Remove the FS thing and use normal paths

Eventually we can have nasin parse cli args and figure out what
files to open, instructing the application to open those files.
We will also be able to have nasin connect to dbus using the
application ID and open files in an already running instance of the
application.

application.go

@@ -2,6 +2,8 @@ package nasin
 
 import "log"
 import "image"
+import "strings"
+import "net/url"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/nasin/internal/registrar"
 
@@ -14,6 +16,20 @@ type Application interface {
 	Init () error
 }
 
+// ApplicationURLOpener is an application that can open a URL.
+type ApplicationURLOpener interface {
+	Application
+
+	// OpenURL opens a new window with the contents of the given URL. If the
+	// given URL is unsupported, it returns an error (for example, an image
+	// viewer is not expected to open a text file). If the URL scheme is
+	// empty, file:// is assumed.
+	//
+	// Applications should support the file:// scheme at the very least, and
+	// should also support others like http:// and https:// if possible.
+	OpenURL (*url.URL) error
+}
+
 // ApplicationDescription describes the name and type of an application.
 type ApplicationDescription struct {
 	// The name of the application.
@@ -76,6 +92,15 @@ type ApplicationRole string; const (
 	RoleChecklist         ApplicationRole = "Checklist"
 )
 
+// Icon returns the icon ID for this role.
+func (role ApplicationRole) Icon () tomo.Icon {
+	if role == "" {
+		return tomo.IconApplication
+	} else {
+		return tomo.Icon("Application" + strings.ReplaceAll(string(role), " ", ""))
+	}
+}
+
 // RunApplication is like tomo.Run, but runs an application. If something fails
 // to initialize, an error is written to the standard logger.
 func RunApplication (application Application) {
@@ -90,10 +115,37 @@ func RunApplication (application Application) {
 
 // NewApplicationWindow creates a window for an application. It will
 // automatically set window information to signal to the OS that the window is
-// owned by the application.
+// owned by the application. The window's icon will be automatically set by
+// looking for an icon with the name of the application's ID. If that is not
+// found, the default icon for the application's ApplicationRole will used.
 func NewApplicationWindow (application Application, bounds image.Rectangle) (tomo.MainWindow, error) {
 	window, err := tomo.NewWindow(bounds)
 	if err != nil { return nil, err }
-	window.SetTitle(application.Describe().String())
+	description := application.Describe()
+	window.SetTitle(description.Name)
+	setApplicationWindowIcon(window, description)
 	return window, nil
 }
+
+func setApplicationWindowIcon (window tomo.Window, description ApplicationDescription) {
+	allSizes := func (icon tomo.Icon) (sizes []image.Image) {
+		small  := icon.Texture(tomo.IconSizeSmall)
+		medium := icon.Texture(tomo.IconSizeMedium)
+		large  := icon.Texture(tomo.IconSizeLarge)
+		if small  != nil { sizes = append(sizes,  small) }
+		if medium != nil { sizes = append(sizes, medium) }
+		if large  != nil { sizes = append(sizes,  large) }
+		return sizes
+	}
+
+	if sizes := allSizes(tomo.Icon(description.ID)); len(sizes) > 0 {
+		println("direct icon worked", tomo.Icon(description.ID))
+		window.SetIcon(sizes...)
+		return
+	}
+	if sizes := allSizes(description.Role.Icon()); len(sizes) > 0 {
+		println("role icon worked", description.Role.Icon())
+		window.SetIcon(sizes...)
+		return
+	}
+}

examples/clock/main.go

@@ -68,7 +68,8 @@ func NewClockFace () *ClockFace {
 	box := &ClockFace {
 		CanvasBox: tomo.NewCanvasBox(),
 	}
-	tomo.Apply(box, tomo.R("nasin", "ClockFace", ""))
+	box.SetRole(tomo.R("nasin", "ClockFace", ""))
+	tomo.Apply(box)
 	box.SetDrawer(box)
 	return box
 }

examples/icons/main.go

@@ -7,6 +7,7 @@ import "git.tebibyte.media/tomo/nasin"
 import "git.tebibyte.media/tomo/objects"
 import "git.tebibyte.media/tomo/tomo/input"
 import "git.tebibyte.media/tomo/objects/layouts"
+import "git.tebibyte.media/tomo/nasin/internal/theme/icons/xdg"
 
 const scrollIcons = true
 
@@ -389,13 +390,15 @@ func (this *Application) iconPopup (icon tomo.Icon) error {
 		icon = "<UNKNOWN>"
 	}
 
-	sizesRow := objects.NewInnerContainer (
+	sizesRow := objects.NewSunkenContainer (
 		layouts.ContractHorizontal,
 		objects.NewIcon(icon, tomo.IconSizeSmall),
 		objects.NewIcon(icon, tomo.IconSizeMedium),
 		objects.NewIcon(icon, tomo.IconSizeLarge))
+	sizesRow.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
 
 	okButton := objects.NewButton("OK")
+	okButton.SetFocused(true)
 	okButton.OnClick(popup.Close)
 	okButton.SetIcon(tomo.IconDialogOkay)
 	controlRow := objects.NewInnerContainer (
@@ -404,8 +407,9 @@ func (this *Application) iconPopup (icon tomo.Icon) error {
 	controlRow.SetAlign(tomo.AlignEnd, tomo.AlignMiddle)
 	
 	popup.SetRoot(objects.NewOuterContainer (
-		layouts.NewGrid([]bool { true }, []bool { true, false }),
+		layouts.NewGrid([]bool { true }, []bool { false, false, true, false }),
 		objects.NewLabel("Icon ID: " + string(icon)),
+		objects.NewLabel("XDG Name: " + xdgIcons.XdgIconName(icon)),
 		sizesRow,
 		controlRow,
 	))

go.mod

@@ -3,9 +3,9 @@ module git.tebibyte.media/tomo/nasin
 go 1.20
 
 require (
-	git.tebibyte.media/tomo/objects v0.15.0
-	git.tebibyte.media/tomo/tomo v0.34.0
-	git.tebibyte.media/tomo/x v0.9.0
+	git.tebibyte.media/tomo/backend v0.2.0
+	git.tebibyte.media/tomo/objects v0.16.0
+	git.tebibyte.media/tomo/tomo v0.35.0
 	git.tebibyte.media/tomo/xdg v0.1.0
 	golang.org/x/image v0.11.0
 )
@@ -15,6 +15,6 @@ require (
 	git.tebibyte.media/tomo/xgbkb v1.0.1 // indirect
 	github.com/BurntSushi/freetype-go v0.0.0-20160129220410-b763ddbfe298 // indirect
 	github.com/BurntSushi/graphics-go v0.0.0-20160129215708-b43f31a4a966 // indirect
-	github.com/jezek/xgb v1.1.0 // indirect
-	github.com/jezek/xgbutil v0.0.0-20230603163917-04188eb39cf0 // indirect
+	github.com/jezek/xgb v1.1.1 // indirect
+	github.com/jezek/xgbutil v0.0.0-20231116234834-47f30c120111 // indirect
 )

go.sum

@@ -1,12 +1,12 @@
 git.tebibyte.media/sashakoshka/xgbkb v1.0.0/go.mod h1:pNcE6TRO93vHd6q42SdwLSTTj25L0Yzggz7yLe0JV6Q=
-git.tebibyte.media/tomo/objects v0.15.0 h1:xCrRqOwCz8jDJk/sWw0B1HyrRCJafAuaPWN9nZj8V1U=
-git.tebibyte.media/tomo/objects v0.15.0/go.mod h1:++pM0y/xuzhgmu1RpHTWQlqrmyHLfPEF9ahyrH8Tqvk=
-git.tebibyte.media/tomo/tomo v0.34.0 h1:r5yJPks9rtzdDI2RyAUdqa1qb6BebG0QFe2cTmcFi+0=
-git.tebibyte.media/tomo/tomo v0.34.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
+git.tebibyte.media/tomo/backend v0.2.0 h1:9vMQxIRnfzyMVGP3wBTz9qoWzSwLcCYzKIogikk05a0=
+git.tebibyte.media/tomo/backend v0.2.0/go.mod h1:os77Uo/YkQ9EmNZK8U1ljsEUkTK36P27dKmp5p8TMeE=
+git.tebibyte.media/tomo/objects v0.16.0 h1:Q/w8yHZepj0ESYtPGvWtXxZXkTU+k03rfPxvoxXU5AQ=
+git.tebibyte.media/tomo/objects v0.16.0/go.mod h1:jRRpraLGpBzwiOv6kl1Ram229BpJZxJaS4eqIhze194=
+git.tebibyte.media/tomo/tomo v0.35.0 h1:1XvcUcWg1rBZXov3KfuX6VfiuBQ2mcJHIslHMLn07no=
+git.tebibyte.media/tomo/tomo v0.35.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
 git.tebibyte.media/tomo/typeset v0.7.1 h1:aZrsHwCG5ZB4f5CruRFsxLv5ezJUCFUFsQJJso2sXQ8=
 git.tebibyte.media/tomo/typeset v0.7.1/go.mod h1:PwDpSdBF3l/EzoIsa2ME7QffVVajnTHZN6l3MHEGe1g=
-git.tebibyte.media/tomo/x v0.9.0 h1:wMcbK0MOE7ea7wcU2Mgrr86ZprVGLRY2PgOG0vDJR6Y=
-git.tebibyte.media/tomo/x v0.9.0/go.mod h1:OO4PYXhzrh4ZAY12d7bg+l/P4MbkFPu6f+YVXNDRhog=
 git.tebibyte.media/tomo/xdg v0.1.0 h1:6G2WYPPiM2IXleCpKKHuJA34BxumwNWuLsUoX3yu5zA=
 git.tebibyte.media/tomo/xdg v0.1.0/go.mod h1:tuaRwRkyYW7mqlxA7P2+V+e10KzcamNoUzcOgaIYKAY=
 git.tebibyte.media/tomo/xgbkb v1.0.1 h1:b3HDUopjdQp1MZrb5Vpil4bOtk3NnNXtfQW27Blw2kE=
@@ -15,10 +15,12 @@ github.com/BurntSushi/freetype-go v0.0.0-20160129220410-b763ddbfe298 h1:1qlsVAQJ
 github.com/BurntSushi/freetype-go v0.0.0-20160129220410-b763ddbfe298/go.mod h1:D+QujdIlUNfa0igpNMk6UIvlb6C252URs4yupRUV4lQ=
 github.com/BurntSushi/graphics-go v0.0.0-20160129215708-b43f31a4a966 h1:lTG4HQym5oPKjL7nGs+csTgiDna685ZXjxijkne828g=
 github.com/BurntSushi/graphics-go v0.0.0-20160129215708-b43f31a4a966/go.mod h1:Mid70uvE93zn9wgF92A/r5ixgnvX8Lh68fxp9KQBaI0=
-github.com/jezek/xgb v1.1.0 h1:wnpxJzP1+rkbGclEkmwpVFQWpuE2PUGNUzP8SbfFobk=
 github.com/jezek/xgb v1.1.0/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
-github.com/jezek/xgbutil v0.0.0-20230603163917-04188eb39cf0 h1:Pf/0BAbppEOq4azPH6fnvUX2dycAwZdGkdxFn25j44c=
+github.com/jezek/xgb v1.1.1 h1:bE/r8ZZtSv7l9gk6nU0mYx51aXrvnyb44892TwSaqS4=
+github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
 github.com/jezek/xgbutil v0.0.0-20230603163917-04188eb39cf0/go.mod h1:AHecLyFNy6AN9f/+0AH/h1MI7X1+JL5bmCz4XlVZk7Y=
+github.com/jezek/xgbutil v0.0.0-20231116234834-47f30c120111 h1:cX/mTy4LgFtWqr5dCadtdJ4zdh/KtPco5yFLsliaFyU=
+github.com/jezek/xgbutil v0.0.0-20231116234834-47f30c120111/go.mod h1:AHecLyFNy6AN9f/+0AH/h1MI7X1+JL5bmCz4XlVZk7Y=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=

internal/registrar/registrar_unix.go

@@ -1,12 +1,38 @@
 //go:build unix && (!darwin)
 package registrar
 
-import "git.tebibyte.media/tomo/x"
+import "os"
+import "log"
+import "git.tebibyte.media/tomo/backend/x"
 import "git.tebibyte.media/tomo/tomo"
-import "git.tebibyte.media/tomo/nasin/internal/theme/default"
+import dataTheme "git.tebibyte.media/tomo/nasin/internal/theme"
+import "git.tebibyte.media/tomo/nasin/internal/theme/icons/xdg"
+import "git.tebibyte.media/tomo/nasin/internal/theme/icons/fallback"
+import "git.tebibyte.media/tomo/nasin/internal/theme/style/fallback"
+import "git.tebibyte.media/tomo/nasin/internal/theme/style/aluminum"
 
 func Init () error {
-	tomo.SetTheme(defaultTheme.Theme())
-	tomo.Register(1, x.NewBackend)
+	var theme *dataTheme.Theme
+	// TODO eventually get rid of this when we make a file format for
+	// storing visual styles
+	if os.Getenv("TOMO_USE_ALUMINUM_STYLE") != "" {
+		theme = aluminumStyle.New()
+	} else {
+		theme = fallbackStyle.New()
+	}
+	theme.IconTheme = fallbackIcons.New()
+	
+	iconThemeName := os.Getenv("TOMO_XDG_ICON_THEME")
+	if iconThemeName != "" {
+		iconTheme, err := xdgIcons.FindThemeWarn(iconThemeName, theme.IconTheme)
+		if err == nil {
+			theme.IconTheme = iconTheme
+		} else {
+			log.Printf("nasin: could not load icon theme '%s': %v", iconThemeName, err)
+		}
+	}
+	
+	tomo.SetTheme(theme)
+	tomo.Register(1, x.New)
 	return nil
 }

internal/theme/icons/fallback/icon.go

@@ -1,4 +1,4 @@
-package defaultTheme
+package fallbackIcons
 
 import "bytes"
 import "image"
@@ -7,6 +7,7 @@ import _ "image/png"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/tomo/data"
 import "git.tebibyte.media/tomo/tomo/canvas"
+import dataTheme "git.tebibyte.media/tomo/nasin/internal/theme"
 
 //go:embed assets/icons-small.png
 var atlasSmallBytes []byte
@@ -416,6 +417,11 @@ type iconTheme struct {
 	texturesLarge map[tomo.Icon] canvas.Texture
 }
 
+// New creates a new fallback icon theme.
+func New () dataTheme.IconTheme {
+	return new(iconTheme)
+}
+
 func (this *iconTheme) ensure () {
 	if this.texturesSmall != nil { return }
 	this.texturesSmall = generateSource(atlasSmallBytes, 16)
@@ -436,7 +442,7 @@ func (this *iconTheme) Icon (icon tomo.Icon, size tomo.IconSize) canvas.Texture
 	if texture, ok := source[icon]; ok {
 		return texture
 	}
-	return source[tomo.IconUnknown]
+	return nil
 }
 
 func (this *iconTheme) MimeIcon (mime data.Mime, size tomo.IconSize) canvas.Texture {

internal/theme/icons/xdg/icon.go

@@ -0,0 +1,183 @@
+package xdgIcons
+
+import "os"
+import "fmt"
+import "log"
+import "image"
+import "regexp"
+import "strings"
+import _ "image/png"
+import "git.tebibyte.media/tomo/tomo"
+import xdgIconTheme "git.tebibyte.media/tomo/xdg/icon-theme"
+import "git.tebibyte.media/tomo/tomo/data"
+import "git.tebibyte.media/tomo/tomo/canvas"
+import "git.tebibyte.media/tomo/nasin/internal/theme"
+
+type iconTheme struct {
+	xdg xdgIconTheme.Theme
+	fallback       theme.IconTheme
+	texturesSmall  map[tomo.Icon] canvas.Texture
+	texturesMedium map[tomo.Icon] canvas.Texture
+	texturesLarge  map[tomo.Icon] canvas.Texture
+}
+
+func FindThemeWarn (name string, fallback theme.IconTheme, path ...string) (theme.IconTheme, error) {
+	this := &iconTheme {
+		fallback:       fallback,
+		texturesLarge:  make(map[tomo.Icon] canvas.Texture),
+		texturesMedium: make(map[tomo.Icon] canvas.Texture),
+		texturesSmall:  make(map[tomo.Icon] canvas.Texture),
+	}
+	
+	xdg, err := xdgIconTheme.FindThemeWarn(name, path...)
+	if err != nil { return nil, err }
+	this.xdg = xdg
+	
+	return this, nil
+}
+
+func (this *iconTheme) selectSource (size tomo.IconSize) map[tomo.Icon] canvas.Texture {
+	switch size {
+	case tomo.IconSizeMedium: return this.texturesMedium
+	case tomo.IconSizeLarge:  return this.texturesLarge
+	default:                  return this.texturesSmall
+	}
+}
+
+func (this *iconTheme) xdgIcon (name string, size tomo.IconSize) (canvas.Texture, bool) {
+	// TODO use scaling factor instead of 1
+	// find icon file
+	icon, err := this.xdg.FindIcon(name, iconSizePixels(size), 1, xdgIconTheme.PNG)
+	if err != nil { return nil, false }
+
+	// open icon file
+	iconFile, err := os.Open(icon.Path)
+	if err != nil {
+		// this failing indicates a broken icon theme
+		log.Printf("nasin: icon file '%s' is inaccessible: %v\n", icon.Path, err)
+		return nil, false
+	}
+
+	iconImage, _, err := image.Decode(iconFile)
+	if err != nil {
+		// this failing indicates a broken icon theme
+		log.Printf("nasin: icon file '%s' is broken: %v\n", icon.Path, err)
+		return nil, false
+	}
+
+	return tomo.NewTexture(iconImage), true
+}
+
+func (this *iconTheme) Icon (icon tomo.Icon, size tomo.IconSize) canvas.Texture {
+	source := this.selectSource(size)
+	texture, ok := source[icon]
+	if !ok {
+		texture = this.icon(icon, size)
+		source[icon] = texture
+	}
+
+	if texture == nil {
+		return this.fallback.Icon(icon, size)
+	} else {
+		return texture
+	}
+}
+
+func (this *iconTheme) MimeIcon (mime data.Mime, size tomo.IconSize) canvas.Texture {
+	icon := tomo.Icon(mime.String())
+	source := this.selectSource(size)
+	texture, ok := source[icon]
+	if !ok {
+		texture = this.mimeIcon(mime, size)
+		source[icon] = texture
+	}
+
+	if texture == nil {
+		return this.fallback.MimeIcon(mime, size)
+	} else {
+		return texture
+	}
+}
+
+func (this *iconTheme) icon (icon tomo.Icon, size tomo.IconSize) canvas.Texture {
+	if texture, ok := this.xdgIcon(XdgIconName(icon), size); ok {
+		return texture
+	}
+	if texture, ok := this.xdgIcon(XdgIconName(generalizeIcon(icon)), size); ok {
+		return texture
+	}
+	return nil
+}
+
+func (this *iconTheme) mimeIcon (mime data.Mime, size tomo.IconSize) canvas.Texture {
+	if texture, ok := this.xdgIcon(xdgFormatMime(mime), size); ok {
+		return texture
+	}
+	if texture, ok := this.xdgIcon(xdgFormatMime(generalizeMimeType(mime)), size); ok {
+		return texture
+	}
+	if texture, ok := this.xdgIcon(xdgFormatMime(data.M("text", "x-generic")), size); ok {
+		return texture
+	}
+	return nil
+}
+
+var kebabMatchFirstCap = regexp.MustCompile("(.)([A-Z][a-z]+)")
+var kebabMatchAllCaps  = regexp.MustCompile("([a-z0-9])([A-Z])")
+
+// XdgIconName returns the best XDG name for the given icon.
+func XdgIconName (icon tomo.Icon) string {
+	if name, ok := xdgIconNames[icon]; ok {
+		return name
+	}
+
+	name := kebabMatchFirstCap.ReplaceAllString(string(icon), "${1}-${2}")
+	name  = kebabMatchAllCaps.ReplaceAllString(string(name), "${1}-${2}")
+	return strings.ToLower(name)
+}
+
+func generalizeIcon (icon tomo.Icon) tomo.Icon {
+	name := string(icon)
+	switch {
+	case strings.HasPrefix(name, "Application"): return tomo.IconApplication
+	case strings.HasPrefix(name, "Preferences"): return tomo.IconPreferences
+	case strings.HasPrefix(name, "Device"):      return tomo.IconDevice
+	case strings.HasPrefix(name, "Hardware"):    return tomo.IconHardware
+	case strings.HasPrefix(name, "Storage"):     return tomo.IconStorageHardDisk
+	case strings.HasPrefix(name, "Input"):       return tomo.IconInputMouse
+	case strings.HasPrefix(name, "Network"):     return tomo.IconNetworkWired
+	case strings.HasPrefix(name, "Place"):       return tomo.IconPlaceDirectory
+	case strings.HasPrefix(name, "Directory"):   return tomo.IconPlaceDirectory
+	case strings.HasPrefix(name, "Trash"):       return tomo.IconPlaceTrash
+	case strings.HasPrefix(name, "Help"):        return tomo.IconHelpContents
+	}
+
+	switch icon {
+	case tomo.IconCellularSignal0: return tomo.IconWirelessSignal0
+	case tomo.IconCellularSignal1: return tomo.IconWirelessSignal1
+	case tomo.IconCellularSignal2: return tomo.IconWirelessSignal2
+	case tomo.IconCellularSignal3: return tomo.IconWirelessSignal3
+	}
+
+	return icon
+}
+
+func xdgFormatMime (mime data.Mime) string {
+	return fmt.Sprintf("%s-%s", mime.Type, mime.Subtype)
+}
+
+func generalizeMimeType (mime data.Mime) data.Mime {
+	// FIXME make this more accurate
+	// https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
+	mime.Subtype = "x-generic"
+	return mime
+}
+
+func iconSizePixels (size tomo.IconSize) int {
+	// TODO: once Tomo has scaling support, take that into account here
+	switch size {
+	case tomo.IconSizeMedium: return 24
+	case tomo.IconSizeLarge:  return 48
+	default:                  return 16
+	}
+}

internal/theme/icons/xdg/xdgiconname.go

@@ -0,0 +1,136 @@
+package xdgIcons
+
+import "git.tebibyte.media/tomo/tomo"
+
+// icons that can't be directly translated with regex
+var xdgIconNames = map[tomo.Icon] string {
+	tomo.IconUnknown:                      "image-missing",
+	tomo.IconFileNew:                      "document-new",
+	tomo.IconDirectoryNew:                 "folder-new",
+	tomo.IconFileOpen:                     "document-open",
+	tomo.IconFileOpenRecent:               "document-open-recent",
+	tomo.IconFilePageSetup:                "document-page-setup",
+	tomo.IconFilePrint:                    "document-print",
+	tomo.IconFilePrintPreview:             "document-print-preview",
+	tomo.IconFilePermissions:              "document-permissions",        // non-standard
+	tomo.IconFileProperties:               "document-properties",
+	tomo.IconFileRename:                   "document-rename",             // non-standard
+	tomo.IconFileRevert:                   "document-revert",
+	tomo.IconFileSave:                     "document-save",
+	tomo.IconFileSaveAs:                   "document-save-as",
+	tomo.IconFileSend:                     "document-send",
+	tomo.IconFormatAlignCenter:            "format-justify-center",
+	tomo.IconFormatAlignEven:              "format-justify-fill",
+	tomo.IconFormatAlignLeft:              "format-justify-left",
+	tomo.IconFormatAlignRight:             "format-justify-right",
+	tomo.IconMailReceive:                  "mail-send-receive",
+	tomo.IconValueIncrement:               "list-add",
+	tomo.IconValueDecrement:               "list-remove",
+	tomo.IconValueReset:                   "value-reset",                 // non-standard
+	tomo.IconApplication:                  "system-run",
+	tomo.IconApplicationWebBrowser:        "web-browser",
+	tomo.IconApplicationMesssanger:        "internet-messanger",          // non-standard
+	tomo.IconApplicationPhone:             "accessories-phone",           // non-standard
+	tomo.IconApplicationMail:              "internet-mail-client",        // non-standard
+	tomo.IconApplicationTerminalEmulator:  "utilities-terminal",
+	tomo.IconApplicationFileBrowser:       "system-file-manager",
+	tomo.IconApplicationTextEditor:        "accessories-text-editor",
+	tomo.IconApplicationDocumentViewer:    "office-document-viewer",      // non-standard
+	tomo.IconApplicationWordProcessor:     "office-word-processor",       // non-standard
+	tomo.IconApplicationSpreadsheet:       "office-spreadsheet",          // non-standard
+	tomo.IconApplicationSlideshow:         "office-slideshow",            // non-standard
+	tomo.IconApplicationCalculator:        "accessories-calculator",
+	tomo.IconApplicationPreferences:       "preferences-system",
+	tomo.IconApplicationProcessManager:    "utilities-system-monitor",
+	tomo.IconApplicationSystemInformation: "distributor-logo",            // non-standard
+	tomo.IconApplicationManual:            "help-browser",
+	tomo.IconApplicationCamera:            "accessories-camera",          // non-standard
+	tomo.IconApplicationImageViewer:       "graphics-image-viewer",       // non-standard
+	tomo.IconApplicationMediaPlayer:       "audio-video-media-player",    // non-standard
+	tomo.IconApplicationImageEditor:       "graphics-image-editor",       // non-standard
+	tomo.IconApplicationAudioEditor:       "audio-audio-editor",          // non-standard
+	tomo.IconApplicationVideoEditor:       "video-video-editor",          // non-standard
+	tomo.IconApplicationClock:             "accessories-clock",           // non-standard
+	tomo.IconApplicationCalendar:          "accessories-calendar",        // non-standard
+	tomo.IconApplicationChecklist:         "accessories-checklist",       // non-standard
+	tomo.IconApplications:                 "applications-other",
+	tomo.IconPreferences:                  "preferences-other",
+	tomo.IconPreferencesNetwork:           "preferences-system-network",
+	tomo.IconDevice:                       "device",                      // non-standard
+	tomo.IconDeviceCamera:                 "camera-photo",
+	tomo.IconDeviceWebCamera:              "camera-web",
+	tomo.IconDeviceComputer:               "computer",
+	tomo.IconDevicePda:                    "pda",
+	tomo.IconDevicePhone:                  "phone",
+	tomo.IconDevicePrinter:                "printer",
+	tomo.IconDeviceScanner:                "scanner",
+	tomo.IconDeviceMultimediaPlayer:       "multimedia-player",
+	tomo.IconDeviceVideoDisplay:           "video-display",
+	tomo.IconDeviceAudioInput:             "audio-input-microphone",
+	tomo.IconDeviceAudioOutput:            "audio-speakers",
+	tomo.IconHardware:                     "card",                        // non-standard
+	tomo.IconHardwareCPU:                  "cpu",
+	tomo.IconHardwareGPU:                  "video-card",
+	tomo.IconHardwareRAM:                  "ram",
+	tomo.IconHardwareSoundCard:            "audio-card",
+	tomo.IconHardwareNetworkAdapter:       "network-card",
+	tomo.IconPowerBattery:                 "battery",
+	tomo.IconStorageHardDisk:              "drive-harddisk",
+	tomo.IconStorageFloppyDisk:            "media-floppy",
+	tomo.IconStorageSolidState:            "drive-solid",
+	tomo.IconStorageOptical:               "media-optical",
+	tomo.IconStorageFlashStick:            "media-removable",
+	tomo.IconStorageFlashCard:             "media-flash",
+	tomo.IconStorageMagneticTape:          "media-tape",
+	tomo.IconEmblemReadOnly:               "emblem-readonly",
+	tomo.IconPlaceDirectory:               "folder",
+	tomo.IconPlaceRemote:                  "folder-remote",
+	tomo.IconPlaceHome:                    "user-home",
+	tomo.IconPlaceDownloads:               "folder-downloads",            // common
+	tomo.IconPlaceDesktop:                 "user-desktop",
+	tomo.IconPlacePhotos:                  "folder-pictures",             // common
+	tomo.IconPlaceBooks:                   "folder-books",                // non-standard
+	tomo.IconPlaceBookmarks:               "user-bookmarks",
+	tomo.IconPlaceTrash:                   "user-trash",
+	tomo.IconPlaceDocuments:               "folder-documents",            // common
+	tomo.IconPlaceRepositories:            "folder-repositories",         // non-standard
+	tomo.IconPlaceMusic:                   "folder-music",                // common
+	tomo.IconPlaceArchives:                "folder-archives",             // non-standard
+	tomo.IconPlaceFonts:                   "folder-fonts",                // non-standard
+	tomo.IconPlaceBinaries:                "folder-executables",          // non-standard
+	tomo.IconPlaceVideos:                  "folder-videos",               // common
+	tomo.IconPlace3DObjects:               "folder-3d-objects",           // non-standard
+	tomo.IconPlaceHistory:                 "folder-history",              // non-standard
+	tomo.IconPlacePreferences:             "preferences-other",
+	tomo.IconDirectoryDragAccept:          "folder-drag-accept",
+	tomo.IconDirectoryFull:                "folder-full",
+	tomo.IconDirectoryOpen:                "folder-open",
+	tomo.IconDirectoryVisiting:            "folder-visiting",
+	tomo.IconTrashFull:                    "user-trash-full",
+	tomo.IconResourceLoading:              "image-loading",
+	tomo.IconResourceMissing:              "image-missing",
+	tomo.IconCellularSignal0:              "nm-signal-00",                // common
+	tomo.IconCellularSignal1:              "nm-signal-25",                // common
+	tomo.IconCellularSignal2:              "nm-signal-75",                // common
+	tomo.IconCellularSignal3:              "nm-signal-100",               // common
+	tomo.IconWirelessSignal0:              "wifi-signal-00",              // common
+	tomo.IconWirelessSignal1:              "wifi-signal-25",              // common
+	tomo.IconWirelessSignal2:              "wifi-signal-75",              // common
+	tomo.IconWirelessSignal3:              "wifi-signal-100",             // common
+	tomo.IconPrintError:                   "printer-error",
+	tomo.IconPrintPrinting:                "printer-printing",
+	tomo.IconBattery0:                     "battery-caution",
+	tomo.IconBattery1:                     "battery-low",
+	tomo.IconBattery2:                     "battery-good",                // common
+	tomo.IconBattery3:                     "battery-full",                // common
+	tomo.IconBrightness0:                  "brightness-dim",              // non-standard
+	tomo.IconBrightness1:                  "brightness-medium",           // non-standard
+	tomo.IconBrightness2:                  "brightness-bright",           // non-standard
+	tomo.IconBrightness3:                  "brightness-full",             // non-standard
+	tomo.IconVolume0:                      "audio-volume-muted",
+	tomo.IconVolume1:                      "audio-volume-low",
+	tomo.IconVolume2:                      "audio-volume-medium",
+	tomo.IconVolume3:                      "audio-volume-high",
+	tomo.IconPlaylistRepeat:               "media-playlist-repeat",
+	tomo.IconPlaylistShuffle:              "media-playlist-shuffle",
+}

internal/theme/style/aluminum/default.go

@@ -0,0 +1,19 @@
+package aluminumStyle
+
+import "image/color"
+import "git.tebibyte.media/tomo/tomo"
+import dataTheme "git.tebibyte.media/tomo/nasin/internal/theme"
+
+// New returns Aluminum, a futuristic, bluish-white style.
+func New () *dataTheme.Theme {
+	return &dataTheme.Theme {
+		Colors: map[tomo.Color] color.Color {
+			tomo.ColorBackground: colorBackground,
+			tomo.ColorForeground: colorForeground,
+			tomo.ColorRaised:     colorRaised,
+			tomo.ColorSunken:     colorSunken,
+			tomo.ColorAccent:     colorFocus,
+		},
+		Rules: rules,
+	}
+}

internal/theme/style/aluminum/style.go

@@ -0,0 +1,311 @@
+package aluminumStyle
+
+import "image/color"
+import "git.tebibyte.media/tomo/tomo"
+import "golang.org/x/image/font/basicfont"
+import dataTheme "git.tebibyte.media/tomo/nasin/internal/theme"
+
+func hex (color uint32) (c color.RGBA) {
+	c.A = uint8(color)
+	c.B = uint8(color >>  8)
+	c.G = uint8(color >> 16)
+	c.R = uint8(color >> 24)
+	return
+}
+
+func border (top, right, bottom, left uint32, width ...int) tomo.Border {
+	return tomo.Border {
+		Width: tomo.I(width...),
+		Color: [4]color.Color {
+			hex(top),    hex(right),
+			hex(bottom), hex(left),
+		},
+	}
+}
+
+var colorDot           = hex(0x7391c080)
+var colorFocus         = hex(0x5f8bc4FF)
+var colorHighlight     = hex(0x5f8bc4FF)
+var colorBackground    = hex(0xd4d4d4FF)
+var colorForeground    = color.Black
+
+var colorOutline       = color.Black
+var colorGutter        = hex(0xbfc6d1FF)
+var colorGutterHovered = hex(0xc5cbd6FF)
+var colorRaised        = hex(0xe9eaeaFF)
+var colorRaisedPressed = hex(0xccd4ddFF)
+var colorRaisedFocused = hex(0xcfd6ddFF)
+var colorRaisedHovered = hex(0xf1f3f5FF)
+var colorSunken        = hex(0xe9eaeaFF)
+var colorSunkenFocused = hex(0xe0e6eeFF)
+var colorSunkenPressed = hex(0xe0e6eeFF)
+
+var outline = tomo.Border {
+	Width: tomo.I(1),
+	Color: [4]color.Color {
+		colorOutline,
+		colorOutline,
+		colorOutline,
+		colorOutline,
+	},
+}
+
+var borderEngraved      = border(0xc3c3c5FF, 0xe3e3e3FF, 0xe9e9e9ff, 0xc2c2c2ff, 1)
+var borderGap           = border(0x697c7cFF, 0x566767FF, 0x566767ff, 0x697c7cff, 1)
+var borderLifted        = border(0xf9fafcFF, 0xc2c8d3FF, 0xa4afc0ff, 0xf5f6f8ff, 1)
+var borderLiftedFocused = border(0xf0f4f9FF, 0xb1bacaFF, 0x9aa6b7ff, 0xe4e9eeff, 1)
+var borderFocused       = border(0x5f8bc4FF, 0x5f8bc4FF, 0x5f8bc4ff, 0x5f8bc4ff, 1)
+var borderInnerShadow   = border(0xa4afc0FF, 0xa4afc0FF, 0xa4afc0ff, 0xa4afc0ff, 1, 0, 0, 1)
+var borderOuterShadow   = border(0xa4afc0FF, 0xa4afc0FF, 0xa4afc0ff, 0xa4afc0ff, 0, 1, 1, 0)
+
+var rules = []dataTheme.Rule {
+	// *.*[*]
+	dataTheme.Rule {
+		Default: dataTheme.AS (
+			dataTheme.AttrFace      { Face:  basicfont.Face7x13    },
+			dataTheme.AttrTextColor { Color: tomo.ColorForeground  },
+			dataTheme.AttrDotColor  { Color: colorDot              },
+			dataTheme.AttrGap       { X: 8, Y: 8                   },
+		),
+	},
+
+	// *.Button[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "Button", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderLifted,
+			},
+			dataTheme.AttrPadding(tomo.I(4, 8)),
+			dataTheme.AttrColor { Color: tomo.ColorRaised },
+		),
+		Pressed: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrPadding(tomo.I(5, 8, 4, 9)),
+			dataTheme.AttrColor { Color: colorRaisedPressed },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderLiftedFocused,
+			},
+			dataTheme.AttrPadding(tomo.I(4, 8)),
+			dataTheme.AttrColor { Color: colorRaisedFocused },
+		),
+		Hovered: dataTheme.AS (
+			dataTheme.AttrColor { Color: colorRaisedHovered },
+		),
+	},
+
+	// *.TextInput[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "TextInput", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorSunken },
+			dataTheme.AttrPadding(tomo.I(5, 4, 4, 5)),
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderFocused,
+				borderInnerShadow,
+			},
+		),
+	},
+
+	// *.TextView[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "TextView", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorSunken },
+			dataTheme.AttrPadding(tomo.I(8)),
+		),
+	},
+	
+	// *.NumberInput[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "NumberInput", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrGap { },
+		),
+	},
+
+	// *.Container[sunken]
+	dataTheme.Rule {
+		Role: tomo.R("", "Container", "sunken"),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorSunken },
+			dataTheme.AttrPadding(tomo.I(8)),
+		),
+	},
+
+	// *.Container[outer]
+	dataTheme.Rule {
+		Role: tomo.R("", "Container", "outer"),
+		Default: dataTheme.AS (
+			dataTheme.AttrColor { Color: tomo.ColorBackground },
+			dataTheme.AttrPadding(tomo.I(8)),
+		),
+	},
+
+	// *.Container[menu]
+	dataTheme.Rule {
+		Role: tomo.R("", "Container", "menu"),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderGap,
+				borderLifted,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorBackground },
+			dataTheme.AttrGap { },
+		),
+	},
+
+	// *.Heading[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "Heading", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrAlign { X: tomo.AlignMiddle, Y: tomo.AlignMiddle },
+		),
+	},
+
+	// *.Separator[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "Separator", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+			},
+		),
+	},
+
+	// *.Slider[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "Slider", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrColor { Color: colorGutter },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderFocused,
+				borderInnerShadow,
+			},
+		),
+		Hovered: dataTheme.AS (
+			dataTheme.AttrColor { Color: colorGutterHovered },
+		),
+	},
+	
+	// *.Slider[horizontal]
+	dataTheme.Rule {
+		Role: tomo.R("", "Slider", "horizontal"),
+		Default: dataTheme.AS(dataTheme.AttrMinimumSize { X: 48 }),
+	},
+	
+	// *.Slider[vertical]
+	dataTheme.Rule {
+		Role: tomo.R("", "Slider", "vertical"),
+		Default: dataTheme.AS(dataTheme.AttrMinimumSize { Y: 48 }),
+	},
+
+	// *.SliderHandle[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "SliderHandle", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderOuterShadow,
+				borderGap,
+				borderLifted,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorRaised },
+			dataTheme.AttrMinimumSize { X: 12, Y: 12, },
+		),
+	},
+
+	// *.Checkbox[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "Checkbox", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderGap,
+				borderInnerShadow,
+			},
+			dataTheme.AttrColor { Color: tomo.ColorSunken },
+			dataTheme.AttrPadding(tomo.I(0, 1, 1, 0)),
+			dataTheme.AttrMinimumSize { X: 19, Y: 19 },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrBorder {
+				borderEngraved,
+				borderFocused,
+				borderInnerShadow,
+			},
+			dataTheme.AttrPadding(tomo.I(0)),
+			dataTheme.AttrColor { Color: colorSunkenFocused },
+		),
+	},
+
+	// *.LabelCheckbox[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "LabelCheckbox", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrGap { X: 8, Y: 8 },
+		),
+	},
+
+	// *.MenuItem[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "MenuItem", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrPadding(tomo.I(4)),
+			dataTheme.AttrGap { X: 4, Y: 4 },
+			dataTheme.AttrColor { Color: color.Transparent },
+		),
+		Hovered: dataTheme.AS (
+			dataTheme.AttrColor { Color: colorDot },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrColor { Color: colorDot },
+		),
+	},
+
+	// *.File[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "File", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrColor { Color: color.Transparent },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrColor { Color: colorDot },
+		),
+	},
+}

internal/theme/style/fallback/style.go

@@ -1,4 +1,4 @@
-package defaultTheme
+package fallbackStyle
 
 import "image/color"
 import "git.tebibyte.media/tomo/tomo"
@@ -154,6 +154,22 @@ var rules = []dataTheme.Rule {
 		),
 	},
 
+	// *.Container[menu]
+	dataTheme.Rule {
+		Role: tomo.R("", "Container", "menu"),
+		Default: dataTheme.AS (
+			dataTheme.AttrBorder {
+				outline,
+				tomo.Border {
+					Width: tomo.I(1),
+					Color: borderColorLifted,
+				},
+			},
+			dataTheme.AttrColor { Color: tomo.ColorBackground },
+			dataTheme.AttrGap { },
+		),
+	},
+
 	// *.Heading[*]
 	dataTheme.Rule {
 		Role: tomo.R("", "Heading", ""),
@@ -263,4 +279,31 @@ var rules = []dataTheme.Rule {
 			dataTheme.AttrGap { X: 8, Y: 8 },
 		),
 	},
+
+	// *.MenuItem[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "MenuItem", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrPadding(tomo.I(4)),
+			dataTheme.AttrGap { X: 4, Y: 4 },
+			dataTheme.AttrColor { Color: color.Transparent },
+		),
+		Hovered: dataTheme.AS (
+			dataTheme.AttrColor { Color: tomo.ColorAccent },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrColor { Color: tomo.ColorAccent },
+		),
+	},
+
+	// *.File[*]
+	dataTheme.Rule {
+		Role: tomo.R("", "File", ""),
+		Default: dataTheme.AS (
+			dataTheme.AttrColor { Color: color.Transparent },
+		),
+		Focused: dataTheme.AS (
+			dataTheme.AttrColor { Color: tomo.ColorAccent },
+		),
+	},
 }

internal/theme/style/fallback/wintergreen.go

@@ -1,12 +1,12 @@
-package defaultTheme
+package fallbackStyle
 
 import "image/color"
 import "git.tebibyte.media/tomo/tomo"
 import dataTheme "git.tebibyte.media/tomo/nasin/internal/theme"
 
-// Theme returns Wintergreen, the default Tomo tomo. It is neutral-gray with
-// green and turquoise accents.
-func Theme () tomo.Theme {
+// New returns Wintergreen, the default Tomo tomo. It is neutral-gray with green
+// and turquoise accents.
+func New () *dataTheme.Theme {
 	return &dataTheme.Theme {
 		Colors: map[tomo.Color] color.Color {
 			tomo.ColorBackground: colorBackground,
@@ -16,6 +16,5 @@ func Theme () tomo.Theme {
 			tomo.ColorAccent:     colorFocus,
 		},
 		Rules: rules,
-		IconTheme: &iconTheme { },
 	}
 }

internal/theme/theme.go

@@ -186,10 +186,11 @@ func (this *Theme) setsFor (role tomo.Role) (defaul, hovered, pressed, focused A
 	return defaul, hovered, pressed, focused
 }
 
-func (this *Theme) Apply (object tomo.Object, role tomo.Role) event.Cookie {
+func (this *Theme) Apply (object tomo.Object) event.Cookie {
 	pressed := false
 	hovered := false
-	box := object.GetBox()
+	box  := object.GetBox()
+	role := box.Role()
 
 	defaultSet, hoveredSet, pressedSet, focusedSet := this.setsFor(role)
 

path.go

@@ -1,190 +1,32 @@
 package nasin
 
-import "io"
 import "os"
-import "io/fs"
-import "strings"
 import "path/filepath"
 
-// FS is Tomo's implementation of fs.FS. It provides access to a specific part
-// of the filesystem.
-type FS struct {
-	path string
+// ApplicationUserDataDir returns the directory path where an application can
+// store its user data files. If the directory does not exist, it will be
+// created.
+func ApplicationUserDataDir (app ApplicationDescription) (string, error) {
+	return userMkdirAll(app.ID, userDataDir)
 }
 
-// FileWriter is a writable version of fs.File.
-type FileWriter interface {
-	fs.File
-	io.Writer
+// ApplicationUserConfigDir returns the directory path where an application can
+// store its user configuration files.
+func ApplicationUserConfigDir (app ApplicationDescription) (string, error) {
+	return userMkdirAll(app.ID, userConfigDir)
 }
 
-// ApplicationUserDataFS returns an FS that an application can use to store user
-// data files.
-func ApplicationUserDataFS (app ApplicationDescription) (*FS, error) {
-	dataDir, err := userDataDir()
-	if err != nil { return nil, err }
-	return appFs(dataDir, app)
+// ApplicationUserCacheDir returns the directory path where an application can
+// store its user cache files.
+func ApplicationUserCacheDir (app ApplicationDescription) (string, error) {
+	return userMkdirAll(app.ID, userCacheDir)
 }
 
-// ApplicationUserConfigFS returns an FS that an application can use to store
-// user configuration files.
-func ApplicationUserConfigFS (app ApplicationDescription) (*FS, error) {
-	configDir, err := userConfigDir()
-	if err != nil { return nil, err }
-	return appFs(configDir, app)
-}
-
-// ApplicationUserCacheFS returns an FS that an application can use to store
-// user cache files.
-func ApplicationUserCacheFS (app ApplicationDescription) (*FS, error) {
-	cacheDir, err := userCacheDir()
-	if err != nil { return nil, err }
-	return appFs(cacheDir, app)
-}
-
-func pathErr (op, path string, err error) error {
-	return &fs.PathError {
-		Op:   op,
-		Path: path,
-		Err:  err,
-	}
-}
-
-func appFs (root string, app ApplicationDescription) (*FS, error) {
-	// remove slashes
-	appid := app.ID
-	appid = strings.ReplaceAll(appid, "/", "-")
-	appid = strings.ReplaceAll(appid, "\\", "-")
-
-	path := filepath.Join(root, appid)
-
-	// ensure the directory actually exists
-	err := os.MkdirAll(path, 700)
-	if err != nil { return nil, err }
-
-	return &FS { path: path }, nil
-}
-
-func (this FS) subPath (name string) (string, error) {
-	if !fs.ValidPath(name)         { return "", fs.ErrInvalid }
-	if strings.Contains(name, "/") { return "", fs.ErrInvalid }
-	return filepath.Join(this.path, name), nil
-}
-
-// Open opens the named file.
-func (this FS) Open (name string) (fs.File, error) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("open", name, err)
-	}
-
-	return os.Open(path)
-}
-
-// Create creates or truncates the named file.
-func (this FS) Create (name string) (FileWriter, error) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("create", name, err)
-	}
-
-	return os.Create(path)
-}
-
-// OpenFile is the generalized open call; most users will use Open or Create
-// instead.
-func (this FS) OpenFile (
-	name string,
-	flag int,
-	perm os.FileMode,
-) (
-	FileWriter,
-	error,
-) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("open", name, err)
-	}
-
-	return os.OpenFile(path, flag, perm)
-}
-
-// ReadDir reads the named directory and returns a list of directory entries
-// sorted by filename.
-func (this FS) ReadDir (name string) ([]fs.DirEntry, error) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("readdir", name, err)
-	}
-
-	return os.ReadDir(path)
-}
-
-// ReadFile reads the named file and returns its contents.
-// A successful call returns a nil error, not io.EOF.
-// (Because ReadFile reads the whole file, the expected EOF
-// from the final Read is not treated as an error to be reported.)
-//
-// The caller is permitted to modify the returned byte slice.
-func (this FS) ReadFile (name string) ([]byte, error) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("readfile", name, err)
-	}
-
-	return os.ReadFile(path)
-}
-
-// WriteFile writes data to the named file, creating it if necessary.
-func (this FS) WriteFile (name string, data []byte, perm os.FileMode) error {
-	path, err := this.subPath(name)
-	if err != nil {
-		return pathErr("writefile", name, err)
-	}
-
-	return os.WriteFile(path, data, perm)
-}
-
-// Stat returns a FileInfo describing the file.
-func (this FS) Stat (name string) (fs.FileInfo, error) {
-	path, err := this.subPath(name)
-	if err != nil {
-		return nil, pathErr("stat", name, err)
-	}
-
-	return os.Stat(path)
-}
-
-// Remove removes the named file or (empty) directory.
-func (this FS) Remove (name string) error {
-	path, err := this.subPath(name)
-	if err != nil {
-		return pathErr("remove", name, err)
-	}
-
-	return os.Remove(path)
-}
-
-// RemoveAll removes name and any children it contains.
-func (this FS) RemoveAll (name string) error {
-	path, err := this.subPath(name)
-	if err != nil {
-		return pathErr("removeall", name, err)
-	}
-
-	return os.RemoveAll(path)
-}
-
-// Rename renames (moves) oldname to newname.
-func (this FS) Rename (oldname, newname string) error {
-	oldpath, err := this.subPath(oldname)
-	if err != nil {
-		return pathErr("rename", oldname, err)
-	}
-	newpath, err := this.subPath(newname)
-	if err != nil {
-		return pathErr("rename", newname, err)
-	}
-
-	return os.Rename(oldpath, newpath)
+func userMkdirAll (sub string, getter func () (string, error)) (string, error) {
+	path, err := getter()
+	if err != nil { return "", err }
+	path = filepath.Join(path, sub)
+	err = os.MkdirAll(path, 0700)
+	if err != nil { return "", err }
+	return path, nil
 }