Stanislav N. aka pztrn
48d43ca097
Pagination now works. Temporary hardcoded 10 pastes per page, will be put in configuration later. Maybe. From now user will receive readable error message if error occured. Started to work on syntax highlighting, tried to make lexers detection work but apparently to no avail.
154 lines
4.2 KiB
Go
154 lines
4.2 KiB
Go
package chroma
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import (
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"fmt"
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"math"
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"strconv"
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"strings"
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)
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// ANSI2RGB maps ANSI colour names, as supported by Chroma, to hex RGB values.
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var ANSI2RGB = map[string]string{
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"#ansiblack": "000000",
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"#ansidarkred": "7f0000",
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"#ansidarkgreen": "007f00",
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"#ansibrown": "7f7fe0",
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"#ansidarkblue": "00007f",
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"#ansipurple": "7f007f",
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"#ansiteal": "007f7f",
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"#ansilightgray": "e5e5e5",
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// Normal
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"#ansidarkgray": "555555",
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"#ansired": "ff0000",
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"#ansigreen": "00ff00",
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"#ansiyellow": "ffff00",
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"#ansiblue": "0000ff",
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"#ansifuchsia": "ff00ff",
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"#ansiturquoise": "00ffff",
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"#ansiwhite": "ffffff",
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// Aliases without the "ansi" prefix, because...why?
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"#black": "000000",
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"#darkred": "7f0000",
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"#darkgreen": "007f00",
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"#brown": "7f7fe0",
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"#darkblue": "00007f",
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"#purple": "7f007f",
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"#teal": "007f7f",
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"#lightgray": "e5e5e5",
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// Normal
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"#darkgray": "555555",
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"#red": "ff0000",
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"#green": "00ff00",
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"#yellow": "ffff00",
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"#blue": "0000ff",
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"#fuchsia": "ff00ff",
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"#turquoise": "00ffff",
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"#white": "ffffff",
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}
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// Colour represents an RGB colour.
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type Colour int32
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// NewColour creates a Colour directly from RGB values.
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func NewColour(r, g, b uint8) Colour {
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return ParseColour(fmt.Sprintf("%02x%02x%02x", r, g, b))
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}
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// Distance between this colour and another.
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//
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// This uses the approach described here (https://www.compuphase.com/cmetric.htm).
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// This is not as accurate as LAB, et. al. but is *vastly* simpler and sufficient for our needs.
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func (c Colour) Distance(e2 Colour) float64 {
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rmean := int(c.Red()+e2.Red()) / 2
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r := int(c.Red() - e2.Red())
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g := int(c.Green() - e2.Green())
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b := int(c.Blue() - e2.Blue())
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return math.Sqrt(float64((((512 + rmean) * r * r) >> 8) + 4*g*g + (((767 - rmean) * b * b) >> 8)))
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}
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// Brighten returns a copy of this colour with its brightness adjusted.
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//
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// If factor is negative, the colour is darkened.
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//
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// Uses approach described here (http://www.pvladov.com/2012/09/make-color-lighter-or-darker.html).
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func (c Colour) Brighten(factor float64) Colour {
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r := float64(c.Red())
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g := float64(c.Green())
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b := float64(c.Blue())
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if factor < 0 {
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factor++
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r *= factor
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g *= factor
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b *= factor
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} else {
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r = (255-r)*factor + r
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g = (255-g)*factor + g
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b = (255-b)*factor + b
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}
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return NewColour(uint8(r), uint8(g), uint8(b))
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}
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// Brightness of the colour (roughly) in the range 0.0 to 1.0
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func (c Colour) Brightness() float64 {
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return (float64(c.Red()) + float64(c.Green()) + float64(c.Blue())) / 255.0 / 3.0
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}
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// ParseColour in the forms #rgb, #rrggbb, #ansi<colour>, or #<colour>.
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// Will return an "unset" colour if invalid.
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func ParseColour(colour string) Colour {
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colour = normaliseColour(colour)
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n, err := strconv.ParseUint(colour, 16, 32)
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if err != nil {
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return 0
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}
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return Colour(n + 1)
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}
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// MustParseColour is like ParseColour except it panics if the colour is invalid.
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//
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// Will panic if colour is in an invalid format.
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func MustParseColour(colour string) Colour {
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parsed := ParseColour(colour)
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if !parsed.IsSet() {
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panic(fmt.Errorf("invalid colour %q", colour))
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}
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return parsed
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}
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func (c Colour) IsSet() bool { return c != 0 }
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func (c Colour) String() string { return fmt.Sprintf("#%06x", int(c-1)) }
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func (c Colour) GoString() string { return fmt.Sprintf("Colour(0x%06x)", int(c-1)) }
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// Red component of colour.
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func (c Colour) Red() uint8 { return uint8(((c - 1) >> 16) & 0xff) }
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// Green component of colour.
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func (c Colour) Green() uint8 { return uint8(((c - 1) >> 8) & 0xff) }
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// Blue component of colour.
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func (c Colour) Blue() uint8 { return uint8((c - 1) & 0xff) }
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// Colours is an orderable set of colours.
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type Colours []Colour
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func (c Colours) Len() int { return len(c) }
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func (c Colours) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
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func (c Colours) Less(i, j int) bool { return c[i] < c[j] }
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// Convert colours to #rrggbb.
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func normaliseColour(colour string) string {
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if ansi, ok := ANSI2RGB[colour]; ok {
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return ansi
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}
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if strings.HasPrefix(colour, "#") {
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colour = colour[1:]
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if len(colour) == 3 {
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return colour[0:1] + colour[0:1] + colour[1:2] + colour[1:2] + colour[2:3] + colour[2:3]
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}
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}
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return colour
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}
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