go-chart/yaxis.go
2018-12-06 16:38:58 +01:00

230 lines
5.6 KiB
Go

package chart
import (
"math"
util "git.gutmet.org/go-chart.git/util"
)
// YAxis is a veritcal rule of the range.
// There can be (2) y-axes; a primary and secondary.
type YAxis struct {
Name string
NameStyle Style
Style Style
Zero GridLine
AxisType YAxisType
Ascending bool
ValueFormatter ValueFormatter
Range Range
TickStyle Style
Ticks []Tick
GridLines []GridLine
GridMajorStyle Style
GridMinorStyle Style
}
// GetName returns the name.
func (ya YAxis) GetName() string {
return ya.Name
}
// GetNameStyle returns the name style.
func (ya YAxis) GetNameStyle() Style {
return ya.NameStyle
}
// GetStyle returns the style.
func (ya YAxis) GetStyle() Style {
return ya.Style
}
// GetValueFormatter returns the value formatter for the axis.
func (ya YAxis) GetValueFormatter() ValueFormatter {
if ya.ValueFormatter != nil {
return ya.ValueFormatter
}
return FloatValueFormatter
}
// GetTickStyle returns the tick style.
func (ya YAxis) GetTickStyle() Style {
return ya.TickStyle
}
// GetTicks returns the ticks for a series.
// The coalesce priority is:
// - User Supplied Ticks (i.e. Ticks array on the axis itself).
// - Range ticks (i.e. if the range provides ticks).
// - Generating continuous ticks based on minimum spacing and canvas width.
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(r, defaults, vf)
}
tickStyle := ya.Style.InheritFrom(defaults)
return GenerateContinuousTicks(r, ra, true, tickStyle, 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, ya.GridMajorStyle, ya.GridMinorStyle)
}
// Measure returns the bounds of the axis.
func (ya YAxis) Measure(r Renderer, canvasBox Box, ra Range, defaults Style, ticks []Tick) Box {
var tx int
if ya.AxisType == YAxisPrimary {
tx = canvasBox.Right + DefaultYAxisMargin
} else if ya.AxisType == YAxisSecondary {
tx = canvasBox.Left - DefaultYAxisMargin
}
ya.TickStyle.InheritFrom(ya.Style.InheritFrom(defaults)).WriteToRenderer(r)
var minx, maxx, miny, maxy = math.MaxInt32, 0, math.MaxInt32, 0
var maxTextHeight int
for _, t := range ticks {
v := t.Value
ly := canvasBox.Bottom - ra.Translate(v)
tb := r.MeasureText(t.Label)
tbh2 := tb.Height() >> 1
finalTextX := tx
if ya.AxisType == YAxisSecondary {
finalTextX = tx - tb.Width()
}
maxTextHeight = util.Math.MaxInt(tb.Height(), maxTextHeight)
if ya.AxisType == YAxisPrimary {
minx = canvasBox.Right
maxx = util.Math.MaxInt(maxx, tx+tb.Width())
} else if ya.AxisType == YAxisSecondary {
minx = util.Math.MinInt(minx, finalTextX)
maxx = util.Math.MaxInt(maxx, tx)
}
miny = util.Math.MinInt(miny, ly-tbh2)
maxy = util.Math.MaxInt(maxy, ly+tbh2)
}
if ya.NameStyle.Show && len(ya.Name) > 0 {
maxx += (DefaultYAxisMargin + maxTextHeight)
}
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) {
tickStyle := ya.TickStyle.InheritFrom(ya.Style.InheritFrom(defaults))
tickStyle.WriteToRenderer(r)
sw := tickStyle.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()
var maxTextWidth int
var finalTextX, finalTextY int
for _, t := range ticks {
v := t.Value
ly := canvasBox.Bottom - ra.Translate(v)
tb := Draw.MeasureText(r, t.Label, tickStyle)
if tb.Width() > maxTextWidth {
maxTextWidth = tb.Width()
}
if ya.AxisType == YAxisSecondary {
finalTextX = tx - tb.Width()
} else {
finalTextX = tx
}
if tickStyle.TextRotationDegrees == 0 {
finalTextY = ly + tb.Height()>>1
} else {
finalTextY = ly
}
tickStyle.WriteToRenderer(r)
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()
Draw.Text(r, t.Label, finalTextX, finalTextY, tickStyle)
}
nameStyle := ya.NameStyle.InheritFrom(defaults.InheritFrom(Style{TextRotationDegrees: 90}))
if ya.NameStyle.Show && len(ya.Name) > 0 {
nameStyle.GetTextOptions().WriteToRenderer(r)
tb := Draw.MeasureText(r, ya.Name, nameStyle)
var tx int
if ya.AxisType == YAxisPrimary {
tx = canvasBox.Right + int(sw) + DefaultYAxisMargin + maxTextWidth + DefaultYAxisMargin
} else if ya.AxisType == YAxisSecondary {
tx = canvasBox.Left - (DefaultYAxisMargin + int(sw) + maxTextWidth + DefaultYAxisMargin)
}
var ty int
if nameStyle.TextRotationDegrees == 0 {
ty = canvasBox.Top + (canvasBox.Height()>>1 - tb.Width()>>1)
} else {
ty = canvasBox.Top + (canvasBox.Height()>>1 - tb.Height()>>1)
}
Draw.Text(r, ya.Name, tx, ty, nameStyle)
}
if ya.Zero.Style.Show {
ya.Zero.Render(r, canvasBox, ra, false, Style{})
}
if ya.GridMajorStyle.Show || ya.GridMinorStyle.Show {
for _, gl := range ya.GetGridLines(ticks) {
if (gl.IsMinor && ya.GridMinorStyle.Show) || (!gl.IsMinor && ya.GridMajorStyle.Show) {
defaults := ya.GridMajorStyle
if gl.IsMinor {
defaults = ya.GridMinorStyle
}
gl.Render(r, canvasBox, ra, false, gl.Style.InheritFrom(defaults))
}
}
}
}