Support custom annotation

mark_line.go

@@ -78,10 +78,24 @@ func (m *markLinePainter) Render() (Box, error) {
 		}
 		summary := s.Summary()
 		for _, markLine := range s.MarkLine.Data {
-			// 由于mark line会修改style，因此每次重新设置
+			fillColor := opt.FillColor
+			if markLine.FillColor != nil {
+				fillColor = *markLine.FillColor
+			}
+
+			strokeColor := opt.StrokeColor
+			if markLine.StrokeColor != nil {
+				strokeColor = *markLine.StrokeColor
+			}
+
+			fontColor := opt.FontColor
+			if markLine.FontColor != nil {
+				fontColor = *markLine.FontColor
+			}
+
 			painter.OverrideDrawingStyle(Style{
-				FillColor:   opt.FillColor,
+				FillColor:   fillColor,
-				StrokeColor: opt.StrokeColor,
+				StrokeColor: strokeColor,
 				StrokeWidth: 1,
 				StrokeDashArray: []float64{
 					4,
@@ -89,7 +103,7 @@ func (m *markLinePainter) Render() (Box, error) {
 				},
 			}).OverrideTextStyle(Style{
 				Font:      font,
-				FontColor: opt.FontColor,
+				FontColor: fontColor,
 				FontSize:  labelFontSize,
 			})
 			value := float64(0)
@@ -98,6 +112,8 @@ func (m *markLinePainter) Render() (Box, error) {
 				value = summary.MaxValue
 			case SeriesMarkDataTypeMin:
 				value = summary.MinValue
+			case SeriesMarkDataTypeCustom:
+				value = markLine.CustomYVal
 			default:
 				value = summary.AverageValue
 			}

mark_point.go

@@ -81,15 +81,25 @@ func (m *markPointPainter) Render() (Box, error) {
 			StrokeWidth: 1,
 			Font:        opt.Font,
 		}
-		if isLightColor(opt.FillColor) {
-			textStyle.FontColor = defaultLightFontColor
-		} else {
-			textStyle.FontColor = defaultDarkFontColor
-		}
-		painter.OverrideDrawingStyle(Style{
-			FillColor: opt.FillColor,
-		}).OverrideTextStyle(textStyle)
 		for _, markPointData := range s.MarkPoint.Data {
+			fillColor := opt.FillColor
+			if markPointData.FillColor != nil {
+				fillColor = *markPointData.FillColor
+			}
+
+			if markPointData.FontColor != nil {
+				textStyle.FontColor = *markPointData.FontColor
+			} else {
+				if isLightColor(fillColor) {
+					textStyle.FontColor = defaultLightFontColor
+				} else {
+					textStyle.FontColor = defaultDarkFontColor
+				}
+			}
+
+			painter.OverrideDrawingStyle(Style{
+				FillColor: fillColor,
+			}).OverrideTextStyle(textStyle)
 			textStyle.FontSize = labelFontSize
 			painter.OverrideTextStyle(textStyle)
 			p := points[summary.MinIndex]
@@ -98,6 +108,9 @@ func (m *markPointPainter) Render() (Box, error) {
 			case SeriesMarkDataTypeMax:
 				p = points[summary.MaxIndex]
 				value = summary.MaxValue
+			case SeriesMarkDataTypeCustom:
+				p = points[markPointData.XAxisIndex]
+				value = markPointData.CustomYVal
 			}
 
 			painter.Pin(p.X, p.Y-symbolSize>>1, symbolSize)

series.go

@@ -91,12 +91,20 @@ const (
 	SeriesMarkDataTypeMax     = "max"
 	SeriesMarkDataTypeMin     = "min"
 	SeriesMarkDataTypeAverage = "average"
+	SeriesMarkDataTypeCustom  = "custom"
 )
 
 type SeriesMarkData struct {
 	// The mark data type, it can be "max", "min", "average".
 	// The "average" is only for mark line
 	Type string
+
+	// Custom options.
+	XAxisIndex  int
+	CustomYVal  float64
+	FillColor   *Color
+	StrokeColor *Color
+	FontColor   *Color
 }
 type SeriesMarkPoint struct {
 	// The width of symbol, default value is 30