Make ScrollView work, still needs scroll bar indicators

Terminal.Gui/Core.cs

@@ -150,6 +150,13 @@ namespace Terminal.Gui {
 	///    Using ColorSchemes has the advantage that your application will work both
 	///    in color as well as black and white displays.
 	/// </para>
+	/// <para>
+	///    Views that are focusable should implement the PositionCursor to make sure that
+	///    the cursor is placed in a location that makes sense.   Unix terminals do not have
+	///    a way of hiding the cursor, so it can be distracting to have the cursor left at 
+	///    the last focused view.   So views should make sure that they place the cursor
+	///    in a visually sensible place.
+	/// </para>
 	/// </remarks>
 	public class View : Responder, IEnumerable {
 		View container = null;
@@ -441,6 +448,28 @@ namespace Terminal.Gui {
 			return new Rect (x, y, w, h);
 		}
 
+		/// <summary>
+		/// Sets the Console driver's clip region to the current View's Bounds.
+		/// </summary>
+		/// <returns>The existing driver's Clip region, which can be then set by setting the Driver.Clip property.</returns>
+		public Rect ClipToBounds ()
+		{
+			return SetClip (Bounds);
+		}
+
+		/// <summary>
+		/// Sets the clipping region to the specified region, the region is view-relative
+		/// </summary>
+		/// <returns>The previous clip region.</returns>
+		/// <param name="rect">Rectangle region to clip into, the region is view-relative.</param>
+		public Rect SetClip (Rect rect)
+		{
+			var bscreen = RectToScreen (rect);
+			var previous = Driver.Clip;
+			Driver.Clip = ScreenClip (RectToScreen (Bounds));
+			return previous;
+		}
+
 		/// <summary>
 		/// Draws a frame in the current view, clipped by the boundary of this view
 		/// </summary>
@@ -592,8 +621,12 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Performs a redraw of this view and its subviews, only redraws the views that have been flagged for a re-display.
 		/// </summary>
+		/// <param name="region">The region to redraw, this is relative to the view itself.</param>
 		/// <remarks>
-		/// The region argument is relative to the view itself.
+		/// <para>
+		///    Views should set the color that they want to use on entry, as otherwise this will inherit
+		///    the last color that was set globaly on the driver.
+		/// </para>
 		/// </remarks>
 		public virtual void Redraw (Rect region)
 		{

Terminal.Gui/Driver.cs

@@ -276,7 +276,7 @@ namespace Terminal.Gui {
 			}
 		}
 
-		static bool sync = false;
+		static bool sync = true;
 		public override void AddRune (Rune rune)
 		{
 			if (Clip.Contains (ccol, crow)) {

Terminal.Gui/Views/ScrollView.cs

@@ -14,11 +14,15 @@ namespace Terminal.Gui {
 	/// </para>
 	/// </remarks>
 	public class ScrollView : View {
+		View contentView;
+
 		public ScrollView (Rect frame) : base (frame)
 		{
+			contentView = new View (frame);
+			base.Add (contentView);
 		}
 
-		Rect contentSize;
+		Size contentSize;
 		Point contentOffset;
 		bool showHorizontalScrollIndicator;
 		bool showVerticalScrollIndicator;
@@ -27,12 +31,13 @@ namespace Terminal.Gui {
 		/// Represents the contents of the data shown inside the scrolview
 		/// </summary>
 		/// <value>The size of the content.</value>
-		public Rect ContentSize {
+		public Size ContentSize {
 			get {
 				return contentSize;
 			}
 			set {
 				contentSize = value;
+				contentView.Frame = new Rect (contentOffset, value);
 			}
 		}
 
@@ -45,10 +50,20 @@ namespace Terminal.Gui {
 				return contentOffset;
 			}
 			set {
-				contentOffset = value;
+				contentOffset = new Point (-value.X, -value.Y);
+				contentView.Frame = new Rect (contentOffset, contentSize);
 			}
 		}
 
+		/// <summary>
+		/// Adds the view to the scrollview.
+		/// </summary>
+		/// <param name="view">The view to add to the scrollview.</param>
+		public override void Add (View view)
+		{
+			contentView.Add (view);
+		}
+
 		/// <summary>
 		/// Gets or sets the visibility for the horizontal scroll indicator.
 		/// </summary>
@@ -81,7 +96,12 @@ namespace Terminal.Gui {
 
 		public override void Redraw(Rect region)
 		{
+			var oldClip = ClipToBounds ();
 			base.Redraw(region);
+			Driver.SetAttribute (ColorScheme.Normal);
+
+			DrawFrame (Bounds);
+			Driver.Clip = oldClip;
 		}
 	}
 }

demo.cs

@@ -1,6 +1,28 @@
 using Terminal.Gui;
+using System;
 
 class Demo {
+	class MyView : View {
+		public MyView (int x, int y) : base (new Rect (x, y, 10, 10))
+		{
+		}
+
+		public override void Redraw(Rect region)
+		{
+			Driver.SetAttribute (ColorScheme.Focus);
+
+			for (int y = 0; y < 10; y++) {
+				Move (0, y);
+				for (int x = 0; x < 10; x++) {
+					
+					Driver.AddRune ((Rune)('0' + (x+y)%10));
+				}
+			}
+	
+		}
+
+	}
+
 	static void ShowTextAlignments (View container)
 	{
 		container.Add (
@@ -12,6 +34,13 @@ class Demo {
 
 	static void ShowEntries (View container)
 	{
+		var scrollView = new ScrollView (new Rect (50, 10, 20, 8)) {
+			ContentSize = new Size (100, 100),
+			ContentOffset = new Point (-1, -1)
+		};
+
+		scrollView.Add (new MyView (0, 0));
+
 		container.Add (
 			new Label (3, 6, "Login: "),
 			new TextField (14, 6, 40, ""),
@@ -21,6 +50,7 @@ class Demo {
 				new CheckBox (1, 0, "Remember me"),
 				new RadioGroup (1, 2, new [] { "_Personal", "_Company" }),
 			},
+			scrollView,
 			new Button (3, 19, "Ok"),
 			new Button (10, 19, "Cancel"),
 			new Label (3, 22, "Press ESC and 9 to activate the menubar")
@@ -75,7 +105,7 @@ class Demo {
 
 		ShowEntries (win);
 		int count = 0;
-		ml = new Label (new Rect (3, 17, 50, 1), "Mouse: ");
+		ml = new Label (new Rect (3, 17, 47, 1), "Mouse: ");
 		Application.RootMouseEvent += delegate (MouseEvent me) {
 
 			ml.Text = $"Mouse: ({me.X},{me.Y}) - {me.Flags} {count++}";