Fixes #16 - Add columned lists to TableView (with ListTableSource)

Terminal.Gui/Views/TableView/DataTableSource.cs

@@ -9,27 +9,30 @@ namespace Terminal.Gui {
 	/// </summary>
 	public class DataTableSource : ITableSource
 	{
-		private readonly DataTable table;
+		/// <summary>
+		/// The data table this source wraps.
+		/// </summary>
+		public DataTable DataTable { get; private set; }
 
 		/// <summary>
 		/// Creates a new instance based on the data in <paramref name="table"/>.
 		/// </summary>
 		/// <param name="table"></param>
 		public DataTableSource(DataTable table)
 		{
-			this.table = table;
+			this.DataTable = table;
 		}
 
 		/// <inheritdoc/>
-		public object this [int row, int col] => table.Rows[row][col];
+		public object this [int row, int col] => DataTable.Rows[row][col];
 
 		/// <inheritdoc/>
-		public int Rows => table.Rows.Count;
+		public int Rows => DataTable.Rows.Count;
 
 		/// <inheritdoc/>
-		public int Columns => table.Columns.Count;
+		public int Columns => DataTable.Columns.Count;
 
 		/// <inheritdoc/>
-		public string [] ColumnNames => table.Columns.Cast<DataColumn>().Select (c => c.ColumnName).ToArray ();
+		public string [] ColumnNames => DataTable.Columns.Cast<DataColumn>().Select (c => c.ColumnName).ToArray ();
 	}
 }

Terminal.Gui/Views/TableView/ListColumnView.cs

@@ -0,0 +1,166 @@
+using NStack;
+using System;
+using System.Collections;
+
+namespace Terminal.Gui {
+
+	/// <summary>
+	/// View for columned data based on an <see cref="IList"/>.
+	/// 
+	/// <a href="https://gui-cs.github.io/Terminal.Gui/articles/tableview.html">See TableView Deep Dive for more information</a>.
+	/// </summary>
+	public partial class ListColumnView : TableView {
+
+		private IList listData;
+
+		/// <summary>
+		/// Returns the number of elements to display
+		/// </summary>
+		public int Count { get => ListData.Count; }
+
+		/// <summary>
+		/// Returns the maximum length of elements to display
+		/// </summary>
+		public int Length { get => CalculateMaxLength (); }
+
+		private ListColumnStyle listStyle = new ListColumnStyle ();
+
+		/// <summary>
+		/// A list to render in the view.  Setting this property automatically updates and redraws the control.
+		/// </summary>
+		public IList ListData { get => listData; set { listData = value; ListUpdate (); } }
+
+		/// <summary>
+		/// Contains options for changing how the table is rendered when set via <see cref="ListColumnView.ListData"/>
+		/// </summary>
+		public ListColumnStyle ListStyle { get => listStyle; set { listStyle = value; ListUpdate (); } }
+
+		/// <summary>
+		/// Initializes a <see cref="ListColumnView"/> class using <see cref="LayoutStyle.Computed"/> layout. 
+		/// </summary>
+		/// <param name="list">The list of items to display in columns in the control</param>
+		public ListColumnView (ListTableSource list) : this ()
+		{
+			for (var i = 0; i < list.Rows; i++) {
+				this.ListData.Add (list [i, 0]);
+			}
+			this.Table = (ITableSource)list.DataTable;
+		}
+
+		/// <summary>
+		/// Initializes a <see cref="ListColumnView"/> class using <see cref="LayoutStyle.Computed"/> layout.
+		/// Set the <see cref="ListData"/> property to begin editing.
+		/// </summary>
+		public ListColumnView () : base ()
+		{
+			ListData?.Clear ();
+			Update ();
+		}
+
+		/// <summary>
+		/// Returns the size in characters of the longest value read from <see cref="ListColumnView.ListData"/>
+		/// </summary>
+		/// <returns></returns>
+		private int CalculateMaxLength ()
+		{
+			if (listData == null || listData?.Count == 0) {
+				return 0;
+			}
+
+			int maxLength = 0;
+			for (int i = 0; i < listData.Count; i++) {
+				var t = listData [i];
+				int l;
+				if (t is ustring u) {
+					l = TextFormatter.GetTextWidth (u);
+				} else if (t is string s) {
+					l = s.Length;
+				} else {
+					l = t.ToString ().Length;
+				}
+
+				if (l > maxLength) {
+					maxLength = l;
+				}
+			}
+
+			return maxLength;
+		}
+
+		/// <summary>
+		/// Creates a columned list from an IList to display in a <see cref="TableView"/>
+		/// </summary>
+		public void FlowTable ()
+		{
+			if (listData == null || listData?.Count == 0) {
+				return;
+			}
+			int colWidth = CalculateMaxLength ();
+			if (colWidth == 0) {
+				return;
+			}
+
+			if (colWidth > MaxCellWidth) {
+				colWidth = MaxCellWidth;
+			}
+
+			if (MinCellWidth > 0 && colWidth < MinCellWidth) {
+				if (MinCellWidth > MaxCellWidth) {
+					colWidth = MaxCellWidth;
+				} else {
+					colWidth = MinCellWidth;
+				}
+			}
+
+			int itemsPerSublist = 1;
+			if (listStyle.VerticalOrientation && listStyle.ScrollParallel) {
+				decimal m = ((decimal)(this.Bounds.Width - 1) / colWidth) - 2;
+				itemsPerSublist = (int)Math.Ceiling (listData.Count / m);
+			} else if (listStyle.VerticalOrientation && !listStyle.ScrollParallel) {
+				itemsPerSublist = this.Bounds.Height - GetHeaderHeight ();
+			} else if (!listStyle.VerticalOrientation && listStyle.ScrollParallel) {
+				decimal m = (decimal)this.Bounds.Height - GetHeaderHeight ();
+				itemsPerSublist = (int)Math.Ceiling (listData.Count / m);
+			} else if (!listStyle.VerticalOrientation && !listStyle.ScrollParallel) {
+				itemsPerSublist = ((int)Math.Ceiling (((decimal)this.Bounds.Width - 1) / colWidth)) - 2;
+			}
+			if (itemsPerSublist < 1) itemsPerSublist = 1;
+
+			if (listStyle.VerticalOrientation) {
+				this.Table = new ListTableSource (listData, itemsPerSublist, true);
+			} else {
+				this.Table = new ListTableSource (listData, itemsPerSublist, false);
+			}
+		}
+
+		/// <summary>
+		/// Updates the view to reflect changes to <see cref="ListData"/>
+		/// </summary>
+		public void ListUpdate ()
+		{
+			FlowTable ();
+			Update ();
+		}
+
+		/// TODO: Update TableView Deep Dive
+		/// <summary>
+		/// Defines rendering options that affect how the view is displayed.
+		/// 
+		/// <a href="https://gui-cs.github.io/Terminal.Gui/articles/tableview.html">See TableView Deep Dive for more information</a>.
+		/// </summary>
+		public class ListColumnStyle {
+
+			/// <summary>
+			/// Gets or sets a flag indicating whether to populate data of a <see cref="ListColumnView"/> down its columns rather than across its rows.
+			/// Defaults to <see langword="false"/>.
+			/// </summary>
+			public bool VerticalOrientation { get; set; } = false;
+
+			/// <summary>
+			/// Gets or sets a flag indicating whether to scroll a <see cref="ListColumnView"/> in the same direction as item population.
+			/// Defaults to <see langword="false"/>.
+			/// </summary>
+			public bool ScrollParallel { get; set; } = false;
+		}
+	}
+}

Terminal.Gui/Views/TableView/ListTableSource.cs

@@ -0,0 +1,124 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Data;
+
+namespace Terminal.Gui {
+	/// <summary>
+	/// <see cref="ITableSource"/> implementation that wraps 
+	/// a <see cref="System.Collections.IList"/>.  This class is
+	/// mutable: changes are permitted to the wrapped <see cref="IList"/>.
+	/// </summary>
+	public class ListTableSource : ITableSource
+	{
+		/// <summary>
+		/// The list this source wraps.
+		/// </summary>
+		public IList List;
+
+		/// <summary>
+		/// The data table this source creates.
+		/// </summary>
+		public DataTable DataTable;
+
+		/// <summary>
+		/// Creates a new table instance based on the data in <paramref name="list"/>.
+		/// </summary>
+		/// <param name="list"></param>
+		public ListTableSource (IList list)
+		{
+			this.List = list;
+			this.DataTable = CreateTable ();
+		}
+
+		/// <summary>
+		/// Creates a new table instance based on the data in <paramref name="list"/>.
+		/// </summary>
+		/// <param name="list"></param>
+		/// <param name="cols"></param>
+		/// <param name="transpose"></param>
+		public ListTableSource (IList list, int cols = 1, bool transpose = false)
+		{
+			this.List = list;
+			this.DataTable = transpose ? CreateTransposedTable (cols) : CreateTable (cols);
+		}
+
+		/*
+		/// <inheritdoc/>
+		public object this [int cell] => list [cell];
+		*/
+
+		/// <inheritdoc/>
+		public object this [int row, int col] => DataTable.Rows[row][col];
+
+		/// <inheritdoc/>
+		public int Count => List.Count;
+
+		/// <inheritdoc/>
+		public int Rows => DataTable.Rows.Count;
+
+		/// <inheritdoc/>
+		public int Columns => DataTable.Columns.Count;
+
+		/// <inheritdoc/>
+		public string [] ColumnNames => GenerateColumnNumbers ();
+
+		private string [] GenerateColumnNumbers()
+		{
+			string [] names = new string [Count];
+			for (int i = 0; i < Count; i++) {
+				names [i] = i.ToString ();
+			}
+			return names;
+		}
+
+		/// <summary>
+		/// Creates a DataTable from an IList to display in a <see cref="TableView"/>
+		/// </summary>
+		protected DataTable CreateTable (int cols = 1)
+		{
+			var newTable = new DataTable ();
+
+			int i;
+			for (i = 0; i < cols; i++) {
+				newTable.Columns.Add (new DataColumn (i.ToString ()));
+			}
+
+			var sublist = new List<string> ();
+			int j;
+			for (j = 0; j < List.Count; j++) {
+				if (j % cols == 0 && sublist.Count > 0) {
+					newTable.Rows.Add (sublist.ToArray ());
+					sublist.Clear ();
+				}
+				sublist.Add (List [j].ToString ());
+			}
+			newTable.Rows.Add (sublist.ToArray ());
+
+			return newTable;
+		}
+
+		private DataTable CreateTransposedTable (int cols = 1, bool includeColumnNames = false)
+		{
+			var it = CreateTable (cols);
+			var tt = new DataTable ();
+			int offset = 0;
+			if (includeColumnNames) {
+				tt.Columns.Add (new DataColumn ("0"));
+				offset++;
+			}
+			for (int i = 0; i < it.Columns.Count; i++) {
+				DataRow row = tt.NewRow ();
+				if (includeColumnNames) {
+					row [0] = it.Columns [i].ColumnName;
+				}
+				for (int j = offset; j < it.Rows.Count + offset; j++) {
+					if (tt.Columns.Count < it.Rows.Count + offset)
+						tt.Columns.Add (new DataColumn (j.ToString ()));
+					row [j] = it.Rows [j - offset] [i];
+				}
+				tt.Rows.Add (row);
+			}
+			return tt;
+		}
+	}
+}

Terminal.Gui/Views/TableView/TableView.cs

@@ -121,6 +121,11 @@ public int SelectedRow {
 			}
 		}
 
+		/// <summary>
+		/// The minimum number of characters to render in any given column.
+		/// </summary>
+		public int MinCellWidth { get; set; }
+
 		/// <summary>
 		/// The maximum number of characters to render in any given column.  This prevents one long column from pushing out all the others
 		/// </summary>
@@ -329,7 +334,7 @@ private void ClearLine (int row, int width)
 		/// Returns the amount of vertical space currently occupied by the header or 0 if it is not visible.
 		/// </summary>
 		/// <returns></returns>
-		private int GetHeaderHeightIfAny ()
+		protected int GetHeaderHeightIfAny ()
 		{
 			return ShouldRenderHeaders () ? GetHeaderHeight () : 0;
 		}
@@ -338,7 +343,7 @@ private int GetHeaderHeightIfAny ()
 		/// Returns the amount of vertical space required to display the header
 		/// </summary>
 		/// <returns></returns>
-		private int GetHeaderHeight ()
+		protected int GetHeaderHeight ()
 		{
 			int heightRequired = Style.ShowHeaders ? 1 : 0;
 
@@ -1619,6 +1624,18 @@ private IEnumerable<ColumnToRender> CalculateViewport (Rect bounds, int padding
 				// is there enough space for this column (and it's data)?
 				colWidth = CalculateMaxCellWidth (col, rowsToRender, colStyle) + padding;
 
+				if (colWidth > MaxCellWidth) {
+					colWidth = MaxCellWidth;
+				}
+
+				if (MinCellWidth > 0 && colWidth < MinCellWidth) {
+					if (MinCellWidth > MaxCellWidth) {
+						colWidth = MaxCellWidth;
+					} else {
+						colWidth = MinCellWidth;
+					}
+				}
+
 				// there is not enough space for this columns 
 				// visible content
 				if (usedSpace + colWidth > availableHorizontalSpace) {