feat: support fill area of line chart

examples/area_line_chart/main.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/vicanso/go-charts/v2"
+)
+
+func writeFile(buf []byte) error {
+	tmpPath := "./tmp"
+	err := os.MkdirAll(tmpPath, 0700)
+	if err != nil {
+		return err
+	}
+
+	file := filepath.Join(tmpPath, "area-line-chart.png")
+	err = ioutil.WriteFile(file, buf, 0600)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func main() {
+	values := [][]float64{
+		{
+			120,
+			132,
+			101,
+			134,
+			90,
+			230,
+			210,
+		},
+	}
+	p, err := charts.LineRender(
+		values,
+		charts.TitleTextOptionFunc("Line"),
+		charts.XAxisDataOptionFunc([]string{
+			"Mon",
+			"Tue",
+			"Wed",
+			"Thu",
+			"Fri",
+			"Sat",
+			"Sun",
+		}),
+		charts.LegendLabelsOptionFunc([]string{
+			"Email",
+		}, "50"),
+		func(opt *charts.ChartOption) {
+			opt.Legend.Padding = charts.Box{
+				Top:    5,
+				Bottom: 10,
+			}
+			opt.FillArea = true
+		},
+	)
+
+	if err != nil {
+		panic(err)
+	}
+
+	buf, err := p.Bytes()
+	if err != nil {
+		panic(err)
+	}
+	err = writeFile(buf)
+	if err != nil {
+		panic(err)
+	}
+}

examples/charts/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"net/http"
 	"strconv"
 
@@ -261,6 +262,35 @@ func indexHandler(w http.ResponseWriter, req *http.Request) {
 				},
 			},
 		},
+		{
+			Title: charts.TitleOption{
+				Text: "Line Area",
+			},
+			Legend: charts.NewLegendOption([]string{
+				"Email",
+			}),
+			XAxis: charts.NewXAxisOption([]string{
+				"Mon",
+				"Tue",
+				"Wed",
+				"Thu",
+				"Fri",
+				"Sat",
+				"Sun",
+			}),
+			SeriesList: []charts.Series{
+				charts.NewSeriesFromValues([]float64{
+					120,
+					132,
+					101,
+					134,
+					90,
+					230,
+					210,
+				}),
+			},
+			FillArea: true,
+		},
 		// 柱状图
 		{
 			Title: charts.TitleOption{
@@ -1935,5 +1965,6 @@ func echartsHandler(w http.ResponseWriter, req *http.Request) {
 func main() {
 	http.HandleFunc("/", indexHandler)
 	http.HandleFunc("/echarts", echartsHandler)
+	fmt.Println("http://127.0.0.1:3012/")
 	http.ListenAndServe(":3012", nil)
 }