Initial stylesheet support

application.go

@@ -65,6 +65,15 @@ type ApplicationDescription struct {
 	Role ApplicationRole
 }
 
+// GlobalApplicationDescription returns the global application description which
+// points to cache, data, config, etc. used by Nasin itself.
+func GlobalApplicationDescription () ApplicationDescription {
+	return ApplicationDescription {
+		Name: "Nasin",
+		ID:   "xyz.holanet.Nasin",
+	}
+}
+
 // String satisfies the fmt.Stringer interface.
 func (application ApplicationDescription) String () string {
 	if application.Name == "" {
@@ -133,8 +142,9 @@ func RunApplication (application Application) {
 	if err != nil { log.Fatalln("nasin: could not register backend:", err) }
 	err = tomo.Run(func () {
 		err := registrar.SetTheme()
-		err := registrar.SetIconSet()
 		if err != nil { log.Fatalln("nasin: could not set theme:", err) }
+		err = registrar.SetIconSet()
+		if err != nil { log.Fatalln("nasin: could not set icon set:", err) }
 		err = application.Init()
 		if err != nil { log.Fatalln("nasin: could not run application:", err) }
 

internal/registrar/registrar_unix.go

@@ -5,6 +5,7 @@ import "os"
 import "log"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/backend/x"
+import "git.tebibyte.media/sashakoshka/goparse"
 import "git.tebibyte.media/tomo/nasin/internal/icons/xdg"
 import "git.tebibyte.media/tomo/nasin/internal/style/tss"
 import "git.tebibyte.media/tomo/nasin/internal/icons/fallback"
@@ -23,8 +24,11 @@ func SetTheme () error {
 		styl, _, err := tss.LoadFile(styleSheetName)
 		if err == nil {
 			tomo.SetStyle(styl)
+			return nil
 		} else {
-			log.Printf("nasin: could not load style sheet '%s': %v", styleSheetName, err)
+			log.Printf (
+				"nasin: could not load style sheet '%s'\n%v",
+				styleSheetName, parse.Format(err))
 		}
 	}
 	

internal/style/styleminimal.tss

@@ -0,0 +1,14 @@
+$ColorBackground = #FFF;
+$ColorForeground = #000;
+$ColorRaised     = #AAA;
+$ColorSunken     = #888;
+$ColorAccent     = #0FF;
+
+*.* {
+	Color:     $ColorBackground;
+	Border:    $ColorForeground / 1;
+	TextColor: $ColorForeground;
+	DotColor:  $ColorAccent;
+	Padding:   2;
+}
+

internal/style/tss/build.go

@@ -0,0 +1,351 @@
+package tss
+
+import "fmt"
+import "image"
+import "errors"
+import "image/color"
+import "git.tebibyte.media/tomo/tomo"
+import "git.tebibyte.media/tomo/tomo/event"
+
+// BuildStyle builds a Tomo style from the specified sheet. Resources associated
+// with it (such as textures) can be freed by closing the returned cookie.
+func BuildStyle (sheet Sheet) (*tomo.Style, event.Cookie, error) {
+	err := sheet.Flatten()
+	if err != nil { return nil, nil, err }
+	
+	getColor := func (name string) color.Color {
+		if list, ok := sheet.Variables[name]; ok {
+			if len(list) > 0 {
+				if col, ok := list[0].(ValueColor); ok {
+					return col				
+				}
+			}
+		}
+		return color.RGBA { R: 255, B: 255, A: 255 }
+	}
+	
+	cookies := []event.Cookie { }
+	style := &tomo.Style {
+		Rules: make([]tomo.Rule, len(sheet.Rules)),
+		Colors: map[tomo.Color] color.Color {
+			tomo.ColorBackground: getColor("ColorBackground"),
+			tomo.ColorForeground: getColor("ColorForeground"),
+			tomo.ColorRaised:     getColor("ColorRaised"),
+			tomo.ColorSunken:     getColor("ColorSunken"),
+			tomo.ColorAccent:     getColor("ColorAccent"),
+		},
+	}
+	
+	for index, rule := range sheet.Rules {
+		styleRule := tomo.Rule {
+			Role: tomo.Role {
+				Package: rule.Selector.Package,
+				Object:  rule.Selector.Object,
+			},
+			Tags: rule.Selector.Tags,
+			Set:  make(tomo.AttrSet),
+		}
+		for name, attr := range rule.Attrs {
+			styleAttr, cookie, err := buildAttr(name, attr)
+			if err != nil { return nil, nil, err }
+			styleRule.Set.Add(styleAttr)
+			if cookie != nil {
+				cookies = append(cookies, cookie)
+			}
+		}
+		style.Rules[index] = styleRule
+	}
+
+	return style, event.MultiCookie(cookies...), nil
+}
+
+func buildAttr (name string, attr []ValueList) (tomo.Attr, event.Cookie, error) {
+	expectSingle := func () error {
+		if len(attr) != 1 {
+			return errors.New(fmt.Sprintf (
+				"%s attribute requires exactly one value list",
+				name))
+		}
+		return nil
+	}
+	expectSingleSingle := func () error {
+		err := expectSingle()
+		if err != nil { return err }
+		if len(attr[0]) != 1 {
+			return errors.New(fmt.Sprintf (
+				"%s attribute requires exactly one value",
+				name))
+		}
+		return nil
+	}
+	expectNumbers := func (list ValueList) error {
+		for _, value := range list {
+			if _, ok := value.(ValueNumber); ok { continue }
+			return errors.New(fmt.Sprintf (
+				"wrong type for %s attribute",
+				name))
+		}
+		return nil
+	}
+	numbers := func (list ValueList) ([]int, error) {
+		nums := make([]int, len(list))
+		for index, value := range list {
+			if value, ok := value.(ValueNumber); ok {
+				nums[index] = int(value)
+				continue
+			}
+			return nil, errors.New(fmt.Sprintf (
+				"wrong type for %s attribute",
+				name))
+		}
+		return nums, nil
+	}
+	bools := func (list ValueList) ([]bool, error) {
+		bools := make([]bool, len(list))
+		for index, value := range list {
+			if value, ok := value.(ValueKeyword); ok {
+				switch value {
+				case "true":
+					bools[index] = true
+					continue
+				case "false":
+					bools[index] = false
+					continue
+				}
+			}
+			return nil, errors.New(fmt.Sprintf (
+				"wrong type for %s attribute",
+				name))
+		}
+		return bools, nil
+	}
+	point := func (list ValueList) (image.Point, error) {
+		err := expectNumbers(list)
+		if err != nil { return image.Point { }, err }
+		
+		vector := image.Point { }
+		switch len(attr[0]) {
+		case 1:
+			vector.X = int(list[0].(ValueNumber))
+			vector.Y = int(list[0].(ValueNumber))
+		case 2:
+			vector.X = int(list[0].(ValueNumber))
+			vector.Y = int(list[1].(ValueNumber))
+		default:
+			return image.Point { }, errors.New(fmt.Sprintf (
+				"%s attribute requires exactly one or two values",
+				name))
+		}
+		return vector, nil
+	}
+	
+	switch name {
+	case "Color":
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if col, ok := attr[0][0].(ValueColor); ok {
+			return tomo.AColor(col), nil, nil
+		}
+		return nil, nil, errors.New(fmt.Sprintf (
+			"wrong type for %s attribute",
+			name))
+		
+	case "Texture":
+		// TODO load image from file
+	
+	case "TextureMode":
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if keyword, ok := attr[0][0].(ValueKeyword); ok {
+			switch keyword {
+			case "tile":   return tomo.ATextureMode(tomo.TextureModeCenter), nil, nil
+			case "center": return tomo.ATextureMode(tomo.TextureModeCenter), nil, nil
+			}
+			return nil, nil, errors.New(fmt.Sprintf (
+				"unknown texture mode: %s",
+				keyword))
+		}
+		return nil, nil, errors.New(fmt.Sprintf (
+			"wrong type for %s attribute",
+			name))
+	
+	case "Border":
+		attrBorder, err := buildAttrBorder(attr)
+		if err != nil { return nil, nil, err }
+		return attrBorder, nil, nil
+	
+	case "MinimumSize":
+		err := expectSingle()
+		if err != nil { return nil, nil, err }
+		vector, err := point(attr[0])
+		if err != nil { return nil, nil, err }
+		return tomo.AttrMinimumSize(vector), nil, nil
+	
+	case "Padding":
+		err := expectSingle()
+		if err != nil { return nil, nil, err }
+		numbers, err := numbers(attr[0])
+		if err != nil { return nil, nil, err }
+		inset := tomo.Inset { }
+		if !copyBorderValue(inset[:], numbers) {
+			return nil, nil, errors.New(fmt.Sprintf (
+				"%s attribute requires exactly one, two, or four values",
+				name))
+		}
+		return tomo.AttrPadding(inset), nil, nil
+		
+	case "Gap":
+		err := expectSingle()
+		if err != nil { return nil, nil, err }
+		vector, err := point(attr[0])
+		if err != nil { return nil, nil, err }
+		return tomo.AttrGap(vector), nil, nil
+	
+	case "TextColor":
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if col, ok := attr[0][0].(ValueColor); ok {
+			return tomo.ATextColor(col), nil, nil
+		}
+		return nil, nil, errors.New(fmt.Sprintf (
+			"wrong type for %s attribute",
+			name))
+			
+	case "DotColor":
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if col, ok := attr[0][0].(ValueColor); ok {
+			return tomo.ADotColor(col), nil, nil
+		}
+		return nil, nil, errors.New(fmt.Sprintf (
+			"wrong type for %s attribute",
+			name))
+			
+	case "Face":
+		// TODO: load font from file with some parameters
+		
+	case "Wrap":
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if value, ok := attr[0][0].(ValueKeyword); ok {
+			switch value {
+			case "true":  return tomo.AWrap(true),  nil, nil
+			case "false": return tomo.AWrap(false), nil, nil
+			}
+		}
+		return nil, nil, errors.New(fmt.Sprintf (
+			"wrong type for %s attribute",
+			name))
+		
+	case "Align":
+		err := expectSingle()
+		if err != nil { return nil, nil, err }
+		list := attr[0]
+		if len(list) != 2 {
+			return nil, nil, errors.New(fmt.Sprintf (
+				"%s attribute requires exactly two values",
+				name))
+		}
+		aligns := [2]tomo.Align { }
+		for index, value := range list {
+			if keyword, ok := value.(ValueKeyword); ok {
+				switch keyword {
+				case "start":  aligns[index] = tomo.AlignStart
+				case "middle": aligns[index] = tomo.AlignMiddle
+				case "end":    aligns[index] = tomo.AlignEnd
+				case "even":   aligns[index] = tomo.AlignEven
+				default: return nil, nil, errors.New(fmt.Sprintf (
+					"unknown texture mode: %s",
+					keyword))					
+				}
+			}
+			return nil, nil, errors.New(fmt.Sprintf (
+				"wrong type for %s attribute",
+				name))
+		}
+		return tomo.AAlign(aligns[0], aligns[1]), nil, nil
+		
+	case "Overflow":
+		err := expectSingle()
+		if err != nil { return nil, nil, err }
+		bools, err := bools(attr[0])
+		if err != nil { return nil, nil, err }
+		if len(bools) != 2 {
+			return nil, nil, errors.New(fmt.Sprintf (
+				"%s attribute requires exactly two values",
+				name))
+		}
+		return tomo.AOverflow(bools[0], bools[1]), nil, nil
+		
+	case "Layout":
+		// TODO allow use of some layouts in the objects package
+		
+	default: return nil, nil, errors.New(fmt.Sprintf("unknown attribute name %s", name))
+	}
+	return nil, nil, errors.New(fmt.Sprintf("unimplemented attribute name %s", name))
+}
+
+func buildAttrBorder (attr []ValueList) (tomo.Attr, error) {
+	borders := make([]tomo.Border, len(attr))
+	for index, list := range attr {
+		colors := make([]color.Color, 0, len(list))
+		sizes  := make([]int, 0, len(list))
+		
+		capturingSize := false
+		for _, value := range list {
+			if capturingSize {
+				if value, ok := value.(ValueNumber); ok {
+					sizes = append(sizes, int(value))
+					continue
+				}
+			} else {
+				if _, ok := value.(ValueCut); ok {
+					capturingSize = true
+					continue
+				}
+				if value, ok := value.(ValueColor); ok {
+					colors = append(colors, value)
+					continue
+				}
+			}
+			return nil, errors.New("malformed Border attribute value list")
+		}
+		
+		border := tomo.Border { }
+		if !copyBorderValue(border.Width[:], sizes) {
+			return nil, errors.New("malformed Border attribute width list")
+		}
+		if !copyBorderValue(border.Color[:], colors) {
+			return nil, errors.New("malformed Border attribute color list")
+		}
+		borders[index] = border
+	}
+	
+	return tomo.ABorder(borders...), nil
+}
+
+func copyBorderValue[T any, U ~[]T] (destination, source U) bool {
+	if len(source) > len(destination) { return false } 
+	switch len(source) {
+	case 1:
+		destination[0] = source[0]
+		destination[1] = source[0]
+		destination[2] = source[0]
+		destination[3] = source[0]
+		return true
+	case 2:
+		destination[0] = source[0]
+		destination[1] = source[1]
+		destination[2] = source[0]
+		destination[3] = source[1]
+		return true
+	case 4:
+		destination[0] = source[0]
+		destination[1] = source[1]
+		destination[2] = source[2]
+		destination[3] = source[3]
+		return true
+	default:
+		return false
+	}
+}

internal/style/tss/flatten.go

@@ -0,0 +1,53 @@
+package tss
+
+import "fmt"
+import "errors"
+
+// Flatten evaluates all variables recursively, thereby eliminating all
+// instances of ValueVariable.
+func (this *Sheet) Flatten () error {
+	if this.flat { return nil }
+	this.flat = true
+	
+	for name, variable := range this.Variables {
+		variable, err := this.eval(variable)
+		if err != nil { return err }
+		this.Variables[name] = variable
+	}
+	
+	for index, rule := range this.Rules {
+		for name, attr := range rule.Attrs {
+			for index, list := range attr {
+				list, err := this.eval(list)
+				if err != nil { return err }
+				attr[index] = list
+			}
+			rule.Attrs[name] = attr
+		}
+		this.Rules[index] = rule
+	}
+	
+	return nil
+}
+
+func (this *Sheet) eval (source ValueList) (ValueList, error) {
+	destination := make(ValueList, 0, len(source))
+	for _, value := range source {
+		if name, ok := value.(ValueVariable); ok {
+			variable, ok := this.Variables[string(name)]
+			if !ok {
+				return nil, errors.New(fmt.Sprintf(
+					"variable $%s does not exist",
+					value))
+			}
+			variable, err := this.eval(variable)
+			if err != nil { return nil, err }
+			destination = append(destination, variable...)
+			continue
+		} else {
+			destination = append(destination, value)
+		}
+	}
+	
+	return destination, nil
+}

internal/style/tss/lex.go

@@ -19,6 +19,7 @@ const (
 	Star
 	Dot
 	Dollar
+	Slash
 	Color
 	Ident
 	Number
@@ -39,6 +40,7 @@ var tokenNames = map[parse.TokenKind] string {
 	Star: "Star",
 	Dot: "Dot",
 	Dollar: "Dollar",
+	Slash: "Slash",
 	Color: "Color",
 	Ident: "Ident",
 	Number: "Number",
@@ -115,6 +117,8 @@ func (this *lexer) next () (token parse.Token, err error) {
 				skipRune()
 				if err != nil { return }
 			}
+		} else {
+			token.Kind = Slash
 		}
 		if this.eof { err = nil; return }
 

internal/style/tss/parse.go

@@ -4,43 +4,6 @@ import "io"
 import "strconv"
 import "git.tebibyte.media/sashakoshka/goparse"
 
-type Sheet struct {
-	Variables map[string] ValueList
-	Rules     []Rule
-}
-
-type Rule struct {
-	Selector Selector
-	Attrs    map[string] []ValueList
-}
-
-type Selector struct {
-	Package string
-	Object  string
-	Tags    []string
-}
-
-type ValueList []Value
-
-type Value interface {
-	value ()
-}
-
-func (ValueNumber) value () { }
-type ValueNumber int
-
-func (ValueColor) value () { }
-type ValueColor uint32
-
-func (ValueString) value () { }
-type ValueString string
-
-func (ValueKeyword) value () { }
-type ValueKeyword string
-
-func (ValueVariable) value () { }
-type ValueVariable string
-
 type parser struct {
 	parse.Parser
 	sheet Sheet
@@ -105,9 +68,9 @@ func (this *parser) parseVariable () (string, ValueList, error) {
 	if err != nil { return "", nil, err }
 	err = this.ExpectNext(Ident)
 	if err != nil { return "", nil, err }
+	name := this.Value()
 	err = this.ExpectNext(Equals)
 	if err != nil { return "", nil, err }
-	name := this.Value()
 	this.Next()
 	values, err := this.parseValueList()
 	if err != nil { return "", nil, err }
@@ -124,15 +87,18 @@ func (this *parser) parseRule () (Rule, error) {
 	selector, err := this.parseSelector()
 	if err != nil { return Rule { }, err }
 	rule.Selector = selector
-	err = this.Expect(LBracket)
+	err = this.Expect(LBrace)
 	if err != nil { return Rule { }, err }
 	
 	for {
+		this.Next()
+		if this.Is(RBrace) { break }
 		pos := this.Pos()
 		name, attr, err := this.parseAttr()
-		if err != nil { break }
-		_, exists := rule.Attrs[name]
-		if !exists {
+		if err != nil { return Rule { }, err }
+		err = this.Expect(Semicolon)
+		if err != nil { return Rule { }, err }
+		if _, exists := rule.Attrs[name]; exists {
 			return Rule { }, parse.Errorf (
 				pos,
 				"attribute %s already declared in this rule",
@@ -141,8 +107,6 @@ func (this *parser) parseRule () (Rule, error) {
 		rule.Attrs[name] = attr
 	}
 	
-	err = this.Expect(LBracket)
-	if err != nil { return Rule { }, err }
 	return rule, this.Next()
 }
 
@@ -167,7 +131,7 @@ func (this *parser) parseSelector () (Selector, error) {
 	}
 
 	// tags
-	err = this.ExpectNext(LBrace)
+	err = this.ExpectNext(LBracket)
 	if err == nil {
 		this.Next()
 		for {
@@ -175,12 +139,12 @@ func (this *parser) parseSelector () (Selector, error) {
 			if err != nil { return Selector { }, err }
 			if this.Is(RBrace) { break }
 			selector.Tags = append(selector.Tags, this.Value())
-			err = this.ExpectNext(Comma, RBrace)
+			err = this.ExpectNext(Comma, RBracket)
 			if err != nil { return Selector { }, err }
 		}
 	}
 	
-	return selector, this.Next()
+	return selector, nil
 }
 
 func (this *parser) parseAttr () (string, []ValueList, error) {
@@ -195,18 +159,19 @@ func (this *parser) parseAttr () (string, []ValueList, error) {
 	this.Next()
 	for {
 		err := this.ExpectDesc (
-			"value, comma, or semicolon",
-			Number, Color, String, Ident, Dollar, Comma, Semicolon)
+			"value, Comma, or Semicolon",
+			Number, Color, String, Ident, Dollar, Slash,
+			Comma, Semicolon)
 		if err != nil { return "", nil, err }
 		if this.Is(Semicolon) { break }
 		valueList, err := this.parseValueList()
 		if err != nil { return "", nil, err }
 		attr = append(attr, valueList)
-		err = this.ExpectNext(Comma, Semicolon)
+		err = this.Expect(Comma, Semicolon)
 		if err != nil { return "", nil, err }
 	}
 	
-	return name, attr, this.Next()
+	return name, attr, nil
 }
 
 func (this *parser) parseValueList () (ValueList, error) {
@@ -214,7 +179,7 @@ func (this *parser) parseValueList () (ValueList, error) {
 	for {
 		err := this.ExpectDesc (
 			"value",
-			Number, Color, String, Ident, Dollar)
+			Number, Color, String, Ident, Dollar, Slash)
 		if err != nil { break }
 		switch this.Kind() {
 		case Number:
@@ -237,9 +202,12 @@ func (this *parser) parseValueList () (ValueList, error) {
 			err := this.ExpectNext(Ident)
 			if err != nil { return nil, err }
 			list = append(list, ValueVariable(this.Value()))
+		case Slash:
+			list = append(list, ValueCut { })
 		}
+		this.Next()
 	}
-	return list, this.Next()
+	return list, nil
 }
 
 func parseColor (runes []rune) (uint32, bool) {

internal/style/tss/tss.go

@@ -1,15 +1,70 @@
 package tss
 
-import "io"
 import "os"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/tomo/event"
 
-func BuildStyle (sheet Sheet) (*tomo.Style, event.Cookie, error) {
-	// TODO
-	return nil, nil, nil
+type Sheet struct {
+	Variables map[string] ValueList
+	Rules     []Rule
+	flat      bool
 }
 
+type Rule struct {
+	Selector Selector
+	Attrs    map[string] []ValueList
+}
+
+type Selector struct {
+	Package string
+	Object  string
+	Tags    []string
+}
+
+type ValueList []Value
+
+type Value interface {
+	value ()
+}
+
+type ValueNumber int
+func (ValueNumber) value () { }
+
+type ValueColor uint32
+func (ValueColor) value () { }
+func (value ValueColor) RGBA () (r, g, b, a uint32) {
+	// extract components
+	bits := uint32(value)
+	r = (bits & 0xF000) >> 24
+	g = (bits & 0x0F00) >> 16
+	b = (bits & 0x00F0) >> 8
+	a = (bits & 0x000A)
+	// extend to 16 bits per channel
+	r = r << 8 | r
+	g = g << 8 | g
+	b = b << 8 | b
+	a = a << 8 | a
+	// alpha premultiply
+	r = (r * a) / 256
+	g = (g * a) / 256
+	b = (b * a) / 256
+	return
+}
+
+type ValueString string
+func (ValueString) value () { }
+
+type ValueKeyword string
+func (ValueKeyword) value () { }
+
+type ValueVariable string
+func (ValueVariable) value () { }
+
+type ValueCut struct { }
+func (ValueCut) value () { }
+
+// LoadFile loads the stylesheet from the specified file. This may return a
+// parse.Error, so use parse.Format to print it.
 func LoadFile (name string) (*tomo.Style, event.Cookie, error) {
 	// TODO check cache for gobbed sheet. if the cache is nonexistent or
 	// invalid, then open/load/cache.
@@ -17,5 +72,8 @@ func LoadFile (name string) (*tomo.Style, event.Cookie, error) {
 	file, err := os.Open(name)
 	if err != nil { return nil, nil, err }
 	defer file.Close()
-	return Load(file)
+
+	sheet, err := Parse(Lex(name, file))
+	if err != nil { return nil, nil, err }
+	return BuildStyle(sheet)
 }