gui-cs.Terminal.Gui/UnitTests/Views/ScrollTests.cs

using Microsoft.VisualStudio.TestPlatform.Utilities;
using Xunit.Abstractions;

namespace Terminal.Gui.ViewsTests;

public class ScrollTests
{
    public ScrollTests (ITestOutputHelper output) { _output = output; }
    private readonly ITestOutputHelper _output;


    [Fact]
    public void OnOrientationChanged_Keeps_Size ()
    {
        var scroll = new Scroll ();
        scroll.Layout ();
        scroll.Size = 1;

        scroll.Orientation = Orientation.Horizontal;
        Assert.Equal (1, scroll.Size);
    }

    [Fact]
    public void OnOrientationChanged_Sets_Position_To_0 ()
    {
        View super = new View ()
        {
            Id = "super",
            Width = 10,
            Height = 10
        };
        var scroll = new Scroll ()
        {
        };
        super.Add (scroll);
        scroll.Layout ();
        scroll.SliderPosition = 1;
        scroll.Orientation = Orientation.Horizontal;

        Assert.Equal (0, scroll.SliderPosition);
    }


    //    [Theory]
    //    [AutoInitShutdown]
    //    [InlineData (
    //                    20,
    //                    @"
    //█
    //█
    //█
    //█
    //█
    //░
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    //                    @"
    //░
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    //                    @"
    //░
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    //                    @"
    //░
    //░
    //█
    //█
    //█
    //░
    //░
    //░
    //░
    //░",
    //                    @"
    //█████░░░░░",
    //                    @"
    //░░█████░░░",
    //                    @"
    //░░░░░█████",
    //                    @"
    //░░███░░░░░")]
    //    [InlineData (
    //                    40,
    //                    @"
    //█
    //█
    //█
    //░
    //░
    //░
    //░
    //░
    //░
    //░",
    //                    @"
    //░
    //█
    //█
    //█
    //░
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    //░
    //░
    //░
    //░",
    //                    @"
    //░
    //░
    //█
    //█
    //█
    //░
    //░
    //░
    //░
    //░",
    //                    @"
    //░
    //█
    //█
    //░
    //░
    //░
    //░
    //░
    //░
    //░",
    //                    @"
    //███░░░░░░░",
    //                    @"
    //░███░░░░░░",
    //                    @"
    //░░███░░░░░",
    //                    @"
    //░██░░░░░░░")]
    //    public void Changing_Position_Size_Orientation_Draws_Correctly_KeepContentInAllViewport_True (
    //        int size,
    //        string firstVertExpected,
    //        string middleVertExpected,
    //        string endVertExpected,
    //        string sizeVertExpected,
    //        string firstHoriExpected,
    //        string middleHoriExpected,
    //        string endHoriExpected,
    //        string sizeHoriExpected
    //    )
    //    {
    //        var scroll = new Scroll
    //        {
    //            Orientation = Orientation.Vertical,
    //            Size = size,
    //            Height = 10,
    //            KeepContentInAllViewport = true
    //        };
    //        var top = new Toplevel ();
    //        top.Add (scroll);
    //        RunState rs = Application.Begin (top);
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (firstVertExpected, _output);

    //        scroll.Position = 4;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (middleVertExpected, _output);

    //        scroll.Position = 10;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (endVertExpected, _output);

    //        scroll.Size = size * 2;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (sizeVertExpected, _output);

    //        scroll.Orientation = Orientation.Horizontal;
    //        scroll.Width = 10;
    //        scroll.Height = 1;
    //        scroll.Position = 0;
    //        scroll.Size = size;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (firstHoriExpected, _output);

    //        scroll.Position = 4;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (middleHoriExpected, _output);

    //        scroll.Position = 10;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (endHoriExpected, _output);

    //        scroll.Size = size * 2;
    //        Application.RunIteration (ref rs);

    //        _ = TestHelpers.AssertDriverContentsWithFrameAre (sizeHoriExpected, _output);
    //    }

    [Fact]
    public void Constructor_Defaults ()
    {
        var scroll = new Scroll ();
        Assert.False (scroll.CanFocus);
        Assert.Equal (Orientation.Vertical, scroll.Orientation);
        Assert.Equal (0, scroll.Size);
        Assert.Equal (0, scroll.SliderPosition);
    }

    //[Fact]
    //[AutoInitShutdown]
    //public void KeepContentInAllViewport_True_False_KeepContentInAllViewport_True ()
    //{
    //    var view = new View { Width = Dim.Fill (), Height = Dim.Fill () };
    //    view.Padding.Thickness = new (0, 0, 2, 0);
    //    view.SetContentSize (new (view.Viewport.Width, 30));
    //    var scroll = new Scroll { Width = 2, Height = Dim.Fill (), Size = view.GetContentSize ().Height, KeepContentInAllViewport = true };
    //    scroll.PositionChanged += (_, e) => view.Viewport = view.Viewport with { Y = e.CurrentValue };
    //    view.Padding.Add (scroll);
    //    var top = new Toplevel ();
    //    top.Add (view);
    //    Application.Begin (top);

    //    Assert.True (scroll.KeepContentInAllViewport);
    //    Assert.Equal (80, view.Padding.Viewport.Width);
    //    Assert.Equal (25, view.Padding.Viewport.Height);
    //    Assert.Equal (2, scroll.Viewport.Width);
    //    Assert.Equal (25, scroll.Viewport.Height);
    //    Assert.Equal (30, scroll.Size);

    //    scroll.KeepContentInAllViewport = false;
    //    scroll.Position = 50;
    //    Assert.Equal (scroll.Position, scroll.Size - 1);
    //    Assert.Equal (scroll.Position, view.Viewport.Y);
    //    Assert.Equal (29, scroll.Position);
    //    Assert.Equal (29, view.Viewport.Y);

    //    top.Dispose ();
    //}


    //[Theory]
    //[AutoInitShutdown]
    //[InlineData (Orientation.Vertical)]
    //[InlineData (Orientation.Horizontal)]
    //public void Moving_Mouse_Outside_Host_Ensures_Correct_Location_KeepContentInAllViewport_True (Orientation orientation)
    //{
    //    var scroll = new Scroll
    //    {
    //        X = 10, Y = 10, Width = orientation == Orientation.Vertical ? 1 : 10, Height = orientation == Orientation.Vertical ? 10 : 1, Size = 20,
    //        SliderPosition = 5, Orientation = orientation
    //    };
    //    var top = new Toplevel ();
    //    top.Add (scroll);
    //    RunState rs = Application.Begin (top);

    //    Rectangle scrollSliderFrame = scroll.Subviews.FirstOrDefault (x => x.Id == "scrollSlider")!.Frame;
    //    Assert.Equal (scrollSliderFrame, orientation == Orientation.Vertical ? new (0, 2, 1, 5) : new (2, 0, 5, 1));

    //    Application.RaiseMouseEvent (new () { ScreenPosition = orientation == Orientation.Vertical ? new (10, 12) : new (12, 10), Flags = MouseFlags.Button1Pressed });
    //    Application.RunIteration (ref rs);

    //    Application.RaiseMouseEvent (
    //                              new ()
    //                              {
    //                                  ScreenPosition = orientation == Orientation.Vertical ? new (10, 0) : new (0, 10),
    //                                  Flags = MouseFlags.Button1Pressed | MouseFlags.ReportMousePosition
    //                              });
    //    Application.RunIteration (ref rs);
    //    Assert.Equal (new (0, 0), scroll.Subviews.FirstOrDefault (x => x.Id == "scrollSlider")!.Frame.Location);

    //    Application.RaiseMouseEvent (
    //                              new ()
    //                              {
    //                                  ScreenPosition = orientation == Orientation.Vertical ? new (0, 25) : new (80, 0),
    //                                  Flags = MouseFlags.Button1Pressed | MouseFlags.ReportMousePosition
    //                              });
    //    Application.RunIteration (ref rs);

    //    Assert.Equal (
    //                  orientation == Orientation.Vertical ? new (0, 5) : new (5, 0),
    //                  scroll.Subviews.FirstOrDefault (x => x.Id == "scrollSlider")!.Frame.Location);
    //}

    [Theory]
    [CombinatorialData]
    [AutoInitShutdown]
    public void Mouse_Wheel_Increments_Position ([CombinatorialRange (1, 3, 1)] int increment, Orientation orientation)
    {
        var top = new Toplevel ()
        {
            Id = "top",
            Width = 10,
            Height = 10
        };
        var scroll = new Scroll
        {
            Id = "scroll",
            Orientation = orientation,
            Size = 20,
            Increment = increment
        };

        top.Add (scroll);
        RunState rs = Application.Begin (top);

        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (0, scroll.ContentPosition);

        Application.RaiseMouseEvent (new ()
        {
            ScreenPosition = new (0, 0),
            Flags = orientation == Orientation.Vertical ? MouseFlags.WheeledDown : MouseFlags.WheeledRight
        });
        Application.RunIteration (ref rs);

        Assert.Equal (increment, scroll.ContentPosition);

        Application.RaiseMouseEvent (new ()
        {
            ScreenPosition = new (0, 0),
            Flags = orientation == Orientation.Vertical ? MouseFlags.WheeledDown : MouseFlags.WheeledRight
        });
        Application.RunIteration (ref rs);

        Assert.Equal (increment * 2, scroll.ContentPosition);

        Application.RaiseMouseEvent (new ()
        {
            ScreenPosition = new (0, 0),
            Flags = orientation == Orientation.Vertical ? MouseFlags.WheeledUp : MouseFlags.WheeledLeft
        });
        Application.RunIteration (ref rs);

        Assert.Equal (increment, scroll.ContentPosition);

        Application.ResetState (true);
    }

    [Theory]
    [CombinatorialData]
    [AutoInitShutdown]
    public void Mouse_Click_Outside_Slider_Moves (Orientation orientation)
    {
        var top = new Toplevel ()
        {
            Id = "top",
            Width = 10,
            Height = 10
        };
        var scroll = new Scroll
        {
            Id = "scroll",
            Orientation = orientation,
            Size = 20,
        };

        top.Add (scroll);
        RunState rs = Application.Begin (top);
        scroll.SliderPosition = 5;
        Application.RunIteration (ref rs);

        Assert.Equal (5, scroll.SliderPosition);
        Assert.Equal (10, scroll.ContentPosition);

        Application.RaiseMouseEvent (new ()
        {
            ScreenPosition = new (0, 0),
            Flags = MouseFlags.Button1Clicked
        });
        Application.RunIteration (ref rs);

        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (0, scroll.ContentPosition);

        Application.ResetState (true);
    }

    [Theory]
    [CombinatorialData]
    public void Position_Clamps_To_Size (
        [CombinatorialRange (1, 6, 1)] int scrollSize,
        [CombinatorialRange (-1, 6, 1)] int scrollPosition,
        Orientation orientation
    )
    {
        var super = new View
        {
            Id = "super",
            Width = 5,
            Height = 5
        };

        var scroll = new Scroll
        {
            Orientation = orientation,
            Width = Dim.Fill (),
            Height = Dim.Fill ()
        };
        super.Add (scroll);
        scroll.Size = scrollSize;
        super.Layout ();

        scroll.SliderPosition = scrollPosition;
        super.Layout ();

        Assert.True (scroll.SliderPosition <= scrollSize);
    }

    [Fact]
    public void SliderPosition_Event_Cancelables ()
    {
        var changingCount = 0;
        var changedCount = 0;
        var scroll = new Scroll { };
        scroll.Layout ();
        scroll.Size = scroll.Viewport.Height * 2;
        scroll.Layout ();

        scroll.SliderPositionChanging += (s, e) =>
                                   {
                                       if (changingCount == 0)
                                       {
                                           e.Cancel = true;
                                       }

                                       changingCount++;
                                   };
        scroll.SliderPositionChanged += (s, e) => changedCount++;

        scroll.SliderPosition = 1;
        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (1, changingCount);
        Assert.Equal (0, changedCount);

        scroll.SliderPosition = 1;
        Assert.Equal (1, scroll.SliderPosition);
        Assert.Equal (2, changingCount);
        Assert.Equal (1, changedCount);
    }

    [Fact]
    public void PositionChanging_PositionChanged_Events_Only_Raises_Once_If_Position_Was_Really_Changed ()
    {
        var changing = 0;
        var cancel = false;
        var changed = 0;
        var scroll = new Scroll { Height = 10, Size = 20 };
        scroll.SliderPositionChanging += Scroll_PositionChanging;
        scroll.SliderPositionChanged += Scroll_PositionChanged;

        Assert.Equal (Orientation.Vertical, scroll.Orientation);
        scroll.Layout ();
        Assert.Equal (new (0, 0, 1, 10), scroll.Viewport);
        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (0, changing);
        Assert.Equal (0, changed);

        scroll.SliderPosition = 0;
        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (0, changing);
        Assert.Equal (0, changed);

        scroll.SliderPosition = 1;
        Assert.Equal (1, scroll.SliderPosition);
        Assert.Equal (1, changing);
        Assert.Equal (1, changed);

        Reset ();
        cancel = true;
        scroll.SliderPosition = 2;
        Assert.Equal (1, scroll.SliderPosition);
        Assert.Equal (1, changing);
        Assert.Equal (0, changed);

        Reset ();
        scroll.SliderPosition = 10;
        Assert.Equal (5, scroll.SliderPosition);
        Assert.Equal (1, changing);
        Assert.Equal (1, changed);

        Reset ();
        scroll.SliderPosition = 11;
        Assert.Equal (5, scroll.SliderPosition);
        Assert.Equal (1, changing);
        Assert.Equal (1, changed);

        Reset ();
        scroll.SliderPosition = 0;
        Assert.Equal (0, scroll.SliderPosition);
        Assert.Equal (1, changing);
        Assert.Equal (1, changed);

        scroll.SliderPositionChanging -= Scroll_PositionChanging;
        scroll.SliderPositionChanged -= Scroll_PositionChanged;

        void Scroll_PositionChanging (object sender, CancelEventArgs<int> e)
        {
            changing++;
            e.Cancel = cancel;
        }

        void Scroll_PositionChanged (object sender, EventArgs<int> e) { changed++; }

        void Reset ()
        {
            changing = 0;
            cancel = false;
            changed = 0;
        }
    }

    [Fact]
    public void Size_Cannot_Be_Negative ()
    {
        var scroll = new Scroll { Height = 10, Size = -1 };
        Assert.Equal (0, scroll.Size);
        scroll.Size = -10;
        Assert.Equal (0, scroll.Size);
    }

    [Fact]
    public void SizeChanged_Event ()
    {
        var count = 0;
        var scroll = new Scroll ();
        scroll.Layout ();
        scroll.SizeChanged += (s, e) => count++;

        scroll.Size = 10;
        Assert.Equal (10, scroll.Size);
        Assert.Equal (1, count);
    }

    [Theory]
    [SetupFakeDriver]
    [InlineData (
                    10,
                    1,
                    20,
                    0,
                    Orientation.Horizontal,
                    @"
┌──────────┐
│█████░░░░░│
└──────────┘")]

    [InlineData (
                    10,
                    3,
                    20,
                    1,
                    Orientation.Horizontal,
                    @"
┌──────────┐
│░█████░░░░│
│░█████░░░░│
│░█████░░░░│
└──────────┘")]

    [InlineData (
                    3,
                    10,
                    20,
                    0,
                    Orientation.Vertical,
                    @"
┌───┐
│███│
│███│
│███│
│███│
│███│
│░░░│
│░░░│
│░░░│
│░░░│
│░░░│
└───┘")]


    public void Draws_Correctly (int superViewportWidth, int superViewportHeight, int sliderSize, int sliderPosition, Orientation orientation, string expected)
    {
        var super = new Window
        {
            Id = "super",
            Width = superViewportWidth + 2,
            Height = superViewportHeight + 2
        };

        var scroll = new Scroll
        {
            Orientation = orientation,
        };

        if (orientation == Orientation.Vertical)
        {
            scroll.Width = Dim.Fill ();
        }
        else
        {
            scroll.Height = Dim.Fill ();
        }
        super.Add (scroll);

        scroll.Size = sliderSize;
        scroll.Layout ();
        scroll.SliderPosition = sliderPosition;

        super.BeginInit ();
        super.EndInit ();
        super.Layout ();
        super.Draw ();

        _ = TestHelpers.AssertDriverContentsWithFrameAre (expected, _output);
    }
}