almost got clip rect working

Terminal.Gui/Core/View.cs

@@ -890,7 +890,15 @@ namespace Terminal.Gui {
 							if (view.layoutNeeded)
 								view.LayoutSubviews ();
 							Application.CurrentView = view;
-							view.Redraw (view.Bounds);
+
+							// Ensure we don't make the Driver's clip rect any bigger
+							if (Driver.Clip.IsEmpty || Driver.Clip.Contains(RectToScreen (view.Bounds))) {
+								var savedClip = ClipToBounds ();
+								view.Redraw (view.Bounds);
+								Driver.Clip = savedClip;
+							} else {
+								view.Redraw (view.Bounds);
+							}
 						}
 						view.NeedDisplay = Rect.Empty;
 						view.childNeedsDisplay = false;

Terminal.Gui/Core/Window.cs

@@ -153,16 +153,24 @@ namespace Terminal.Gui {
 		///<inheritdoc cref="Redraw"/>
 		public override void Redraw (Rect bounds)
 		{
+			//var padding = 0;
 			Application.CurrentView = this;
 			var scrRect = RectToScreen (new Rect (0, 0, Frame.Width, Frame.Height));
-			var savedClip = Driver.Clip;
-			Driver.Clip = ScreenClip (RectToScreen (Bounds));
 
 			if (NeedDisplay != null && !NeedDisplay.IsEmpty) {
 				Driver.SetAttribute (ColorScheme.Normal);
 				Driver.DrawFrame (scrRect, padding, true);
 			}
-			contentView.Redraw (contentView.Bounds);
+
+			
+			if (Driver.Clip.IsEmpty || Driver.Clip.Contains (RectToScreen (contentView.Bounds))) {
+				var savedClip = Driver.Clip;
+				Driver.Clip = ClipToBounds();
+				contentView.Redraw (contentView.Bounds);
+				Driver.Clip = savedClip;
+			} else {
+				contentView.Redraw (contentView.Bounds);
+			}
 			ClearNeedsDisplay ();
 			Driver.SetAttribute (ColorScheme.Normal);
 			Driver.DrawFrame (scrRect, padding, false);
@@ -170,7 +178,6 @@ namespace Terminal.Gui {
 			if (HasFocus)
 				Driver.SetAttribute (ColorScheme.HotNormal);
 			Driver.DrawWindowTitle (scrRect, Title, padding, padding, padding, padding);
-			Driver.Clip = savedClip;
 			Driver.SetAttribute (ColorScheme.Normal);
 		}
 

Terminal.Gui/Views/FrameView.cs

@@ -137,14 +137,20 @@ namespace Terminal.Gui {
 			var padding = 0;
 			Application.CurrentView = this;
 			var scrRect = RectToScreen (new Rect (0, 0, Frame.Width, Frame.Height));
-			var savedClip = Driver.Clip;
-			Driver.Clip = ScreenClip (RectToScreen (Bounds));
 
 			if (NeedDisplay != null && !NeedDisplay.IsEmpty) {
 				Driver.SetAttribute (ColorScheme.Normal);
 				Driver.DrawFrame (scrRect, padding, true);
 			}
-			contentView.Redraw (contentView.Bounds);
+
+			if (Driver.Clip.IsEmpty || Driver.Clip.Contains (contentView.RectToScreen (contentView.Bounds))) {
+				var savedClip = Driver.Clip;
+				Driver.Clip = ScreenClip (RectToScreen (Bounds));
+				contentView.Redraw (contentView.Bounds);
+				Driver.Clip = savedClip;
+			} else {
+				contentView.Redraw (contentView.Bounds);
+			}
 			ClearNeedsDisplay ();
 			Driver.SetAttribute (ColorScheme.Normal);
 			Driver.DrawFrame (scrRect, padding, false);
@@ -152,7 +158,6 @@ namespace Terminal.Gui {
 			if (HasFocus)
 				Driver.SetAttribute (ColorScheme.HotNormal);
 			Driver.DrawWindowTitle (scrRect, Title, padding, padding, padding, padding);
-			Driver.Clip = savedClip;
 			Driver.SetAttribute (ColorScheme.Normal);
 		}
 	}

Terminal.Gui/Views/ScrollView.cs

@@ -401,11 +401,21 @@ namespace Terminal.Gui {
 		public override void Redraw(Rect region)
 		{
 			SetViewsNeedsDisplay ();
-			var oldClip = ClipToBounds ();
 			Driver.SetAttribute (ColorScheme.Normal);
 			Clear ();
-			base.Redraw(region);
-			Driver.Clip = oldClip;
+
+			//if (Driver.Clip.IsEmpty || Driver.Clip.Contains (RectToScreen (Bounds)) || Driver.Clip.Contains (contentView.RectToScreen (contentView.Bounds))) {
+				var savedClip = Driver.Clip;
+				Driver.Clip = ClipToBounds ();
+				//vertical.Redraw (vertical.Bounds);
+				//horizontal.Redraw (vertical.Bounds);
+				contentView.Redraw (contentView.Bounds);
+				Driver.Clip = savedClip;
+			//} else {
+			//	vertical.Redraw (vertical.Bounds);
+			//	horizontal.Redraw (vertical.Bounds);
+			//	contentView.Redraw (contentView.Bounds);
+			//}
 			Driver.SetAttribute (ColorScheme.Normal);
 		}
 

UICatalog/Properties/launchSettings.json

@@ -1,7 +1,8 @@
 {
   "profiles": {
     "UICatalog": {
-      "commandName": "Project"
+      "commandName": "Project",
+      "commandLineArgs": "Scrolling"
     }
   }
 }

UICatalog/Scenarios/MessageBoxes.cs

@@ -110,7 +110,7 @@ namespace UICatalog {
 			var styleRadioGroup = new RadioGroup (new [] { "_Query", "_Error" } ) {
 				X = Pos.Right (label) + 1,
 				Y = Pos.Top (label),
-				Width = 5, // BUGBUG: This should cause clipping!
+				Width = 5, // BUGBUG: This should cause clipping! #399
 			};
 			frame.Add (styleRadioGroup);
 

UICatalog/Scenarios/Progress.cs

@@ -41,7 +41,7 @@ namespace UICatalog {
 				LeftFrame = new FrameView ("Settings") {
 					X = 0,
 					Y = 0,
-					Height = Dim.Percent (100) + 1, // BUGBUG: This +1 should not be needed
+					Height = Dim.Percent (100), // BUGBUG: This +1 should not be needed
 					Width = Dim.Percent (25)
 				};
 				var lbl = new Label (1, 1, "Tick every (ms):");
@@ -223,14 +223,13 @@ namespace UICatalog {
 
 			var startBoth = new Button ("Start Both") {
 				X = Pos.Center (),
-				Y = Pos.AnchorEnd () - 1,
+				Y = Pos.Bottom(mainLoopTimeoutDemo) + 1,
 			};
 			startBoth.Clicked = () => {
 				systemTimerDemo.Start ();
 				mainLoopTimeoutDemo.Start ();
 			};
 			Win.Add (startBoth);
-
 		}
 
 		protected override void Dispose (bool disposing)

UICatalog/Scenarios/Scrolling.cs

@@ -0,0 +1,96 @@
+using System;
+using Terminal.Gui;
+
+namespace UICatalog {
+	[ScenarioMetadata (Name: "Scrolling", Description: "Demonstrates ScrollView etc...")]
+	[ScenarioCategory ("Controls")]
+	[ScenarioCategory ("Bug Repro")]
+
+	class Scrolling : Scenario {
+		public override void Setup ()
+		{
+			var label = new Label ("ScrollView (new Rect (2, 2, 50, 20)) with a 100, 100 ContentSize...") {
+				X = 0, Y = 0,
+				ColorScheme = Colors.Dialog
+			};
+			Win.Add (label);
+
+			// BUGBUG: ScrollView only supports Absolute Positioning (#72)
+			var scrollView = new ScrollView (new Rect (2, 2, 50, 20));
+			scrollView.ColorScheme = Colors.TopLevel;
+			scrollView.ContentSize = new Size (100, 100);
+			//ContentOffset = new Point (0, 0),
+			scrollView.ShowVerticalScrollIndicator = true;
+			scrollView.ShowHorizontalScrollIndicator = true;
+
+			const string rule = "|123456789";
+			var horizontalRuler = new Label ("") {
+				X = 0,
+				Y = 0,
+				Width = Dim.Fill (1),  // BUGBUG: I don't think this should be needed; DimFill() should respect container's frame. X does.
+				ColorScheme = Colors.Error
+			};
+			scrollView.Add (horizontalRuler);
+			const string vrule = "|\n1\n2\n3\n4\n5\n6\n7\n8\n9\n";
+
+			var verticalRuler = new Label ("") {
+				X = 0,
+				Y = 0,
+				Width = 1,
+				Height = Dim.Fill (),
+				ColorScheme = Colors.Error
+			};
+			scrollView.Add (verticalRuler);
+
+			Application.Resized += (sender, a) => {
+				horizontalRuler.Text = rule.Repeat ((int)Math.Ceiling ((double)(horizontalRuler.Bounds.Width) / (double)rule.Length)) [0..(horizontalRuler.Bounds.Width)];
+				verticalRuler.Text = vrule.Repeat ((int)Math.Ceiling ((double)(verticalRuler.Bounds.Height * 2) / (double)rule.Length)) [0..(verticalRuler.Bounds.Height * 2)];
+			};
+
+			scrollView.Add (new Button ("Press me!") {
+				X = 3,
+				Y = 3,
+				Clicked = () => MessageBox.Query (20, 7, "MessageBox", "Neat?", "Yes", "No")
+			});
+
+			scrollView.Add (new TextField ("This is a test of...") {
+				X = 3,
+				Y = 5,
+				Width = 50,
+				ColorScheme = Colors.Dialog
+			});
+
+			scrollView.Add (new TextField ("... the emergency broadcast sytem.") {
+				X = 3,
+				Y = 10,
+				Width = 50,
+				ColorScheme = Colors.Dialog
+			});
+
+			scrollView.Add (new TextField ("Last line") {
+				X = 3,
+				Y = 99,
+				Width = 50,
+				ColorScheme = Colors.Dialog
+			});
+
+			// Demonstrate AnchorEnd - Button is anchored to bottom/right
+			var anchorButton = new Button ("Bottom Right") {
+				Y = Pos.AnchorEnd () - 1,
+			};
+			// TODO: Use Pos.Width instead of (Right-Left) when implemented (#502)
+			anchorButton.X = Pos.AnchorEnd () - (Pos.Right (anchorButton) - Pos.Left (anchorButton));
+			anchorButton.Clicked = () => {
+				// Ths demonstrates how to have a dynamically sized button
+				// Each time the button is clicked the button's text gets longer
+				// The call to Win.LayoutSubviews causes the Computed layout to
+				// get updated. 
+				anchorButton.Text += "!";
+				Win.LayoutSubviews ();
+			};
+			scrollView.Add (anchorButton);
+
+			Win.Add (scrollView);
+		}
+	}
+}

UICatalog/Scenarios/WindowsAndFrameViews.cs

@@ -104,11 +104,11 @@ namespace UICatalog {
 				Height = height,
 			};
 			frame.ColorScheme = Colors.Dialog;
-			frame.Add (new Button ("Press me! (Y = 0)") {
+			frame.Add (new Label ("This is a Label! (Y = 0)") {
 				X = Pos.Center (),
 				Y = 0,
 				ColorScheme = Colors.Error,
-				Clicked = () => MessageBox.ErrorQuery (30, 10, frame.Title.ToString (), "Neat?", "Yes", "No")
+				//Clicked = () => MessageBox.ErrorQuery (30, 10, frame.Title.ToString (), "Neat?", "Yes", "No")
 			});
 			var subWinofFV = new Window ("this is a Sub-Window") {
 				X = Pos.Percent (0),