Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

colors.go

@@ -0,0 +1,184 @@
+package chart
+
+import "github.com/wcharczuk/go-chart/v2/drawing"
+
+var (
+	// ColorWhite is white.
+	ColorWhite = drawing.Color{R: 255, G: 255, B: 255, A: 255}
+	// ColorBlue is the basic theme blue color.
+	ColorBlue = drawing.Color{R: 0, G: 116, B: 217, A: 255}
+	// ColorCyan is the basic theme cyan color.
+	ColorCyan = drawing.Color{R: 0, G: 217, B: 210, A: 255}
+	// ColorGreen is the basic theme green color.
+	ColorGreen = drawing.Color{R: 0, G: 217, B: 101, A: 255}
+	// ColorRed is the basic theme red color.
+	ColorRed = drawing.Color{R: 217, G: 0, B: 116, A: 255}
+	// ColorOrange is the basic theme orange color.
+	ColorOrange = drawing.Color{R: 217, G: 101, B: 0, A: 255}
+	// ColorYellow is the basic theme yellow color.
+	ColorYellow = drawing.Color{R: 217, G: 210, B: 0, A: 255}
+	// ColorBlack is the basic theme black color.
+	ColorBlack = drawing.Color{R: 51, G: 51, B: 51, A: 255}
+	// ColorLightGray is the basic theme light gray color.
+	ColorLightGray = drawing.Color{R: 239, G: 239, B: 239, A: 255}
+
+	// ColorAlternateBlue is a alternate theme color.
+	ColorAlternateBlue = drawing.Color{R: 106, G: 195, B: 203, A: 255}
+	// ColorAlternateGreen is a alternate theme color.
+	ColorAlternateGreen = drawing.Color{R: 42, G: 190, B: 137, A: 255}
+	// ColorAlternateGray is a alternate theme color.
+	ColorAlternateGray = drawing.Color{R: 110, G: 128, B: 139, A: 255}
+	// ColorAlternateYellow is a alternate theme color.
+	ColorAlternateYellow = drawing.Color{R: 240, G: 174, B: 90, A: 255}
+	// ColorAlternateLightGray is a alternate theme color.
+	ColorAlternateLightGray = drawing.Color{R: 187, G: 190, B: 191, A: 255}
+
+	// ColorTransparent is a transparent (alpha zero) color.
+	ColorTransparent = drawing.Color{R: 1, G: 1, B: 1, A: 0}
+)
+
+var (
+	// DefaultBackgroundColor is the default chart background color.
+	// It is equivalent to css color:white.
+	DefaultBackgroundColor = ColorWhite
+	// DefaultBackgroundStrokeColor is the default chart border color.
+	// It is equivalent to color:white.
+	DefaultBackgroundStrokeColor = ColorWhite
+	// DefaultCanvasColor is the default chart canvas color.
+	// It is equivalent to css color:white.
+	DefaultCanvasColor = ColorWhite
+	// DefaultCanvasStrokeColor is the default chart canvas stroke color.
+	// It is equivalent to css color:white.
+	DefaultCanvasStrokeColor = ColorWhite
+	// DefaultTextColor is the default chart text color.
+	// It is equivalent to #333333.
+	DefaultTextColor = ColorBlack
+	// DefaultAxisColor is the default chart axis line color.
+	// It is equivalent to #333333.
+	DefaultAxisColor = ColorBlack
+	// DefaultStrokeColor is the default chart border color.
+	// It is equivalent to #efefef.
+	DefaultStrokeColor = ColorLightGray
+	// DefaultFillColor is the default fill color.
+	// It is equivalent to #0074d9.
+	DefaultFillColor = ColorBlue
+	// DefaultAnnotationFillColor is the default annotation background color.
+	DefaultAnnotationFillColor = ColorWhite
+	// DefaultGridLineColor is the default grid line color.
+	DefaultGridLineColor = ColorLightGray
+)
+
+var (
+	// DefaultColors are a couple default series colors.
+	DefaultColors = []drawing.Color{
+		ColorBlue,
+		ColorGreen,
+		ColorRed,
+		ColorCyan,
+		ColorOrange,
+	}
+
+	// DefaultAlternateColors are a couple alternate colors.
+	DefaultAlternateColors = []drawing.Color{
+		ColorAlternateBlue,
+		ColorAlternateGreen,
+		ColorAlternateGray,
+		ColorAlternateYellow,
+		ColorBlue,
+		ColorGreen,
+		ColorRed,
+		ColorCyan,
+		ColorOrange,
+	}
+)
+
+// GetDefaultColor returns a color from the default list by index.
+// NOTE: the index will wrap around (using a modulo).
+func GetDefaultColor(index int) drawing.Color {
+	finalIndex := index % len(DefaultColors)
+	return DefaultColors[finalIndex]
+}
+
+// GetAlternateColor returns a color from the default list by index.
+// NOTE: the index will wrap around (using a modulo).
+func GetAlternateColor(index int) drawing.Color {
+	finalIndex := index % len(DefaultAlternateColors)
+	return DefaultAlternateColors[finalIndex]
+}
+
+// ColorPalette is a set of colors that.
+type ColorPalette interface {
+	BackgroundColor() drawing.Color
+	BackgroundStrokeColor() drawing.Color
+	CanvasColor() drawing.Color
+	CanvasStrokeColor() drawing.Color
+	AxisStrokeColor() drawing.Color
+	TextColor() drawing.Color
+	GetSeriesColor(index int) drawing.Color
+}
+
+// DefaultColorPalette represents the default palatte.
+var DefaultColorPalette defaultColorPalette
+
+type defaultColorPalette struct{}
+
+func (dp defaultColorPalette) BackgroundColor() drawing.Color {
+	return DefaultBackgroundColor
+}
+
+func (dp defaultColorPalette) BackgroundStrokeColor() drawing.Color {
+	return DefaultBackgroundStrokeColor
+}
+
+func (dp defaultColorPalette) CanvasColor() drawing.Color {
+	return DefaultCanvasColor
+}
+
+func (dp defaultColorPalette) CanvasStrokeColor() drawing.Color {
+	return DefaultCanvasStrokeColor
+}
+
+func (dp defaultColorPalette) AxisStrokeColor() drawing.Color {
+	return DefaultAxisColor
+}
+
+func (dp defaultColorPalette) TextColor() drawing.Color {
+	return DefaultTextColor
+}
+
+func (dp defaultColorPalette) GetSeriesColor(index int) drawing.Color {
+	return GetDefaultColor(index)
+}
+
+// AlternateColorPalette represents the default palatte.
+var AlternateColorPalette alternateColorPalette
+
+type alternateColorPalette struct{}
+
+func (ap alternateColorPalette) BackgroundColor() drawing.Color {
+	return DefaultBackgroundColor
+}
+
+func (ap alternateColorPalette) BackgroundStrokeColor() drawing.Color {
+	return DefaultBackgroundStrokeColor
+}
+
+func (ap alternateColorPalette) CanvasColor() drawing.Color {
+	return DefaultCanvasColor
+}
+
+func (ap alternateColorPalette) CanvasStrokeColor() drawing.Color {
+	return DefaultCanvasStrokeColor
+}
+
+func (ap alternateColorPalette) AxisStrokeColor() drawing.Color {
+	return DefaultAxisColor
+}
+
+func (ap alternateColorPalette) TextColor() drawing.Color {
+	return DefaultTextColor
+}
+
+func (ap alternateColorPalette) GetSeriesColor(index int) drawing.Color {
+	return GetAlternateColor(index)
+}