go-chart/legend.go

330 lines
8.4 KiB
Go

package chart
import "github.com/wcharczuk/go-chart/drawing"
// Legend returns a legend renderable function.
func Legend(c *Chart, userDefaults ...Style) Renderable {
return func(r Renderer, cb Box, chartDefaults Style) {
legendDefaults := Style{
FillColor: drawing.ColorWhite,
FontColor: DefaultTextColor,
FontSize: 8.0,
StrokeColor: DefaultAxisColor,
StrokeWidth: DefaultAxisLineWidth,
}
var legendStyle Style
if len(userDefaults) > 0 {
legendStyle = userDefaults[0].InheritFrom(chartDefaults.InheritFrom(legendDefaults))
} else {
legendStyle = chartDefaults.InheritFrom(legendDefaults)
}
// DEFAULTS
legendPadding := Box{
Top: 5,
Left: 5,
Right: 5,
Bottom: 5,
}
lineTextGap := 5
lineLengthMinimum := 25
var labels []string
var lines []Style
for index, s := range c.Series {
if s.GetStyle().IsZero() || s.GetStyle().Show {
if _, isAnnotationSeries := s.(AnnotationSeries); !isAnnotationSeries {
labels = append(labels, s.GetName())
lines = append(lines, s.GetStyle().InheritFrom(c.styleDefaultsSeries(index)))
}
}
}
legend := Box{
Top: cb.Top,
Left: cb.Left,
// bottom and right will be sized by the legend content + relevant padding.
}
legendContent := Box{
Top: legend.Top + legendPadding.Top,
Left: legend.Left + legendPadding.Left,
Right: legend.Left + legendPadding.Left,
Bottom: legend.Top + legendPadding.Top,
}
legendStyle.GetTextOptions().WriteToRenderer(r)
// measure
labelCount := 0
for x := 0; x < len(labels); x++ {
if len(labels[x]) > 0 {
tb := r.MeasureText(labels[x])
if labelCount > 0 {
legendContent.Bottom += DefaultMinimumTickVerticalSpacing
}
legendContent.Bottom += tb.Height()
right := legendContent.Left + tb.Width() + lineTextGap + lineLengthMinimum
legendContent.Right = Math.MaxInt(legendContent.Right, right)
labelCount++
}
}
legend = legend.Grow(legendContent)
legend.Right = legendContent.Right + legendPadding.Right
legend.Bottom = legendContent.Bottom + legendPadding.Bottom
Draw.Box(r, legend, legendStyle)
legendStyle.GetTextOptions().WriteToRenderer(r)
ycursor := legendContent.Top
tx := legendContent.Left
legendCount := 0
var label string
for x := 0; x < len(labels); x++ {
label = labels[x]
if len(label) > 0 {
if legendCount > 0 {
ycursor += DefaultMinimumTickVerticalSpacing
}
tb := r.MeasureText(label)
ty := ycursor + tb.Height()
r.Text(label, tx, ty)
th2 := tb.Height() >> 1
lx := tx + tb.Width() + lineTextGap
ly := ty - th2
lx2 := legendContent.Right - legendPadding.Right
r.SetStrokeColor(lines[x].GetStrokeColor())
r.SetStrokeWidth(lines[x].GetStrokeWidth())
r.SetStrokeDashArray(lines[x].GetStrokeDashArray())
r.MoveTo(lx, ly)
r.LineTo(lx2, ly)
r.Stroke()
ycursor += tb.Height()
legendCount++
}
}
}
}
// LegendThin is a legend that doesn't obscure the chart area.
func LegendThin(c *Chart, userDefaults ...Style) Renderable {
return func(r Renderer, cb Box, chartDefaults Style) {
legendDefaults := Style{
FillColor: drawing.ColorWhite,
FontColor: DefaultTextColor,
FontSize: 8.0,
StrokeColor: DefaultAxisColor,
StrokeWidth: DefaultAxisLineWidth,
Padding: Box{
Top: 2,
Left: 7,
Right: 7,
Bottom: 5,
},
}
var legendStyle Style
if len(userDefaults) > 0 {
legendStyle = userDefaults[0].InheritFrom(chartDefaults.InheritFrom(legendDefaults))
} else {
legendStyle = chartDefaults.InheritFrom(legendDefaults)
}
r.SetFont(legendStyle.GetFont())
r.SetFontColor(legendStyle.GetFontColor())
r.SetFontSize(legendStyle.GetFontSize())
var labels []string
var lines []Style
for index, s := range c.Series {
if s.GetStyle().IsZero() || s.GetStyle().Show {
if _, isAnnotationSeries := s.(AnnotationSeries); !isAnnotationSeries {
labels = append(labels, s.GetName())
lines = append(lines, s.GetStyle().InheritFrom(c.styleDefaultsSeries(index)))
}
}
}
var textHeight int
var textWidth int
var textBox Box
for x := 0; x < len(labels); x++ {
if len(labels[x]) > 0 {
textBox = r.MeasureText(labels[x])
textHeight = Math.MaxInt(textBox.Height(), textHeight)
textWidth = Math.MaxInt(textBox.Width(), textWidth)
}
}
legendBoxHeight := textHeight + legendStyle.Padding.Top + legendStyle.Padding.Bottom
chartPadding := cb.Top
legendYMargin := (chartPadding - legendBoxHeight) >> 1
legendBox := Box{
Left: cb.Left,
Right: cb.Right,
Top: legendYMargin,
Bottom: legendYMargin + legendBoxHeight,
}
Draw.Box(r, legendBox, legendDefaults)
r.SetFont(legendStyle.GetFont())
r.SetFontColor(legendStyle.GetFontColor())
r.SetFontSize(legendStyle.GetFontSize())
lineTextGap := 5
lineLengthMinimum := 25
tx := legendBox.Left + legendStyle.Padding.Left
ty := legendYMargin + legendStyle.Padding.Top + textHeight
var label string
var lx, ly int
th2 := textHeight >> 1
for index := range labels {
label = labels[index]
if len(label) > 0 {
textBox = r.MeasureText(label)
r.Text(label, tx, ty)
lx = tx + textBox.Width() + lineTextGap
ly = ty - th2
r.SetStrokeColor(lines[index].GetStrokeColor())
r.SetStrokeWidth(lines[index].GetStrokeWidth())
r.SetStrokeDashArray(lines[index].GetStrokeDashArray())
r.MoveTo(lx, ly)
r.LineTo(lx+lineLengthMinimum, ly)
r.Stroke()
tx += textBox.Width() + DefaultMinimumTickHorizontalSpacing + lineTextGap + lineLengthMinimum
}
}
}
}
// LegendLeft is a legend that is designed for longer series lists.
func LegendLeft(c *Chart, userDefaults ...Style) Renderable {
return func(r Renderer, cb Box, chartDefaults Style) {
legendDefaults := Style{
FillColor: drawing.ColorWhite,
FontColor: DefaultTextColor,
FontSize: 8.0,
StrokeColor: DefaultAxisColor,
StrokeWidth: DefaultAxisLineWidth,
}
var legendStyle Style
if len(userDefaults) > 0 {
legendStyle = userDefaults[0].InheritFrom(chartDefaults.InheritFrom(legendDefaults))
} else {
legendStyle = chartDefaults.InheritFrom(legendDefaults)
}
// DEFAULTS
legendPadding := Box{
Top: 5,
Left: 5,
Right: 5,
Bottom: 5,
}
lineTextGap := 5
lineLengthMinimum := 25
var labels []string
var lines []Style
for index, s := range c.Series {
if s.GetStyle().IsZero() || s.GetStyle().Show {
if _, isAnnotationSeries := s.(AnnotationSeries); !isAnnotationSeries {
labels = append(labels, s.GetName())
lines = append(lines, s.GetStyle().InheritFrom(c.styleDefaultsSeries(index)))
}
}
}
legend := Box{
Top: 5,
Left: 5,
// bottom and right will be sized by the legend content + relevant padding.
}
legendContent := Box{
Top: legend.Top + legendPadding.Top,
Left: legend.Left + legendPadding.Left,
Right: legend.Left + legendPadding.Left,
Bottom: legend.Top + legendPadding.Top,
}
legendStyle.GetTextOptions().WriteToRenderer(r)
// measure
labelCount := 0
for x := 0; x < len(labels); x++ {
if len(labels[x]) > 0 {
tb := r.MeasureText(labels[x])
if labelCount > 0 {
legendContent.Bottom += DefaultMinimumTickVerticalSpacing
}
legendContent.Bottom += tb.Height()
right := legendContent.Left + tb.Width() + lineTextGap + lineLengthMinimum
legendContent.Right = Math.MaxInt(legendContent.Right, right)
labelCount++
}
}
legend = legend.Grow(legendContent)
legend.Right = legendContent.Right + legendPadding.Right
legend.Bottom = legendContent.Bottom + legendPadding.Bottom
Draw.Box(r, legend, legendStyle)
legendStyle.GetTextOptions().WriteToRenderer(r)
ycursor := legendContent.Top
tx := legendContent.Left
legendCount := 0
var label string
for x := 0; x < len(labels); x++ {
label = labels[x]
if len(label) > 0 {
if legendCount > 0 {
ycursor += DefaultMinimumTickVerticalSpacing
}
tb := r.MeasureText(label)
ty := ycursor + tb.Height()
r.Text(label, tx, ty)
th2 := tb.Height() >> 1
lx := tx + tb.Width() + lineTextGap
ly := ty - th2
lx2 := legendContent.Right - legendPadding.Right
r.SetStrokeColor(lines[x].GetStrokeColor())
r.SetStrokeWidth(lines[x].GetStrokeWidth())
r.SetStrokeDashArray(lines[x].GetStrokeDashArray())
r.MoveTo(lx, ly)
r.LineTo(lx2, ly)
r.Stroke()
ycursor += tb.Height()
legendCount++
}
}
}
}