go-chart/yaxis.go
2016-07-23 15:35:49 -07:00

160 lines
3.6 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
}
if tp, isTickProvider := ra.(TicksProvider); isTickProvider {
return tp.GetTicks(vf)
}
step := CalculateContinuousTickStep(r, ra, true, ya.Style.InheritFrom(defaults), vf)
return GenerateContinuousTicksWithStep(ra, step, vf)
}
// 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 {
ya.Style.InheritFrom(defaults).PersistToRenderer(r)
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) {
ya.Style.InheritFrom(defaults).PersistToRenderer(r)
sort.Sort(Ticks(ticks))
sw := ya.Style.GetStrokeWidth(defaults.StrokeWidth)
var lx int
var tx int
if ya.AxisType == YAxisPrimary {
lx = canvasBox.Right + int(sw)
tx = lx + DefaultYAxisMargin
} else if ya.AxisType == YAxisSecondary {
lx = canvasBox.Left - int(sw)
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)
}
}
}
}