ref: af660f135883e955653e0d6b5324d5bc83f8a48e
dir: /style/stylesheets.go/
package style
import (
"9fans.net/go/draw"
"fmt"
"github.com/chris-ramon/douceur/css"
"github.com/chris-ramon/douceur/inliner"
"github.com/chris-ramon/douceur/parser"
cssSel "github.com/psilva261/css"
"github.com/mjl-/duit"
"golang.org/x/image/colornames"
"golang.org/x/net/html"
"io/ioutil"
"github.com/psilva261/opossum/logger"
"os/exec"
"regexp"
"strconv"
"strings"
)
var CssFonts = true
var fontCache = make(map[string]*draw.Font)
// experimentalUseBoxBackgrounds should probably be combined with
// setting stashElements to false
var ExperimentalUseBoxBackgrounds = false
var dui *duit.DUI
var availableFontNames []string
var log *logger.Logger
var rMinWidth = regexp.MustCompile(`min-width: (\d+)px`)
var rMaxWidth = regexp.MustCompile(`max-width: (\d+)px`)
const FontBaseSize = 11.0
const AddOnCSS = `
a, span, i, tt, b {
display: inline;
}
button, textarea, input, select {
display: inline-block;
}
h1, h2, h3, h4. h5, h6, div, center, frame, frameset, p, ul, menu, pre, dir {
display: block;
}
a {
color: blue;
}
`
func Init(d *duit.DUI, l *logger.Logger) {
dui = d
log = l
initFontserver()
}
func initFontserver() {
buf, err := exec.Command("fontsrv", "-p", ".").Output()
if err == nil {
availableFontNames = strings.Split(string(buf), "\n")
} else {
log.Printf("exec fontsrv: %v", err)
}
}
func Hrefs(doc *html.Node) (hrefs []string) {
hrefs = make([]string, 0, 3)
var f func(n *html.Node)
f = func(n *html.Node) {
if n.Type == html.ElementNode && n.Data == "link" {
isStylesheet := false
isPrint := false
href := ""
for _, a := range n.Attr {
switch strings.ToLower(a.Key) {
case "rel":
if a.Val == "stylesheet" {
isStylesheet = true
}
case "href":
href = a.Val
case "media":
isPrint = a.Val == "print"
}
}
if isStylesheet && !isPrint {
hrefs = append(hrefs, href)
}
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
f(c)
}
}
f(doc)
return
}
func MergeNodeMaps(m, addOn map[*html.Node]Map) {
for n, mp := range addOn {
// "zero" valued Map if it doesn't exist yet
initial := m[n]
m[n] = initial.ApplyChildStyle(mp)
}
}
func FetchNodeMap(doc *html.Node, cssText string, windowWidth int) (m map[*html.Node]Map, err error) {
mr, err := FetchNodeRules(doc, cssText, windowWidth)
if err != nil {
return nil, fmt.Errorf("fetch rules: %w", err)
}
m = make(map[*html.Node]Map)
for n, rs := range mr {
ds := make(map[string]css.Declaration)
for _, r := range rs {
for _, d := range r.Declarations {
if exist, ok := ds[d.Property]; ok && smaller(*d, exist) {
continue
}
ds[d.Property] = *d
}
}
m[n] = Map{ds}
}
return
}
func smaller(d, dd css.Declaration) bool {
return dd.Important
}
func FetchNodeRules(doc *html.Node, cssText string, windowWidth int) (m map[*html.Node][]*css.Rule, err error) {
m = make(map[*html.Node][]*css.Rule)
s, err := parser.Parse(cssText)
if err != nil {
return nil, fmt.Errorf("douceur parse: %w", err)
}
processRule := func(m map[*html.Node][]*css.Rule, r *css.Rule) (err error) {
for _, sel := range r.Selectors {
cs, err := cssSel.Compile(sel.Value)
if err != nil {
log.Printf("cssSel compile %v: %v", sel.Value, err)
continue
}
for _, el := range cs.Select(doc) {
existing, ok := m[el]
if !ok {
existing = make([]*css.Rule, 0, 3)
}
existing = append(existing, r)
m[el] = existing
}
}
return
}
for _, r := range s.Rules {
if err := processRule(m, r); err != nil {
return nil, fmt.Errorf("process rule: %w", err)
}
// for media queries
if strings.Contains(r.Prelude, "print") {
continue
}
if rMaxWidth.MatchString(r.Prelude) {
maxWidth, err := strconv.Atoi(rMaxWidth.FindStringSubmatch(r.Prelude)[1])
if err != nil {
return nil, fmt.Errorf("atoi: %w", err)
}
if windowWidth > maxWidth {
continue
}
}
if rMinWidth.MatchString(r.Prelude) {
minWidth, err := strconv.Atoi(rMinWidth.FindStringSubmatch(r.Prelude)[1])
if err != nil {
return nil, fmt.Errorf("atoi: %w", err)
}
if windowWidth < minWidth {
continue
}
}
for _, rr := range r.Rules {
if err := processRule(m, rr); err != nil {
return nil, fmt.Errorf("process embedded rule: %w", err)
}
}
}
return
}
func Inline(html string, csss ...string) (string, error) {
revertCSS, err := ioutil.ReadFile("normalize.css")
if err != nil {
return "", fmt.Errorf("revert ffox css: %w", err)
}
csss = append([]string{string(revertCSS), AddOnCSS}, csss...)
style := "<style>" + strings.Join(csss, "\n\n") + "</style>"
var replaced string
if strings.Contains(html, "</head>") {
replaced = strings.Replace(html, "</head>", style+"\n</head>", 1)
} else if strings.Contains(html, "<body") {
replaced = strings.Replace(html, "<body", style+"\n<body", 1)
} else {
replaced = style + html
}
if replaced == html {
panic("woot")
}
inlined, err := inliner.Inline(replaced)
if err == nil {
html = inlined
} else {
err = fmt.Errorf("inling failed: %w", err)
}
return html, err
}
type Map struct {
Declarations map[string]css.Declaration
}
func NewMap(n *html.Node) Map {
s := Map{
Declarations: make(map[string]css.Declaration),
}
for _, a := range n.Attr {
if a.Key == "style" {
decls, err := parser.ParseDeclarations(a.Val)
if err != nil {
log.Printf("could not parse '%v'", a.Val)
break
}
for _, d := range decls {
s.Declarations[d.Property] = *d
}
} else if a.Key == "height" || a.Key == "width" {
v := a.Val
if !strings.HasSuffix(v, "%") {
v += "px"
}
s.Declarations[a.Key] = css.Declaration{
Property: a.Key,
Value: v,
}
} else if a.Key == "bgcolor" {
s.Declarations["background-color"] = css.Declaration{
Property: "background-color",
Value: a.Val,
}
}
}
return s
}
func (cs Map) ApplyChildStyle(ccs Map) (res Map) {
res.Declarations = make(map[string]css.Declaration)
for k, v := range cs.Declarations {
res.Declarations[k] = v
}
// overwrite with higher prio child props
for k, v := range ccs.Declarations {
switch k {
/*case "height", "width":
parentL, ok := res.Declarations[k]
if ok && strings.HasSuffix(v.Value, "%") && strings.HasSuffix(parentL.Value, "px") {
parentLNum, err := strconv.Atoi(strings.TrimSuffix(parentL.Value, "px"))
if err != nil {
log.Errorf("atoi: %v", err)
continue
}
percentNum, err := strconv.ParseFloat(strings.TrimSuffix(v.Value, "%"), 64)
if err != nil {
log.Errorf("atoi: %v", err)
continue
}
prod := int(percentNum * float64(parentLNum) / 100.0)
res.Declarations[k] = css.Declaration{
Property: k,
Value: fmt.Sprintf("%vpx", prod),
}
continue
}
fallthrough*/
default:
res.Declarations[k] = v
}
}
return
}
func (cs Map) Font() *draw.Font {
if !CssFonts {
return nil
}
fn := cs.FontFilename()
if dui == nil {
return nil
}
font, ok := fontCache[fn]
if ok {
return font
}
font, err := dui.Display.OpenFont(fn)
if err != nil {
log.Printf("%v is not avail", fn)
return nil
}
fontCache[fn] = font
return font
}
func (cs Map) preferedFontName(preferences []string) string {
avails := availableFontNames
if len(avails) == 0 {
return preferences[0]
}
for len(preferences) > 0 {
var pref string
pref, preferences = preferences[0], preferences[1:]
for _, avail := range avails {
if pref == strings.TrimSuffix(avail, "/") {
return avail
}
}
}
return avails[0]
}
func (cs Map) FontSize() float64 {
fs, ok := cs.Declarations["font-size"]
if !ok || fs.Value == "" {
return FontBaseSize
}
if len(fs.Value) <= 2 {
log.Printf("error parsing font size %v", fs.Value)
return FontBaseSize
}
numStr := fs.Value[0 : len(fs.Value)-2]
f, err := strconv.ParseFloat(numStr, 64)
if err != nil {
log.Printf("error parsing font size %v", fs.Value)
return FontBaseSize
}
if strings.HasSuffix(fs.Value, "em") {
f *= FontBaseSize
}
return f
}
func (cs Map) Color() draw.Color {
h, ok := cs.colorHex("color")
if !ok {
return draw.Black
}
c := draw.Color(h)
return c
}
func (cs Map) colorHex(cssPropName string) (c draw.Color, ok bool) {
propVal, ok := cs.Declarations[cssPropName]
if ok {
var r, g, b uint32
if strings.HasPrefix(propVal.Value, "rgb") {
val := propVal.Value[3:]
val = strings.TrimPrefix(val, "(")
val = strings.TrimSuffix(val, ")")
vals := strings.Split(val, ",")
rr, err := strconv.ParseInt(vals[0], 10, 32)
if err != nil {
goto default_value
}
gg, err := strconv.ParseInt(vals[1], 10, 32)
if err != nil {
goto default_value
}
bb, err := strconv.ParseInt(vals[2], 10, 32)
if err != nil {
goto default_value
}
r = uint32(rr) * 256
g = uint32(gg) * 256
b = uint32(bb) * 256
} else if strings.HasPrefix(propVal.Value, "#") {
hexColor := propVal.Value[1:]
if len(hexColor) == 3 {
rr, err := strconv.ParseInt(hexColor[0:1], 16, 32)
if err != nil {
goto default_value
}
gg, err := strconv.ParseInt(hexColor[1:2], 16, 32)
if err != nil {
goto default_value
}
bb, err := strconv.ParseInt(hexColor[2:3], 16, 32)
if err != nil {
goto default_value
}
r = uint32(rr) * 256 * 16
g = uint32(gg) * 256 * 16
b = uint32(bb) * 256 * 16
} else if len(hexColor) == 6 {
rr, err := strconv.ParseInt(hexColor[0:2], 16, 32)
if err != nil {
goto default_value
}
gg, err := strconv.ParseInt(hexColor[2:4], 16, 32)
if err != nil {
goto default_value
}
bb, err := strconv.ParseInt(hexColor[4:6], 16, 32)
if err != nil {
goto default_value
}
r = uint32(rr) * 256
g = uint32(gg) * 256
b = uint32(bb) * 256
} else {
goto default_value
}
} else if propVal.Value == "inherit" {
// TODO: handle properly
goto default_value
} else {
colorRGBA, ok := colornames.Map[propVal.Value]
if !ok {
goto default_value
}
r, g, b, _ = colorRGBA.RGBA()
}
x := (r / 256) << 24
x = x | ((g / 256) << 16)
x = x | ((b / 256) << 8)
x = x | 0x000000ff
return draw.Color(uint32(x)), true
} else {
return 0, false
}
default_value:
log.Printf("could not interpret %v", propVal)
return 0, false
}
func (cs Map) IsInline() bool {
propVal, ok := cs.Declarations["float"]
if ok && propVal.Value == "left" {
return true
}
propVal, ok = cs.Declarations["display"]
if ok {
return propVal.Value == "inline" ||
propVal.Value == "inline-block"
}
return false
}
func (cs Map) IsDisplayNone() bool {
propVal, ok := cs.Declarations["display"]
if ok && propVal.Value == "none" {
return true
}
/*propVal, ok = cs.Declarations["position"]
if ok && propVal.Value == "fixed" {
return true
}*/
propVal, ok = cs.Declarations["clip"]
if ok && strings.ReplaceAll(propVal.Value, " ", "") == "rect(1px,1px,1px,1px)" {
return true
}
propVal, ok = cs.Declarations["width"]
if ok && propVal.Value == "1px" {
propVal, ok = cs.Declarations["height"]
if ok && propVal.Value == "1px" {
return true
}
}
return false
}
func (cs Map) IsFlex() bool {
propVal, ok := cs.Declarations["display"]
if ok {
return propVal.Value == "flex"
}
return false
}
func (cs Map) IsFlexDirectionRow() bool {
propVal, ok := cs.Declarations["flex-direction"]
if ok {
switch propVal.Value {
case "row":
return true
case "column":
return false
}
}
return true // TODO: be more specific
}
func length(l string) (f float64, unit string, err error) {
var s string
if l == "auto" {
return 0, "px", nil
}
for _, suffix := range []string{"px", "%", "rem", "em"} {
if strings.HasSuffix(l, suffix) {
s = strings.TrimSuffix(l, suffix)
unit = suffix
break
}
}
switch unit {
case "":
return f, unit, fmt.Errorf("unknown suffix: %v", l)
case "px", "em":
f, err = strconv.ParseFloat(s, 64)
}
if unit == "em" {
f *= FontBaseSize
}
f = float64(dui.Scale(int(f)))
return
}
func (cs Map) Height() int {
d, ok := cs.Declarations["height"]
if ok {
f, _, err := length(d.Value)
if err != nil {
log.Errorf("cannot parse height: %v", err)
}
return int(f)
}
return 0
}
func (cs Map) Width() int {
d, ok := cs.Declarations["width"]
if ok {
f, _, err := length(d.Value)
if err != nil {
log.Errorf("cannot parse width: %v", err)
}
return int(f)
}
return 0
}
func (cs Map) Css(propName string) string {
d, ok := cs.Declarations[propName]
if !ok {
return ""
}
return d.Value
}