Add support for bar charts

Closes #103

src/Spectre.Console/Widgets/BarChart.cs

@@ -0,0 +1,82 @@
+using System.Collections.Generic;
+using System.Linq;
+using Spectre.Console.Rendering;
+
+namespace Spectre.Console
+{
+    /// <summary>
+    /// A renderable (horizontal) bar chart.
+    /// </summary>
+    public sealed class BarChart : Renderable
+    {
+        /// <summary>
+        /// Gets the bar chart data.
+        /// </summary>
+        public List<BarChartItem> Data { get; }
+
+        /// <summary>
+        /// Gets or sets the width of the bar chart.
+        /// </summary>
+        public int? Width { get; set; }
+
+        /// <summary>
+        /// Gets or sets the bar chart label.
+        /// </summary>
+        public string? Label { get; set; }
+
+        /// <summary>
+        /// Gets or sets the bar chart label alignment.
+        /// </summary>
+        public Justify? LabelAlignment { get; set; } = Justify.Center;
+
+        /// <summary>
+        /// Gets or sets a value indicating whether or not
+        /// values should be shown next to each bar.
+        /// </summary>
+        public bool ShowValues { get; set; } = true;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BarChart"/> class.
+        /// </summary>
+        public BarChart()
+        {
+            Data = new List<BarChartItem>();
+        }
+
+        /// <inheritdoc/>
+        protected override IEnumerable<Segment> Render(RenderContext context, int maxWidth)
+        {
+            var maxValue = Data.Max(item => item.Value);
+
+            var table = new Grid();
+            table.Collapse();
+            table.AddColumn(new GridColumn().PadRight(2).RightAligned());
+            table.AddColumn(new GridColumn().PadLeft(0));
+            table.Width = Width;
+
+            if (!string.IsNullOrWhiteSpace(Label))
+            {
+                table.AddRow(Text.Empty, new Markup(Label).Alignment(LabelAlignment));
+            }
+
+            foreach (var item in Data)
+            {
+                table.AddRow(
+                    new Markup(item.Label),
+                    new ProgressBar()
+                    {
+                        Value = item.Value,
+                        MaxValue = maxValue,
+                        ShowRemaining = false,
+                        CompletedStyle = new Style().Foreground(item.Color ?? Color.Default),
+                        FinishedStyle = new Style().Foreground(item.Color ?? Color.Default),
+                        UnicodeBar = '█',
+                        AsciiBar = '█',
+                        ShowValue = ShowValues,
+                    });
+            }
+
+            return ((IRenderable)table).Render(context, maxWidth);
+        }
+    }
+}

src/Spectre.Console/Widgets/BarChartItem.cs

@@ -0,0 +1,38 @@
+using System;
+
+namespace Spectre.Console
+{
+    /// <summary>
+    /// An item that's shown in a bar chart.
+    /// </summary>
+    public sealed class BarChartItem : IBarChartItem
+    {
+        /// <summary>
+        /// Gets the item label.
+        /// </summary>
+        public string Label { get; }
+
+        /// <summary>
+        /// Gets the item value.
+        /// </summary>
+        public double Value { get; }
+
+        /// <summary>
+        /// Gets the item color.
+        /// </summary>
+        public Color? Color { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BarChartItem"/> class.
+        /// </summary>
+        /// <param name="label">The item label.</param>
+        /// <param name="value">The item value.</param>
+        /// <param name="color">The item color.</param>
+        public BarChartItem(string label, double value, Color? color = null)
+        {
+            Label = label ?? throw new ArgumentNullException(nameof(label));
+            Value = value;
+            Color = color;
+        }
+    }
+}

src/Spectre.Console/Widgets/Grid.cs

@@ -42,6 +42,11 @@ namespace Spectre.Console
             set => MarkAsDirty(() => _alignment = value);
         }
 
+        /// <summary>
+        /// Gets or sets the width of the grid.
+        /// </summary>
+        public int? Width { get; set; }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="Grid"/> class.
         /// </summary>
@@ -124,6 +129,7 @@ namespace Spectre.Console
                 ShowHeaders = false,
                 IsGrid = true,
                 PadRightCell = _padRightCell,
+                Width = Width,
             };
 
             foreach (var column in _columns)

src/Spectre.Console/Widgets/IBarGraphItem.cs

@@ -0,0 +1,23 @@
+namespace Spectre.Console
+{
+    /// <summary>
+    /// Represents a bar chart item.
+    /// </summary>
+    public interface IBarChartItem
+    {
+        /// <summary>
+        /// Gets the item label.
+        /// </summary>
+        string Label { get; }
+
+        /// <summary>
+        /// Gets the item value.
+        /// </summary>
+        double Value { get; }
+
+        /// <summary>
+        /// Gets the item color.
+        /// </summary>
+        Color? Color { get; }
+    }
+}

src/Spectre.Console/Widgets/ProgressBar.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using Spectre.Console.Rendering;
 
 namespace Spectre.Console
@@ -10,6 +11,10 @@ namespace Spectre.Console
         public double MaxValue { get; set; } = 100;
 
         public int? Width { get; set; }
+        public bool ShowRemaining { get; set; } = true;
+        public char UnicodeBar { get; set; } = '━';
+        public char AsciiBar { get; set; } = '-';
+        public bool ShowValue { get; set; }
 
         public Style CompletedStyle { get; set; } = new Style(foreground: Color.Yellow);
         public Style FinishedStyle { get; set; } = new Style(foreground: Color.Green);
@@ -26,15 +31,38 @@ namespace Spectre.Console
             var width = Math.Min(Width ?? maxWidth, maxWidth);
             var completed = Math.Min(MaxValue, Math.Max(0, Value));
 
-            var token = !context.Unicode || context.LegacyConsole ? '-' : '━';
+            var token = !context.Unicode || context.LegacyConsole ? AsciiBar : UnicodeBar;
             var style = completed >= MaxValue ? FinishedStyle : CompletedStyle;
 
             var bars = Math.Max(0, (int)(width * (completed / MaxValue)));
+
+            var value = completed.ToString(CultureInfo.InvariantCulture);
+            if (ShowValue)
+            {
+                bars = bars - value.Length - 1;
+            }
+
             yield return new Segment(new string(token, bars), style);
 
+            if (ShowValue)
+            {
+                yield return new Segment(" " + value, style);
+            }
+
             if (bars < width)
             {
-                yield return new Segment(new string(token, width - bars), RemainingStyle);
+                var diff = width - bars;
+                if (ShowValue)
+                {
+                    diff = diff - value.Length - 1;
+                    if (diff <= 0)
+                    {
+                        yield break;
+                    }
+                }
+
+                var remainingToken = ShowRemaining ? token : ' ';
+                yield return new Segment(new string(remainingToken, diff), RemainingStyle);
             }
         }
     }