package chart import ( "image/color" "sync" "github.com/golang/freetype/truetype" ) const ( // DefaultChartHeight is the default chart height. DefaultChartHeight = 400 // DefaultChartWidth is the default chart width. DefaultChartWidth = 200 // DefaultStrokeWidth is the default chart line/stroke width. DefaultStrokeWidth = 1.0 // DefaultAxisLineWidth is the line width of the axis lines. DefaultAxisLineWidth = 1.0 //DefaultDPI is the default dots per inch for the chart. DefaultDPI = 92.0 // DefaultMinimumFontSize is the default minimum font size. DefaultMinimumFontSize = 8.0 // DefaultFontSize is the default font size. DefaultFontSize = 10.0 // DefaultTitleFontSize is the default title font size. DefaultTitleFontSize = 18.0 // DefaultFinalLabelDeltaWidth is the width of the left triangle out of the final label. DefaultFinalLabelDeltaWidth = 10 // DefaultFinalLabelFontSize is the font size of the final label. DefaultFinalLabelFontSize = 10.0 // DefaultAxisFontSize is the font size of the axis labels. DefaultAxisFontSize = 10.0 // DefaultTitleTop is the default distance from the top of the chart to put the title. DefaultTitleTop = 10 // DefaultXAxisMargin is the default distance from bottom of the canvas to the x axis labels. DefaultXAxisMargin = 10 // DefaultMinimumTickHorizontalSpacing is the minimum distance between horizontal ticks. DefaultMinimumTickHorizontalSpacing = 20 // DefaultMinimumTickVerticalSpacing is the minimum distance between vertical ticks. DefaultMinimumTickVerticalSpacing = 20 // DefaultDateFormat is the default date format. DefaultDateFormat = "2006-01-02" // DefaultMaxTickCount is the maximum number of ticks to draw DefaultMaxTickCount = 7 ) 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} // DefaultAxisColor is the default chart axis line color. // It is equivalent to #333333. DefaultAxisColor = color.RGBA{R: 51, G: 51, B: 51, A: 255} // DefaultStrokeColor is the default chart border color. // It is equivalent to #efefef. DefaultStrokeColor = color.RGBA{R: 239, G: 239, B: 239, A: 255} // DefaultFillColor is the default fill color. // It is equivalent to #0074d9. DefaultFillColor = color.RGBA{R: 0, G: 217, B: 116, A: 255} // DefaultFinalLabelBackgroundColor is the default final label background color. DefaultFinalLabelBackgroundColor = color.RGBA{R: 255, G: 255, B: 255, A: 255} ) var ( // DefaultSeriesStrokeColors are a couple default series colors. DefaultSeriesStrokeColors = []color.RGBA{ color.RGBA{R: 0, G: 116, B: 217, A: 255}, color.RGBA{R: 0, G: 217, B: 116, A: 255}, color.RGBA{R: 217, G: 0, B: 116, A: 255}, } ) // GetDefaultSeriesStrokeColor returns a color from the default list by index. // NOTE: the index will wrap around (using a modulo).g func GetDefaultSeriesStrokeColor(index int) color.RGBA { finalIndex := index % len(DefaultSeriesStrokeColors) return DefaultSeriesStrokeColors[finalIndex] } 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: 5, Bottom: 5} ) var ( _defaultFontLock sync.Mutex _defaultFont *truetype.Font ) // GetDefaultFont returns the default font (Roboto-Medium). func GetDefaultFont() (*truetype.Font, error) { if _defaultFont == nil { _defaultFontLock.Lock() defer _defaultFontLock.Unlock() if _defaultFont == nil { font, err := truetype.Parse(roboto) if err != nil { return nil, err } _defaultFont = font } } return _defaultFont, nil }