feat: support hide symbol of line chart

chart_option.go

@@ -62,6 +62,8 @@ type ChartOption struct {
 	RadarIndicators []RadarIndicator
 	// The background color of chart
 	BackgroundColor Color
+	// The flag for show symbol of line, set this to *false will hide symbol
+	SymbolShow *bool
 	// The child charts
 	Children []ChartOption
 }

charts.go

@@ -377,9 +377,10 @@ func Render(opt ChartOption, opts ...OptionFunc) (*Painter, error) {
 	if len(lineSeriesList) != 0 {
 		handler.Add(func() error {
 			_, err := NewLineChart(p, LineChartOption{
-				Theme: opt.theme,
-				Font:  opt.font,
-				XAxis: opt.XAxis,
+				Theme:      opt.theme,
+				Font:       opt.font,
+				XAxis:      opt.XAxis,
+				SymbolShow: opt.SymbolShow,
 			}).render(renderResult, lineSeriesList)
 			return err
 		})

examples/line_chart/main.go

@@ -95,6 +95,7 @@ func main() {
 				Top:    5,
 				Bottom: 10,
 			}
+			opt.SymbolShow = charts.FalseFlag()
 		},
 	)
 

line_chart.go

@@ -60,6 +60,8 @@ type LineChartOption struct {
 	Title TitleOption
 	// The legend option
 	Legend LegendOption
+	// The flag for show symbol of line, set this to *false will hide symbol
+	SymbolShow *bool
 	// background is filled
 	backgroundIsFilled bool
 }
@@ -123,7 +125,9 @@ func (l *lineChart) render(result *defaultRenderResult, seriesList SeriesList) (
 		}
 		drawingStyle.StrokeWidth = 1
 		seriesPainter.SetDrawingStyle(drawingStyle)
-		seriesPainter.Dots(points)
+		if !isFalse(opt.SymbolShow) {
+			seriesPainter.Dots(points)
+		}
 		markPointPainter.Add(markPointRenderOption{
 			FillColor: seriesColor,
 			Font:      opt.Font,