feat: support mark line and mark point render

chart_option.go

@@ -0,0 +1,120 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"sort"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/v2"
+)
+
+type ChartOption struct {
+	theme ColorPalette
+	font  *truetype.Font
+	// The output type of chart, "svg" or "png", default value is "svg"
+	Type string
+	// The font family, which should be installed first
+	FontFamily string
+	// The theme of chart, "light" and "dark".
+	// The default theme is "light"
+	Theme string
+	// The title option
+	Title TitleOption
+	// The legend option
+	Legend LegendOption
+	// The x axis option
+	XAxis XAxisOption
+	// The y axis option list
+	YAxisOptions []YAxisOption
+	// The width of chart, default width is 600
+	Width int
+	// The height of chart, default height is 400
+	Height int
+	Parent *Painter
+	// The padding for chart, default padding is [20, 10, 10, 10]
+	Padding Box
+	// The canvas box for chart
+	Box Box
+	// The series list
+	SeriesList SeriesList
+	// The radar indicator list
+	// RadarIndicators []RadarIndicator
+	// The background color of chart
+	BackgroundColor Color
+	// The child charts
+	Children []ChartOption
+}
+
+func (o *ChartOption) fillDefault() {
+	t := NewTheme(o.Theme)
+	o.theme = t
+	// 如果为空，初始化
+	axisCount := 1
+	for _, series := range o.SeriesList {
+		if series.AxisIndex >= axisCount {
+			axisCount++
+		}
+	}
+	o.Width = getDefaultInt(o.Width, defaultChartWidth)
+	o.Height = getDefaultInt(o.Height, defaultChartHeight)
+	yAxisOptions := make([]YAxisOption, axisCount)
+	copy(yAxisOptions, o.YAxisOptions)
+	o.YAxisOptions = yAxisOptions
+	o.font, _ = GetFont(o.FontFamily)
+
+	if o.font == nil {
+		o.font, _ = chart.GetDefaultFont()
+	}
+	if o.BackgroundColor.IsZero() {
+		o.BackgroundColor = t.GetBackgroundColor()
+	}
+	if o.Padding.IsZero() {
+		o.Padding = chart.Box{
+			Top:    10,
+			Right:  10,
+			Bottom: 10,
+			Left:   10,
+		}
+	}
+	// legend与series name的关联
+	if len(o.Legend.Data) == 0 {
+		o.Legend.Data = o.SeriesList.Names()
+	} else {
+		seriesCount := len(o.SeriesList)
+		for index, name := range o.Legend.Data {
+			if index < seriesCount &&
+				len(o.SeriesList[index].Name) == 0 {
+				o.SeriesList[index].Name = name
+			}
+		}
+		nameIndexDict := map[string]int{}
+		for index, name := range o.Legend.Data {
+			nameIndexDict[name] = index
+		}
+		// 保证series的顺序与legend一致
+		sort.Slice(o.SeriesList, func(i, j int) bool {
+			return nameIndexDict[o.SeriesList[i].Name] < nameIndexDict[o.SeriesList[j].Name]
+		})
+	}
+}

charts.go

@@ -22,6 +22,24 @@
 
 package charts
 
+const labelFontSize = 10
+const defaultDotWidth = 2.0
+const defaultStrokeWidth = 2.0
+
+var defaultChartWidth = 600
+var defaultChartHeight = 400
+
+func SetDefaultWidth(width int) {
+	if width > 0 {
+		defaultChartWidth = width
+	}
+}
+func SetDefaultHeight(height int) {
+	if height > 0 {
+		defaultChartHeight = height
+	}
+}
+
 type Renderer interface {
 	Render() (Box, error)
 }
@@ -34,6 +52,10 @@ type defaultRenderOption struct {
 	YAxisOptions []YAxisOption
 	// The x axis option
 	XAxis XAxisOption
+	// The title option
+	TitleOption TitleOption
+	// The legend option
+	LegendOption LegendOption
 }
 
 type defaultRenderResult struct {
@@ -42,10 +64,37 @@ type defaultRenderResult struct {
 }
 
 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))
 	}
+
+	if len(opt.LegendOption.Data) != 0 {
+		if opt.LegendOption.Theme == nil {
+			opt.LegendOption.Theme = opt.Theme
+		}
+		_, err := NewLegendPainter(p, opt.LegendOption).Render()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// 如果有标题
+	if opt.TitleOption.Text != "" {
+		if opt.TitleOption.Theme == nil {
+			opt.TitleOption.Theme = opt.Theme
+		}
+		titlePainter := NewTitlePainter(p, opt.TitleOption)
+
+		titleBox, err := titlePainter.Render()
+		if err != nil {
+			return nil, err
+		}
+		p = p.Child(PainterPaddingOption(Box{
+			// 标题下留白
+			Top: titleBox.Height() + 20,
+		}))
+	}
+
 	result := defaultRenderResult{
 		axisRanges: make(map[int]axisRange),
 	}
@@ -60,7 +109,8 @@ func defaultRender(p *Painter, opt defaultRenderOption) (*defaultRenderResult, e
 	}
 	// 高度需要减去x轴的高度
 	rangeHeight := p.Height() - defaultXAxisHeight
-	rangeWidth := 0
+	rangeWidthLeft := 0
+	rangeWidthRight := 0
 
 	// 计算对应的axis range
 	for _, index := range axisIndexList {
@@ -89,28 +139,28 @@ func defaultRender(p *Painter, opt defaultRenderOption) (*defaultRenderResult, e
 		if err != nil {
 			return nil, err
 		}
-		rangeWidth += yAxisBox.Width()
+		if index == 0 {
+			rangeWidthLeft += yAxisBox.Width()
+		} else {
+			rangeWidthRight += yAxisBox.Width()
+		}
 	}
 
 	if opt.XAxis.Theme == nil {
 		opt.XAxis.Theme = opt.Theme
 	}
 	xAxis := NewBottomXAxis(p.Child(PainterPaddingOption(Box{
-		Left: rangeWidth,
+		Left: rangeWidthLeft,
 	})), 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,
+		Left:   rangeWidthLeft,
+		Right:  rangeWidthRight,
 	}))
 	return &result, nil
 }
@@ -124,3 +174,50 @@ func doRender(renderers ...Renderer) error {
 	}
 	return nil
 }
+
+func Render(opt ChartOption) (*Painter, error) {
+	opt.fillDefault()
+
+	if opt.Parent == nil {
+		p, err := NewPainter(PainterOptions{
+			Type:   opt.Type,
+			Width:  opt.Width,
+			Height: opt.Height,
+		})
+		if err != nil {
+			return nil, err
+		}
+		opt.Parent = p
+	}
+	p := opt.Parent
+	p.SetBackground(p.Width(), p.Height(), opt.BackgroundColor)
+	seriesList := opt.SeriesList
+	seriesList.init()
+
+	rendererList := make([]Renderer, 0)
+
+	// line chart
+	lineChartSeriesList := seriesList.Filter(ChartTypeLine)
+	if len(lineChartSeriesList) != 0 {
+		renderer := NewLineChart(p, LineChartOption{
+			Theme:        opt.theme,
+			Font:         opt.font,
+			SeriesList:   lineChartSeriesList,
+			XAxis:        opt.XAxis,
+			Padding:      opt.Padding,
+			YAxisOptions: opt.YAxisOptions,
+			TitleOption:  opt.Title,
+			LegendOption: opt.Legend,
+		})
+		rendererList = append(rendererList, renderer)
+	}
+
+	for _, renderer := range rendererList {
+		_, err := renderer.Render()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return p, nil
+}

examples/line_chart/main.go

@@ -39,6 +39,19 @@ func main() {
 			Right:  10,
 			Bottom: 10,
 		},
+		TitleOption: charts.TitleOption{
+			Text: "Line",
+		},
+		LegendOption: charts.LegendOption{
+			Data: []string{
+				"Email",
+				"Union Ads",
+				"Video Ads",
+				"Direct",
+				"Search Engine",
+			},
+			Left: charts.PositionCenter,
+		},
 		XAxis: charts.NewXAxisOption([]string{
 			"Mon",
 			"Tue",

legend.go

@@ -29,13 +29,13 @@ import (
 
 type legendPainter struct {
 	p   *Painter
-	opt *LegendPainterOption
+	opt *LegendOption
 }
 
 const IconRect = "rect"
 const IconLineDot = "lineDot"
 
-type LegendPainterOption struct {
+type LegendOption struct {
 	Theme ColorPalette
 	// Text array of legend
 	Data []string
@@ -58,7 +58,17 @@ type LegendPainterOption struct {
 	FontColor Color
 }
 
-func NewLegendPainter(p *Painter, opt LegendPainterOption) *legendPainter {
+func NewLegendOption(labels []string, left ...string) LegendOption {
+	opt := LegendOption{
+		Data: labels,
+	}
+	if len(left) != 0 {
+		opt.Left = left[0]
+	}
+	return opt
+}
+
+func NewLegendPainter(p *Painter, opt LegendOption) *legendPainter {
 	return &legendPainter{
 		p:   p,
 		opt: &opt,
@@ -71,6 +81,12 @@ func (l *legendPainter) Render() (Box, error) {
 	if theme == nil {
 		theme = l.p.theme
 	}
+	if opt.FontSize == 0 {
+		opt.FontSize = theme.GetFontSize()
+	}
+	if opt.FontColor.IsZero() {
+		opt.FontColor = theme.GetTextColor()
+	}
 	p := l.p
 	p.SetTextStyle(Style{
 		FontSize:  opt.FontSize,
@@ -129,7 +145,7 @@ func (l *legendPainter) Render() (Box, error) {
 	top, _ := strconv.Atoi(opt.Top)
 
 	x := int(left)
-	y := int(top)
+	y := int(top) + 10
 	x0 := x
 	y0 := y
 

line_chart.go

@@ -23,7 +23,9 @@
 package charts
 
 import (
+	"github.com/golang/freetype/truetype"
 	"github.com/wcharczuk/go-chart/v2"
+	"github.com/wcharczuk/go-chart/v2/drawing"
 )
 
 type lineChart struct {
@@ -43,6 +45,8 @@ func NewLineChart(p *Painter, opt LineChartOption) *lineChart {
 
 type LineChartOption struct {
 	Theme ColorPalette
+	// The font size
+	Font *truetype.Font
 	// The data series list
 	SeriesList SeriesList
 	// The x axis option
@@ -51,6 +55,10 @@ type LineChartOption struct {
 	Padding Box
 	// The y axis option
 	YAxisOptions []YAxisOption
+	// The option of title
+	TitleOption TitleOption
+	// The legend option
+	LegendOption LegendOption
 }
 
 func (l *lineChart) Render() (Box, error) {
@@ -64,6 +72,8 @@ func (l *lineChart) Render() (Box, error) {
 		SeriesList:   seriesList,
 		XAxis:        opt.XAxis,
 		YAxisOptions: opt.YAxisOptions,
+		TitleOption:  opt.TitleOption,
+		LegendOption: opt.LegendOption,
 	})
 	if err != nil {
 		return chart.BoxZero, err
@@ -78,13 +88,20 @@ func (l *lineChart) Render() (Box, error) {
 	for i := 0; i < len(xDivideValues)-1; i++ {
 		xValues[i] = (xDivideValues[i] + xDivideValues[i+1]) >> 1
 	}
+	markPointPainter := NewMarkPointPainter(seriesPainter)
+	markLinePainter := NewMarkLinePainter(seriesPainter)
+	rendererList := []Renderer{
+		markPointPainter,
+		markLinePainter,
+	}
 	for index, series := range seriesList {
 		seriesColor := opt.Theme.GetSeriesColor(index)
-		seriesPainter.SetDrawingStyle(Style{
+		drawingStyle := Style{
 			StrokeColor: seriesColor,
-			StrokeWidth: 2,
+			StrokeWidth: defaultStrokeWidth,
-			FillColor:   seriesColor,
+		}
-		})
+
+		seriesPainter.SetDrawingStyle(drawingStyle)
 		yr := renderResult.axisRanges[series.AxisIndex]
 		points := make([]Point, 0)
 		for i, item := range series.Data {
@@ -95,8 +112,39 @@ func (l *lineChart) Render() (Box, error) {
 			}
 			points = append(points, p)
 		}
+		// 画线
 		seriesPainter.LineStroke(points)
+
+		// 画点
+		if opt.Theme.IsDark() {
+			drawingStyle.FillColor = drawingStyle.StrokeColor
+		} else {
+			drawingStyle.FillColor = drawing.ColorWhite
+		}
+		drawingStyle.StrokeWidth = 1
+		seriesPainter.SetDrawingStyle(drawingStyle)
 		seriesPainter.Dots(points)
+		markPointPainter.Add(markPointRenderOption{
+			FillColor: seriesColor,
+			Font:      opt.Font,
+			Points:    points,
+			Series:    series,
+		})
+		markLinePainter.Add(markLineRenderOption{
+			FillColor:   seriesColor,
+			FontColor:   opt.Theme.GetTextColor(),
+			StrokeColor: seriesColor,
+			Font:        opt.Font,
+			Series:      series,
+			Range:       yr,
+		})
+	}
+	// 最大、最小的mark point
+	for _, renderer := range rendererList {
+		_, err = renderer.Render()
+		if err != nil {
+			return chart.BoxZero, err
+		}
 	}
 
 	return p.box, nil

mark_line.go

@@ -0,0 +1,118 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/v2"
+)
+
+func NewMarkLine(markLineTypes ...string) SeriesMarkLine {
+	data := make([]SeriesMarkData, len(markLineTypes))
+	for index, t := range markLineTypes {
+		data[index] = SeriesMarkData{
+			Type: t,
+		}
+	}
+	return SeriesMarkLine{
+		Data: data,
+	}
+}
+
+type markLinePainter struct {
+	p       *Painter
+	options []markLineRenderOption
+}
+
+func (m *markLinePainter) Add(opt markLineRenderOption) {
+	m.options = append(m.options, opt)
+}
+
+func NewMarkLinePainter(p *Painter) *markLinePainter {
+	return &markLinePainter{
+		p:       p,
+		options: make([]markLineRenderOption, 0),
+	}
+}
+
+type markLineRenderOption struct {
+	FillColor   Color
+	FontColor   Color
+	StrokeColor Color
+	Font        *truetype.Font
+	Series      Series
+	Range       axisRange
+}
+
+func (m *markLinePainter) Render() (Box, error) {
+	painter := m.p
+	for _, opt := range m.options {
+		s := opt.Series
+		if len(s.MarkLine.Data) == 0 {
+			continue
+		}
+		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
+			painter.OverrideDrawingStyle(Style{
+				FillColor:   opt.FillColor,
+				StrokeColor: opt.StrokeColor,
+				StrokeWidth: 1,
+				StrokeDashArray: []float64{
+					4,
+					2,
+				},
+			}).OverrideTextStyle(Style{
+				Font:      opt.Font,
+				FontColor: opt.FontColor,
+				FontSize:  labelFontSize,
+			})
+			value := float64(0)
+			switch markLine.Type {
+			case SeriesMarkDataTypeMax:
+				value = summary.MaxValue
+			case SeriesMarkDataTypeMin:
+				value = summary.MinValue
+			default:
+				value = summary.AverageValue
+			}
+			y := opt.Range.getRestHeight(value)
+			width := painter.Width()
+			text := commafWithDigits(value)
+			textBox := painter.MeasureText(text)
+			painter.MarkLine(0, y, width-2)
+			painter.Text(text, width, y+textBox.Height()>>1-2)
+		}
+	}
+	return chart.BoxZero, nil
+}
+
+func markLineRender(opt markLineRenderOption) {
+	// d := opt.Draw
+	// s := opt.Series
+	// if len(s.MarkLine.Data) == 0 {
+	// 	return
+	// }
+	// r := d.Render
+
+}

mark_point.go

@@ -0,0 +1,102 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/v2"
+)
+
+func NewMarkPoint(markPointTypes ...string) SeriesMarkPoint {
+	data := make([]SeriesMarkData, len(markPointTypes))
+	for index, t := range markPointTypes {
+		data[index] = SeriesMarkData{
+			Type: t,
+		}
+	}
+	return SeriesMarkPoint{
+		Data: data,
+	}
+}
+
+type markPointPainter struct {
+	p       *Painter
+	options []markPointRenderOption
+}
+
+func (m *markPointPainter) Add(opt markPointRenderOption) {
+	m.options = append(m.options, opt)
+}
+
+type markPointRenderOption struct {
+	FillColor Color
+	Font      *truetype.Font
+	Series    Series
+	Points    []Point
+}
+
+func NewMarkPointPainter(p *Painter) *markPointPainter {
+	return &markPointPainter{
+		p:       p,
+		options: make([]markPointRenderOption, 0),
+	}
+}
+
+func (m *markPointPainter) Render() (Box, error) {
+	painter := m.p
+	for _, opt := range m.options {
+		s := opt.Series
+		if len(s.MarkPoint.Data) == 0 {
+			continue
+		}
+		points := opt.Points
+		summary := s.Summary()
+		symbolSize := s.MarkPoint.SymbolSize
+		if symbolSize == 0 {
+			symbolSize = 30
+		}
+		painter.OverrideDrawingStyle(Style{
+			FillColor: opt.FillColor,
+		}).OverrideTextStyle(Style{
+			FontColor:   NewTheme(ThemeDark).GetTextColor(),
+			FontSize:    labelFontSize,
+			StrokeWidth: 1,
+			Font:        opt.Font,
+		})
+		for _, markPointData := range s.MarkPoint.Data {
+			p := points[summary.MinIndex]
+			value := summary.MinValue
+			switch markPointData.Type {
+			case SeriesMarkDataTypeMax:
+				p = points[summary.MaxIndex]
+				value = summary.MaxValue
+			}
+
+			painter.Pin(p.X, p.Y-symbolSize>>1, symbolSize)
+			text := commafWithDigits(value)
+			textBox := painter.MeasureText(text)
+			painter.Text(text, p.X-textBox.Width()>>1, p.Y-symbolSize>>1-2)
+		}
+	}
+	return chart.BoxZero, nil
+}

painter.go

@@ -700,7 +700,7 @@ func (p *Painter) Grid(opt GridOption) *Painter {
 
 func (p *Painter) Dots(points []Point) *Painter {
 	for _, item := range points {
-		p.Circle(3, item.X, item.Y)
+		p.Circle(2, item.X, item.Y)
 	}
 	p.FillStroke()
 	return p

title.go

@@ -0,0 +1,192 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/golang/freetype/truetype"
+)
+
+type TitleOption struct {
+	// The theme of chart
+	Theme ColorPalette
+	// Title text, support \n for new line
+	Text string
+	// Subtitle text, support \n for new line
+	Subtext string
+	// // Title style
+	// Style Style
+	// // Subtitle style
+	// SubtextStyle Style
+	// Distance between title component and the left side of the container.
+	// It can be pixel value: 20, percentage value: 20%,
+	// or position value: right, center.
+	Left string
+	// Distance between title component and the top side of the container.
+	// It can be pixel value: 20.
+	Top string
+	// The font of label
+	Font *truetype.Font
+	// The font size of label
+	FontSize float64
+	// The color of label
+	FontColor Color
+	// The subtext font size of label
+	SubtextFontSize float64
+	// The subtext font color of label
+	SubtextFontColor Color
+}
+
+type titleMeasureOption struct {
+	width  int
+	height int
+	text   string
+	style  Style
+}
+
+func splitTitleText(text string) []string {
+	arr := strings.Split(text, "\n")
+	result := make([]string, 0)
+	for _, v := range arr {
+		v = strings.TrimSpace(v)
+		if v == "" {
+			continue
+		}
+		result = append(result, v)
+	}
+	return result
+}
+
+type titlePainter struct {
+	p   *Painter
+	opt *TitleOption
+}
+
+func NewTitlePainter(p *Painter, opt TitleOption) *titlePainter {
+	return &titlePainter{
+		p:   p,
+		opt: &opt,
+	}
+}
+
+func (t *titlePainter) Render() (Box, error) {
+	opt := t.opt
+	p := t.p
+	theme := opt.Theme
+	measureOptions := make([]titleMeasureOption, 0)
+
+	if opt.Font == nil {
+		opt.Font = theme.GetFont()
+	}
+	if opt.FontColor.IsZero() {
+		opt.FontColor = theme.GetTextColor()
+	}
+	if opt.FontSize == 0 {
+		opt.FontSize = theme.GetFontSize()
+	}
+	if opt.SubtextFontColor.IsZero() {
+		opt.SubtextFontColor = opt.FontColor
+	}
+	if opt.SubtextFontSize == 0 {
+		opt.SubtextFontSize = opt.FontSize
+	}
+
+	titleTextStyle := Style{
+		Font:      opt.Font,
+		FontSize:  opt.FontSize,
+		FontColor: opt.FontColor,
+	}
+	// 主标题
+	for _, v := range splitTitleText(opt.Text) {
+		measureOptions = append(measureOptions, titleMeasureOption{
+			text:  v,
+			style: titleTextStyle,
+		})
+	}
+	subtextStyle := Style{
+		Font:      opt.Font,
+		FontSize:  opt.SubtextFontSize,
+		FontColor: opt.SubtextFontColor,
+	}
+	// 副标题
+	for _, v := range splitTitleText(opt.Subtext) {
+		measureOptions = append(measureOptions, titleMeasureOption{
+			text:  v,
+			style: subtextStyle,
+		})
+	}
+	textMaxWidth := 0
+	textMaxHeight := 0
+	for index, item := range measureOptions {
+		p.OverrideTextStyle(item.style)
+		textBox := p.MeasureText(item.text)
+
+		w := textBox.Width()
+		h := textBox.Height()
+		if w > textMaxWidth {
+			textMaxWidth = w
+		}
+		if h > textMaxHeight {
+			textMaxHeight = h
+		}
+		measureOptions[index].height = h
+		measureOptions[index].width = w
+	}
+	width := textMaxWidth
+
+	titleX := 0
+	switch opt.Left {
+	case PositionRight:
+		titleX = p.Width() - textMaxWidth
+	case PositionCenter:
+		titleX = p.Width()>>1 - (textMaxWidth >> 1)
+	default:
+		if strings.HasSuffix(opt.Left, "%") {
+			value, _ := strconv.Atoi(strings.ReplaceAll(opt.Left, "%", ""))
+			titleX = p.Width() * value / 100
+		} else {
+			value, _ := strconv.Atoi(opt.Left)
+			titleX = value
+		}
+	}
+	titleY := 0
+	// TODO TOP 暂只支持数值
+	if opt.Top != "" {
+		value, _ := strconv.Atoi(opt.Top)
+		titleY += value
+	}
+	for _, item := range measureOptions {
+		p.OverrideTextStyle(item.style)
+		x := titleX + (textMaxWidth-item.width)>>1
+		y := titleY + item.height
+		p.Text(item.text, x, y)
+		titleY += item.height
+	}
+
+	return Box{
+		Bottom: titleY,
+		Right:  titleX + width,
+	}, nil
+}