go-chart/yaxis.go
Will Charczuk 07c96b1948 updates
2016-07-12 22:55:46 -07:00

183 lines
4.6 KiB
Go

package chart
import (
"math"
"sort"
)
// YAxis is a veritcal rule of the range.
// There can be (2) y-axes; a primary and secondary.
type YAxis struct {
Name string
Style Style
Zero GridLine
AxisType YAxisType
ValueFormatter ValueFormatter
Range Range
Ticks []Tick
GridLines []GridLine
GridMajorStyle Style
GridMinorStyle Style
}
// GetName returns the name.
func (ya YAxis) GetName() string {
return ya.Name
}
// GetStyle returns the style.
func (ya YAxis) GetStyle() Style {
return ya.Style
}
// GetTicks returns the ticks for a series. It coalesces between user provided ticks and
// generated ticks.
func (ya YAxis) GetTicks(r Renderer, ra Range, defaults Style, vf ValueFormatter) []Tick {
if len(ya.Ticks) > 0 {
return ya.Ticks
}
return ya.generateTicks(r, ra, defaults, vf)
}
func (ya YAxis) generateTicks(r Renderer, ra Range, defaults Style, vf ValueFormatter) []Tick {
step := ya.getTickStep(r, ra, defaults, vf)
ticks := GenerateTicksWithStep(ra, step, vf)
return ticks
}
func (ya YAxis) getTickStep(r Renderer, ra Range, defaults Style, vf ValueFormatter) float64 {
tickCount := ya.getTickCount(r, ra, defaults, vf)
step := ra.Delta() / float64(tickCount)
return step
}
func (ya YAxis) getTickCount(r Renderer, ra Range, defaults Style, vf ValueFormatter) int {
r.SetFont(ya.Style.GetFont(defaults.GetFont()))
r.SetFontSize(ya.Style.GetFontSize(defaults.GetFontSize(DefaultFontSize)))
//given the domain, figure out how many ticks we can draw ...
label := vf(ra.Min)
tb := r.MeasureText(label)
count := int(math.Ceil(float64(ra.Domain) / float64(tb.Height()+DefaultMinimumTickVerticalSpacing)))
return count
}
// GetGridLines returns the gridlines for the axis.
func (ya YAxis) GetGridLines(ticks []Tick) []GridLine {
if len(ya.GridLines) > 0 {
return ya.GridLines
}
return GenerateGridLines(ticks, false)
}
// Measure returns the bounds of the axis.
func (ya YAxis) Measure(r Renderer, canvasBox Box, ra Range, defaults Style, ticks []Tick) Box {
r.SetStrokeColor(ya.Style.GetStrokeColor(defaults.StrokeColor))
r.SetStrokeWidth(ya.Style.GetStrokeWidth(defaults.StrokeWidth))
r.SetFont(ya.Style.GetFont(defaults.GetFont()))
r.SetFontColor(ya.Style.GetFontColor(DefaultAxisColor))
r.SetFontSize(ya.Style.GetFontSize(defaults.GetFontSize()))
sort.Sort(Ticks(ticks))
var tx int
if ya.AxisType == YAxisPrimary {
tx = canvasBox.Right + DefaultYAxisMargin
} else if ya.AxisType == YAxisSecondary {
tx = canvasBox.Left - DefaultYAxisMargin
}
var minx, maxx, miny, maxy = math.MaxInt32, 0, math.MaxInt32, 0
for _, t := range ticks {
v := t.Value
ly := canvasBox.Bottom - ra.Translate(v)
tb := r.MeasureText(t.Label)
finalTextX := tx
if ya.AxisType == YAxisSecondary {
finalTextX = tx - tb.Width()
}
if ya.AxisType == YAxisPrimary {
minx = canvasBox.Right
maxx = MaxInt(maxx, tx+tb.Width())
} else if ya.AxisType == YAxisSecondary {
minx = MinInt(minx, finalTextX)
maxx = MaxInt(maxx, tx)
}
miny = MinInt(miny, ly-tb.Height()>>1)
maxy = MaxInt(maxy, ly+tb.Height()>>1)
}
return Box{
Top: miny,
Left: minx,
Right: maxx,
Bottom: maxy,
}
}
// Render renders the axis.
func (ya YAxis) Render(r Renderer, canvasBox Box, ra Range, defaults Style, ticks []Tick) {
r.SetStrokeColor(ya.Style.GetStrokeColor(defaults.StrokeColor))
r.SetStrokeWidth(ya.Style.GetStrokeWidth(defaults.StrokeWidth))
r.SetFont(ya.Style.GetFont(defaults.GetFont()))
r.SetFontColor(ya.Style.GetFontColor(DefaultAxisColor))
r.SetFontSize(ya.Style.GetFontSize(defaults.GetFontSize(DefaultFontSize)))
sort.Sort(Ticks(ticks))
var lx int
var tx int
if ya.AxisType == YAxisPrimary {
lx = canvasBox.Right
tx = lx + DefaultYAxisMargin
} else if ya.AxisType == YAxisSecondary {
lx = canvasBox.Left
tx = lx - DefaultYAxisMargin
}
r.MoveTo(lx, canvasBox.Bottom)
r.LineTo(lx, canvasBox.Top)
r.Stroke()
for _, t := range ticks {
v := t.Value
ly := canvasBox.Bottom - ra.Translate(v)
tb := r.MeasureText(t.Label)
finalTextX := tx
finalTextY := ly + tb.Height()>>1
if ya.AxisType == YAxisSecondary {
finalTextX = tx - tb.Width()
}
r.Text(t.Label, finalTextX, finalTextY)
r.MoveTo(lx, ly)
if ya.AxisType == YAxisPrimary {
r.LineTo(lx+DefaultHorizontalTickWidth, ly)
} else if ya.AxisType == YAxisSecondary {
r.LineTo(lx-DefaultHorizontalTickWidth, ly)
}
r.Stroke()
}
if ya.Zero.Style.Show {
ya.Zero.Render(r, canvasBox, ra)
}
if ya.GridMajorStyle.Show || ya.GridMinorStyle.Show {
for _, gl := range ya.GetGridLines(ticks) {
if (gl.IsMinor && ya.GridMinorStyle.Show) ||
(!gl.IsMinor && ya.GridMajorStyle.Show) {
gl.Render(r, canvasBox, ra)
}
}
}
}