zeni/go-chart
1
0
Fork 0
Code Issues Pull requests Projects Releases 2 Packages Wiki Activity Actions

better default handling around final value labels.

Browse source
This commit is contained in:
Will Charczuk 2016-07-07 19:11:30 -07:00
parent b10ead7cc1
commit 5c8836f9bd
4 changed files with 115 additions and 80 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
box.go
View file

@ -8,6 +8,9 @@ type Box struct {
Left int
Right int
Bottom int
Height int
Width int
}
// IsZero returns if the box is set or not.

159
chart.go
View file

@ -27,40 +27,6 @@ type Chart struct {
Series []Series
}
// GetCanvasTop gets the top corner pixel.
func (c Chart) GetCanvasTop() int {
return c.Background.Padding.GetTop(DefaultBackgroundPadding.Top)
}
// GetCanvasLeft gets the left corner pixel.
func (c Chart) GetCanvasLeft() int {
return c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
}
// GetCanvasBottom gets the bottom corner pixel.
func (c Chart) GetCanvasBottom() int {
return c.Height - c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
}
// GetCanvasRight gets the right corner pixel.
func (c Chart) GetCanvasRight() int {
return c.Width - c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
}
// GetCanvasWidth returns the width of the canvas.
func (c Chart) GetCanvasWidth() int {
pl := c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
pr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
return c.Width - (pl + pr)
}
// GetCanvasHeight returns the height of the canvas.
func (c Chart) GetCanvasHeight() int {
pt := c.Background.Padding.GetTop(DefaultBackgroundPadding.Top)
pb := c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
return c.Height - (pt + pb)
}
// GetFont returns the text font.
func (c Chart) GetFont() (*truetype.Font, error) {
if c.Font != nil {
@ -71,26 +37,78 @@ func (c Chart) GetFont() (*truetype.Font, error) {
// Render renders the chart with the given renderer to the given io.Writer.
func (c *Chart) Render(provider RendererProvider, w io.Writer) error {
xrange, yrange := c.initRanges()
font, err := c.GetFont()
if err != nil {
return err
r := provider(c.Width, c.Height)
if c.hasText() {
font, err := c.GetFont()
if err != nil {
return err
}
r.SetFont(font)
}
r := provider(c.Width, c.Height)
r.SetFont(font)
canvasBox := c.calculateCanvasBox(r)
xrange, yrange := c.initRanges(canvasBox)
c.drawBackground(r)
c.drawCanvas(r)
c.drawAxes(r, xrange, yrange)
c.drawCanvas(r, canvasBox)
c.drawAxes(r, canvasBox, xrange, yrange)
for index, series := range c.Series {
c.drawSeries(r, index, series, xrange, yrange)
c.drawSeries(r, canvasBox, index, series, xrange, yrange)
}
c.drawTitle(r)
return r.Save(w)
}
func (c Chart) initRanges() (xrange Range, yrange Range) {
func (c Chart) hasText() bool {
return c.TitleStyle.Show || c.Axes.Show
}
func (c Chart) calculateCanvasBox(r Renderer) Box {
dpr := DefaultBackgroundPadding.Right
finalLabelWidth := c.calculateFinalLabelWidth(r)
if finalLabelWidth > dpr {
dpr = finalLabelWidth
}
dpb := DefaultBackgroundPadding.Bottom
cb := Box{
Top: c.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
Left: c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
Right: c.Width - c.Background.Padding.GetRight(dpr),
Bottom: c.Height - c.Background.Padding.GetBottom(dpb),
}
cb.Height = cb.Bottom - cb.Top
cb.Width = cb.Right - cb.Left
return cb
}
func (c Chart) calculateFinalLabelWidth(r Renderer) int {
if !c.FinalValueLabel.Show {
return 0
}
var finalLabelText string
for _, s := range c.Series {
_, ll := s.GetLabel(s.Len() - 1)
if len(finalLabelText) < len(ll) {
finalLabelText = ll
}
}
r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
textWidth := r.MeasureText(finalLabelText)
pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
pr := c.FinalValueLabel.Padding.GetRight(DefaultFinalLabelPadding.Right)
asw := int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
lsw := int(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
return DefaultFinalLabelDeltaWidth +
pl + pr +
textWidth + asw + 2*lsw
}
func (c Chart) initRanges(canvasBox Box) (xrange Range, yrange Range) {
//iterate over each series, pull out the min/max for x,y
var didSetFirstValues bool
var globalMinY, globalMinX float64
@ -127,7 +145,7 @@ func (c Chart) initRanges() (xrange Range, yrange Range) {
xrange.Min = c.XRange.Min
xrange.Max = c.XRange.Max
}
xrange.Domain = c.GetCanvasWidth()
xrange.Domain = canvasBox.Width
if c.YRange.IsZero() {
yrange.Min = globalMinY
@ -136,40 +154,44 @@ func (c Chart) initRanges() (xrange Range, yrange Range) {
yrange.Min = c.YRange.Min
yrange.Max = c.YRange.Max
}
yrange.Domain = c.GetCanvasHeight()
yrange.Domain = canvasBox.Height
return
}
func (c Chart) drawBackground(r Renderer) {
r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
r.SetStrokeColor(c.Background.GetStrokeColor(DefaultBackgroundStrokeColor))
r.SetLineWidth(c.Background.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(0, 0)
r.LineTo(c.Width, 0)
r.LineTo(c.Width, c.Height)
r.LineTo(0, c.Height)
r.LineTo(0, 0)
r.Close()
r.Fill()
r.FillStroke()
}
func (c Chart) drawCanvas(r Renderer) {
func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
r.SetFillColor(c.Canvas.GetFillColor(DefaultCanvasColor))
r.MoveTo(c.GetCanvasLeft(), c.GetCanvasTop())
r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
r.LineTo(c.GetCanvasLeft(), c.GetCanvasBottom())
r.LineTo(c.GetCanvasLeft(), c.GetCanvasTop())
r.Fill()
r.SetStrokeColor(c.Canvas.GetStrokeColor(DefaultCanvasStrokColor))
r.SetLineWidth(c.Canvas.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(canvasBox.Left, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.LineTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Left, canvasBox.Top)
r.Close()
r.FillStroke()
}
func (c Chart) drawAxes(r Renderer, xrange, yrange Range) {
func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange Range) {
if c.Axes.Show {
r.SetStrokeColor(c.Axes.GetStrokeColor(DefaultAxisColor))
r.SetLineWidth(c.Axes.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(c.GetCanvasLeft(), c.GetCanvasBottom())
r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
r.MoveTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Top)
r.Stroke()
c.drawAxesLabels(r, xrange, yrange)
@ -181,7 +203,7 @@ func (c Chart) drawAxesLabels(r Renderer, xrange, yrange Range) {
// do y axis
}
func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range) {
func (c Chart) drawSeries(r Renderer, canvasBox Box, index int, s Series, xrange, yrange Range) {
r.SetStrokeColor(s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index)))
r.SetLineWidth(s.GetStyle().GetStrokeWidth(DefaultStrokeWidth))
@ -189,9 +211,9 @@ func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range)
return
}
cx := c.GetCanvasLeft()
cy := c.GetCanvasTop()
cw := c.GetCanvasWidth()
cx := canvasBox.Left
cy := canvasBox.Top
cw := canvasBox.Width
v0x, v0y := s.GetValue(0)
x0 := cw - xrange.Translate(v0x)
@ -208,24 +230,23 @@ func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range)
}
r.Stroke()
c.drawFinalValueLabel(r, index, s, yrange)
c.drawFinalValueLabel(r, canvasBox, index, s, yrange)
}
func (c Chart) drawFinalValueLabel(r Renderer, index int, s Series, yrange Range) {
func (c Chart) drawFinalValueLabel(r Renderer, canvasBox Box, index int, s Series, yrange Range) {
if c.FinalValueLabel.Show {
_, lv := s.GetValue(s.Len() - 1)
_, ll := s.GetLabel(s.Len() - 1)
py := c.GetCanvasTop()
py := canvasBox.Top
ly := yrange.Translate(lv) + py
r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
textWidth := r.MeasureText(ll)
textHeight := int(math.Floor(DefaultFinalLabelFontSize))
halfTextHeight := textHeight >> 1
cx := c.GetCanvasRight() + int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
cx := canvasBox.Right + int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
pt := c.FinalValueLabel.Padding.GetTop(DefaultFinalLabelPadding.Top)
pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
@ -272,7 +293,7 @@ func (c Chart) drawTitle(r Renderer) error {
r.SetFontSize(titleFontSize)
textWidth := r.MeasureText(c.Title)
titleX := (c.Width >> 1) - (textWidth >> 1)
titleY := c.GetCanvasTop() + int(titleFontSize)
titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + int(titleFontSize)
r.Text(c.Title, titleX, titleY)
}
return nil

10
defaults.go
View file

@ -28,6 +28,8 @@ const (
DefaultFinalLabelDeltaWidth = 10
// DefaultFinalLabelFontSize is the font size of the final label.
DefaultFinalLabelFontSize = 10.0
// DefaultTitleTop is the default distance from the top of the chart to put the title.
DefaultTitleTop = 10
// DefaultDateFormat is the default date format.
DefaultDateFormat = "2006-01-02"
)
@ -36,9 +38,15 @@ var (
// DefaultBackgroundColor is the default chart background color.
// It is equivalent to css color:white.
DefaultBackgroundColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
// DefaultBackgroundStrokeColor is the default chart border color.
// It is equivalent to color:white.
DefaultBackgroundStrokeColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
// DefaultCanvasColor is the default chart canvas color.
// It is equivalent to css color:white.
DefaultCanvasColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
// DefaultCanvasStrokColor is the default chart canvas stroke color.
// It is equivalent to css color:white.
DefaultCanvasStrokColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
// DefaultTextColor is the default chart text color.
// It is equivalent to #333333.
DefaultTextColor = color.RGBA{R: 51, G: 51, B: 51, A: 255}
@ -75,7 +83,7 @@ var (
// DefaultFinalLabelPadding is the padding around the final label.
DefaultFinalLabelPadding = Box{Top: 5, Left: 0, Right: 5, Bottom: 5}
// DefaultBackgroundPadding is the default canvas padding config.
DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 40, Bottom: 40}
DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 5, Bottom: 5}
)
var (

23
testserver/main.go
View file

@ -17,31 +17,34 @@ func main() {
rc.Response.Header().Set("Content-Type", "image/png")
now := time.Now()
c := chart.Chart{
Title: "Stocks Bruh.",
Title: "A Test Chart",
TitleStyle: chart.Style{
Show: true,
},
Width: 1024,
Height: 400,
Canvas: chart.Style{
Padding: chart.Box{
Right: 40,
Bottom: 40,
},
},
Width: 800,
Height: 380,
Axes: chart.Style{
Show: true,
StrokeWidth: 1.0,
},
YRange: chart.Range{
Min: 0.0,
Max: 7.0,
},
FinalValueLabel: chart.Style{
Show: true,
},
Series: []chart.Series{
chart.TimeSeries{
Name: "goog",
Name: "a",
XValues: []time.Time{now.AddDate(0, 0, -4), now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
YValues: []float64{2.5, 5.0, 2.0, 3.0},
},
chart.TimeSeries{
Name: "b",
XValues: []time.Time{now.AddDate(0, 0, -4), now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
YValues: []float64{6.0, 5.0, 4.0, 1.0},
},
},
}