gui-cs.Terminal.Gui/UnitTests/View/Layout/SetRelativeLayoutTests.cs

using Xunit;
using Xunit.Abstractions;

namespace Terminal.Gui.ViewTests;

public class SetRelativeLayoutTests {
	readonly ITestOutputHelper _output;

	public SetRelativeLayoutTests (ITestOutputHelper output) => _output = output;

	[Fact]
	public void ComputedPosDim_StayComputed ()
	{
		var screen = new Rect (0, 0, 10, 15);
		var view = new View {
			X = 1,
			Y = 2,
			Width = Dim.Fill (),
			Height = Dim.Fill ()
		};

		Assert.Equal ("Absolute(1)", view.X.ToString ());
		Assert.Equal ("Absolute(2)", view.Y.ToString ());
		Assert.Equal ("Fill(0)", view.Width.ToString ());
		Assert.Equal ("Fill(0)", view.Height.ToString ());
		view.SetRelativeLayout (screen);
		Assert.Equal ("Fill(0)", view.Width.ToString ());
		Assert.Equal ("Fill(0)", view.Height.ToString ());
	}

	[Fact]
	public void AbsolutePosDim_DontChange ()
	{
		var screen = new Rect (0, 0, 10, 15);
		var view = new View {
			X = 1, // outside of screen +10
			Y = 2, // outside of screen -10
			Width = 3,
			Height = 4
		};

		// Layout is Absolute. So the X and Y are not changed.
		view.SetRelativeLayout (screen);
		Assert.Equal (1, view.Frame.X);
		Assert.Equal (2, view.Frame.Y);
		Assert.Equal (3, view.Frame.Width);
		Assert.Equal (4, view.Frame.Height);
	}

	[Fact]
	public void Fill_Pos_Within_Bounds ()
	{
		var screen = new Rect (0, 0, 80, 25);
		var view = new View {
			X = 1,
			Y = 1,
			Width = 5,
			Height = 4
		};

		view.SetRelativeLayout (screen);
		Assert.Equal (1, view.Frame.X);
		Assert.Equal (1, view.Frame.Y);
		Assert.Equal (5, view.Frame.Width);
		Assert.Equal (4, view.Frame.Height);

		view.Width = 80;
		view.Height = 25;
		view.SetRelativeLayout (screen);
		Assert.Equal (1, view.Frame.X);
		Assert.Equal (1, view.Frame.Y);
		Assert.Equal (80, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.Width = Dim.Fill ();
		view.Height = Dim.Fill ();
		view.SetRelativeLayout (screen);
		Assert.Equal (1, view.Frame.X);
		Assert.Equal (1, view.Frame.Y);
		Assert.Equal (79, view.Frame.Width); // proof (80 - 1)
		Assert.Equal (24, view.Frame.Height); // proof (25 - 1)

		view.X = 79;
		view.Width = Dim.Fill ();
		view.Height = Dim.Fill ();
		view.SetRelativeLayout (screen);
		Assert.Equal (79, view.Frame.X);
		Assert.Equal (1, view.Frame.Y);
		Assert.Equal (1, view.Frame.Width); // proof (80 - 79)
		Assert.Equal (24, view.Frame.Height);

		view.X = 80;
		view.Width = Dim.Fill ();
		view.Height = Dim.Fill ();
		view.SetRelativeLayout (screen);
		Assert.Equal (80, view.Frame.X);
		Assert.Equal (1, view.Frame.Y);
		Assert.Equal (0, view.Frame.Width); // proof (80 - 80)
		Assert.Equal (24, view.Frame.Height);
	}

	[Fact]
	public void Fill_Pos_Outside_Bounds ()
	{
		var screen = new Rect (0, 0, 80, 25);
		var view = new View {
			X = 90, // outside of screen +10
			Y = -10, // outside of screen -10
			Width = 15,
			Height = 15
		};

		// Layout is Absolute. So the X and Y are not changed.
		view.SetRelativeLayout (screen);
		Assert.Equal (90, view.Frame.X);
		Assert.Equal (-10, view.Frame.Y);
		Assert.Equal (15, view.Frame.Width);
		Assert.Equal (15, view.Frame.Height);

		// prove Width=Height= same as screen size
		view.Width = 80;
		view.Height = 25;
		view.SetRelativeLayout (screen);
		Assert.Equal (90, view.Frame.X);
		Assert.Equal (-10, view.Frame.Y);
		Assert.Equal (80, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.Width = Dim.Fill ();
		view.Height = Dim.Fill ();
		view.SetRelativeLayout (screen);
		Assert.Equal (90, view.Frame.X);
		Assert.Equal (-10, view.Frame.Y);
		Assert.Equal (0, view.Frame.Width); // proof: 15x15 view is placed beyond right side of screen, so fill width is 0
		Assert.Equal (35, view.Frame.Height); // proof: 15x15 view is placed beyond top of screen 10 rows, screen is 25 rows. so fill height is 25 + 10 = 35
	}

	[Fact]
	public void PosCombine_PosCenter_Minus_Absolute ()
	{
		// This test used to be in ViewTests.cs Internal_Tests. It was moved here because it is testing
		// SetRelativeLayout. In addition, the old test was bogus because it was testing the wrong thing (and 
		// because in v1 Pos.Center was broken in this regard!

		var screen = new Rect (0, 0, 80, 25);
		var view = new View {
			X = Pos.Center () - 41, // -2 off left edge of screen
			Y = Pos.Center () - 13, // -1 off top edge of screen
			Width = 1,
			Height = 1
		};

		view.SetRelativeLayout (screen);
		Assert.Equal (-2, view.Frame.X); // proof: 1x1 view centered in 80x25 screen has x of 39, so -41 is -2
		Assert.Equal (-1, view.Frame.Y); // proof: 1x1 view centered in 80x25 screen has y of 12, so -13 is -1

		view.Width = 80;
		view.Height = 25;
		view.SetRelativeLayout (screen);
		Assert.Equal (-41, view.Frame.X);
		Assert.Equal (-13, view.Frame.Y);
		Assert.Equal (80, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.Width = Dim.Fill ();
		view.Height = Dim.Fill ();
		view.SetRelativeLayout (screen);
		Assert.Equal (-41, view.Frame.X);
		Assert.Equal (-13, view.Frame.Y);
		Assert.Equal (121, view.Frame.Width); // 121 = screen.Width - (-Center - 41)
		Assert.Equal (38, view.Frame.Height);
	}

	[Fact]
	public void Fill_And_PosCenter ()
	{
		var screen = new Rect (0, 0, 80, 25);
		var view = new View {
			X = Pos.Center (),
			Y = Pos.Center (),
			Width = Dim.Fill (),
			Height = Dim.Fill ()
		};

		view.SetRelativeLayout (screen);
		Assert.Equal (0, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (80, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () + 1;
		view.SetRelativeLayout (screen);
		Assert.Equal (1, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (79, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () + 79;
		view.SetRelativeLayout (screen);
		Assert.Equal (79, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (1, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () + 80;
		view.SetRelativeLayout (screen);
		Assert.Equal (80, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (0, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () - 1;
		view.SetRelativeLayout (screen);
		Assert.Equal (-1, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (81, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () - 2; // Fill means all the way to right. So width will be 82. (dim gets calc'd before pos).
		view.SetRelativeLayout (screen);
		Assert.Equal (-2, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (82, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () - 3; // Fill means all the way to right. So width will be 83. (dim gets calc'd before pos).
		view.SetRelativeLayout (screen);
		Assert.Equal (-3, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (83, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

		view.X = Pos.Center () - 41; // Fill means all the way to right. So width will be . (dim gets calc'd before pos).
		view.SetRelativeLayout (screen);
		Assert.Equal (-41, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (121, view.Frame.Width);
		Assert.Equal (25, view.Frame.Height);

	}

	[Fact]
	public void PosCombine_PosCenter_Plus_Absolute ()
	{
		var screen = new Rect (0, 0, 80, 25);
		var view = new View {
			X = Pos.Center () + 41, // ((80 / 2) - (5 / 2)) + 41 = (40 - 3 + 41) = 78
			Y = Pos.Center () + 13, // ((25 / 2) - (4 / 2)) + 13 = (12 - 2 + 13) = 23
			Width = 5,
			Height = 4
		};

		view.SetRelativeLayout (screen);
		Assert.Equal (78, view.Frame.X);
		Assert.Equal (23, view.Frame.Y);
	}

	[Fact]
	[TestRespondersDisposed]
	public void PosCombine_Plus_Absolute ()
	{
		var superView = new View {
			AutoSize = false,
			Width = 10,
			Height = 10
		};

		var testView = new View {
			AutoSize = false,
			X = Pos.Center (),
			Y = Pos.Center (),
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (4, testView.Frame.X);
		Assert.Equal (4, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = Pos.Center () + 1, // ((10 / 2) - (1 / 2)) + 1 = 5 - 1 + 1 = 5
			Y = Pos.Center () + 1,
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (5, testView.Frame.X);
		Assert.Equal (5, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = 1 + Pos.Center (),
			Y = 1 + Pos.Center (),
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (5, testView.Frame.X);
		Assert.Equal (5, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = 1 + Pos.Percent (50),
			Y = Pos.Percent (50) + 1,
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (6, testView.Frame.X);
		Assert.Equal (6, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = Pos.Percent (10) + Pos.Percent (40),
			Y = Pos.Percent (10) + Pos.Percent (40),
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (5, testView.Frame.X);
		Assert.Equal (5, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = 1 + Pos.Percent (10) + Pos.Percent (40) - 1,
			Y = 5 + Pos.Percent (10) + Pos.Percent (40) - 5,
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (5, testView.Frame.X);
		Assert.Equal (5, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = Pos.Left (testView),
			Y = Pos.Left (testView),
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (5, testView.Frame.X);
		Assert.Equal (5, testView.Frame.Y);

		testView = new View {
			AutoSize = false,
			X = 1 + Pos.Left (testView),
			Y = Pos.Top (testView) + 1,
			Width = 1,
			Height = 1
		};
		superView.Add (testView);
		testView.SetRelativeLayout (superView.Frame);
		Assert.Equal (6, testView.Frame.X);
		Assert.Equal (6, testView.Frame.Y);

		superView.Dispose ();

	}


	[Fact]
	public void PosDimFunction ()
	{
		var screen = new Rect (0, 0, 30, 1);
		var view = new View ("abc");
		view.X = Pos.AnchorEnd () - Pos.Function (GetViewWidth);

		int GetViewWidth ()
		{
			return view.Frame.Width;
		}

		// view will be 3 chars wide. It's X will be 27 (30 - 3).
		view.SetRelativeLayout (screen);
		Assert.Equal (27, view.Frame.X);
		Assert.Equal (0, view.Frame.Y);
		Assert.Equal (3, view.Frame.Width);
		Assert.Equal (1, view.Frame.Height);

		var tf = new TextField ("01234567890123456789");
		tf.Width = Dim.Fill (1) - Dim.Function (GetViewWidth);

		// tf will fill the screen minus 1 minus the width of view (3).
		// so it's width will be 26 (30 - 1 - 3).
		tf.SetRelativeLayout (screen);
		Assert.Equal (0, tf.Frame.X);
		Assert.Equal (0, tf.Frame.Y);
		Assert.Equal (26, tf.Frame.Width);
		Assert.Equal (1, tf.Frame.Height);

	}
}