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badge-gen/vendor/github.com/tdewolff/minify/css/css.go
2016-06-28 19:38:58 +02:00

517 lines
15 KiB
Go

// Package css minifies CSS3 following the specifications at http://www.w3.org/TR/css-syntax-3/.
package css
import (
"bytes"
"encoding/hex"
"io"
"strconv"
"github.com/tdewolff/minify"
"github.com/tdewolff/parse"
"github.com/tdewolff/parse/css"
)
var (
spaceBytes = []byte(" ")
colonBytes = []byte(":")
semicolonBytes = []byte(";")
leftBracketBytes = []byte("{")
rightBracketBytes = []byte("}")
zeroBytes = []byte("0")
msfilterBytes = []byte("-ms-filter")
backgroundNoneBytes = []byte("0 0")
)
type cssMinifier struct {
m *minify.M
w io.Writer
p *css.Parser
o *Minifier
}
////////////////////////////////////////////////////////////////
// Minifier is a CSS minifier.
type Minifier struct {
Decimals int
}
// Minify minifies CSS data, it reads from r and writes to w.
func Minify(m *minify.M, w io.Writer, r io.Reader, params map[string]string) error {
return (&Minifier{Decimals: -1}).Minify(m, w, r, params)
}
// Minify minifies CSS data, it reads from r and writes to w.
func (o *Minifier) Minify(m *minify.M, w io.Writer, r io.Reader, params map[string]string) error {
isInline := params != nil && params["inline"] == "1"
c := &cssMinifier{
m: m,
w: w,
p: css.NewParser(r, isInline),
o: o,
}
if err := c.minifyGrammar(); err != nil && err != io.EOF {
return err
}
return nil
}
func (c *cssMinifier) minifyGrammar() error {
semicolonQueued := false
for {
gt, _, data := c.p.Next()
if gt == css.ErrorGrammar {
return c.p.Err()
} else if gt == css.EndAtRuleGrammar || gt == css.EndRulesetGrammar {
if _, err := c.w.Write(rightBracketBytes); err != nil {
return err
}
semicolonQueued = false
continue
}
if semicolonQueued {
if _, err := c.w.Write(semicolonBytes); err != nil {
return err
}
semicolonQueued = false
}
if gt == css.AtRuleGrammar {
if _, err := c.w.Write(data); err != nil {
return err
}
for _, val := range c.p.Values() {
if _, err := c.w.Write(val.Data); err != nil {
return err
}
}
semicolonQueued = true
} else if gt == css.BeginAtRuleGrammar {
if _, err := c.w.Write(data); err != nil {
return err
}
for _, val := range c.p.Values() {
if _, err := c.w.Write(val.Data); err != nil {
return err
}
}
if _, err := c.w.Write(leftBracketBytes); err != nil {
return err
}
} else if gt == css.BeginRulesetGrammar {
if err := c.minifySelectors(data, c.p.Values()); err != nil {
return err
}
if _, err := c.w.Write(leftBracketBytes); err != nil {
return err
}
} else if gt == css.DeclarationGrammar {
if _, err := c.w.Write(data); err != nil {
return err
}
if _, err := c.w.Write(colonBytes); err != nil {
return err
}
if err := c.minifyDeclaration(data, c.p.Values()); err != nil {
return err
}
semicolonQueued = true
} else if gt == css.CommentGrammar {
if len(data) > 5 && data[1] == '*' && data[2] == '!' {
if _, err := c.w.Write(data[:3]); err != nil {
return err
}
comment := parse.TrimWhitespace(parse.ReplaceMultipleWhitespace(data[3 : len(data)-2]))
if _, err := c.w.Write(comment); err != nil {
return err
}
if _, err := c.w.Write(data[len(data)-2:]); err != nil {
return err
}
}
} else if _, err := c.w.Write(data); err != nil {
return err
}
}
}
func (c *cssMinifier) minifySelectors(property []byte, values []css.Token) error {
inAttr := false
isClass := false
for _, val := range c.p.Values() {
if !inAttr {
if val.TokenType == css.IdentToken {
if !isClass {
parse.ToLower(val.Data)
}
isClass = false
} else if val.TokenType == css.DelimToken && val.Data[0] == '.' {
isClass = true
} else if val.TokenType == css.LeftBracketToken {
inAttr = true
}
} else {
if val.TokenType == css.StringToken && len(val.Data) > 2 {
s := val.Data[1 : len(val.Data)-1]
if css.IsIdent([]byte(s)) {
if _, err := c.w.Write(s); err != nil {
return err
}
continue
}
} else if val.TokenType == css.RightBracketToken {
inAttr = false
}
}
if _, err := c.w.Write(val.Data); err != nil {
return err
}
}
return nil
}
func (c *cssMinifier) minifyDeclaration(property []byte, values []css.Token) error {
if len(values) == 0 {
return nil
}
prop := css.ToHash(property)
inProgid := false
for i, value := range values {
if inProgid {
if value.TokenType == css.FunctionToken {
inProgid = false
}
continue
} else if value.TokenType == css.IdentToken && css.ToHash(value.Data) == css.Progid {
inProgid = true
continue
}
value.TokenType, value.Data = c.shortenToken(prop, value.TokenType, value.Data)
if prop == css.Font || prop == css.Font_Family || prop == css.Font_Weight {
if value.TokenType == css.IdentToken && (prop == css.Font || prop == css.Font_Weight) {
val := css.ToHash(value.Data)
if val == css.Normal && prop == css.Font_Weight {
// normal could also be specified for font-variant, not just font-weight
value.TokenType = css.NumberToken
value.Data = []byte("400")
} else if val == css.Bold {
value.TokenType = css.NumberToken
value.Data = []byte("700")
}
} else if value.TokenType == css.StringToken && (prop == css.Font || prop == css.Font_Family) && len(value.Data) > 2 {
unquote := true
parse.ToLower(value.Data)
s := value.Data[1 : len(value.Data)-1]
if len(s) > 0 {
for _, split := range bytes.Split(s, spaceBytes) {
val := css.ToHash(split)
// if len is zero, it contains two consecutive spaces
if val == css.Inherit || val == css.Serif || val == css.Sans_Serif || val == css.Monospace || val == css.Fantasy || val == css.Cursive || val == css.Initial || val == css.Default ||
len(split) == 0 || !css.IsIdent(split) {
unquote = false
break
}
}
}
if unquote {
value.Data = s
}
}
} else if prop == css.Outline || prop == css.Border || prop == css.Border_Bottom || prop == css.Border_Left || prop == css.Border_Right || prop == css.Border_Top {
if css.ToHash(value.Data) == css.None {
value.TokenType = css.NumberToken
value.Data = zeroBytes
}
}
values[i].TokenType, values[i].Data = value.TokenType, value.Data
}
important := false
if len(values) > 2 && values[len(values)-2].TokenType == css.DelimToken && values[len(values)-2].Data[0] == '!' && css.ToHash(values[len(values)-1].Data) == css.Important {
values = values[:len(values)-2]
important = true
}
if len(values) == 1 {
if prop == css.Background && css.ToHash(values[0].Data) == css.None {
values[0].Data = backgroundNoneBytes
} else if bytes.Equal(property, msfilterBytes) {
alpha := []byte("progid:DXImageTransform.Microsoft.Alpha(Opacity=")
if values[0].TokenType == css.StringToken && bytes.HasPrefix(values[0].Data[1:len(values[0].Data)-1], alpha) {
values[0].Data = append(append([]byte{values[0].Data[0]}, []byte("alpha(opacity=")...), values[0].Data[1+len(alpha):]...)
}
}
} else {
if prop == css.Margin || prop == css.Padding || prop == css.Border_Width {
if (values[0].TokenType == css.NumberToken || values[0].TokenType == css.DimensionToken || values[0].TokenType == css.PercentageToken) && (len(values)+1)%2 == 0 {
valid := true
for i := 1; i < len(values); i += 2 {
if values[i].TokenType != css.WhitespaceToken || values[i+1].TokenType != css.NumberToken && values[i+1].TokenType != css.DimensionToken && values[i+1].TokenType != css.PercentageToken {
valid = false
break
}
}
if valid {
n := (len(values) + 1) / 2
if n == 2 {
if bytes.Equal(values[0].Data, values[2].Data) {
values = values[:1]
}
} else if n == 3 {
if bytes.Equal(values[0].Data, values[2].Data) && bytes.Equal(values[0].Data, values[4].Data) {
values = values[:1]
} else if bytes.Equal(values[0].Data, values[4].Data) {
values = values[:3]
}
} else if n == 4 {
if bytes.Equal(values[0].Data, values[2].Data) && bytes.Equal(values[0].Data, values[4].Data) && bytes.Equal(values[0].Data, values[6].Data) {
values = values[:1]
} else if bytes.Equal(values[0].Data, values[4].Data) && bytes.Equal(values[2].Data, values[6].Data) {
values = values[:3]
} else if bytes.Equal(values[2].Data, values[6].Data) {
values = values[:5]
}
}
}
}
} else if prop == css.Filter && len(values) == 11 {
if bytes.Equal(values[0].Data, []byte("progid")) &&
values[1].TokenType == css.ColonToken &&
bytes.Equal(values[2].Data, []byte("DXImageTransform")) &&
values[3].Data[0] == '.' &&
bytes.Equal(values[4].Data, []byte("Microsoft")) &&
values[5].Data[0] == '.' &&
bytes.Equal(values[6].Data, []byte("Alpha(")) &&
bytes.Equal(parse.ToLower(values[7].Data), []byte("opacity")) &&
values[8].Data[0] == '=' &&
values[10].Data[0] == ')' {
values = values[6:]
values[0].Data = []byte("alpha(")
}
}
}
for i := 0; i < len(values); i++ {
if values[i].TokenType == css.FunctionToken {
n, err := c.minifyFunction(values[i:])
if err != nil {
return err
}
i += n - 1
} else if _, err := c.w.Write(values[i].Data); err != nil {
return err
}
}
if important {
if _, err := c.w.Write([]byte("!important")); err != nil {
return err
}
}
return nil
}
func (c *cssMinifier) minifyFunction(values []css.Token) (int, error) {
n := 1
simple := true
for i, value := range values[1:] {
if value.TokenType == css.RightParenthesisToken {
n++
break
}
if i%2 == 0 && (value.TokenType != css.NumberToken && value.TokenType != css.PercentageToken) || (i%2 == 1 && value.TokenType != css.CommaToken) {
simple = false
}
n++
}
values = values[:n]
if simple && (n-1)%2 == 0 {
fun := css.ToHash(values[0].Data[:len(values[0].Data)-1])
nArgs := (n - 1) / 2
if (fun == css.Rgba || fun == css.Hsla) && nArgs == 4 {
d, _ := strconv.ParseFloat(string(values[7].Data), 32) // can never fail because if simple == true than this is a NumberToken or PercentageToken
if d-1.0 > -minify.Epsilon {
if fun == css.Rgba {
values[0].Data = []byte("rgb(")
fun = css.Rgb
} else {
values[0].Data = []byte("hsl(")
fun = css.Hsl
}
values = values[:len(values)-2]
values[len(values)-1].Data = []byte(")")
nArgs = 3
} else if d < minify.Epsilon {
values[0].Data = []byte("transparent")
values = values[:1]
fun = 0
nArgs = 0
}
}
if fun == css.Rgb && nArgs == 3 {
var err [3]error
rgb := [3]byte{}
for j := 0; j < 3; j++ {
val := values[j*2+1]
if val.TokenType == css.NumberToken {
var d int64
d, err[j] = strconv.ParseInt(string(val.Data), 10, 32)
if d < 0 {
d = 0
} else if d > 255 {
d = 255
}
rgb[j] = byte(d)
} else if val.TokenType == css.PercentageToken {
var d float64
d, err[j] = strconv.ParseFloat(string(val.Data[:len(val.Data)-1]), 32)
if d < 0.0 {
d = 0.0
} else if d > 100.0 {
d = 100.0
}
rgb[j] = byte((d / 100.0 * 255.0) + 0.5)
}
}
if err[0] == nil && err[1] == nil && err[2] == nil {
val := make([]byte, 7)
val[0] = '#'
hex.Encode(val[1:], rgb[:])
parse.ToLower(val)
if s, ok := ShortenColorHex[string(val)]; ok {
if _, err := c.w.Write(s); err != nil {
return 0, err
}
} else {
if len(val) == 7 && val[1] == val[2] && val[3] == val[4] && val[5] == val[6] {
val[2] = val[3]
val[3] = val[5]
val = val[:4]
}
if _, err := c.w.Write(val); err != nil {
return 0, err
}
}
return n, nil
}
} else if fun == css.Hsl && nArgs == 3 {
if values[1].TokenType == css.NumberToken && values[3].TokenType == css.PercentageToken && values[5].TokenType == css.PercentageToken {
h, err1 := strconv.ParseFloat(string(values[1].Data), 32)
s, err2 := strconv.ParseFloat(string(values[3].Data[:len(values[3].Data)-1]), 32)
l, err3 := strconv.ParseFloat(string(values[5].Data[:len(values[5].Data)-1]), 32)
if err1 == nil && err2 == nil && err3 == nil {
r, g, b := css.HSL2RGB(h/360.0, s/100.0, l/100.0)
rgb := []byte{byte((r * 255.0) + 0.5), byte((g * 255.0) + 0.5), byte((b * 255.0) + 0.5)}
val := make([]byte, 7)
val[0] = '#'
hex.Encode(val[1:], rgb[:])
parse.ToLower(val)
if s, ok := ShortenColorHex[string(val)]; ok {
if _, err := c.w.Write(s); err != nil {
return 0, err
}
} else {
if len(val) == 7 && val[1] == val[2] && val[3] == val[4] && val[5] == val[6] {
val[2] = val[3]
val[3] = val[5]
val = val[:4]
}
if _, err := c.w.Write(val); err != nil {
return 0, err
}
}
return n, nil
}
}
}
}
for _, value := range values {
if _, err := c.w.Write(value.Data); err != nil {
return 0, err
}
}
return n, nil
}
func (c *cssMinifier) shortenToken(prop css.Hash, tt css.TokenType, data []byte) (css.TokenType, []byte) {
if tt == css.NumberToken || tt == css.PercentageToken || tt == css.DimensionToken {
if tt == css.NumberToken && (prop == css.Z_Index || prop == css.Counter_Increment || prop == css.Counter_Reset || prop == css.Orphans || prop == css.Widows) {
return tt, data // integers
}
n := len(data)
if tt == css.PercentageToken {
n--
} else if tt == css.DimensionToken {
n = parse.Number(data)
}
dim := data[n:]
data = minify.Number(data[:n], c.o.Decimals)
if len(data) != 1 || data[0] != '0' {
if tt == css.PercentageToken {
data = append(data, '%')
} else if tt == css.DimensionToken {
parse.ToLower(dim)
data = append(data, dim...)
}
}
} else if tt == css.IdentToken {
parse.ToLower(data)
if hex, ok := ShortenColorName[css.ToHash(data)]; ok {
tt = css.HashToken
data = hex
}
} else if tt == css.HashToken {
parse.ToLower(data)
if ident, ok := ShortenColorHex[string(data)]; ok {
tt = css.IdentToken
data = ident
} else if len(data) == 7 && data[1] == data[2] && data[3] == data[4] && data[5] == data[6] {
tt = css.HashToken
data[2] = data[3]
data[3] = data[5]
data = data[:4]
}
} else if tt == css.StringToken {
// remove any \\\r\n \\\r \\\n
for i := 1; i < len(data)-2; i++ {
if data[i] == '\\' && (data[i+1] == '\n' || data[i+1] == '\r') {
// encountered first replacee, now start to move bytes to the front
j := i + 2
if data[i+1] == '\r' && len(data) > i+2 && data[i+2] == '\n' {
j++
}
for ; j < len(data); j++ {
if data[j] == '\\' && len(data) > j+1 && (data[j+1] == '\n' || data[j+1] == '\r') {
if data[j+1] == '\r' && len(data) > j+2 && data[j+2] == '\n' {
j++
}
j++
} else {
data[i] = data[j]
i++
}
}
data = data[:i]
break
}
}
} else if tt == css.URLToken {
parse.ToLower(data[:3])
if len(data) > 10 {
uri := data[4 : len(data)-1]
delim := byte('"')
if uri[0] == '\'' || uri[0] == '"' {
delim = uri[0]
uri = uri[1 : len(uri)-1]
}
uri = minify.DataURI(c.m, uri)
if css.IsURLUnquoted(uri) {
data = append(append([]byte("url("), uri...), ')')
} else {
data = append(append(append([]byte("url("), delim), uri...), delim, ')')
}
}
}
return tt, data
}