Data labels

src/LiveChartsCore/BarSeries.cs

@@ -127,7 +127,7 @@ protected class MeasureHelper
             uw = scaler.MeasureInPixels(axis.UnitWidth);
             actualUw = uw;
 
-            var gp = (float)barSeries.GroupPadding;
+            var gp = (float)barSeries.Padding;
 
             if (uw - gp < 1) gp -= uw - gp;
 

src/LiveChartsCore/ColumnSeries.cs

@@ -246,6 +246,10 @@ public override void Invalidate(Chart<TDrawingContext> chart)
                 label.X = labelPosition.X;
                 label.Y = labelPosition.Y;
             }
+            else
+            {
+                // ....
+            }
 
             OnPointMeasured(point);
         }

src/LiveChartsCore/Drawing/IDoughnutGeometry.cs

@@ -63,15 +63,15 @@ public interface IDoughnutGeometry<TDrawingContext> : IGeometry<TDrawingContext>
     float Height { get; set; }
 
     /// <summary>
-    /// Gets or sets the start angle.
+    /// Gets or sets the start angle in degrees.
     /// </summary>
     /// <value>
     /// The start angle.
     /// </value>
     float StartAngle { get; set; }
 
     /// <summary>
-    /// Gets or sets the sweep angle.
+    /// Gets or sets the sweep angle in degrees.
     /// </summary>
     /// <value>
     /// The sweep angle.

src/LiveChartsCore/FinancialSeries.cs

@@ -64,10 +64,11 @@ protected FinancialSeries()
              SeriesProperties.Solid | SeriesProperties.PrefersXStrategyTooltips)
     {
         YToolTipLabelFormatter = p =>
-            $"H {p.PrimaryValue:N2}{Environment.NewLine}" +
-            $"O {p.TertiaryValue:N2}{Environment.NewLine}" +
-            $"C {p.QuaternaryValue:N2}{Environment.NewLine}" +
-            $"L {p.QuinaryValue:N2}";
+            $"H {p.PrimaryValue:C2}{Environment.NewLine}" +
+            $"O {p.TertiaryValue:C2}{Environment.NewLine}" +
+            $"C {p.QuaternaryValue:C2}{Environment.NewLine}" +
+            $"L {p.QuinaryValue:C2}";
+        DataLabelsFormatter = point => $"{point.PrimaryValue:C2} - {point.QuinaryValue:C2}";
     }
 
     /// <inheritdoc cref="IFinancialSeries{TDrawingContext}.MaxBarWidth"/>

src/LiveChartsCore/HeatSeries.cs

@@ -76,6 +76,7 @@ protected HeatSeries()
 
             return $"{labeler(point.PrimaryValue)} {point.TertiaryValue}";
         };
+        DataLabelsPosition = DataLabelsPosition.Middle;
     }
 
     /// <inheritdoc cref="IHeatSeries{TDrawingContext}.HeatMap"/>
@@ -231,8 +232,8 @@ public override void Invalidate(Chart<TDrawingContext> chart)
                 label.TextSize = dls;
                 label.Padding = DataLabelsPadding;
                 var labelPosition = GetLabelPosition(
-                     secondary, primary, uws, uws, label.Measure(DataLabelsPaint), DataLabelsPosition,
-                     SeriesProperties, point.PrimaryValue > Pivot, drawLocation, drawMarginSize);
+                     secondary - uws * 0.5f + p.Left, primary - uwp * 0.5f + p.Top, uws - p.Left - p.Right, uwp - p.Top - p.Bottom,
+                     label.Measure(DataLabelsPaint), DataLabelsPosition, SeriesProperties, point.PrimaryValue > Pivot, drawLocation, drawMarginSize);
                 label.X = labelPosition.X;
                 label.Y = labelPosition.Y;
             }

src/LiveChartsCore/Motion/MotionCanvas.cs

@@ -35,8 +35,8 @@ namespace LiveChartsCore.Motion;
 public class MotionCanvas<TDrawingContext> : IDisposable
     where TDrawingContext : DrawingContext
 {
+    internal HashSet<IPaint<TDrawingContext>> _paintTasks = new();
     private readonly Stopwatch _stopwatch = new();
-    private HashSet<IPaint<TDrawingContext>> _paintTasks = new();
     private readonly List<double> _fpsStack = new();
     private long _previousFrameTime;
     private long _previousLogTime;

src/LiveChartsCore/PieSeries.cs

@@ -611,6 +611,7 @@ protected virtual void SoftDeleteOrDisposePoint(ChartPoint point, Scaler primary
                 break;
             case PolarLabelsPosition.Middle:
                 angle = startAngle + sweepAngle * 0.5f;
+                radius *= 1.15f;
                 break;
             case PolarLabelsPosition.ChartCenter:
                 return new LvcPoint(centerX, centerY);
@@ -621,6 +622,7 @@ protected virtual void SoftDeleteOrDisposePoint(ChartPoint point, Scaler primary
         //angle %= 360;
         //if (angle < 0) angle += 360;
         angle *= toRadians;
+        radius += 0.5f * (float)Math.Sqrt(Math.Pow(labelSize.Width, 2) + Math.Pow(labelSize.Height, 2));
 
         return new LvcPoint(
              (float)(centerX + Math.Cos(angle) * radius),

src/LiveChartsCore/Series.cs

@@ -26,6 +26,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Linq;
 using LiveChartsCore.Drawing;
 using LiveChartsCore.Kernel;
@@ -34,8 +35,6 @@
 using LiveChartsCore.Kernel.Providers;
 using LiveChartsCore.Kernel.Sketches;
 using LiveChartsCore.Measure;
-using LiveChartsCore.Motion;
-
 namespace LiveChartsCore;
 
 /// <summary>
@@ -101,7 +100,7 @@ public abstract class Series<TModel, TVisual, TLabel, TDrawingContext>
     private string? _name;
     private Action<TModel, ChartPoint>? _mapping;
     private int _zIndex;
-    private Func<ChartPoint<TModel, TVisual, TLabel>, string>? _dataLabelsFormatter = x => x.PrimaryValue.ToString();
+    private Func<ChartPoint<TModel, TVisual, TLabel>, string> _dataLabelsFormatter = x => x.PrimaryValue.ToString();
     private bool _isVisible = true;
     private LvcPoint _dataPadding = new(0.5f, 0.5f);
     private DataFactory<TModel, TDrawingContext>? _dataFactory;
@@ -227,7 +226,7 @@ protected Series(SeriesProperties properties)
     /// <value>
     /// The data label formatter.
     /// </value>
-    public Func<ChartPoint<TModel, TVisual, TLabel>, string>? DataLabelsFormatter
+    public Func<ChartPoint<TModel, TVisual, TLabel>, string> DataLabelsFormatter
     {
         get => _dataLabelsFormatter;
         set => SetProperty(ref _dataLabelsFormatter, value);
@@ -273,6 +272,11 @@ public bool IsVisible
         }
     }
 
+    /// <summary>
+    /// Called when a point is measured.
+    /// </summary>
+    public Action<ChartPoint<TModel, TVisual, TLabel>>? WhenPointMeasured { get; set; }
+
     /// <summary>
     /// Gets or sets the size of the legend shape.
     /// </summary>
@@ -447,6 +451,7 @@ public override void RemoveFromUI(Chart<TDrawingContext> chart)
     /// <param name="chartPoint">The chart point.</param>
     protected internal virtual void OnPointMeasured(ChartPoint chartPoint)
     {
+        WhenPointMeasured?.Invoke(new ChartPoint<TModel, TVisual, TLabel>(chartPoint));
         PointMeasured?.Invoke(new ChartPoint<TModel, TVisual, TLabel>(chartPoint));
     }
 

src/skiasharp/LiveChartsCore.SkiaSharp/LiveChartsSkiaSharp.cs

@@ -149,40 +149,99 @@ public static string MatchChar(char @char)
     /// <summary>
     /// Converts an IEnumerable to an ObservableCollection of pie series.
     /// </summary>
-    /// <typeparam name="T">The type.</typeparam>
+    /// <typeparam name="TModel">The type of the model.</typeparam>
     /// <param name="source">The data source.</param>
-    /// <param name="buider">An optional builder.</param>
+    /// <param name="builder">An optional builder.</param>
     /// <returns></returns>
-    public static ObservableCollection<PieSeries<T>> AsPieSeries<T>(
-        this IEnumerable<T> source,
-        Action<T, PieSeries<T>>? buider = null)
+    public static ObservableCollection<PieSeries<TModel>> AsPieSeries<TModel>(
+        this IEnumerable<TModel> source,
+        Action<TModel, PieSeries<TModel>>? builder = null)
     {
-        return AsLiveChartsPieSeries(source, buider);
+        builder ??= (instance, series) => { };
+
+        return new ObservableCollection<PieSeries<TModel>>(
+            source.Select(instance =>
+            {
+                var series = new PieSeries<TModel> { Values = new ObservableCollection<TModel> { instance } };
+                builder(instance, series);
+                return series;
+            })
+            .ToArray());
     }
 
     /// <summary>
     /// Converts an IEnumerable to an ObservableCollection of pie series.
     /// </summary>
-    /// <typeparam name="T">The type.</typeparam>
+    /// <typeparam name="TModel">The type of the model.</typeparam>
+    /// <typeparam name="TVisual">The type of the visual.</typeparam>
     /// <param name="source">The data source.</param>
-    /// <param name="buider">An optional builder.</param>
+    /// <param name="builder">An optional builder.</param>
     /// <returns></returns>
-    public static ObservableCollection<PieSeries<T>> AsLiveChartsPieSeries<T>(
-        this IEnumerable<T> source,
-        Action<T, PieSeries<T>>? buider = null)
+    public static ObservableCollection<PieSeries<TModel, TVisual>> AsPieSeries<TModel, TVisual>(
+        this IEnumerable<TModel> source,
+        Action<TModel, PieSeries<TModel, TVisual>>? builder = null)
+            where TVisual : class, IDoughnutGeometry<SkiaSharpDrawingContext>, new()
+    {
+        builder ??= (instance, series) => { };
+
+        return new ObservableCollection<PieSeries<TModel, TVisual>>(
+            source.Select(instance =>
+            {
+                var series = new PieSeries<TModel, TVisual>
+                {
+                    Values = new ObservableCollection<TModel> { instance }
+                };
+                builder(instance, series);
+                return series;
+            })
+            .ToArray());
+    }
+
+    /// <summary>
+    /// Converts an IEnumerable to an ObservableCollection of pie series.
+    /// </summary>
+    /// <typeparam name="TModel">The type of the model.</typeparam>
+    /// <typeparam name="TVisual">The type of the visual.</typeparam>
+    /// <typeparam name="TLabel">The type of the label.</typeparam>
+    /// <param name="source">The data source.</param>
+    /// <param name="builder">An optional builder.</param>
+    /// <returns></returns>
+    public static ObservableCollection<PieSeries<TModel, TVisual, TLabel>> AsPieSeries<TModel, TVisual, TLabel>(
+        this IEnumerable<TModel> source,
+        Action<TModel, PieSeries<TModel, TVisual, TLabel>>? builder = null)
+            where TVisual : class, IDoughnutGeometry<SkiaSharpDrawingContext>, new()
+            where TLabel : class, ILabelGeometry<SkiaSharpDrawingContext>, new()
     {
-        buider ??= (instance, series) => { };
+        builder ??= (instance, series) => { };
 
-        return new ObservableCollection<PieSeries<T>>(
+        return new ObservableCollection<PieSeries<TModel, TVisual, TLabel>>(
             source.Select(instance =>
             {
-                var series = new PieSeries<T> { Values = new ObservableCollection<T> { instance } };
-                buider(instance, series);
+                var series = new PieSeries<TModel, TVisual, TLabel>
+                {
+                    Values = new ObservableCollection<TModel> { instance }
+                };
+                builder(instance, series);
                 return series;
             })
             .ToArray());
     }
 
+    /// <summary>
+    /// Converts an IEnumerable to an ObservableCollection of pie series.
+    /// </summary>
+    /// <typeparam name="T">The type.</typeparam>
+    /// <param name="source">The data source.</param>
+    /// <param name="buider">An optional builder.</param>
+    /// <returns></returns>
+    [Obsolete($"Renamed to {nameof(AsPieSeries)}.")]
+    public static ObservableCollection<PieSeries<T>> AsLiveChartsPieSeries<T>(
+        this IEnumerable<T> source,
+        Action<T, PieSeries<T>>? buider = null)
+    {
+        return AsPieSeries(source, buider);
+    }
+
     /// <summary>
     /// Calculates the distance in pixels from the target <see cref="ChartPoint"/> to the given location in the UI.
     /// </summary>

tests/LiveChartsCore.UnitTesting/MockedObjects/TestLabel.cs

@@ -0,0 +1,33 @@
+// The MIT License(MIT)
+//
+// Copyright(c) 2021 Alberto Rodriguez Orozco & LiveCharts Contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+using LiveChartsCore.SkiaSharpView.Drawing.Geometries;
+
+namespace LiveChartsCore.UnitTesting.MockedObjects;
+
+public class TestLabel : LabelGeometry
+{
+    public TestLabel()
+    {
+        Background = new Drawing.LvcColor(200, 200, 200, 50);
+    }
+}

tests/LiveChartsCore.UnitTesting/MockedObjects/TestObserver.cs

@@ -23,6 +23,7 @@
 using System;
 using System.Collections.Generic;
 using LiveChartsCore.Kernel;
+using LiveChartsCore.SkiaSharpView.Drawing.Geometries;
 
 namespace LiveChartsCore.UnitTesting.MockedObjects;