From df29c3caaedd937179d9af93d69adb10553dde1f Mon Sep 17 00:00:00 2001
From: Miguel de Icaza <miguel@gnome.org>
Date: Tue, 6 Feb 2018 22:41:55 -0500
Subject: [PATCH] Some work on ListView

---
 Terminal.Gui/Terminal.Gui.csproj |   6 +-
 Terminal.Gui/Views/ListView.cs   | 127 ++++++++++++++++++++++++++++++-
 Terminal.Gui/packages.config     |   2 +-
 3 files changed, 130 insertions(+), 5 deletions(-)

diff --git a/Terminal.Gui/Terminal.Gui.csproj b/Terminal.Gui/Terminal.Gui.csproj
index cc5419151..099f29d2e 100644
--- a/Terminal.Gui/Terminal.Gui.csproj
+++ b/Terminal.Gui/Terminal.Gui.csproj
@@ -31,13 +31,13 @@
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="Mono.Posix" />
-    <Reference Include="NStack">
-      <HintPath>..\packages\NStack.Core.0.7.0\lib\netstandard1.5\NStack.dll</HintPath>
-    </Reference>
     <Reference Include="System.ValueTuple">
       <HintPath>..\packages\System.ValueTuple.4.4.0\lib\net461\System.ValueTuple.dll</HintPath>
     </Reference>
     <Reference Include="mscorlib" />
+    <Reference Include="NStack">
+      <HintPath>..\packages\NStack.Core.0.8.0\lib\netstandard1.5\NStack.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Folder Include="Properties\" />
diff --git a/Terminal.Gui/Views/ListView.cs b/Terminal.Gui/Views/ListView.cs
index 587c20c44..522ab3ef9 100644
--- a/Terminal.Gui/Views/ListView.cs
+++ b/Terminal.Gui/Views/ListView.cs
@@ -12,15 +12,140 @@ using NStack;
 namespace Terminal.Gui {
 	public interface IListDataSource {
 		int Count { get; }
-
+		void Render (int item, int col, int line, int width);
 	}
 
 	/// <summary>
 	/// ListView widget renders a list of data.
 	/// </summary>
+	/// <remarks>
+	/// </remarks>
 	public class ListView : View {
+		int top;
+		int selected;
+
+		class ListWrapper : IListDataSource {
+			IList src;
+			public ListView Container;
+			public ConsoleDriver Driver;
+
+			public ListWrapper (IList source)
+			{
+				this.src = source;
+			}
+
+			public int Count => src.Count;
+
+			void RenderUstr (ustring ustr, int col, int line, int width)
+			{
+				int byteLen = ustr.Length;
+				int used = 0;
+				for (int i = 0; i < byteLen;) {
+					(var rune, var size) = Utf8.DecodeRune (ustr, i, i - byteLen);
+					var count = Rune.ColumnWidth (rune);
+					if (used+count >= width)
+						break;
+					Driver.AddRune (rune);
+					used += count;
+					i += size;
+				}
+				for (; used < width; used++) {
+					Driver.AddRune (' ');
+				}
+			}
+
+			public void Render (int item, int col, int line, int width)
+			{
+				Container.Move (col, line);
+				var t = src [item];
+				if (t is ustring) {
+					RenderUstr (t as ustring, col, line, width);
+				} else if (t is string) {
+					RenderUstr (t as string, col, line, width);
+				} else
+					RenderUstr (((string)t).ToString (), col, line, width);
+			}
+		}
+
+		IListDataSource source;
+		/// <summary>
+		/// Gets or sets the IListDataSource backing this view.
+		/// </summary>
+		/// <value>The source.</value>
+		public IListDataSource Source {
+			get => source;
+			set {
+				if (value == null)
+					throw new ArgumentNullException ("value");
+				source = value;
+				top = 0;
+				selected = 0;
+				SetNeedsDisplay ();
+			}
+		}
+
+		bool allowsMarking;
+		/// <summary>
+		/// Gets or sets a value indicating whether this <see cref="T:Terminal.Gui.ListView"/> allows items to be marked.
+		/// </summary>
+		/// <value><c>true</c> if allows marking elements of the list; otherwise, <c>false</c>.</value>
+		public bool AllowsMarking {
+			get => allowsMarking;
+			set {
+				allowsMarking = value;
+				SetNeedsDisplay ();
+			}
+		}
+
+		/// <summary>
+		/// Gets or sets the item that is displayed at the top of the listview
+		/// </summary>
+		/// <value>The top item.</value>
+		public int TopItem {
+			get => top;
+			set {
+				if (top < 0 || top >= source.Count)
+					throw new ArgumentException ("value");
+				top = value;
+				SetNeedsDisplay ();
+			}
+		}
+
+		/// <summary>
+		/// Gets or sets the currently selecteded item.
+		/// </summary>
+		/// <value>The selected item.</value>
+		public int SelectedItem {
+			get => selected;
+			set {
+				if (selected < 0 || selected >= source.Count)
+					throw new ArgumentException ("value");
+				selected = value;
+				if (selected < top)
+					top = selected;
+				else if (selected >= top + Frame.Height)
+					top = selected;
+			}
+		}
+
+
+		static IListDataSource MakeWrapper (IList source)
+		{
+			return new ListWrapper (source);
+		}
+
+		public ListView (Rect rect, IList source, (ustring title, int width) [] headers = null) : this (rect, MakeWrapper (source), headers)
+		{
+			((ListWrapper)(Source)).Container = this;
+			((ListWrapper)(Source)).Driver = Driver;
+		}
+
 		public ListView (Rect rect, IListDataSource source, (ustring title, int width) [] headers = null) : base (rect)
 		{
+			if (source == null)
+				throw new ArgumentNullException (nameof (source));
+			Source = source;
 		}
+
 	}
 }
diff --git a/Terminal.Gui/packages.config b/Terminal.Gui/packages.config
index 62939e85c..c86d262a1 100644
--- a/Terminal.Gui/packages.config
+++ b/Terminal.Gui/packages.config
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="NStack.Core" version="0.7.0" targetFramework="net461" />
+  <package id="NStack.Core" version="0.8.0" targetFramework="net461" />
   <package id="System.ValueTuple" version="4.4.0" targetFramework="net461" />
 </packages>
\ No newline at end of file