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