Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

annotation_series.go

@@ -0,0 +1,91 @@
+package chart
+
+import (
+	"fmt"
+	"math"
+)
+
+// Interface Assertions.
+var (
+	_ Series = (*AnnotationSeries)(nil)
+)
+
+// AnnotationSeries is a series of labels on the chart.
+type AnnotationSeries struct {
+	Name        string
+	Style       Style
+	YAxis       YAxisType
+	Annotations []Value2
+}
+
+// GetName returns the name of the time series.
+func (as AnnotationSeries) GetName() string {
+	return as.Name
+}
+
+// GetStyle returns the line style.
+func (as AnnotationSeries) GetStyle() Style {
+	return as.Style
+}
+
+// GetYAxis returns which YAxis the series draws on.
+func (as AnnotationSeries) GetYAxis() YAxisType {
+	return as.YAxis
+}
+
+func (as AnnotationSeries) annotationStyleDefaults(defaults Style) Style {
+	return Style{
+		FontColor:   DefaultTextColor,
+		Font:        defaults.Font,
+		FillColor:   DefaultAnnotationFillColor,
+		FontSize:    DefaultAnnotationFontSize,
+		StrokeColor: defaults.StrokeColor,
+		StrokeWidth: defaults.StrokeWidth,
+		Padding:     DefaultAnnotationPadding,
+	}
+}
+
+// Measure returns a bounds box of the series.
+func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) Box {
+	box := Box{
+		Top:    math.MaxInt32,
+		Left:   math.MaxInt32,
+		Right:  0,
+		Bottom: 0,
+	}
+	if !as.Style.Hidden {
+		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
+		for _, a := range as.Annotations {
+			style := a.Style.InheritFrom(seriesStyle)
+			lx := canvasBox.Left + xrange.Translate(a.XValue)
+			ly := canvasBox.Bottom - yrange.Translate(a.YValue)
+			ab := Draw.MeasureAnnotation(r, canvasBox, style, lx, ly, a.Label)
+			box.Top = MinInt(box.Top, ab.Top)
+			box.Left = MinInt(box.Left, ab.Left)
+			box.Right = MaxInt(box.Right, ab.Right)
+			box.Bottom = MaxInt(box.Bottom, ab.Bottom)
+		}
+	}
+	return box
+}
+
+// Render draws the series.
+func (as AnnotationSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
+	if !as.Style.Hidden {
+		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
+		for _, a := range as.Annotations {
+			style := a.Style.InheritFrom(seriesStyle)
+			lx := canvasBox.Left + xrange.Translate(a.XValue)
+			ly := canvasBox.Bottom - yrange.Translate(a.YValue)
+			Draw.Annotation(r, canvasBox, style, lx, ly, a.Label)
+		}
+	}
+}
+
+// Validate validates the series.
+func (as AnnotationSeries) Validate() error {
+	if len(as.Annotations) == 0 {
+		return fmt.Errorf("annotation series requires annotations to be set and not empty")
+	}
+	return nil
+}