Add tests

UICatalog/Scenarios/Drawing.cs

@@ -6,7 +6,7 @@ using Terminal.Gui.Graphs;
 
 namespace UICatalog.Scenarios {
 
-	[ScenarioMetadata (Name: "Drawing", Description: "Demonstrates StraightLineCanvas.")]
+	[ScenarioMetadata (Name: "Drawing", Description: "Demonstrates LineCanvas.")]
 	[ScenarioCategory ("Controls")]
 	[ScenarioCategory ("Layout")]
 	public class Drawing : Scenario {

UnitTests/LineCanvasTests.cs

@@ -0,0 +1,200 @@
+using Terminal.Gui.Graphs;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Terminal.Gui.Core {
+	public class LineCanvasTests {
+
+		readonly ITestOutputHelper output;
+
+		public LineCanvasTests (ITestOutputHelper output)
+		{
+			this.output = output;
+		}
+
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Dot ()
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 0, Orientation.Horizontal, BorderStyle.Single);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+.";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		[InlineData (BorderStyle.Single)]
+		[InlineData (BorderStyle.Rounded)]
+		[Theory, AutoInitShutdown]
+		public void TestLineCanvas_Horizontal (BorderStyle style)
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Horizontal, style);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+──";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Horizontal_Double ()
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Horizontal, BorderStyle.Double);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@" 
+══";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		[InlineData (BorderStyle.Single)]
+		[InlineData(BorderStyle.Rounded)]
+		[Theory, AutoInitShutdown]
+		public void TestLineCanvas_Vertical (BorderStyle style)
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Vertical, style);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+│
+│";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Vertical_Double ()
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Vertical, BorderStyle.Double);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+║
+║";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		/// <summary>
+		/// This test demonstrates that corners are only drawn when lines overlap.
+		/// Not when they terminate adjacent to one another.
+		/// </summary>
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Corner_NoOverlap()
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Horizontal, BorderStyle.Single);
+			canvas.AddLine (new Point (0, 1), 1, Orientation.Vertical, BorderStyle.Single);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+──
+│
+│";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+		/// <summary>
+		/// This test demonstrates how to correctly trigger a corner.  By
+		/// overlapping the lines in the same cell
+		/// </summary>
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Corner_Correct ()
+		{
+			var v = GetCanvas (out var canvas);
+			canvas.AddLine (new Point (0, 0), 1, Orientation.Horizontal, BorderStyle.Single);
+			canvas.AddLine (new Point (0, 0), 2, Orientation.Vertical, BorderStyle.Single);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+┌─
+│
+│";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		
+		}
+		[Fact,AutoInitShutdown]
+		public void TestLineCanvas_Window ()
+		{
+			var v = GetCanvas (out var canvas);
+			
+			// outer box
+			canvas.AddLine (new Point (0, 0), 9, Orientation.Horizontal, BorderStyle.Single);
+			canvas.AddLine (new Point (9, 0), 4, Orientation.Vertical, BorderStyle.Single);
+			canvas.AddLine (new Point (9, 4), -9, Orientation.Horizontal, BorderStyle.Single);
+			canvas.AddLine (new Point (0, 4), -4, Orientation.Vertical, BorderStyle.Single);
+
+
+			canvas.AddLine (new Point (5, 0), 4, Orientation.Vertical, BorderStyle.Single);
+			canvas.AddLine (new Point (0, 2), 9, Orientation.Horizontal, BorderStyle.Single);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+┌────┬───┐
+│    │   │
+├────┼───┤
+│    │   │
+└────┴───┘";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		[Fact, AutoInitShutdown]
+		public void TestLineCanvas_Window_Double ()
+		{
+			var v = GetCanvas (out var canvas);
+
+			// outer box
+			canvas.AddLine (new Point (0, 0), 9, Orientation.Horizontal, BorderStyle.Double);
+			canvas.AddLine (new Point (9, 0), 4, Orientation.Vertical, BorderStyle.Double);
+			canvas.AddLine (new Point (9, 4), -9, Orientation.Horizontal, BorderStyle.Double);
+			canvas.AddLine (new Point (0, 4), -4, Orientation.Vertical, BorderStyle.Double);
+
+
+			canvas.AddLine (new Point (5, 0), 4, Orientation.Vertical, BorderStyle.Double);
+			canvas.AddLine (new Point (0, 2), 9, Orientation.Horizontal, BorderStyle.Double);
+
+			v.Redraw (v.Bounds);
+
+			string looksLike =
+@"    
+╔════╦═══╗
+║    ║   ║
+╠════╬═══╣
+║    ║   ║
+╚════╩═══╝";
+			TestHelpers.AssertDriverContentsAre (looksLike, output);
+		}
+
+		private View GetCanvas (out LineCanvas canvas)
+		{
+			var v = new View {
+				Width = 10,
+				Height = 5,
+				Bounds = new Rect (0, 0, 10, 5)
+			};
+
+			var canvasCopy = canvas =  new LineCanvas (Application.Driver);
+			v.DrawContentComplete += (r)=> canvasCopy.Draw (v, v.Bounds);
+
+			return v;
+		}
+	}
+}