTemplate();

-                var presenter = (ContentPresenter)button.Presenter;
+                var presenter = button.Presenter;
                Assert.Equal("Foo", presenter.Content);

                var diagnostic = presenter.GetDiagnostic(ContentPresenter.ContentProperty);
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs
@ -32,7 +32,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.Null(target.Presenter.Child);
            }
@ -59,7 +59,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.IsType<Canvas>(target.Presenter.Child);
            }
@ -117,7 +117,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                
                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();
                
                Assert.Equal(typeof(string), template.DataType);
                Assert.IsType<Canvas>(target.Presenter.Child);
@ -145,7 +145,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                Assert.IsType<Canvas>(target.Presenter.Child);
            }
@ -175,7 +175,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                
                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                var dataTemplate = (CustomDataTemplate)target.ContentTemplate;
                Assert.Null(dataTemplate.FancyDataType);
@ -217,11 +217,11 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml

                window.ApplyTemplate();
                target.ApplyTemplate();
-                ((ContentPresenter)target.Presenter).UpdateChild();
+                target.Presenter.UpdateChild();

                var canvas = (Canvas)target.Presenter.Child;
                Assert.Same(viewModel, target.DataContext);
-                Assert.Same(viewModel.Child, ((Control)target.Presenter).DataContext);
+                Assert.Same(viewModel.Child, target.Presenter.DataContext);
                Assert.Same(viewModel.Child.Child, canvas.DataContext);
            }
        }
--- a/tests/Avalonia.ReactiveUI.UnitTests/TransitioningContentControlTest.cs
+++ b/tests/Avalonia.ReactiveUI.UnitTests/TransitioningContentControlTest.cs
@ -22,7 +22,7 @@ namespace Avalonia.ReactiveUI.UnitTests
                Content = "Foo"
            };
            target.ApplyTemplate();
-            ((ContentPresenter)target.Presenter).UpdateChild();
+            target.Presenter.UpdateChild();

            var child = ((Visual)target).GetVisualChildren().Single();
            Assert.IsType<Border>(child);
--- a/tests/Avalonia.UnitTests/TestExtensions.cs
+++ b/tests/Avalonia.UnitTests/TestExtensions.cs
@ -1,13 +0,0 @@
-using System;
-using Avalonia.Controls.Presenters;
-using Avalonia.Controls.Primitives;
-using Avalonia.Layout;
-using Avalonia.Styling;
-
-namespace Avalonia.UnitTests
-{
-    public static class TestExtensions
-    {
-        public static void ApplyTemplate(this IContentPresenter presenter) => ((Layoutable)presenter).ApplyTemplate();
-    }
-}