go-chart/style.go

225 lines
5.1 KiB
Go

package chart
import (
"fmt"
"strings"
"github.com/golang/freetype/truetype"
"github.com/wcharczuk/go-chart/drawing"
)
// Style is a simple style set.
type Style struct {
Show bool
Padding Box
StrokeWidth float64
StrokeColor drawing.Color
StrokeDashArray []float64
FillColor drawing.Color
FontSize float64
FontColor drawing.Color
Font *truetype.Font
}
// IsZero returns if the object is set or not.
func (s Style) IsZero() bool {
return s.StrokeColor.IsZero() && s.FillColor.IsZero() && s.StrokeWidth == 0 && s.FontColor.IsZero() && s.FontSize == 0 && s.Font == nil
}
// GetStrokeColor returns the stroke color.
func (s Style) GetStrokeColor(defaults ...drawing.Color) drawing.Color {
if s.StrokeColor.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return drawing.ColorTransparent
}
return s.StrokeColor
}
// GetFillColor returns the fill color.
func (s Style) GetFillColor(defaults ...drawing.Color) drawing.Color {
if s.FillColor.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return drawing.ColorTransparent
}
return s.FillColor
}
// GetStrokeWidth returns the stroke width.
func (s Style) GetStrokeWidth(defaults ...float64) float64 {
if s.StrokeWidth == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return DefaultStrokeWidth
}
return s.StrokeWidth
}
// GetStrokeDashArray returns the stroke dash array.
func (s Style) GetStrokeDashArray(defaults ...[]float64) []float64 {
if len(s.StrokeDashArray) == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return nil
}
return s.StrokeDashArray
}
// GetFontSize gets the font size.
func (s Style) GetFontSize(defaults ...float64) float64 {
if s.FontSize == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return DefaultFontSize
}
return s.FontSize
}
// GetFontColor gets the font size.
func (s Style) GetFontColor(defaults ...drawing.Color) drawing.Color {
if s.FontColor.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return drawing.ColorTransparent
}
return s.FontColor
}
// GetFont returns the font face.
func (s Style) GetFont(defaults ...*truetype.Font) *truetype.Font {
if s.Font == nil {
if len(defaults) > 0 {
return defaults[0]
}
return nil
}
return s.Font
}
// GetPadding returns the padding.
func (s Style) GetPadding(defaults ...Box) Box {
if s.Padding.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return Box{}
}
return s.Padding
}
// WithDefaultsFrom coalesces two styles into a new style.
func (s Style) WithDefaultsFrom(defaults Style) (final Style) {
final.StrokeColor = s.GetStrokeColor(defaults.StrokeColor)
final.StrokeWidth = s.GetStrokeWidth(defaults.StrokeWidth)
final.StrokeDashArray = s.GetStrokeDashArray(defaults.StrokeDashArray)
final.FillColor = s.GetFillColor(defaults.FillColor)
final.FontColor = s.GetFontColor(defaults.FontColor)
final.FontSize = s.GetFontSize(defaults.FontSize)
final.Font = s.GetFont(defaults.Font)
final.Padding = s.GetPadding(defaults.Padding)
return
}
// SVG returns the style as a svg style string.
func (s Style) SVG(dpi float64) string {
sw := s.StrokeWidth
sc := s.StrokeColor
fc := s.FillColor
fs := s.FontSize
fnc := s.FontColor
strokeWidthText := "stroke-width:0"
if sw != 0 {
strokeWidthText = "stroke-width:" + fmt.Sprintf("%d", int(sw))
}
strokeText := "stroke:none"
if !sc.IsZero() {
strokeText = "stroke:" + sc.String()
}
fillText := "fill:none"
if !fc.IsZero() {
fillText = "fill:" + fc.String()
}
fontSizeText := ""
if fs != 0 {
fontSizeText = "font-size:" + fmt.Sprintf("%.1fpx", drawing.PointsToPixels(dpi, fs))
}
if !fnc.IsZero() {
fillText = "fill:" + fnc.String()
}
fontText := s.SVGFontFace()
return strings.Join([]string{strokeWidthText, strokeText, fillText, fontSizeText, fontText}, ";")
}
// SVGStroke returns the stroke components.
func (s Style) SVGStroke() Style {
return Style{
StrokeDashArray: s.StrokeDashArray,
StrokeColor: s.StrokeColor,
StrokeWidth: s.StrokeWidth,
}
}
// SVGFill returns the fill components.
func (s Style) SVGFill() Style {
return Style{
FillColor: s.FillColor,
}
}
// SVGFillAndStroke returns the fill and stroke components.
func (s Style) SVGFillAndStroke() Style {
return Style{
StrokeDashArray: s.StrokeDashArray,
FillColor: s.FillColor,
StrokeColor: s.StrokeColor,
StrokeWidth: s.StrokeWidth,
}
}
// SVGText returns just the text components of the style.
func (s Style) SVGText() Style {
return Style{
FontColor: s.FontColor,
FontSize: s.FontSize,
}
}
// SVGFontFace returns the font face for the style.
func (s Style) SVGFontFace() string {
family := "sans-serif"
if s.GetFont() != nil {
name := s.GetFont().Name(truetype.NameIDFontFamily)
if len(name) != 0 {
family = fmt.Sprintf(`'%s',%s`, name, family)
}
}
return fmt.Sprintf("font-family:%s", family)
}
// SVGStrokeDashArray returns the stroke-dasharray property of a style.
func (s Style) SVGStrokeDashArray() string {
if len(s.StrokeDashArray) > 0 {
var values []string
for _, v := range s.StrokeDashArray {
values = append(values, fmt.Sprintf("%0.1f", v))
}
return "stroke-dasharray=\"" + strings.Join(values, ", ") + "\""
}
return ""
}