feat: support axis render

axis.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 (
+	"github.com/golang/freetype/truetype"
+)
+
+type axisPainter struct {
+	p   *Painter
+	opt *AxisPainterOption
+}
+
+func NewAxisPainter(p *Painter, opt AxisPainterOption) *axisPainter {
+	return &axisPainter{
+		p:   p,
+		opt: &opt,
+	}
+}
+
+type AxisPainterOption struct {
+	// The label of axis
+	Data []string
+	// The boundary gap on both sides of a coordinate axis.
+	// Nil or *true means the center part of two axis ticks
+	BoundaryGap *bool
+	// The position of axis, it can be 'left', 'top', 'right' or 'bottom'
+	Position string
+	// Number of segments that the axis is split into. Note that this number serves only as a recommendation.
+	SplitNumber int
+	// The line color of axis
+	StrokeColor Color
+	// The line width
+	StrokeWidth float64
+	// The length of the axis tick
+	TickLength int
+	// The margin value of label
+	LabelMargin int
+	// The font size of label
+	FontSize float64
+	// The font of label
+	Font *truetype.Font
+	// The color of label
+	FontColor Color
+	// The flag for show axis split line, set this to true will show axis split line
+	SplitLineShow bool
+	// The color of split line
+	SplitLineColor Color
+}
+
+func (a *axisPainter) Render() (Box, error) {
+	opt := a.opt
+	p := a.p
+
+	strokeWidth := opt.StrokeWidth
+	if strokeWidth == 0 {
+		strokeWidth = 1
+	}
+
+	tickCount := opt.SplitNumber
+	if tickCount == 0 {
+		tickCount = len(opt.Data)
+	}
+
+	boundaryGap := true
+	if opt.BoundaryGap != nil && !*opt.BoundaryGap {
+		boundaryGap = false
+	}
+
+	labelPosition := ""
+	if !boundaryGap {
+		tickCount--
+		labelPosition = PositionLeft
+	}
+
+	// TODO 计算unit
+	unit := 1
+	// 如果小于0，则表示不处理
+	tickLength := getDefaultInt(opt.TickLength, 5)
+	labelMargin := getDefaultInt(opt.LabelMargin, 5)
+
+	textMaxWidth, textMaxHeight := p.MeasureTextMaxWidthHeight(opt.Data)
+
+	width := 0
+	height := 0
+	// 垂直
+	if opt.Position == PositionLeft ||
+		opt.Position == PositionRight {
+		width = textMaxWidth + tickLength<<1
+		height = p.Height()
+	} else {
+		width = p.Width()
+		height = tickLength<<1 + textMaxHeight
+	}
+	padding := Box{}
+	switch opt.Position {
+	case PositionTop:
+		padding.Top = p.Height() - height
+	case PositionLeft:
+		padding.Right = p.Width() - width
+	}
+	p = p.Child(PainterPaddingOption(padding))
+	p.SetDrawingStyle(Style{
+		StrokeColor: opt.StrokeColor,
+		StrokeWidth: strokeWidth,
+	}).OverrideTextStyle(Style{
+		Font:      opt.Font,
+		FontColor: opt.FontColor,
+		FontSize:  opt.FontSize,
+	})
+
+	x0 := 0
+	y0 := 0
+	x1 := 0
+	y1 := 0
+	ticksPadding := 0
+	labelPadding := 0
+	orient := ""
+	textAlign := ""
+
+	switch opt.Position {
+	case PositionTop:
+		labelPadding = labelMargin
+		x1 = p.Width()
+		y0 = labelMargin + int(opt.FontSize)
+		ticksPadding = int(opt.FontSize)
+		y1 = y0
+		orient = OrientHorizontal
+	case PositionLeft:
+		orient = OrientVertical
+		textAlign = AlignRight
+	default:
+		labelPadding = height
+		x1 = p.Width()
+		orient = OrientHorizontal
+	}
+
+	p.Child(PainterPaddingOption(Box{
+		Top: ticksPadding,
+	})).Ticks(TicksOption{
+		Count:  tickCount,
+		Length: tickLength,
+		Unit:   unit,
+		Orient: orient,
+	})
+
+	p.LineStroke([]Point{
+		{
+			X: x0,
+			Y: y0,
+		},
+		{
+			X: x1,
+			Y: y1,
+		},
+	})
+
+	p.Child(PainterPaddingOption(Box{
+		Top: labelPadding,
+	})).MultiText(MultiTextOption{
+		Align:    textAlign,
+		TextList: opt.Data,
+		Orient:   orient,
+		Unit:     unit,
+		Position: labelPosition,
+	})
+
+	return Box{
+		Bottom: height,
+		Right:  width,
+	}, nil
+}

examples/painter/main.go

@@ -27,7 +27,7 @@ func writeFile(buf []byte) error {
 func main() {
 	p, err := charts.NewPainter(charts.PainterOptions{
 		Width:  600,
-		Height: 1200,
+		Height: 2000,
 		Type:   charts.ChartOutputPNG,
 	})
 	if err != nil {
@@ -429,6 +429,7 @@ func main() {
 		Right:  p.Width() - 1,
 		Bottom: top + 30,
 	})), charts.LegendPainterOption{
+		Left: "10",
 		Data: []string{
 			"Email",
 			"Union Ads",
@@ -446,6 +447,7 @@ func main() {
 		Right:  p.Width() - 1,
 		Bottom: top + 30,
 	})), charts.LegendPainterOption{
+		Left: charts.PositionRight,
 		Data: []string{
 			"Email",
 			"Union Ads",
@@ -465,6 +467,7 @@ func main() {
 		Right:  p.Width() - 1,
 		Bottom: top + 100,
 	})), charts.LegendPainterOption{
+		Top: "10",
 		Data: []string{
 			"Email",
 			"Union Ads",
@@ -476,6 +479,72 @@ func main() {
 		FontColor: drawing.ColorBlack,
 	}).Render()
 
+	top += 100
+	charts.NewAxisPainter(p.Child(charts.PainterBoxOption(charts.Box{
+		Top:    top,
+		Left:   1,
+		Right:  p.Width() - 1,
+		Bottom: top + 50,
+	})), charts.AxisPainterOption{
+		Data: []string{
+			"Mon",
+			"Tue",
+			"Wed",
+			"Thu",
+			"Fri",
+			"Sat",
+			"Sun",
+		},
+		StrokeColor: drawing.ColorBlack,
+		FontSize:    12,
+		FontColor:   drawing.ColorBlack,
+	}).Render()
+
+	top += 50
+	charts.NewAxisPainter(p.Child(charts.PainterBoxOption(charts.Box{
+		Top:    top,
+		Left:   1,
+		Right:  p.Width() - 1,
+		Bottom: top + 50,
+	})), charts.AxisPainterOption{
+		Position:    charts.PositionTop,
+		BoundaryGap: charts.FalseFlag(),
+		Data: []string{
+			"Mon",
+			"Tue",
+			"Wed",
+			"Thu",
+			"Fri",
+			"Sat",
+			"Sun",
+		},
+		StrokeColor: drawing.ColorBlack,
+		FontSize:    12,
+		FontColor:   drawing.ColorBlack,
+	}).Render()
+
+	top += 50
+	charts.NewAxisPainter(p.Child(charts.PainterBoxOption(charts.Box{
+		Top:    top,
+		Left:   10,
+		Right:  p.Width() - 1,
+		Bottom: top + 200,
+	})), charts.AxisPainterOption{
+		Position: charts.PositionLeft,
+		Data: []string{
+			"Mon",
+			"Tue",
+			"Wed",
+			"Thu",
+			"Fri",
+			"Sat",
+			"Sun",
+		},
+		StrokeColor: drawing.ColorBlack,
+		FontSize:    12,
+		FontColor:   drawing.ColorBlack,
+	}).Render()
+
 	buf, err := p.Bytes()
 	if err != nil {
 		panic(err)

grid.go

@@ -22,7 +22,7 @@
 
 package charts
 
-type GridPainter struct {
+type gridPainter struct {
 	p   *Painter
 	opt *GridPainterOption
 }
@@ -38,14 +38,14 @@ type GridPainterOption struct {
 	IgnoreLastColumn  bool
 }
 
-func NewGridPainter(p *Painter, opt GridPainterOption) *GridPainter {
+func NewGridPainter(p *Painter, opt GridPainterOption) *gridPainter {
-	return &GridPainter{
+	return &gridPainter{
 		p:   p,
 		opt: &opt,
 	}
 }
 
-func (g *GridPainter) Render() (Box, error) {
+func (g *gridPainter) Render() (Box, error) {
 	opt := g.opt
 	ignoreColumnLines := make([]int, 0)
 	if opt.IgnoreFirstColumn {

legend.go

@@ -22,7 +22,12 @@
 
 package charts
 
-type LegendPainter struct {
+import (
+	"strconv"
+	"strings"
+)
+
+type legendPainter struct {
 	p   *Painter
 	opt *LegendPainterOption
 }
@@ -53,14 +58,14 @@ type LegendPainterOption struct {
 	FontColor Color
 }
 
-func NewLegendPainter(p *Painter, opt LegendPainterOption) *LegendPainter {
+func NewLegendPainter(p *Painter, opt LegendPainterOption) *legendPainter {
-	return &LegendPainter{
+	return &legendPainter{
 		p:   p,
 		opt: &opt,
 	}
 }
 
-func (l *LegendPainter) Render() (Box, error) {
+func (l *legendPainter) Render() (Box, error) {
 	opt := l.opt
 	theme := opt.Theme
 	if theme == nil {
@@ -80,12 +85,54 @@ func (l *LegendPainter) Render() (Box, error) {
 		}
 		measureList[index] = b
 	}
-	x := 0
+
-	y := 0
+	// 计算展示的宽高
+	width := 0
+	height := 0
 	offset := 20
 	textOffset := 2
 	legendWidth := 30
 	legendHeight := 20
+	for _, item := range measureList {
+		if opt.Orient == OrientVertical {
+			height += item.Height()
+		} else {
+			width += item.Width()
+		}
+	}
+	if opt.Orient == OrientVertical {
+		width = maxTextWidth + textOffset + legendWidth
+		height = offset * len(opt.Data)
+	} else {
+		height = legendHeight
+		offsetValue := (len(opt.Data) - 1) * (offset + textOffset)
+		allLegendWidth := len(opt.Data) * legendWidth
+		width += (offsetValue + allLegendWidth)
+	}
+
+	// 计算开始的位置
+	left := 0
+	switch opt.Left {
+	case PositionRight:
+		left = p.Width() - width
+	case PositionCenter:
+		left = (p.Width() - width) >> 1
+	default:
+		if strings.HasSuffix(opt.Left, "%") {
+			value, _ := strconv.Atoi(strings.ReplaceAll(opt.Left, "%", ""))
+			left = p.Width() * value / 100
+		} else {
+			value, _ := strconv.Atoi(opt.Left)
+			left = value
+		}
+	}
+	top, _ := strconv.Atoi(opt.Top)
+
+	x := int(left)
+	y := int(top)
+	x0 := x
+	y0 := y
+
 	drawIcon := func(top, left int) int {
 		if opt.Icon == IconRect {
 			p.Rect(Box{
@@ -111,41 +158,23 @@ func (l *LegendPainter) Render() (Box, error) {
 			StrokeColor: color,
 		})
 		if opt.Align != AlignRight {
-			x = drawIcon(y, x)
+			x0 = drawIcon(y0, x0)
-			x += textOffset
+			x0 += textOffset
 		}
-		p.Text(text, x, y)
+		p.Text(text, x0, y0)
-		x += measureList[index].Width()
+		x0 += measureList[index].Width()
 		if opt.Align == AlignRight {
-			x += textOffset
+			x0 += textOffset
-			x = drawIcon(0, x)
+			x0 = drawIcon(0, x0)
 		}
 		if opt.Orient == OrientVertical {
-			y += offset
+			y0 += offset
-			x = 0
+			x0 = x
 		} else {
-			x += offset
+			x0 += offset
-			y = 0
+			y0 = y
 		}
 	}
-	width := 0
-	height := 0
-	for _, item := range measureList {
-		if opt.Orient == OrientVertical {
-			height += item.Height()
-		} else {
-			width += item.Width()
-		}
-	}
-	if opt.Orient == OrientVertical {
-		width = maxTextWidth + textOffset + legendWidth
-		height = offset * len(opt.Data)
-	} else {
-		height = legendHeight
-		offsetValue := (len(opt.Data) - 1) * (offset + textOffset)
-		allLegendWidth := len(opt.Data) * legendWidth
-		width += (offsetValue + allLegendWidth)
-	}
 
 	return Box{
 		Right:  width,

painter.go

@@ -417,6 +417,21 @@ func (p *Painter) MeasureText(text string) Box {
 	return p.render.MeasureText(text)
 }
 
+func (p *Painter) MeasureTextMaxWidthHeight(textList []string) (int, int) {
+	maxWidth := 0
+	maxHeight := 0
+	for _, text := range textList {
+		box := p.MeasureText(text)
+		if maxWidth < box.Width() {
+			maxWidth = box.Width()
+		}
+		if maxHeight < box.Height() {
+			maxHeight = box.Height()
+		}
+	}
+	return maxWidth, maxHeight
+}
+
 func (p *Painter) LineStroke(points []Point) *Painter {
 	for index, point := range points {
 		x := point.X