Use LineCanvas to draw TableView borders

Terminal.Gui/Views/TableView/TableStyle.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 
 namespace Terminal.Gui; 
 
@@ -9,6 +10,36 @@ namespace Terminal.Gui;
 /// </summary>
 public class TableStyle {
 
+	/// <summary>
+	/// Gets or sets the LineStyle for the borders surrounding header rows of a <see cref="TableView"/>.
+	/// Defaults to <see cref="LineStyle.Single"/>.
+	/// </summary>
+	public LineStyle OuterHeaderBorderStyle { get; set; } = LineStyle.Single;
+
+	/// <summary>
+	/// Gets or sets the LineStyle for the vertical lines separating header items in a <see cref="TableView"/>.
+	/// Defaults to <see cref="LineStyle.Single"/>.
+	/// </summary>
+	public LineStyle InnerHeaderBorderStyle { get; set; } = LineStyle.Single;
+
+	/// <summary>
+	/// Gets or sets the LineStyle for the borders surrounding the regular (non-header) portion of a <see cref="TableView"/>.
+	/// Defaults to <see cref="LineStyle.Single"/>.
+	/// </summary>
+	public LineStyle OuterBorderStyle { get; set; } = LineStyle.Single;
+
+	/// <summary>
+	/// Gets or sets the LineStyle for the lines separating regular (non-header) items in a <see cref="TableView"/>.
+	/// Defaults to <see cref="LineStyle.Single"/>.
+	/// </summary>
+	public LineStyle InnerBorderStyle { get; set; } = LineStyle.Single;
+
+	/// <summary>
+	/// Gets or sets the color Attribute of the inner and outer borders of a <see cref="TableView"/>.
+	/// Defaults to Attribute(-1, -1) which results in <see cref="Border.ColorScheme.Normal"/>.
+	/// </summary>
+	public Attribute BorderColor { get; set; } = new Attribute(-1, -1);
+
 	/// <summary>
 	/// Gets or sets a flag indicating whether to render headers of a <see cref="TableView"/>.
 	/// Defaults to <see langword="true"/>.
@@ -32,6 +63,11 @@ public class TableStyle {
 	/// </summary>
 	public bool ShowHorizontalHeaderUnderline { get; set; } = true;
 
+	/// <summary>
+	/// True to render a solid line through the headers (only when Overline and/or Underline are <see langword="false"/>)
+	/// </summary>
+	public bool ShowHorizontalHeaderThroughline { get; set; } = false;
+
 	/// <summary>
 	/// True to render a solid line vertical line between cells
 	/// </summary>
@@ -57,18 +93,62 @@ public class TableStyle {
 	/// </summary>
 	public bool ShowHorizontalBottomline { get; set; } = false;
 
+	/// <summary>
+	/// True to invert the colors of the entire selected cell in the <see cref="TableView"/>.
+	/// Helpful for when <see cref="TableView.FullRowSelect"/> is on, especially when the <see cref="ConsoleDriver"/> doesn't show
+	/// the cursor
+	/// </summary>
+	public bool InvertSelectedCell { get; set; } = false;
+
 	/// <summary>
 	/// True to invert the colors of the first symbol of the selected cell in the <see cref="TableView"/>.
 	/// This gives the appearance of a cursor for when the <see cref="ConsoleDriver"/> doesn't otherwise show
 	/// this
 	/// </summary>
 	public bool InvertSelectedCellFirstCharacter { get; set; } = false;
 
+	// NOTE: This is equivalent to True by default after change to LineCanvas borders and can't be turned off
+	// without disabling ShowVerticalCellLines, however  SeparatorSymbol and HeaderSeparatorSymbol could be
+	// used to approximate the previous default behavior with FullRowSelect
+	// TODO: Explore ways of changing this without a workaround
 	/// <summary>
 	/// Gets or sets a flag indicating whether to force <see cref="ColorScheme.Normal"/> use when rendering
 	/// vertical cell lines (even when <see cref="TableView.FullRowSelect"/> is on).
 	/// </summary>
-	public bool AlwaysUseNormalColorForVerticalCellLines { get; set; } = false;
+	//public bool AlwaysUseNormalColorForVerticalCellLines { get; set; } = false;
+
+	/// <summary>
+	/// The symbol to add after each header value to visually seperate values (if not using vertical gridlines)
+	/// <remarks>CM.Glyphs.VLine can be used to emulate vertical grindlines that highlight with <see cref="TableView.FullRowSelect"/></remarks>
+	/// </summary>
+	public Rune HeaderSeparatorSymbol { get; set; } = (Rune)' ';
+
+	/// <summary>
+	/// The symbol to add after each cell value to visually seperate values (if not using vertical gridlines)
+	/// <remarks>CM.Glyphs.VLine can be used to emulate vertical grindlines that highlight with <see cref="TableView.FullRowSelect"/></remarks>
+	/// </summary>
+	public Rune SeparatorSymbol { get; set; } = (Rune)' ';
+
+	/// <summary>
+	/// The text representation that should be rendered for cells with the value <see cref="DBNull.Value"/>
+	/// </summary>
+	public string NullSymbol { get; set; } = "-";
+
+	/// <summary>
+	/// The symbol to pad around values (between separators) in the header line
+	/// </summary>
+	public char HeaderPaddingSymbol { get; set; } = ' ';
+
+	/// <summary>
+	/// The symbol to pad around values (between separators)
+	/// </summary>
+	public char CellPaddingSymbol { get; set; } = ' ';
+
+	/// <summary>
+	/// The symbol to pad outside table (if both <see cref="ExpandLastColumn"/> and <see cref="AddEmptyColumn"/>
+	/// are False)
+	/// </summary>
+	public Rune BackgroundSymbol { get; set; } = (Rune)' ';
 
 	/// <summary>
 	/// Collection of columns for which you want special rendering (e.g. custom column lengths, text alignment etc)
@@ -82,15 +162,25 @@ public class TableStyle {
 	public RowColorGetterDelegate RowColorGetter { get; set; }
 
 	/// <summary>
-	/// Determines rendering when the last column in the table is visible but it's
+	/// Determines rendering when the last column in the table is visible but its
 	/// content or <see cref="ColumnStyle.MaxWidth"/> is less than the remaining 
 	/// space in the control.  True (the default) will expand the column to fill
-	/// the remaining bounds of the control.  False will draw a column ending line
-	/// and leave a blank column that cannot be selected in the remaining space.  
+	/// the remaining bounds of the control.  If false, <see cref="AddEmptyColumn"/>
+	/// determines the behavior of the remaining space.
 	/// </summary>
 	/// <value></value>
 	public bool ExpandLastColumn { get; set; } = true;
 
+	/// <summary>
+	/// Determines rendering when the last column in the table is visible but its
+	/// content or <see cref="ColumnStyle.MaxWidth"/> is less than the remaining 
+	/// space in the control *and* <see cref="ExpandLastColumn"/> is False.  True (the default)
+	/// will add a blank column that cannot be selected in the remaining space.
+	/// False will fill the remaining space with <see cref="BackgroundSymbol"/>.
+	/// </summary>
+	/// <value></value>
+	public bool AddEmptyColumn { get; set; } = true;
+
 	/// <summary>
 	/// <para>
 	/// Determines how <see cref="TableView.ColumnOffset"/> is updated when scrolling