axes label example and thin legend.

This commit is contained in:
Will Charczuk 2016-08-27 13:45:38 -07:00
parent dd89d27af5
commit 6fbc6caa9c
3 changed files with 109 additions and 5 deletions

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After

Width:  |  Height:  |  Size: 23 KiB

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@ -72,6 +72,11 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
graph := chart.Chart{
Width: 1280,
Height: 720,
Background: chart.Style{
Padding: chart.Box{
Top: 50,
},
},
YAxis: chart.YAxis{
Name: "Elapsed Millis",
NameStyle: chart.StyleShow(),
@ -96,7 +101,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
},
}
graph.Elements = []chart.Renderable{chart.Legend(&graph)}
graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
res.Header().Set("Content-Type", "image/png")
graph.Render(chart.PNG, res)

107
legend.go
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@ -82,17 +82,18 @@ func Legend(c *Chart, userDefaults ...Style) Renderable {
ycursor := legendContent.Top
tx := legendContent.Left
legendCount := 0
var label string
for x := 0; x < len(labels); x++ {
if len(labels[x]) > 0 {
label = labels[x]
if len(label) > 0 {
if legendCount > 0 {
ycursor += DefaultMinimumTickVerticalSpacing
}
tb := r.MeasureText(labels[x])
tb := r.MeasureText(label)
ty := ycursor + tb.Height()
r.Text(labels[x], tx, ty)
r.Text(label, tx, ty)
th2 := tb.Height() >> 1
@ -114,3 +115,101 @@ func Legend(c *Chart, userDefaults ...Style) Renderable {
}
}
}
// 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
}
}
}
}