gui-cs.Terminal.Gui/Tests/UnitTests/Views/GraphViewTests.cs

using System.Text;
using UnitTests;
using Xunit.Abstractions;

namespace Terminal.Gui.ViewsTests;

#region Helper Classes

internal class FakeHAxis : HorizontalAxis
{
    public List<Point> DrawAxisLinePoints = new ();
    public List<int> LabelPoints = new ();

    public override void DrawAxisLabel (GraphView graph, int screenPosition, string text)
    {
        base.DrawAxisLabel (graph, screenPosition, text);
        LabelPoints.Add (screenPosition);
    }

    protected override void DrawAxisLine (GraphView graph, int x, int y)
    {
        base.DrawAxisLine (graph, x, y);
        DrawAxisLinePoints.Add (new Point (x, y));
    }
}

internal class FakeVAxis : VerticalAxis
{
    public List<Point> DrawAxisLinePoints = new ();
    public List<int> LabelPoints = new ();

    public override void DrawAxisLabel (GraphView graph, int screenPosition, string text)
    {
        base.DrawAxisLabel (graph, screenPosition, text);
        LabelPoints.Add (screenPosition);
    }

    protected override void DrawAxisLine (GraphView graph, int x, int y)
    {
        base.DrawAxisLine (graph, x, y);
        DrawAxisLinePoints.Add (new Point (x, y));
    }
}

#endregion

public class GraphViewTests
{
    /// <summary>
    ///     A cell size of 0 would result in mapping all graph space into the same cell of the console.  Since
    ///     <see cref="GraphView.CellSize"/> is mutable a sensible place to check this is in redraw.
    /// </summary>
    [Fact]
    [AutoInitShutdown]
    public void CellSizeZero ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        //gv.Scheme = new Scheme ();
        gv.Viewport = new Rectangle (0, 0, 50, 30);
        gv.Series.Add (new ScatterSeries { Points = new List<PointF> { new (1, 1) } });
        gv.CellSize = new PointF (0, 5);
        var ex = Assert.Throws<Exception> (() => gv.Draw ());

        Assert.Equal ("CellSize cannot be 0", ex.Message);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    /// <summary>Returns a basic very small graph (10 x 5)</summary>
    /// <returns></returns>
    public static GraphView GetGraph ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        //gv.Scheme = new Scheme ();
        gv.MarginBottom = 1;
        gv.MarginLeft = 1;
        gv.Viewport = new Rectangle (0, 0, 10, 5);

        return gv;
    }


    /// <summary>
    ///     Tests that each point in the screen space maps to a rectangle of (float) graph space and that each corner of
    ///     that rectangle of graph space maps back to the same row/col of the graph that was fed in
    /// </summary>
    [Fact]
    public void TestReversing_ScreenToGraphSpace ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();
        gv.Viewport = new Rectangle (0, 0, 50, 30);

        // How much graph space each cell of the console depicts
        gv.CellSize = new PointF (0.1f, 0.25f);
        gv.AxisX.Increment = 1;
        gv.AxisX.ShowLabelsEvery = 1;

        gv.AxisY.Increment = 1;
        gv.AxisY.ShowLabelsEvery = 1;

        // Start the graph at 80
        gv.ScrollOffset = new PointF (0, 80);

        for (var x = 0; x < gv.Viewport.Width; x++)
        {
            for (var y = 0; y < gv.Viewport.Height; y++)
            {
                RectangleF graphSpace = gv.ScreenToGraphSpace (x, y);

                // See 
                // https://en.wikipedia.org/wiki/Machine_epsilon
                var epsilon = 0.0001f;

                Point p = gv.GraphSpaceToScreen (
                                                 new PointF (
                                                             graphSpace.Left + epsilon,
                                                             graphSpace.Top + epsilon
                                                            )
                                                );
                Assert.Equal (x, p.X);
                Assert.Equal (y, p.Y);

                p = gv.GraphSpaceToScreen (
                                           new PointF (
                                                       graphSpace.Right - epsilon,
                                                       graphSpace.Top + epsilon
                                                      )
                                          );
                Assert.Equal (x, p.X);
                Assert.Equal (y, p.Y);

                p = gv.GraphSpaceToScreen (
                                           new PointF (
                                                       graphSpace.Left + epsilon,
                                                       graphSpace.Bottom - epsilon
                                                      )
                                          );
                Assert.Equal (x, p.X);
                Assert.Equal (y, p.Y);

                p = gv.GraphSpaceToScreen (
                                           new PointF (
                                                       graphSpace.Right - epsilon,
                                                       graphSpace.Bottom - epsilon
                                                      )
                                          );
                Assert.Equal (x, p.X);
                Assert.Equal (y, p.Y);
            }
        }
    }

    #region Screen to Graph Tests

    [Fact]
    public void ScreenToGraphSpace_DefaultCellSize ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // origin should be bottom left
        RectangleF botLeft = gv.ScreenToGraphSpace (0, 9);
        Assert.Equal (0, botLeft.X);
        Assert.Equal (0, botLeft.Y);
        Assert.Equal (1, botLeft.Width);
        Assert.Equal (1, botLeft.Height);

        // up 2 rows of the console and along 1 col
        RectangleF up2along1 = gv.ScreenToGraphSpace (1, 7);
        Assert.Equal (1, up2along1.X);
        Assert.Equal (2, up2along1.Y);
    }

    [Fact]
    public void ScreenToGraphSpace_DefaultCellSize_WithMargin ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // origin should be bottom left
        RectangleF botLeft = gv.ScreenToGraphSpace (0, 9);
        Assert.Equal (0, botLeft.X);
        Assert.Equal (0, botLeft.Y);
        Assert.Equal (1, botLeft.Width);
        Assert.Equal (1, botLeft.Height);

        gv.MarginLeft = 1;

        botLeft = gv.ScreenToGraphSpace (0, 9);

        // Origin should be at 1,9 now to leave a margin of 1
        // so screen position 0,9 would be data space -1,0
        Assert.Equal (-1, botLeft.X);
        Assert.Equal (0, botLeft.Y);
        Assert.Equal (1, botLeft.Width);
        Assert.Equal (1, botLeft.Height);

        gv.MarginLeft = 1;
        gv.MarginBottom = 1;

        botLeft = gv.ScreenToGraphSpace (0, 9);

        // Origin should be at 1,0 (to leave a margin of 1 in both sides)
        // so screen position 0,9 would be data space -1,-1
        Assert.Equal (-1, botLeft.X);
        Assert.Equal (-1, botLeft.Y);
        Assert.Equal (1, botLeft.Width);
        Assert.Equal (1, botLeft.Height);
    }

    [Fact]
    public void ScreenToGraphSpace_CustomCellSize ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // Each cell of screen measures 5 units in graph data model vertically and 1/4 horizontally
        gv.CellSize = new PointF (0.25f, 5);

        // origin should be bottom left 
        // (note that y=10 is actually overspilling the control, the last row is 9)
        RectangleF botLeft = gv.ScreenToGraphSpace (0, 9);
        Assert.Equal (0, botLeft.X);
        Assert.Equal (0, botLeft.Y);
        Assert.Equal (0.25f, botLeft.Width);
        Assert.Equal (5, botLeft.Height);

        // up 2 rows of the console and along 1 col
        RectangleF up2along1 = gv.ScreenToGraphSpace (1, 7);
        Assert.Equal (0.25f, up2along1.X);
        Assert.Equal (10, up2along1.Y);
        Assert.Equal (0.25f, botLeft.Width);
        Assert.Equal (5, botLeft.Height);
    }

    #endregion

    #region Graph to Screen Tests

    [Fact]
    public void GraphSpaceToScreen_DefaultCellSize ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // origin should be bottom left
        Point botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (0, botLeft.X);
        Assert.Equal (9, botLeft.Y); // row 9 of the view is the bottom left

        // along 2 and up 1 in graph space
        Point along2up1 = gv.GraphSpaceToScreen (new PointF (2, 1));
        Assert.Equal (2, along2up1.X);
        Assert.Equal (8, along2up1.Y);
    }

    [Fact]
    public void GraphSpaceToScreen_DefaultCellSize_WithMargin ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // origin should be bottom left
        Point botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (0, botLeft.X);
        Assert.Equal (9, botLeft.Y); // row 9 of the view is the bottom left

        gv.MarginLeft = 1;

        // With a margin of 1 the origin should be at x=1 y= 9
        botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (1, botLeft.X);
        Assert.Equal (9, botLeft.Y); // row 9 of the view is the bottom left

        gv.MarginLeft = 1;
        gv.MarginBottom = 1;

        // With a margin of 1 in both directions the origin should be at x=1 y= 9
        botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (1, botLeft.X);
        Assert.Equal (8, botLeft.Y); // row 8 of the view is the bottom left up 1 cell
    }

    [Fact]
    public void GraphSpaceToScreen_ScrollOffset ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        //graph is scrolled to present chart space -5 to 5 in both axes
        gv.ScrollOffset = new PointF (-5, -5);

        // origin should be right in the middle of the control
        Point botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (5, botLeft.X);
        Assert.Equal (4, botLeft.Y);

        // along 2 and up 1 in graph space
        Point along2up1 = gv.GraphSpaceToScreen (new PointF (2, 1));
        Assert.Equal (7, along2up1.X);
        Assert.Equal (3, along2up1.Y);
    }

    [Fact]
    public void GraphSpaceToScreen_CustomCellSize ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // Each cell of screen is responsible for rendering 5 units in graph data model
        // vertically and 1/4 horizontally
        gv.CellSize = new PointF (0.25f, 5);

        // origin should be bottom left
        Point botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (0, botLeft.X);

        // row 9 of the view is the bottom left (height is 10 so 0,1,2,3..9)
        Assert.Equal (9, botLeft.Y);

        // along 2 and up 1 in graph space
        Point along2up1 = gv.GraphSpaceToScreen (new PointF (2, 1));
        Assert.Equal (8, along2up1.X);
        Assert.Equal (9, along2up1.Y);

        // Y value 4 should be rendered in bottom most row
        Assert.Equal (9, gv.GraphSpaceToScreen (new PointF (2, 4)).Y);

        // Cell height is 5 so this is the first point of graph space that should
        // be rendered in the graph in next row up (row 9)
        Assert.Equal (8, gv.GraphSpaceToScreen (new PointF (2, 5)).Y);

        // More boundary testing for this cell size
        Assert.Equal (8, gv.GraphSpaceToScreen (new PointF (2, 6)).Y);
        Assert.Equal (8, gv.GraphSpaceToScreen (new PointF (2, 7)).Y);
        Assert.Equal (8, gv.GraphSpaceToScreen (new PointF (2, 8)).Y);
        Assert.Equal (8, gv.GraphSpaceToScreen (new PointF (2, 9)).Y);
        Assert.Equal (7, gv.GraphSpaceToScreen (new PointF (2, 10)).Y);
        Assert.Equal (7, gv.GraphSpaceToScreen (new PointF (2, 11)).Y);
    }

    [Fact]
    public void GraphSpaceToScreen_CustomCellSize_WithScrollOffset ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        gv.Viewport = new Rectangle (0, 0, 20, 10);

        // Each cell of screen is responsible for rendering 5 units in graph data model
        // vertically and 1/4 horizontally
        gv.CellSize = new PointF (0.25f, 5);

        //graph is scrolled to present some negative chart (4 negative cols and 2 negative rows)
        gv.ScrollOffset = new PointF (-1, -10);

        // origin should be in the lower left (but not right at the bottom)
        Point botLeft = gv.GraphSpaceToScreen (new PointF (0, 0));
        Assert.Equal (4, botLeft.X);
        Assert.Equal (7, botLeft.Y);

        // along 2 and up 1 in graph space
        Point along2up1 = gv.GraphSpaceToScreen (new PointF (2, 1));
        Assert.Equal (12, along2up1.X);
        Assert.Equal (7, along2up1.Y);

        // More boundary testing for this cell size/offset
        Assert.Equal (6, gv.GraphSpaceToScreen (new PointF (2, 6)).Y);
        Assert.Equal (6, gv.GraphSpaceToScreen (new PointF (2, 7)).Y);
        Assert.Equal (6, gv.GraphSpaceToScreen (new PointF (2, 8)).Y);
        Assert.Equal (6, gv.GraphSpaceToScreen (new PointF (2, 9)).Y);
        Assert.Equal (5, gv.GraphSpaceToScreen (new PointF (2, 10)).Y);
        Assert.Equal (5, gv.GraphSpaceToScreen (new PointF (2, 11)).Y);
    }

    #endregion
}

public class SeriesTests
{
    [Fact]
    [AutoInitShutdown]
    public void Series_GetsPassedCorrectViewport_AllAtOnce ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();
        gv.Viewport = new Rectangle (0, 0, 50, 30);
        //gv.Scheme = new Scheme ();

        var fullGraphBounds = RectangleF.Empty;
        var graphScreenBounds = Rectangle.Empty;

        var series = new FakeSeries (
                                     (v, s, g) =>
                                     {
                                         graphScreenBounds = s;
                                         fullGraphBounds = g;
                                     }
                                    );
        gv.Series.Add (series);

        gv.LayoutSubViews ();
        gv.Draw ();
        Assert.Equal (new RectangleF (0, 0, 50, 30), fullGraphBounds);
        Assert.Equal (new Rectangle (0, 0, 50, 30), graphScreenBounds);

        // Now we put a margin in
        // Graph should not spill into the margins

        gv.MarginBottom = 2;
        gv.MarginLeft = 5;

        // Even with a margin the graph should be drawn from 
        // the origin, we just get less visible width/height
        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();
        Assert.Equal (new RectangleF (0, 0, 45, 28), fullGraphBounds);

        // The screen space the graph will be rendered into should
        // not overspill the margins
        Assert.Equal (new Rectangle (5, 0, 45, 28), graphScreenBounds);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    /// <summary>
    ///     Tests that the bounds passed to the ISeries for drawing into are correct even when the
    ///     <see cref="GraphView.CellSize"/> results in multiple units of graph space being condensed into each cell of console
    /// </summary>
    [Fact]
    [AutoInitShutdown]
    public void Series_GetsPassedCorrectViewport_AllAtOnce_LargeCellSize ()
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();
        //gv.Scheme = new Scheme ();
        gv.Viewport = new Rectangle (0, 0, 50, 30);

        // the larger the cell size the more condensed (smaller) the graph space is
        gv.CellSize = new PointF (2, 5);

        var fullGraphBounds = RectangleF.Empty;
        var graphScreenBounds = Rectangle.Empty;

        var series = new FakeSeries (
                                     (v, s, g) =>
                                     {
                                         graphScreenBounds = s;
                                         fullGraphBounds = g;
                                     }
                                    );

        gv.Series.Add (series);

        gv.LayoutSubViews ();
        gv.Draw ();

        // Since each cell of the console is 2x5 of graph space the graph
        // bounds to be rendered are larger
        Assert.Equal (new RectangleF (0, 0, 100, 150), fullGraphBounds);
        Assert.Equal (new Rectangle (0, 0, 50, 30), graphScreenBounds);

        // Graph should not spill into the margins

        gv.MarginBottom = 2;
        gv.MarginLeft = 5;

        // Even with a margin the graph should be drawn from 
        // the origin, we just get less visible width/height
        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();
        Assert.Equal (new RectangleF (0, 0, 90, 140), fullGraphBounds);

        // The screen space the graph will be rendered into should
        // not overspill the margins
        Assert.Equal (new Rectangle (5, 0, 45, 28), graphScreenBounds);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    private class FakeSeries : ISeries
    {
        private readonly Action<GraphView, Rectangle, RectangleF> _drawSeries;

        public FakeSeries (
            Action<GraphView, Rectangle, RectangleF> drawSeries
        )
        {
            _drawSeries = drawSeries;
        }

        public void DrawSeries (GraphView graph, Rectangle bounds, RectangleF graphBounds) { _drawSeries (graph, bounds, graphBounds); }
    }
}

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

    [Fact]
    public void MultiBarSeries_BarSpacing ()
    {
        // Creates clusters of 5 adjacent bars with 2 spaces between clusters
        var series = new MultiBarSeries (5, 7, 1);

        Assert.Equal (5, series.SubSeries.Count);

        Assert.Equal (0, series.SubSeries.ElementAt (0).Offset);
        Assert.Equal (1, series.SubSeries.ElementAt (1).Offset);
        Assert.Equal (2, series.SubSeries.ElementAt (2).Offset);
        Assert.Equal (3, series.SubSeries.ElementAt (3).Offset);
        Assert.Equal (4, series.SubSeries.ElementAt (4).Offset);
    }

    [Fact]
    public void MultiBarSeriesAddValues_WrongNumber ()
    {
        // user asks for 3 bars per category
        var series = new MultiBarSeries (3, 7, 1);

        var ex = Assert.Throws<ArgumentException> (() => series.AddBars ("Cars", (Rune)'#', 1));

        Assert.Equal (
                      "Number of values must match the number of bars per category (Parameter 'values')",
                      ex.Message
                     );
    }

    [Fact]
    public void MultiBarSeriesColors_RightNumber ()
    {
        Attribute [] colors =
        {
            new (Color.Green, Color.Black), new (Color.Green, Color.White), new (Color.BrightYellow, Color.White)
        };

        // user passes 3 colors and asks for 3 bars
        var series = new MultiBarSeries (3, 7, 1, colors);

        Assert.Equal (series.SubSeries.ElementAt (0).OverrideBarColor, colors [0]);
        Assert.Equal (series.SubSeries.ElementAt (1).OverrideBarColor, colors [1]);
        Assert.Equal (series.SubSeries.ElementAt (2).OverrideBarColor, colors [2]);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    public void MultiBarSeriesColors_WrongNumber ()
    {
        Attribute [] colors = { new (Color.Green, Color.Black) };

        // user passes 1 color only but asks for 5 bars
        var ex = Assert.Throws<ArgumentException> (() => new MultiBarSeries (5, 7, 1, colors));

        Assert.Equal (
                      "Number of colors must match the number of bars (Parameter 'numberOfBarsPerCategory')",
                      ex.Message
                     );

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestRendering_MultibarSeries ()
    {
        var gv = new GraphView ();
        //gv.Scheme = new Scheme ();

        // y axis goes from 0.1 to 1 across 10 console rows
        // x axis goes from 0 to 20 across 20 console columns
        gv.Viewport = new Rectangle (0, 0, 20, 10);
        gv.CellSize = new PointF (1f, 0.1f);
        gv.MarginBottom = 1;
        gv.MarginLeft = 1;

        var multibarSeries = new MultiBarSeries (2, 4, 1);

        //nudge them left to avoid float rounding errors at the boundaries of cells
        foreach (BarSeries sub in multibarSeries.SubSeries)
        {
            sub.Offset -= 0.001f;
        }

        gv.Series.Add (multibarSeries);

        FakeHAxis fakeXAxis;

        // don't show axis labels that means any labels
        // that appear are explicitly from the bars
        gv.AxisX = fakeXAxis = new FakeHAxis { Increment = 0 };
        gv.AxisY = new FakeVAxis { Increment = 0 };

        gv.LayoutSubViews ();
        gv.Draw ();

        // Since bar series has no bars yet no labels should be displayed
        Assert.Empty (fakeXAxis.LabelPoints);

        multibarSeries.AddBars ("hey", (Rune)'M', 0.5001f, 0.5001f);
        fakeXAxis.LabelPoints.Clear ();
        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();

        Assert.Equal (4, fakeXAxis.LabelPoints.Single ());

        multibarSeries.AddBars ("there", (Rune)'M', 0.24999f, 0.74999f);
        multibarSeries.AddBars ("bob", (Rune)'M', 1, 2);
        fakeXAxis.LabelPoints.Clear ();
        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        View.SetClipToScreen ();
        gv.Draw ();

        Assert.Equal (3, fakeXAxis.LabelPoints.Count);
        Assert.Equal (4, fakeXAxis.LabelPoints [0]);
        Assert.Equal (8, fakeXAxis.LabelPoints [1]);
        Assert.Equal (12, fakeXAxis.LabelPoints [2]);

        var looksLike =
            @" 
 │          MM
 │       M  MM
 │       M  MM
 │  MM   M  MM
 │  MM   M  MM
 │  MM   M  MM
 │  MM  MM  MM
 │  MM  MM  MM
 ┼──┬M──┬M──┬M──────
   heytherebob  ";
        DriverAssert.AssertDriverContentsAre (looksLike, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }
}

public class BarSeriesTests
{
    [Fact]
    public void TestOneLongOneShortHorizontalBars_WithOffset ()
    {
        GraphView graph = GetGraph (out FakeBarSeries barSeries, out FakeHAxis axisX, out FakeVAxis axisY);
        graph.Draw ();

        // no bars
        Assert.Empty (barSeries.BarScreenStarts);
        Assert.Empty (axisX.LabelPoints);
        Assert.Empty (axisY.LabelPoints);

        // 0.1 units of graph y fit every screen row
        // so 1 unit of graph y space is 10 screen rows
        graph.CellSize = new PointF (0.5f, 0.1f);

        // Start bar 3 screen units up (y = height-3)
        barSeries.Offset = 0.25f;

        // 1 bar every 3 rows of screen
        barSeries.BarEvery = 0.3f;
        barSeries.Orientation = Orientation.Horizontal;

        // 1 bar that is very wide (100 graph units horizontally = screen pos 50 but bounded by screen)
        barSeries.Bars.Add (
                            new BarSeriesBar ("hi1", new GraphCellToRender ((Rune)'.'), 100)
                           );

        // 1 bar that is shorter
        barSeries.Bars.Add (
                            new BarSeriesBar ("hi2", new GraphCellToRender ((Rune)'.'), 5)
                           );

        // redraw graph
        graph.SetNeedsDraw ();
        graph.Draw ();

        // since bars are horizontal all have the same X start cordinates
        Assert.Equal (0, barSeries.BarScreenStarts [0].X);
        Assert.Equal (0, barSeries.BarScreenStarts [1].X);

        // bar goes all the way to the end so bumps up against right screen boundary
        // width of graph is 20
        Assert.Equal (19, barSeries.BarScreenEnds [0].X);

        // shorter bar is 5 graph units wide which is 10 screen units
        Assert.Equal (10, barSeries.BarScreenEnds [1].X);

        // first  bar should be offset 6 screen units (0.25f + 0.3f graph units)
        // since height of control is 10 then first bar should be at screen row 4 (10-6)
        Assert.Equal (4, barSeries.BarScreenStarts [0].Y);

        // second  bar should be offset 9 screen units (0.25f + 0.6f graph units)
        // since height of control is 10 then second bar should be at screen row 1 (10-9)
        Assert.Equal (1, barSeries.BarScreenStarts [1].Y);

        // both bars should have labels but on the y axis
        Assert.Equal (2, axisY.LabelPoints.Count);
        Assert.Empty (axisX.LabelPoints);

        // labels should align with the bars (same screen y axis point)
        Assert.Contains (4, axisY.LabelPoints);
        Assert.Contains (1, axisY.LabelPoints);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestTwoTallBars_WithOffset ()
    {
        GraphView graph = GetGraph (out FakeBarSeries barSeries, out FakeHAxis axisX, out FakeVAxis axisY);
        graph.Draw ();

        // no bars
        Assert.Empty (barSeries.BarScreenStarts);
        Assert.Empty (axisX.LabelPoints);
        Assert.Empty (axisY.LabelPoints);

        // 0.5 units of graph fit every screen cell
        // so 1 unit of graph space is 2 screen columns
        graph.CellSize = new PointF (0.5f, 0.1f);

        // Start bar 1 screen unit along
        barSeries.Offset = 0.5f;
        barSeries.BarEvery = 1f;

        barSeries.Bars.Add (
                            new BarSeriesBar ("hi1", new GraphCellToRender ((Rune)'.'), 100)
                           );

        barSeries.Bars.Add (
                            new BarSeriesBar ("hi2", new GraphCellToRender ((Rune)'.'), 100)
                           );

        barSeries.Orientation = Orientation.Vertical;

        // redraw graph
        graph.SetNeedsDraw ();
        graph.Draw ();

        // bar should be drawn at BarEvery 1f + offset 0.5f = 3 screen units
        Assert.Equal (3, barSeries.BarScreenStarts [0].X);
        Assert.Equal (3, barSeries.BarScreenEnds [0].X);

        // second bar should be BarEveryx2 = 2f + offset 0.5f = 5 screen units
        Assert.Equal (5, barSeries.BarScreenStarts [1].X);
        Assert.Equal (5, barSeries.BarScreenEnds [1].X);

        // both bars should have labels
        Assert.Equal (2, axisX.LabelPoints.Count);
        Assert.Contains (3, axisX.LabelPoints);
        Assert.Contains (5, axisX.LabelPoints);

        // bars are very tall but should not draw up off top of screen
        Assert.Equal (9, barSeries.BarScreenStarts [0].Y);
        Assert.Equal (0, barSeries.BarScreenEnds [0].Y);
        Assert.Equal (9, barSeries.BarScreenStarts [1].Y);
        Assert.Equal (0, barSeries.BarScreenEnds [1].Y);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestZeroHeightBar_WithName ()
    {
        GraphView graph = GetGraph (out FakeBarSeries barSeries, out FakeHAxis axisX, out FakeVAxis axisY);
        graph.Draw ();

        // no bars
        Assert.Empty (barSeries.BarScreenStarts);
        Assert.Empty (axisX.LabelPoints);
        Assert.Empty (axisY.LabelPoints);

        // bar of height 0
        barSeries.Bars.Add (new BarSeriesBar ("hi", new GraphCellToRender ((Rune)'.'), 0));
        barSeries.Orientation = Orientation.Vertical;

        // redraw graph
        graph.SetNeedsDraw ();
        graph.Draw ();

        // bar should not be drawn
        Assert.Empty (barSeries.BarScreenStarts);

        Assert.NotEmpty (axisX.LabelPoints);
        Assert.Empty (axisY.LabelPoints);

        // but bar name should be
        // Screen position x=2 because bars are drawn every 1f of
        // graph space and CellSize.X is 0.5f
        Assert.Contains (2, axisX.LabelPoints);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    private GraphView GetGraph (out FakeBarSeries series, out FakeHAxis axisX, out FakeVAxis axisY)
    {
        var gv = new GraphView ();
        gv.BeginInit ();
        gv.EndInit ();

        // y axis goes from 0.1 to 1 across 10 console rows
        // x axis goes from 0 to 10 across 20 console columns
        gv.Viewport = new Rectangle (0, 0, 20, 10);
       //gv.Scheme = new Scheme ();
        gv.CellSize = new PointF (0.5f, 0.1f);

        gv.Series.Add (series = new FakeBarSeries ());

        // don't show axis labels that means any labels
        // that appaer are explicitly from the bars
        gv.AxisX = axisX = new FakeHAxis { Increment = 0 };
        gv.AxisY = axisY = new FakeVAxis { Increment = 0 };

        return gv;
    }

    private class FakeBarSeries : BarSeries
    {
        public List<Point> BarScreenEnds { get; } = new ();
        public List<Point> BarScreenStarts { get; } = new ();
        public GraphCellToRender FinalColor { get; private set; }
        protected override GraphCellToRender AdjustColor (GraphCellToRender graphCellToRender) { return FinalColor = base.AdjustColor (graphCellToRender); }

        protected override void DrawBarLine (GraphView graph, Point start, Point end, BarSeriesBar beingDrawn)
        {
            base.DrawBarLine (graph, start, end, beingDrawn);

            BarScreenStarts.Add (start);
            BarScreenEnds.Add (end);
        }
    }
}

public class AxisTests
{
    private GraphView GetGraph (out FakeHAxis axis) { return GetGraph (out axis, out _); }
    private GraphView GetGraph (out FakeVAxis axis) { return GetGraph (out _, out axis); }

    private GraphView GetGraph (out FakeHAxis axisX, out FakeVAxis axisY)
    {
        var gv = new GraphView ();
        gv.Viewport = new Rectangle (0, 0, 50, 30);
       // gv.Scheme = new Scheme ();

        // graph can't be completely empty or it won't draw
        gv.Series.Add (new ScatterSeries ());

        axisX = new FakeHAxis ();
        axisY = new FakeVAxis ();
        gv.AxisX = axisX;
        gv.AxisY = axisY;

        return gv;
    }

    #region HorizontalAxis Tests

    /// <summary>Tests that the horizontal axis is computed correctly and does not over spill it's bounds</summary>
    [Fact]
    [AutoInitShutdown]
    public void TestHAxisLocation_NoMargin ()
    {
        GraphView gv = GetGraph (out FakeHAxis axis);
        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (-1, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (1, 29), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (48, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (49, 29), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (50, 29), axis.DrawAxisLinePoints);

        Assert.InRange (axis.LabelPoints.Max (), 0, 49);
        Assert.InRange (axis.LabelPoints.Min (), 0, 49);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestHAxisLocation_MarginBottom ()
    {
        GraphView gv = GetGraph (out FakeHAxis axis);

        gv.MarginBottom = 10;
        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (-1, 19), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 19), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (1, 19), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (48, 19), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (49, 19), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (50, 19), axis.DrawAxisLinePoints);

        Assert.InRange (axis.LabelPoints.Max (), 0, 49);
        Assert.InRange (axis.LabelPoints.Min (), 0, 49);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestHAxisLocation_MarginLeft ()
    {
        GraphView gv = GetGraph (out FakeHAxis axis);

        gv.MarginLeft = 5;
        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (4, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (5, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (6, 29), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (48, 29), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (49, 29), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (50, 29), axis.DrawAxisLinePoints);

        // Axis lables should not be drawn in the margin
        Assert.InRange (axis.LabelPoints.Max (), 5, 49);
        Assert.InRange (axis.LabelPoints.Min (), 5, 49);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    #endregion

    #region VerticalAxisTests

    /// <summary>Tests that the horizontal axis is computed correctly and does not over spill it's bounds</summary>
    [Fact]
    [AutoInitShutdown]
    public void TestVAxisLocation_NoMargin ()
    {
        GraphView gv = GetGraph (out FakeVAxis axis);

        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (0, -1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 2), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (0, 28), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 29), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (0, 30), axis.DrawAxisLinePoints);

        Assert.InRange (axis.LabelPoints.Max (), 0, 29);
        Assert.InRange (axis.LabelPoints.Min (), 0, 29);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestVAxisLocation_MarginBottom ()
    {
        GraphView gv = GetGraph (out FakeVAxis axis);

        gv.MarginBottom = 10;
        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (0, -1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 2), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (0, 18), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (0, 19), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (0, 20), axis.DrawAxisLinePoints);

        // Labels should not be drawn into the axis
        Assert.InRange (axis.LabelPoints.Max (), 0, 19);
        Assert.InRange (axis.LabelPoints.Min (), 0, 19);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestVAxisLocation_MarginLeft ()
    {
        GraphView gv = GetGraph (out FakeVAxis axis);

        gv.MarginLeft = 5;
        gv.LayoutSubViews ();
        gv.Draw ();

        Assert.DoesNotContain (new Point (5, -1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (5, 1), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (5, 2), axis.DrawAxisLinePoints);

        Assert.Contains (new Point (5, 28), axis.DrawAxisLinePoints);
        Assert.Contains (new Point (5, 29), axis.DrawAxisLinePoints);
        Assert.DoesNotContain (new Point (5, 30), axis.DrawAxisLinePoints);

        Assert.InRange (axis.LabelPoints.Max (), 0, 29);
        Assert.InRange (axis.LabelPoints.Min (), 0, 29);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    #endregion
}

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

    [Theory]
    [InlineData (null)]
    [InlineData ("  ")]
    [InlineData ("\t\t")]
    [AutoInitShutdown]
    public void TestTextAnnotation_EmptyText (string whitespace)
    {
        GraphView gv = GraphViewTests.GetGraph ();

        gv.Annotations.Add (
                            new TextAnnotation { Text = whitespace, GraphPosition = new PointF (4, 2) }
                           );

        // add a point a bit further along the graph so if the whitespace were rendered
        // the test would pick it up (AssertDriverContentsAre ignores trailing whitespace on lines)
        var points = new ScatterSeries ();
        points.Points.Add (new PointF (7, 2));
        gv.Series.Add (points);
        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @$"
 │
 ┤      {Glyphs.Dot}
 ┤
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestTextAnnotation_GraphUnits ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        gv.Annotations.Add (
                            new TextAnnotation { Text = "hey!", GraphPosition = new PointF (2, 2) }
                           );

        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @"
 │
 ┤ hey!
 ┤
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // user scrolls up one unit of graph space
        gv.ScrollOffset = new PointF (0, 1f);
        gv.SetNeedsDraw ();
        View.SetClipToScreen ();
        gv.Draw ();

        // we expect the text annotation to go down one line since
        // the scroll offset means that that point of graph space is 
        // lower down in the view.  Note the 1 on the axis too, our viewport
        // (excluding margins) now shows y of 1 to 4 (previously 0 to 5)
        expected =
            @"
 │
 ┤ 
 ┤ hey!
1┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestTextAnnotation_LongText ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        gv.Annotations.Add (
                            new TextAnnotation
                            {
                                Text = "hey there partner hows it going boy its great", GraphPosition = new PointF (2, 2)
                            }
                           );

        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();

        // long text should get truncated
        // margin takes up 1 units
        // the GraphPosition of the anntation is 2
        // Leaving 7 characters of the annotation renderable (including space)
        var expected =
            @"
 │
 ┤ hey the
 ┤
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestTextAnnotation_Offscreen ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        gv.Annotations.Add (
                            new TextAnnotation
                            {
                                Text = "hey there partner hows it going boy its great", GraphPosition = new PointF (9, 2)
                            }
                           );

        gv.LayoutSubViews ();
        gv.Draw ();

        // Text is off the screen (graph x axis runs to 8 not 9)
        var expected =
            @"
 │
 ┤
 ┤
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void TestTextAnnotation_ScreenUnits ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        gv.Annotations.Add (
                            new TextAnnotation { Text = "hey!", ScreenPosition = new Point (3, 1) }
                           );
        gv.LayoutSubViews ();
        View.SetClipToScreen ();
        gv.Draw ();

        var expected =
            @"
 │
 ┤ hey!
 ┤
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // user scrolls up one unit of graph space
        gv.ScrollOffset = new PointF (0, 1f);
        gv.SetNeedsDraw ();
        View.SetClipToScreen ();
        gv.Draw ();

        // we expect no change in the location of the annotation (only the axis label changes)
        // this is because screen units are constant and do not change as the viewport into
        // graph space scrolls to different areas of the graph
        expected =
            @"
 │
 ┤ hey!
 ┤
1┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // user scrolls up one unit of graph space
        gv.ScrollOffset = new PointF (0, 1f);
        gv.SetNeedsDraw ();
        View.SetClipToScreen ();
        gv.Draw ();

        // we expect no change in the location of the annotation (only the axis label changes)
        // this is because screen units are constant and do not change as the viewport into
        // graph space scrolls to different areas of the graph
        expected =
            @"
 │
 ┤ hey!
 ┤
1┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }
}

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

    [Fact]
    public void Constructors_Defaults ()
    {
        var legend = new LegendAnnotation ();
        Assert.Equal (Rectangle.Empty, legend.Viewport);
        Assert.Equal (Rectangle.Empty, legend.Frame);
        Assert.Equal (LineStyle.Single, legend.BorderStyle);
        Assert.False (legend.BeforeSeries);

        var bounds = new Rectangle (1, 2, 10, 3);
        legend = new LegendAnnotation (bounds);
        Assert.Equal (new Rectangle (0, 0, 8, 1), legend.Viewport);
        Assert.Equal (bounds, legend.Frame);
        Assert.Equal (LineStyle.Single, legend.BorderStyle);
        Assert.False (legend.BeforeSeries);
        legend.BorderStyle = LineStyle.None;
        Assert.Equal (new Rectangle (0, 0, 10, 3), legend.Viewport);
        Assert.Equal (bounds, legend.Frame);
    }

    [Fact]
    [AutoInitShutdown]
    public void LegendNormalUsage_WithBorder ()
    {
        GraphView gv = GraphViewTests.GetGraph ();
        var legend = new LegendAnnotation (new Rectangle (2, 0, 5, 3));
        legend.AddEntry (new GraphCellToRender ((Rune)'A'), "Ant");
        legend.AddEntry (new GraphCellToRender ((Rune)'B'), "Bat");

        gv.Annotations.Add (legend);
        gv.Layout ();
        gv.Draw ();

        var expected =
            @"
 │┌───┐
 ┤│AAn│
 ┤└───┘
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void LegendNormalUsage_WithoutBorder ()
    {
        GraphView gv = GraphViewTests.GetGraph ();
        var legend = new LegendAnnotation (new Rectangle (2, 0, 5, 3));
        legend.AddEntry (new GraphCellToRender ((Rune)'A'), "Ant");
        legend.AddEntry (new GraphCellToRender ((Rune)'B'), "?"); // this will exercise pad
        legend.AddEntry (new GraphCellToRender ((Rune)'C'), "Cat");
        legend.AddEntry (new GraphCellToRender ((Rune)'H'), "Hattter"); // not enough space for this oen
        legend.BorderStyle = LineStyle.None;

        gv.Annotations.Add (legend);

        gv.Draw ();

        var expected =
            @"
 │AAnt
 ┤B?
 ┤CCat
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }
}

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

    [Fact]
    public void MarginBottom_BiggerThanHeight_ExpectBlankGraph ()
    {
        GraphView gv = GraphViewTests.GetGraph ();
        gv.Height = 10;
        gv.MarginBottom = 20;

        gv.Series.Add (
                       new ScatterSeries { Points = { new PointF (1, 1), new PointF (5, 0) } }
                      );

        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @"
         
         
          ";
        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    public void MarginLeft_BiggerThanWidth_ExpectBlankGraph ()
    {
        GraphView gv = GraphViewTests.GetGraph ();
        gv.Width = 10;
        gv.MarginLeft = 20;

        gv.Series.Add (
                       new ScatterSeries { Points = { new PointF (1, 1), new PointF (5, 0) } }
                      );

        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @"
         
         
          ";
        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void PathAnnotation_Box ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        var path = new PathAnnotation ();
        path.Points.Add (new PointF (1, 1));
        path.Points.Add (new PointF (1, 3));
        path.Points.Add (new PointF (6, 3));
        path.Points.Add (new PointF (6, 1));

        // list the starting point again so that it draws a complete square
        // (otherwise it will miss out the last line along the bottom)
        path.Points.Add (new PointF (1, 1));

        gv.Annotations.Add (path);
        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @"
 │......
 ┤.    .
 ┤......
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void PathAnnotation_Diamond ()
    {
        GraphView gv = GraphViewTests.GetGraph ();

        var path = new PathAnnotation ();
        path.Points.Add (new PointF (1, 2));
        path.Points.Add (new PointF (3, 3));
        path.Points.Add (new PointF (6, 2));
        path.Points.Add (new PointF (3, 1));

        // list the starting point again to close the shape
        path.Points.Add (new PointF (1, 2));

        gv.Annotations.Add (path);

        gv.LayoutSubViews ();
        gv.Draw ();

        var expected =
            @"
 │  ..
 ┤..  ..
 ┤ ...
0┼┬┬┬┬┬┬┬┬
 0    5";

        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Theory]
    [AutoInitShutdown]
    [InlineData (true)]
    [InlineData (false)]
    public void ViewChangeText_RendersCorrectly (bool useFill)
    {
        // create a wide window
        var mount = new View { Width = 100, Height = 100 };
        var top = new Toplevel ();

        try
        {
            // Create a view with a short text 
            var view = new View { Text = "ff", Width = 2, Height = 1 };

            // Specify that the label should be very wide
            if (useFill)
            {
                view.Width = Dim.Fill ();
            }
            else
            {
                view.Width = 100;
            }

            //put label into view
            mount.Add (view);

            //putting mount into Toplevel since changing size
            top.Add (mount);
            Application.Begin (top);

            // render view
            //view.Scheme = new Scheme ();
            Assert.Equal (1, view.Height);
            mount.SetNeedsDraw ();
            mount.Draw ();

            // should have the initial text
            DriverAssert.AssertDriverContentsAre ("ff", null);

            // change the text and redraw
            view.Text = "ff1234";
            mount.SetNeedsDraw ();
            View.SetClipToScreen ();
            mount.Draw ();

            // should have the new text rendered
            DriverAssert.AssertDriverContentsAre ("ff1234", null);
        }
        finally
        {
            top.Dispose ();
            Application.Shutdown ();
        }
    }

    [Fact]
    [AutoInitShutdown]
    public void XAxisLabels_With_MarginLeft ()
    {
        var gv = new GraphView { Viewport = new Rectangle (0, 0, 10, 7) };

        gv.CellSize = new PointF (1, 0.5f);
        gv.AxisY.Increment = 1;
        gv.AxisY.ShowLabelsEvery = 1;

        gv.Series.Add (
                       new ScatterSeries { Points = { new PointF (1, 1), new PointF (5, 0) } }
                      );

        // reserve 3 cells of the left for the margin
        gv.MarginLeft = 3;
        gv.MarginBottom = 1;

        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();

        var expected =
            @$"
   │
  2┤
   │
  1┤{Glyphs.Dot}
   │ 
  0┼┬┬┬┬{Glyphs.Dot}┬
   0    5
         
          ";
        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }

    [Fact]
    [AutoInitShutdown]
    public void YAxisLabels_With_MarginBottom ()
    {
        var gv = new GraphView { Viewport = new Rectangle (0, 0, 10, 7) };

        gv.CellSize = new PointF (1, 0.5f);
        gv.AxisY.Increment = 1;
        gv.AxisY.ShowLabelsEvery = 1;

        gv.Series.Add (
                       new ScatterSeries { Points = { new PointF (1, 1), new PointF (5, 0) } }
                      );

        // reserve 3 cells of the console for the margin
        gv.MarginBottom = 3;
        gv.MarginLeft = 1;

        gv.LayoutSubViews ();
        gv.SetNeedsDraw ();
        gv.Draw ();

        var expected =
            @$"
 │
1┤{Glyphs.Dot}
 │ 
0┼┬┬┬┬{Glyphs.Dot}┬┬┬
 0    5   
          
          ";
        DriverAssert.AssertDriverContentsAre (expected, _output);

        // Shutdown must be called to safely clean up Application if Init has been called
        Application.Shutdown ();
    }
}

public class AxisIncrementToRenderTests
{
    [Fact]
    public void AxisIncrementToRenderTests_Constructor ()
    {
        var render = new AxisIncrementToRender (Orientation.Horizontal, 1, 6.6f);

        Assert.Equal (Orientation.Horizontal, render.Orientation);
        Assert.Equal (1, render.ScreenLocation);
        Assert.Equal (6.6f, render.Value);
    }
}