refactor: default render function for axis

charts.go

@@ -29,14 +29,90 @@ type Renderer interface {
 type defaultRenderOption struct {
 	Theme      ColorPalette
 	Padding    Box
+	SeriesList SeriesList
+	// The y axis option
+	YAxisOptions []YAxisOption
+	// The x axis option
+	XAxis XAxisOption
 }
 
-func defaultRender(p *Painter, opt defaultRenderOption) *Painter {
+type defaultRenderResult struct {
+	axisRanges map[int]axisRange
+	p          *Painter
+}
+
+func defaultRender(p *Painter, opt defaultRenderOption) (*defaultRenderResult, error) {
 	p.SetBackground(p.Width(), p.Height(), opt.Theme.GetBackgroundColor())
 	if !opt.Padding.IsZero() {
 		p = p.Child(PainterPaddingOption(opt.Padding))
 	}
-	return p
+	result := defaultRenderResult{
+		axisRanges: make(map[int]axisRange),
+	}
+
+	// 计算图表对应的轴有哪些
+	axisIndexList := make([]int, 0)
+	for _, series := range opt.SeriesList {
+		if containsInt(axisIndexList, series.AxisIndex) {
+			continue
+		}
+		axisIndexList = append(axisIndexList, series.index)
+	}
+	// 高度需要减去x轴的高度
+	rangeHeight := p.Height() - defaultXAxisHeight
+	rangeWidth := 0
+
+	// 计算对应的axis range
+	for _, index := range axisIndexList {
+		max, min := opt.SeriesList.GetMaxMin(index)
+		r := NewRange(AxisRangeOption{
+			Min: min,
+			Max: max,
+			// 高度需要减去x轴的高度
+			Size: rangeHeight,
+			// 分隔数量
+			DivideCount: defaultAxisDivideCount,
+		})
+		result.axisRanges[index] = r
+		yAxisOption := YAxisOption{}
+		if len(opt.YAxisOptions) > index {
+			yAxisOption = opt.YAxisOptions[index]
+		}
+		if yAxisOption.Theme == nil {
+			yAxisOption.Theme = opt.Theme
+		}
+		yAxisOption.Data = r.Values()
+		reverseStringSlice(yAxisOption.Data)
+		// TODO生成其它位置既yAxis
+		yAxis := NewLeftYAxis(p, yAxisOption)
+		yAxisBox, err := yAxis.Render()
+		if err != nil {
+			return nil, err
+		}
+		rangeWidth += yAxisBox.Width()
+	}
+
+	if opt.XAxis.Theme == nil {
+		opt.XAxis.Theme = opt.Theme
+	}
+	xAxis := NewBottomXAxis(p.Child(PainterPaddingOption(Box{
+		Left: rangeWidth,
+	})), opt.XAxis)
+	_, err := xAxis.Render()
+	if err != nil {
+		return nil, err
+	}
+
+	// // 生成Y轴
+	// for _, yAxisOption := range opt.YAxisOptions {
+
+	// }
+
+	result.p = p.Child(PainterPaddingOption(Box{
+		Bottom: rangeHeight,
+		Left:   rangeWidth,
+	}))
+	return &result, nil
 }
 
 func doRender(renderers ...Renderer) error {

line_chart.go

@@ -50,53 +50,28 @@ type LineChartOption struct {
 	// The padding of line chart
 	Padding Box
 	// The y axis option
-	YAxis YAxisOption
+	YAxisOptions []YAxisOption
 }
 
 func (l *lineChart) Render() (Box, error) {
 	p := l.p
 	opt := l.opt
-	p = defaultRender(p, defaultRenderOption{
-		Theme:   opt.Theme,
-		Padding: opt.Padding,
-	})
-
 	seriesList := opt.SeriesList
 	seriesList.init()
-	// 过滤前先计算最大最小值
-	max, min := seriesList.GetMaxMin()
-
-	seriesList = seriesList.Filter(ChartTypeLine)
-
-	// Y轴
-	yr := NewRange(AxisRangeOption{
-		Min: min,
-		Max: max,
-		// 高度需要减去x轴的高度
-		Size:        p.Height() - defaultXAxisHeight,
-		DivideCount: defaultAxisDivideCount,
+	renderResult, err := defaultRender(p, defaultRenderOption{
+		Theme:        opt.Theme,
+		Padding:      opt.Padding,
+		SeriesList:   seriesList,
+		XAxis:        opt.XAxis,
+		YAxisOptions: opt.YAxisOptions,
 	})
-	if opt.YAxis.Theme == nil {
-		opt.YAxis.Theme = opt.Theme
-	}
-	opt.YAxis.Data = yr.Values()
-	reverseStringSlice(opt.YAxis.Data)
-	yAxis := NewLeftYAxis(p, opt.YAxis)
-	yAxisBox, err := yAxis.Render()
 	if err != nil {
 		return chart.BoxZero, err
 	}
-	seriesPainter := p.Child(PainterPaddingOption(Box{
-		Bottom: defaultXAxisHeight,
-		Left:   yAxisBox.Width(),
-	}))
 
-	if opt.XAxis.Theme == nil {
-		opt.XAxis.Theme = opt.Theme
-	}
-	xAxis := NewBottomXAxis(p.Child(PainterPaddingOption(Box{
-		Left: yAxisBox.Width(),
-	})), opt.XAxis)
+	seriesList = seriesList.Filter(ChartTypeLine)
+
+	seriesPainter := renderResult.p
 
 	xDivideValues := autoDivide(seriesPainter.Width(), len(opt.XAxis.Data))
 	xValues := make([]int, len(xDivideValues)-1)
@@ -110,6 +85,7 @@ func (l *lineChart) Render() (Box, error) {
 			StrokeWidth: 2,
 			FillColor:   seriesColor,
 		})
+		yr := renderResult.axisRanges[series.AxisIndex]
 		points := make([]Point, 0)
 		for i, item := range series.Data {
 			h := yr.getRestHeight(item.Value)
@@ -123,12 +99,5 @@ func (l *lineChart) Render() (Box, error) {
 		seriesPainter.Dots(points)
 	}
 
-	err = doRender(
-		xAxis,
-	)
-	if err != nil {
-		return chart.BoxZero, err
-	}
-
 	return p.box, nil
 }

series.go

@@ -99,8 +99,8 @@ type Series struct {
 	// The data list of series
 	Data []SeriesData
 	// The Y axis index, it should be 0 or 1.
-	// Default value is 1
-	YAxisIndex int
+	// Default value is 0
+	AxisIndex int
 	// The style for series
 	Style chart.Style
 	// The label for series
@@ -143,10 +143,13 @@ func (sl SeriesList) Filter(chartType string) SeriesList {
 }
 
 // GetMaxMin get max and min value of series list
-func (sl SeriesList) GetMaxMin() (float64, float64) {
+func (sl SeriesList) GetMaxMin(axisIndex int) (float64, float64) {
 	min := math.MaxFloat64
 	max := -math.MaxFloat64
 	for _, series := range sl {
+		if series.AxisIndex != axisIndex {
+			continue
+		}
 		for _, item := range series.Data {
 			if item.Value > max {
 				max = item.Value