private Grid _series; // grid for series of points
#endregion Fields
#region Methods
internal static IEnumerable<double> GetLabelValues(Range dataRange, double maxLabel)
{
double maxValue = Math.Max(-dataRange.Min, dataRange.Max);
if (maxValue <= 0.0) // all values equal to 0
{
yield return 0.0;
}
else
{
double nbDigit = Math.Ceiling(Math.Log10(maxValue / maxLabel));
double step = Math.Pow(10, nbDigit); // increment the label by a power of 10
if (step * 1.5 > maxValue)
step /= 2; // label 5 by 5 else only one label that may be far and thus inelegant
for (double current = 0.0; current <= dataRange.Max + step / 2.0; current += step)
{
yield return current;
}
for (double current = -step; current >= dataRange.Min - step / 2.0; current -= step)
{
yield return current;
}
}
}
private Grid _series; // grid for series of points
#endregion Fields
#region Methods
/// <summary>
/// Generates the column chart.
/// </summary>
protected override void GenerateChart()
{
RootElement.Children.Clear();
var data = ItemsSource;
if (data != null && data.Any())
{
double max = Math.Max(0, data.Values.Max());
double min = Math.Min(0, data.Values.Min());
Range dataRange = new Range(min, max);
// Get the label values
var labels = BarChart.GetLabelValues(dataRange, MaxLabel).ToArray();
// The label might be out of the current range (e.g if max value = '99', there will be a label '100')
// Extend the range to include the labels
dataRange.Min = Math.Min(dataRange.Min, labels.Min());
dataRange.Max = Math.Max(dataRange.Max, labels.Max());
// Create chart main structure
GenerateChartStructure();
// Generate the labels
foreach (double val in labels)
GenerateLabel(val, dataRange);
// Generate data points
foreach (var kvp in data)
{
GenerateDataPoint(kvp, dataRange);
}
}
}
private void GenerateChartStructure(Range range)
{
// Main grid
Grid root = new Grid { Margin = new Thickness(0, 10, 0, 10) }; // Vertical Margin for labels
root.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(0, GridUnitType.Auto) }); // Column for labels
root.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) }); // Column for chart
RootElement.Children.Add(root);
// Grid for labels (column 0)
_labels = new Grid();
root.Children.Add(_labels);
// Grid for chart (column 1)
Grid chart = new Grid();
Grid.SetColumn(chart, 1);
root.Children.Add(chart);
// Grid for Axis in coordinate 0
Grid gridAxis = new Grid();
double fraction = range.Fraction(0);
gridAxis.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1 - fraction, GridUnitType.Star) });
gridAxis.RowDefinitions.Add(new RowDefinition { Height = new GridLength(fraction, GridUnitType.Star) });
chart.Children.Add(gridAxis);
// Axis
Border axisX = new Border
{
BorderThickness = new Thickness(0.75),
BorderBrush = ForegroundColor,
Opacity = 0.5,
HorizontalAlignment = HorizontalAlignment.Stretch,
VerticalAlignment = VerticalAlignment.Bottom,
Margin = new Thickness(-5, 0, -5, 0)
};
gridAxis.Children.Add(axisX);
Border axisY = new Border
{
BorderThickness = new Thickness(0.75),
BorderBrush = ForegroundColor,
Opacity = 0.5,
HorizontalAlignment = HorizontalAlignment.Left,
VerticalAlignment = VerticalAlignment.Stretch,
Margin = new Thickness(0, -5, 0, -5)
};
chart.Children.Add(axisY);
// Grid for series of points
_series = new Grid();
chart.Children.Add(_series);
}
// Generate one label
private void GenerateLabel(double val, Range dataRange)
{
double fraction = dataRange.Fraction(val);
Grid label = new Grid();
_labels.Children.Add(label);
label.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1 - fraction, GridUnitType.Star) });
label.RowDefinitions.Add(new RowDefinition { Height = new GridLength(0, GridUnitType.Pixel) });
label.RowDefinitions.Add(new RowDefinition { Height = new GridLength(fraction, GridUnitType.Star) });
StackPanel stackPanel = new StackPanel
{
VerticalAlignment = VerticalAlignment.Center,
HorizontalAlignment = HorizontalAlignment.Right,
Orientation = Orientation.Horizontal,
Margin = new Thickness(0, -20, 0, -20)
};
Grid.SetRow(stackPanel, 1);
label.Children.Add(stackPanel);
TextBlock text = new TextBlock
{
Text = FormattedValue(val)
};
stackPanel.Children.Add(text);
Rectangle rect = new Rectangle { Stroke = ForegroundColor, Width = 5, Height = 1, Opacity = 0.5, Margin = new Thickness(2, 0, 0, 0) };
stackPanel.Children.Add(rect);
}
private void GenerateDataPoint(KeyValuePair<string, double> kvp, Range range)
{
// Add a column and add a grid in this column
_series.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
Grid point = new Grid();
Grid.SetColumn(point, _series.ColumnDefinitions.Count - 1);
_series.Children.Add(point);
// Divide the grid in 3 rows
double val = kvp.Value;
double negativeFraction = range.Fraction(Math.Min(val, 0));
double positiveFraction = 1 - range.Fraction(Math.Max(val, 0));
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(positiveFraction, GridUnitType.Star) });
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1 - positiveFraction - negativeFraction, GridUnitType.Star), MinHeight = MinBarSize});
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(negativeFraction, GridUnitType.Star) });
Border axisX = new Border
{
BorderThickness = new Thickness(0.75),
BorderBrush = ForegroundColor,
Opacity = 0.5,
HorizontalAlignment = HorizontalAlignment.Stretch,
VerticalAlignment = val > 0 ? VerticalAlignment.Bottom : VerticalAlignment.Top,
Margin = new Thickness(-5, 0, -5, 0)
};
Grid.SetRow(axisX, 1);
point.Children.Add(axisX);
// Put a bar in the middle row
Border bar = new Border
{
Margin = new Thickness(MarginBetweenBars, 0, MarginBetweenBars, 0),
Background = GetColorByIndex(0)
};
Grid.SetRow(bar, 1);
SetTooltip(bar, kvp.Key, FormattedValue(kvp.Value));
point.Children.Add(bar);
}
private void GenerateDataPoints(IDictionary<string, double> data, Range dataRange)
{
int count = data.Count;
// Project the data in order to get the points in percent of the drawing space (rectangle 1*1)
var points = data.Select((kvp, ind) => new { x = (2.0 * ind + 1.0) / (2.0 * count), y = 1.0 - dataRange.Fraction(kvp.Value)});
// Generate the lines from point to point
var firstPoint = points.First();
PathFigure pathFigure = new PathFigure { IsClosed = false, StartPoint = new Point(firstPoint.x, firstPoint.y) };
foreach (var point in points.Skip(1))
{
pathFigure.Segments.Add(new LineSegment {Point = new Point(point.x, point.y)});
}
//Add these two empty line segments to force the drawing to stretch properly
PathFigure pathFigure2 = new PathFigure { StartPoint = new Point(0, 0) };
pathFigure2.Segments.Add(new LineSegment { Point = new Point(0, 0) });
PathFigure pathFigure3 = new PathFigure { StartPoint = new Point(1, 1) };
pathFigure3.Segments.Add(new LineSegment { Point = new Point(1, 1) });
PathGeometry pathGeometry = new PathGeometry();
pathGeometry.Figures.Add(pathFigure2);
pathGeometry.Figures.Add(pathFigure3);
pathGeometry.Figures.Add(pathFigure);
Path path = new Path
{
Stretch = Stretch.Fill, // stretch the polyline to fill the chart drawing space
Stroke = GetColorByIndex(0),
StrokeThickness = 2,
StrokeLineJoin = PenLineJoin.Round,
Data = pathGeometry,
Margin = new Thickness(-1,-1,-1,-1) // half of strokeThickness
};
_series.Children.Add(path);
// Add a new grid for the points
Grid pointsGrid = new Grid();
_series.Children.Add(pointsGrid);
// Generate the points
foreach (var kvp in data)
{
GenerateDataPoint(pointsGrid, kvp, dataRange);
}
}
private void GenerateDataPoint(Grid points, KeyValuePair<string, double> kvp, Range range)
{
// Add a column and add a grid in this column
points.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
Grid point = new Grid();
Grid.SetColumn(point, points.ColumnDefinitions.Count - 1);
points.Children.Add(point);
// Divide the grid in 3 rows
double val = kvp.Value;
double fraction = range.Fraction(val);
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1 - fraction, GridUnitType.Star) });
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(0, GridUnitType.Pixel) });
point.RowDefinitions.Add(new RowDefinition { Height = new GridLength(fraction, GridUnitType.Star) });
// Put a point in the middle row
Ellipse ellipse = new Ellipse
{
Height = 10,
Width = 10,
Fill = GetColorByIndex(0),
HorizontalAlignment = HorizontalAlignment.Center,
VerticalAlignment = VerticalAlignment.Center,
Margin = new Thickness(0, -20, 0, -20),
Stroke = ForegroundColor,
StrokeThickness = 1
};
Grid.SetRow(ellipse, 1);
SetTooltip(ellipse, kvp.Key, FormattedValue(kvp.Value));
point.Children.Add(ellipse);
}