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 } // String returns a text representation of the style. func (s Style) String() string { if s.IsZero() { return "{}" } var output []string if s.Show { output = []string{"\"show\": true"} } else { output = []string{"\"show\": false"} } if !s.Padding.IsZero() { output = append(output, fmt.Sprintf("\"padding\": %s", s.Padding.String())) } else { output = append(output, "\"padding\": null") } if s.StrokeWidth >= 0 { output = append(output, fmt.Sprintf("\"stroke_width\": %0.2f", s.StrokeWidth)) } else { output = append(output, "\"stroke_width\": null") } if !s.StrokeColor.IsZero() { output = append(output, fmt.Sprintf("\"stroke_color\": %s", s.StrokeColor.String())) } else { output = append(output, "\"stroke_color\": null") } if len(s.StrokeDashArray) > 0 { var elements []string for _, v := range s.StrokeDashArray { elements = append(elements, fmt.Sprintf("%.2f", v)) } dashArray := strings.Join(elements, ", ") output = append(output, fmt.Sprintf("\"stroke_dash_array\": [%s]", dashArray)) } else { output = append(output, "\"stroke_dash_array\": null") } if !s.FillColor.IsZero() { output = append(output, fmt.Sprintf("\"fill_color\": %s", s.FillColor.String())) } else { output = append(output, "\"fill_color\": null") } if s.FontSize != 0 { output = append(output, fmt.Sprintf("\"font_size\": \"%0.2fpt\"", s.FontSize)) } else { output = append(output, "\"fill_color\": null") } if !s.FillColor.IsZero() { output = append(output, fmt.Sprintf("\"font_color\": %s", s.FillColor.String())) } else { output = append(output, "\"font_color\": null") } if s.Font != nil { output = append(output, fmt.Sprintf("\"font\": \"%s\"", s.Font.Name(truetype.NameIDFontFamily))) } else { output = append(output, "\"font_color\": null") } return "{" + strings.Join(output, ", ") + "}" } // 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 } // PersistToRenderer passes the style onto a renderer. func (s Style) PersistToRenderer(r Renderer) { r.SetStrokeColor(s.GetStrokeColor()) r.SetStrokeWidth(s.GetStrokeWidth()) r.SetStrokeDashArray(s.GetStrokeDashArray()) r.SetFont(s.GetFont()) r.SetFontColor(s.GetFontColor()) r.SetFontSize(s.GetFontSize()) } // InheritFrom coalesces two styles into a new style. func (s Style) InheritFrom(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 "" }