gui-cs.Terminal.Gui/UnitTests/View/ViewTests.cs

using System.ComponentModel;
using System.Text;
using Xunit.Abstractions;

namespace Terminal.Gui.ViewTests;

public class ViewTests (ITestOutputHelper output)
{
    [Fact]
    [AutoInitShutdown]
    public void Clear_Viewport_Can_Use_Driver_AddRune_Or_AddStr_Methods ()
    {
        var view = new FrameView { Width = Dim.Fill (), Height = Dim.Fill () };

        view.DrawContent += (s, e) =>
                            {
                                Rectangle savedClip = Application.Driver!.Clip;
                                Application.Driver!.Clip = new (1, 1, view.Viewport.Width, view.Viewport.Height);

                                for (var row = 0; row < view.Viewport.Height; row++)
                                {
                                    Application.Driver?.Move (1, row + 1);

                                    for (var col = 0; col < view.Viewport.Width; col++)
                                    {
                                        Application.Driver?.AddStr ($"{col}");
                                    }
                                }

                                Application.Driver!.Clip = savedClip;
                                e.Cancel = true;
                            };
        var top = new Toplevel ();
        top.Add (view);
        Application.Begin (top);
        ((FakeDriver)Application.Driver!).SetBufferSize (20, 10);

        var expected = @"
┌──────────────────┐
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
└──────────────────┘
";

        Rectangle pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
        Assert.Equal (new (0, 0, 20, 10), pos);

        view.FillRect (view.Viewport);

        expected = @"
┌──────────────────┐
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
└──────────────────┘
";

        pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Clear_Can_Use_Driver_AddRune_Or_AddStr_Methods ()
    {
        var view = new FrameView { Width = Dim.Fill (), Height = Dim.Fill () };

        view.DrawContent += (s, e) =>
                            {
                                Rectangle savedClip = Application.Driver!.Clip;
                                Application.Driver!.Clip = new (1, 1, view.Viewport.Width, view.Viewport.Height);

                                for (var row = 0; row < view.Viewport.Height; row++)
                                {
                                    Application.Driver?.Move (1, row + 1);

                                    for (var col = 0; col < view.Viewport.Width; col++)
                                    {
                                        Application.Driver?.AddStr ($"{col}");
                                    }
                                }

                                Application.Driver!.Clip = savedClip;
                                e.Cancel = true;
                            };
        var top = new Toplevel ();
        top.Add (view);
        Application.Begin (top);
        ((FakeDriver)Application.Driver!).SetBufferSize (20, 10);

        var expected = @"
┌──────────────────┐
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
│012345678910111213│
└──────────────────┘
";

        Rectangle pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
        Assert.Equal (new (0, 0, 20, 10), pos);

        view.FillRect (view.Viewport);

        expected = @"
┌──────────────────┐
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
│                  │
└──────────────────┘
";

        pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);

        top.Dispose ();
    }

    [Theory]
    [AutoInitShutdown]
    [InlineData (true)]
    [InlineData (false)]
    public void Clear_Does_Not_Spillover_Its_Parent (bool label)
    {
        var root = new View { Width = 20, Height = 10, ColorScheme = Colors.ColorSchemes ["Base"] };

        string text = new ('c', 100);

        View v = label
                     // Label has Width/Height == AutoSize, so Frame.Size will be (100, 1)
                     ? new Label { Text = text }
                     // TextView has Width/Height == (Dim.Fill, 1), so Frame.Size will be 20 (width of root), 1
                     : new TextView { Width = Dim.Fill (), Height = 1, Text = text };

        root.Add (v);

        var top = new Toplevel ();
        top.Add (root);
        RunState runState = Application.Begin (top);

        if (label)
        {
            Assert.False (v.CanFocus);
            Assert.Equal (new  (0, 0, text.Length, 1), v.Frame);
        }
        else
        {
            Assert.True (v.CanFocus);
            Assert.Equal (new (0, 0, 20, 1), v.Frame);
        }

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
cccccccccccccccccccc",
                                                      output
                                                     );

        Attribute [] attributes =
        {
            Colors.ColorSchemes ["TopLevel"].Normal,
            Colors.ColorSchemes ["Base"].Normal,
            Colors.ColorSchemes ["Base"].Focus
        };

        if (label)
        {
            TestHelpers.AssertDriverAttributesAre (
                                                   @"
111111111111111111110
111111111111111111110",
                                                   Application.Driver,
                                                   attributes
                                                  );
        }
        else
        {
            TestHelpers.AssertDriverAttributesAre (
                                                   @"
222222222222222222220
111111111111111111110",
                                                   Application.Driver,
                                                   attributes
                                                  );
        }

        if (label)
        {
            root.CanFocus = true;
            v.CanFocus = true;
            Assert.False (v.HasFocus);
            v.SetFocus ();
            Assert.True (v.HasFocus);
            Application.Refresh ();

            TestHelpers.AssertDriverAttributesAre (
                                                   @"
222222222222222222220
111111111111111111110",
                                                   Application.Driver,
                                                   attributes
                                                  );
        }

        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Correct_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Down_Right_Using_Frame ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.Frame = new (3, 3, 10, 1);
        Assert.Equal (new (3, 3, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 10, 1), view._needsDisplayRect);
        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0       
             
             
   A text wit",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Correct_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Down_Right_Using_Pos_Dim ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.X = 3;
        view.Y = 3;
        view.Width = 10;
        view.Height = 1;
        Assert.Equal (new (3, 3, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 30, 2), view._needsDisplayRect);
        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0       
             
             
   A text wit",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Correct_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Up_Left_Using_Frame ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.Frame = new (1, 1, 10, 1);
        Assert.Equal (new (1, 1, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 10, 1), view._needsDisplayRect);
        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0     
 A text wit",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Correct_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Up_Left_Using_Pos_Dim ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.X = 1;
        view.Y = 1;
        view.Width = 10;
        view.Height = 1;
        Assert.Equal (new (1, 1, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 30, 2), view._needsDisplayRect);
        top.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0     
 A text wit",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [TestRespondersDisposed]
    public void Dispose_View ()
    {
        var view = new View ();
        Assert.NotNull (view.Margin);
        Assert.NotNull (view.Border);
        Assert.NotNull (view.Padding);

#if DEBUG_IDISPOSABLE
        Assert.Equal (4, Responder.Instances.Count);
#endif

        view.Dispose ();
        Assert.Null (view.Margin);
        Assert.Null (view.Border);
        Assert.Null (view.Padding);
    }

    [Fact]
    [AutoInitShutdown]
    public void DrawContentComplete_Event_Is_Always_Called ()
    {
        var viewCalled = false;
        var tvCalled = false;

        var view = new View { Width = 10, Height = 10, Text = "View" };
        view.DrawContentComplete += (s, e) => viewCalled = true;
        var tv = new TextView { Y = 11, Width = 10, Height = 10 };
        tv.DrawContentComplete += (s, e) => tvCalled = true;

        var top = new Toplevel ();
        top.Add (view, tv);
        Application.Begin (top);

        Assert.True (viewCalled);
        Assert.True (tvCalled);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Frame_Set_After_Initialize_Update_NeededDisplay ()
    {
        var frame = new FrameView ();

        var label = new Label
        {
            ColorScheme = Colors.ColorSchemes ["Menu"], X = 0, Y = 0, Text = "This should be the first line."
        };

        var view = new View
        {
            X = 0, // don't overcomplicate unit tests
            Y = 1,
            Height = Dim.Auto (DimAutoStyle.Text),
            Width = Dim.Auto(DimAutoStyle.Text),
            Text = "Press me!"
        };

        frame.Add (label, view);

        frame.X = Pos.Center ();
        frame.Y = Pos.Center ();
        frame.Width = 40;
        frame.Height = 8;

        Toplevel top = new ();

        top.Add (frame);

        RunState runState = Application.Begin (top);

        top.LayoutComplete += (s, e) => { Assert.Equal (new (0, 0, 80, 25), top._needsDisplayRect); };

        frame.LayoutComplete += (s, e) => { Assert.Equal (new (0, 0, 40, 8), frame._needsDisplayRect); };

        label.LayoutComplete += (s, e) => { Assert.Equal (new (0, 0, 38, 1), label._needsDisplayRect); };

        view.LayoutComplete += (s, e) => { Assert.Equal (new (0, 0, 13, 1), view._needsDisplayRect); };

        Assert.Equal (new (0, 0, 80, 25), top.Frame);
        Assert.Equal (new (20, 8, 40, 8), frame.Frame);

        Assert.Equal (
                      new (20, 8, 60, 16),
                      new Rectangle (
                                     frame.Frame.Left,
                                     frame.Frame.Top,
                                     frame.Frame.Right,
                                     frame.Frame.Bottom
                                    )
                     );
        Assert.Equal (new (0, 0, 30, 1), label.Frame);
        Assert.Equal (new (0, 1, 9, 1), view.Frame); // this proves frame was set
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    public void GetHotNormalColor_ColorScheme ()
    {
        var view = new View { ColorScheme = Colors.ColorSchemes ["Base"] };

        Assert.Equal (view.ColorScheme.HotNormal, view.GetHotNormalColor ());

        view.Enabled = false;
        Assert.Equal (view.ColorScheme.Disabled, view.GetHotNormalColor ());
        view.Dispose ();
    }

    [Fact]
    public void GetNormalColor_ColorScheme ()
    {
        var view = new View { ColorScheme = Colors.ColorSchemes ["Base"] };

        Assert.Equal (view.ColorScheme.Normal, view.GetNormalColor ());

        view.Enabled = false;
        Assert.Equal (view.ColorScheme.Disabled, view.GetNormalColor ());
        view.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Incorrect_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Down_Right_Using_Frame ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.Frame = new (3, 3, 10, 1);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 10, 1), view._needsDisplayRect);
        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   A text witith two lines.  ",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Incorrect_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Down_Right_Using_Pos_Dim ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.X = 3;
        view.Y = 3;
        view.Width = 10;
        view.Height = 1;
        Assert.Equal (new (3, 3, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 30, 2), view._needsDisplayRect);
        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   A text witith two lines.  ",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Incorrect_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Up_Left_Using_Frame ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.Frame = new (1, 1, 10, 1);
        Assert.Equal (new (1, 1, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 10, 1), view._needsDisplayRect);
        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
 A text wit                  
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Incorrect_Redraw_Viewport_NeedDisplay_On_Shrink_And_Move_Up_Left_Using_Pos_Dim ()
    {
        var label = new Label { Text = "At 0,0" };

        var view = new DerivedView
        {
            X = 2,
            Y = 2,
            Width = 30,
            Height = 2,
            Text = "A text with some long width\n and also with two lines."
        };
        Toplevel top = new ();
        top.Add (label, view);
        RunState runState = Application.Begin (top);

        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
                             
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );

        view.X = 1;
        view.Y = 1;
        view.Width = 10;
        view.Height = 1;
        Assert.Equal (new (1, 1, 10, 1), view.Frame);
        Assert.Equal (new (0, 0, 10, 1), view.Viewport);
        Assert.Equal (new (0, 0, 30, 2), view._needsDisplayRect);
        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
At 0,0                       
 A text wit                  
  A text with some long width
   and also with two lines.  ",
                                                      output
                                                     );
        Application.End (runState);
        top.Dispose ();
    }

    [Fact]
    public void Internal_Tests ()
    {
        var rect = new Rectangle (1, 1, 10, 1);
        var view = new View { Frame = rect };
    }

    [Fact]
    [SetupFakeDriver]
    public void SetText_RendersCorrectly ()
    {
        View view;
        var text = "test";

        view = new Label { Text = text };
        view.BeginInit ();
        view.EndInit ();
        view.Draw ();

        TestHelpers.AssertDriverContentsWithFrameAre (text, output);
    }

    [Fact]
    [TestRespondersDisposed]
    public void New_Initializes ()
    {
        // Parameterless
        var r = new View ();
        Assert.NotNull (r);
        Assert.True (r.Enabled);
        Assert.True (r.Visible);

        Assert.Equal ($"View(){r.Viewport}", r.ToString ());
        Assert.False (r.CanFocus);
        Assert.False (r.HasFocus);
        Assert.Equal (new (0, 0, 0, 0), r.Viewport);
        Assert.Equal (new (0, 0, 0, 0), r.Frame);
        Assert.Null (r.Focused);
        Assert.Null (r.ColorScheme);
        Assert.Equal (0, r.Width);
        Assert.Equal (0, r.Height);
        Assert.Equal (0, r.X);
        Assert.Equal (0, r.Y);
        Assert.False (r.IsCurrentTop);
        Assert.Empty (r.Id);
        Assert.Empty (r.Subviews);
        Assert.False (r.WantContinuousButtonPressed);
        Assert.False (r.WantMousePositionReports);
        Assert.Null (r.SuperView);
        Assert.Null (r.MostFocused);
        Assert.Equal (TextDirection.LeftRight_TopBottom, r.TextDirection);
        r.Dispose ();

        // Empty Rect
        r = new() { Frame = Rectangle.Empty };
        Assert.NotNull (r);
        Assert.Equal ($"View(){r.Viewport}", r.ToString ());
        Assert.False (r.CanFocus);
        Assert.False (r.HasFocus);
        Assert.Equal (new (0, 0, 0, 0), r.Viewport);
        Assert.Equal (new (0, 0, 0, 0), r.Frame);
        Assert.Null (r.Focused);
        Assert.Null (r.ColorScheme);
        Assert.Equal (0, r.Width);
        Assert.Equal (0, r.Height);
        Assert.Equal (0, r.X);
        Assert.Equal (0, r.Y);
        Assert.False (r.IsCurrentTop);
        Assert.Empty (r.Id);
        Assert.Empty (r.Subviews);
        Assert.False (r.WantContinuousButtonPressed);
        Assert.False (r.WantMousePositionReports);
        Assert.Null (r.SuperView);
        Assert.Null (r.MostFocused);
        Assert.Equal (TextDirection.LeftRight_TopBottom, r.TextDirection);
        r.Dispose ();

        // Rect with values
        r = new() { Frame = new (1, 2, 3, 4) };
        Assert.NotNull (r);
        Assert.Equal ($"View(){r.Frame}", r.ToString ());
        Assert.False (r.CanFocus);
        Assert.False (r.HasFocus);
        Assert.Equal (new (0, 0, 3, 4), r.Viewport);
        Assert.Equal (new (1, 2, 3, 4), r.Frame);
        Assert.Null (r.Focused);
        Assert.Null (r.ColorScheme);
        Assert.Equal (3, r.Width);
        Assert.Equal (4, r.Height);
        Assert.Equal (1, r.X);
        Assert.Equal (2, r.Y);
        Assert.False (r.IsCurrentTop);
        Assert.Empty (r.Id);
        Assert.Empty (r.Subviews);
        Assert.False (r.WantContinuousButtonPressed);
        Assert.False (r.WantMousePositionReports);
        Assert.Null (r.SuperView);
        Assert.Null (r.MostFocused);
        Assert.Equal (TextDirection.LeftRight_TopBottom, r.TextDirection);
        r.Dispose ();

        // Initializes a view with a vertical direction
        r = new()
        {
            Text = "Vertical View",
            TextDirection = TextDirection.TopBottom_LeftRight,
            Width = Dim.Auto (),
            Height = Dim.Auto ()
        };
        r.TextFormatter.WordWrap = false;
        Assert.NotNull (r);

        r.BeginInit ();
        r.EndInit ();
        Assert.False (r.CanFocus);
        Assert.False (r.HasFocus);
        Assert.Equal (new (0, 0, 1, 13), r.Viewport);
        Assert.Equal (new (0, 0, 1, 13), r.Frame);
        Assert.Null (r.Focused);
        Assert.Null (r.ColorScheme);
        Assert.False (r.IsCurrentTop);
#if DEBUG
        Assert.Equal ("Vertical View", r.Id);
#else
        Assert.Equal (string.Empty, r.Id);
#endif
        Assert.Empty (r.Subviews);
        Assert.False (r.WantContinuousButtonPressed);
        Assert.False (r.WantMousePositionReports);
        Assert.Null (r.SuperView);
        Assert.Null (r.MostFocused);
        Assert.Equal (TextDirection.TopBottom_LeftRight, r.TextDirection);
        r.Dispose ();
    }

    [Fact]
    [TestRespondersDisposed]
    public void New_Methods_Return_False ()
    {
        var r = new View ();

        Assert.False (r.OnKeyDown (new() { KeyCode = KeyCode.Null }));

        //Assert.False (r.OnKeyDown (new KeyEventArgs () { Key = Key.Unknown }));
        Assert.False (r.OnKeyUp (new() { KeyCode = KeyCode.Null }));
        Assert.False (r.NewMouseEvent (new() { Flags = MouseFlags.AllEvents }));
        Assert.False (r.NewMouseEnterEvent (new() { Flags = MouseFlags.AllEvents }));
        Assert.False (r.NewMouseLeaveEvent (new() { Flags = MouseFlags.AllEvents }));

        var v1 = new View ();
        Assert.False (r.OnEnter (v1));
        v1.Dispose ();

        var v2 = new View ();
        Assert.False (r.OnLeave (v2));
        v2.Dispose ();

        r.Dispose ();

        // TODO: Add more
    }

    [Fact]
    [AutoInitShutdown]
    public void Test_Nested_Views_With_Height_Equal_To_One ()
    {
        var v = new View { Width = 11, Height = 3, ColorScheme = new () };

        var top = new View { Width = Dim.Fill (), Height = 1 };
        var bottom = new View { Width = Dim.Fill (), Height = 1, Y = 2 };

        top.Add (new Label { Text = "111" });
        v.Add (top);
        v.Add (new LineView (Orientation.Horizontal) { Y = 1 });
        bottom.Add (new Label { Text = "222" });
        v.Add (bottom);

        v.BeginInit ();
        v.EndInit ();
        v.LayoutSubviews ();
        v.Draw ();

        var looksLike =
            @"    
111
───────────
222";
        TestHelpers.AssertDriverContentsAre (looksLike, output);
        v.Dispose ();
        top.Dispose ();
        bottom.Dispose ();
    }

    [Fact]
    [TestRespondersDisposed]
    public void View_With_No_Difference_Between_An_Object_Initializer_Compute_And_A_Absolute ()
    {
        // Object Initializer Computed
        var view = new View { X = 1, Y = 2, Width = 3, Height = 4 };

        // Object Initializer Absolute
        var super = new View { Frame = new (0, 0, 10, 10) };
        super.Add (view);
        super.BeginInit ();
        super.EndInit ();
        super.LayoutSubviews ();

        Assert.Equal (1, view.X);
        Assert.Equal (2, view.Y);
        Assert.Equal (3, view.Width);
        Assert.Equal (4, view.Height);
        Assert.False (view.Frame.IsEmpty);
        Assert.Equal (new (1, 2, 3, 4), view.Frame);
        Assert.False (view.Viewport.IsEmpty);
        Assert.Equal (new (0, 0, 3, 4), view.Viewport);

        view.LayoutSubviews ();

        Assert.Equal (1, view.X);
        Assert.Equal (2, view.Y);
        Assert.Equal (3, view.Width);
        Assert.Equal (4, view.Height);
        Assert.False (view.Frame.IsEmpty);
        Assert.False (view.Viewport.IsEmpty);
        super.Dispose ();

#if DEBUG_IDISPOSABLE
        Assert.Empty (Responder.Instances);
#endif

        // Default Constructor
        view = new ();
        Assert.Equal (0, view.X);
        Assert.Equal (0, view.Y);
        Assert.Equal (0, view.Width);
        Assert.Equal (0, view.Height);
        Assert.True (view.Frame.IsEmpty);
        Assert.True (view.Viewport.IsEmpty);
        view.Dispose ();

        // Object Initializer
        view = new() { X = 1, Y = 2, Text = "" };
        Assert.Equal (1, view.X);
        Assert.Equal (2, view.Y);
        Assert.Equal (0, view.Width);
        Assert.Equal (0, view.Height);
        Assert.False (view.Frame.IsEmpty);
        Assert.True (view.Viewport.IsEmpty);
        view.Dispose ();

        // Default Constructor and post assignment equivalent to Object Initializer
        view = new ();
        view.X = 1;
        view.Y = 2;
        view.Width = 3;
        view.Height = 4;
        super = new() { Frame = new (0, 0, 10, 10) };
        super.Add (view);
        super.BeginInit ();
        super.EndInit ();
        super.LayoutSubviews ();
        Assert.Equal (1, view.X);
        Assert.Equal (2, view.Y);
        Assert.Equal (3, view.Width);
        Assert.Equal (4, view.Height);
        Assert.False (view.Frame.IsEmpty);
        Assert.Equal (new (1, 2, 3, 4), view.Frame);
        Assert.False (view.Viewport.IsEmpty);
        Assert.Equal (new (0, 0, 3, 4), view.Viewport);
        super.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Visible_Clear_The_View_Output ()
    {
        var view = new View { Text = "Testing visibility." }; // use View, not Label to avoid AutoSize == true

        Assert.Equal (0, view.Frame.Width);
        Assert.Equal (0, view.Height);
        var win = new Window ();
        win.Add (view);
        Toplevel top = new ();
        top.Add (win);
        RunState rs = Application.Begin (top);

        view.Width = Dim.Auto ();
        view.Height = Dim.Auto ();
        Assert.Equal ("Testing visibility.".Length, view.Frame.Width);
        Assert.True (view.Visible);
        ((FakeDriver)Application.Driver!).SetBufferSize (30, 5);

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
┌────────────────────────────┐
│Testing visibility.         │
│                            │
│                            │
└────────────────────────────┘
",
                                                      output
                                                     );

        view.Visible = false;

        var firstIteration = false;
        Application.RunIteration (ref rs, ref firstIteration);

        TestHelpers.AssertDriverContentsWithFrameAre (
                                                      @"
┌────────────────────────────┐
│                            │
│                            │
│                            │
└────────────────────────────┘
",
                                                      output
                                                     );
        Application.End (rs);
        top.Dispose ();
    }

    [Fact]
    [AutoInitShutdown]
    public void Visible_Sets_Also_Sets_Subviews ()
    {
        var button = new Button { Text = "Click Me" };
        var win = new Window { Width = Dim.Fill (), Height = Dim.Fill () };
        win.Add (button);
        Toplevel top = new ();
        top.Add (win);

        var iterations = 0;

        Application.Iteration += (s, a) =>
                                 {
                                     iterations++;

                                     Assert.True (button.Visible);
                                     Assert.True (button.CanFocus);
                                     Assert.True (button.HasFocus);
                                     Assert.True (win.Visible);
                                     Assert.True (win.CanFocus);
                                     Assert.True (win.HasFocus);
                                     Assert.True (RunesCount () > 0);

                                     win.Visible = false;
                                     Assert.True (button.Visible);
                                     Assert.True (button.CanFocus);
                                     Assert.False (button.HasFocus);
                                     Assert.False (win.Visible);
                                     Assert.True (win.CanFocus);
                                     Assert.False (win.HasFocus);
                                     button.SetFocus ();
                                     Assert.False (button.HasFocus);
                                     Assert.False (win.HasFocus);
                                     win.SetFocus ();
                                     Assert.False (button.HasFocus);
                                     Assert.False (win.HasFocus);
                                     top.Draw ();
                                     Assert.True (RunesCount () == 0);

                                     win.Visible = true;
                                     win.FocusFirst (null);
                                     Assert.True (button.HasFocus);
                                     Assert.True (win.HasFocus);
                                     top.Draw ();
                                     Assert.True (RunesCount () > 0);

                                     Application.RequestStop ();
                                 };

        Application.Run (top);
        top.Dispose ();
        Assert.Equal (1, iterations);

        int RunesCount ()
        {
            Cell [,] contents = ((FakeDriver)Application.Driver).Contents;
            var runesCount = 0;

            for (var i = 0; i < Application.Driver!.Rows; i++)
            {
                for (var j = 0; j < Application.Driver!.Cols; j++)
                {
                    if (contents [i, j].Rune != (Rune)' ')
                    {
                        runesCount++;
                    }
                }
            }

            return runesCount;
        }
    }

    public class DerivedView : View
    {
        public DerivedView () { CanFocus = true; }
        public bool IsKeyDown { get; set; }
        public bool IsKeyPress { get; set; }
        public bool IsKeyUp { get; set; }
        public override string Text { get; set; }

        public override void OnDrawContent (Rectangle viewport)
        {
            var idx = 0;

            // BUGBUG: v2 - this should use Viewport, not Frame
            for (var r = 0; r < Frame.Height; r++)
            {
                for (var c = 0; c < Frame.Width; c++)
                {
                    if (idx < Text.Length)
                    {
                        char rune = Text [idx];

                        if (rune != '\n')
                        {
                            AddRune (c, r, (Rune)Text [idx]);
                        }

                        idx++;

                        if (rune == '\n')
                        {
                            break;
                        }
                    }
                }
            }

            ClearLayoutNeeded ();
            ClearNeedsDisplay ();
        }

        public override bool OnKeyDown (Key keyEvent)
        {
            IsKeyDown = true;

            return true;
        }

        public override bool OnKeyUp (Key keyEvent)
        {
            IsKeyUp = true;

            return true;
        }

        public override bool OnProcessKeyDown (Key keyEvent)
        {
            IsKeyPress = true;

            return true;
        }
    }

    // OnAccept/Accept tests
    [Fact]
    public void OnAccept_Fires_Accept ()
    {
        var view = new View ();
        var accepted = false;

        view.Accept += ViewOnAccept;

        view.InvokeCommand (Command.Accept);
        Assert.True (accepted);

        return;

        void ViewOnAccept (object sender, HandledEventArgs e) { accepted = true; }
    }

    [Fact]
    public void Accept_Cancel_Event_OnAccept_Returns_True ()
    {
        var view = new View ();
        var acceptInvoked = false;

        view.Accept += ViewOnAccept;

        bool? ret = view.InvokeCommand (Command.Accept);
        Assert.True (ret);
        Assert.True (acceptInvoked);

        return;

        void ViewOnAccept (object sender, HandledEventArgs e)
        {
            acceptInvoked = true;
            e.Handled = true;
        }
    }

    [Fact]
    public void Accept_Command_Invokes_Accept_Event ()
    {
        var view = new View ();
        var accepted = false;

        view.Accept += ViewOnAccept;

        view.InvokeCommand (Command.Accept);
        Assert.True (accepted);

        return;

        void ViewOnAccept (object sender, HandledEventArgs e) { accepted = true; }
    }

    [Fact]
    public void HotKey_Command_SetsFocus ()
    {
        var view = new View ();

        view.CanFocus = true;
        Assert.False (view.HasFocus);
        view.InvokeCommand (Command.HotKey);
        Assert.True (view.HasFocus);
    }
}