Add home icon

Since Icon can now take in arbitrary strings, we can just have it
serve application icons as well.

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+indent_style = tab
+indent_size = 8
+charset = utf-8
+
+[*.md]
+indent_style = space
+indent_size = 2

README.md

@@ -1,6 +1,5 @@
 # tomo
 
-WIP rewrite of tomo.
+[![Go Reference](https://pkg.go.dev/badge/git.tebibyte.media/tomo/tomo.svg)](https://pkg.go.dev/git.tebibyte.media/tomo/tomo)
 
-This module will serve as a wafer-thin collection of interfaces and glue code so
-that plugins will be an actual viable concept.
+Tomo is a lightweight GUI toolkit written in pure Go.

backend.go

@@ -3,6 +3,7 @@ package tomo
 import "sort"
 import "image"
 import "errors"
+import "git.tebibyte.media/tomo/tomo/canvas"
 
 // Backend is any Tomo implementation. Backends handle window creation, layout,
 // rendering, and events so that there can be as many platform-specific
@@ -10,12 +11,23 @@ import "errors"
 type Backend interface {
 	// These methods create new objects. The backend must reject any object
 	// that was not made by it.
-	NewWindow       (image.Rectangle) (MainWindow, error)
 	NewBox          () Box
 	NewTextBox      () TextBox
 	NewCanvasBox    () CanvasBox
 	NewContainerBox () ContainerBox
 
+	// NewWindow creates a normal MainWindow and returns it.
+	NewWindow (image.Rectangle) (MainWindow, error)
+
+	// NewPlainWindow creates an undecorated window that does not appear in
+	// window lists and returns it. This is intended for making things like
+	// panels, docks, etc.
+	NewPlainWindow (image.Rectangle) (MainWindow, error)
+
+	// NewTexture creates a new texture from an image. The backend must
+	// reject any texture that was not made by it.
+	NewTexture (image.Image) canvas.TextureCloser
+
 	// Run runs the event loop until Stop() is called, or the backend
 	// experiences a fatal error.
 	Run () error

canvas/canvas.go

@@ -44,8 +44,9 @@ type Pen interface {
 	StrokeWeight (int)         // how thick the stroke is
 	StrokeAlign  (StrokeAlign) // where the stroke is drawn
 
-	Stroke (color.Color) // Sets the stroke to a solid color
-	Fill   (color.Color) // Sets the fill to a solid color
+	Stroke  (color.Color) // Sets the stroke to a solid color
+	Fill    (color.Color) // Sets the fill to a solid color
+	Texture (Texture)     // Overlaps a texture onto the fill color
 }
 
 // Canvas is an image that supports drawing paths.

canvas/texture.go

@@ -0,0 +1,20 @@
+package canvas
+
+import "io"
+import "image"
+
+// Texture is a handle that points to a 2D raster image managed by the backend.
+type Texture interface {
+	image.Image
+
+	// Clip returns a smaller section of this texture, pointing to the same
+	// internal data.
+	Clip (image.Rectangle) Texture
+}
+
+// TextureCloser is a texture that can be closed. Anything that receives a
+// TextureCloser must close it after use.
+type TextureCloser interface {
+	Texture
+	io.Closer
+}

go.mod

@@ -2,4 +2,4 @@ module git.tebibyte.media/tomo/tomo
 
 go 1.20
 
-require golang.org/x/image v0.8.0
+require golang.org/x/image v0.11.0

go.sum

@@ -3,6 +3,8 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/image v0.8.0 h1:agUcRXV/+w6L9ryntYYsF2x9fQTMd4T8fiiYXAVW6Jg=
 golang.org/x/image v0.8.0/go.mod h1:PwLxp3opCYg4WR2WO9P0L6ESnsD6bLTWcw8zanLMVFM=
+golang.org/x/image v0.11.0 h1:ds2RoQvBvYTiJkwpSFDwCcDFNX7DqjL2WsUgTNk0Ooo=
+golang.org/x/image v0.11.0/go.mod h1:bglhjqbqVuEb9e9+eNR45Jfu7D+T4Qan+NhQk8Ck2P8=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
@@ -26,6 +28,7 @@ golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.10.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
+golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

object.go

@@ -104,7 +104,7 @@ type Align int; const (
 // Object is any obscreen object. Each object must be linked to a box, even if
 // it is that box.
 type Object interface {
-	Box () Box
+	GetBox () Box
 }
 
 // Box is a basic styled box.
@@ -132,6 +132,10 @@ type Box interface {
 	SetBounds      (image.Rectangle)
 	// SetColor sets the background color of this Box.
 	SetColor       (color.Color)
+	// SetTexture sets a repeating background texture. If the texture is
+	// transparent, it will be overlayed atop the color specified by
+	// SetColor().
+	SetTexture     (canvas.Texture)
 	// SetBorder sets the Border(s) of the box. The first Border will be the
 	// most outset, and the last Border will be the most inset.
 	SetBorder      (...Border)
@@ -212,7 +216,7 @@ type ContentBox interface {
 	// vertically.
 	SetAlign              (x, y Align)
 	// ContentBounds returns the bounds of the inner content of the Box
-	// relative to the window.
+	// relative to the Box's InnerBounds.
 	ContentBounds         () image.Rectangle
 	// ScrollTo shifts the origin of the Box's content to the origin of the
 	// Box's InnerBounds, offset by the given point.
@@ -254,11 +258,6 @@ type TextBox interface {
 type ContainerBox interface {
 	ContentBox
 
-	// SetPropagateEvents specifies whether or not child Objects will
-	// receive user input events. It is true by default. If it is false, all
-	// user input that would otherwise be directed to a child Box is
-	// directed to this Box.
-	SetPropagateEvents (bool)
 	// SetGap sets the gap between child Objects.
 	SetGap             (image.Point)
 	// Add appends a child Object.
@@ -271,13 +270,22 @@ type ContainerBox interface {
 	Insert             (child Object, before Object)
 	// Clear removes all child Objects.
 	Clear              ()
-	// Length returns the amount of child objects.
+	// Length returns the amount of child Objects.
 	Length             () int
 	// At returns the child Object at the specified index.
 	At                 (int) Object
 	// SetLayout sets the layout of this Box. Child Objects will be
 	// positioned according to it.
 	SetLayout          (Layout)
+
+	// These methods control whether certain user input events get
+	// propagated to child Objects. If set to true, the relevant events will
+	// be sent to this container. If set to false (which is the default),
+	// the events will be sent to the appropriate child Object.
+	CaptureDND      (bool)
+	CaptureMouse    (bool)
+	CaptureScroll   (bool)
+	CaptureKeyboard (bool)
 }
 
 // LayoutHints are passed to a layout to tell it how to arrange child boxes.

plugin.go

@@ -1,55 +0,0 @@
-package tomo
-
-import "os"
-import "plugin"
-import "path/filepath"
-
-var pluginPaths []string
-
-func loadPlugins () {
-	for _, dir := range pluginPaths {
-		if dir != "" {
-			loadPluginsFrom(dir)
-		}
-	}
-}
-
-func loadPluginsFrom (dir string) {
-	entries, err := os.ReadDir(dir)
-	// its no big deal if one of the dirs doesn't exist
-	if err != nil { return }
-
-	for _, entry := range entries {
-		if entry.IsDir() { continue }
-		if filepath.Ext(entry.Name()) != ".so" { continue }
-		pluginPath := filepath.Join(dir, entry.Name())
-		loadPlugin(pluginPath)
-	}
-}
-
-func loadPlugin (path string) {
-	die := func (reason string) {
-		println("tomo: could not load plugin at", path + ":", reason)
-	}
-
-	plugin, err := plugin.Open(path)
-	if err != nil {
-		die(err.Error())
-		return
-	}
-
-	// check for and obtain basic plugin functions
-	name, ok := extract[func () string](plugin, "Name")
-	if !ok { die("does not implement Name() string"); return }
-	_, ok = extract[func () string](plugin, "Description")
-	if !ok { die("does not implement Description() string"); return }
-
-	println("tomo: loaded plugin", name())
-}
-
-func extract[T any] (plugin *plugin.Plugin, name string) (value T, ok bool) {
-	symbol, err := plugin.Lookup(name)
-	if err != nil { return }
-	value, ok = symbol.(T)
-	return
-}

theme/icon.go

@@ -0,0 +1,278 @@
+package theme
+
+import "git.tebibyte.media/tomo/tomo/data"
+import "git.tebibyte.media/tomo/tomo/canvas"
+
+// IconSize represents the size of an icon.
+type IconSize int; const (
+	IconSizeSmall IconSize = iota;
+	IconSizeMedium
+	IconSizeLarge
+)
+
+// String satisfies the fmt.Stringer interface.
+func (size IconSize) String () string {
+	switch size {
+	case IconSizeSmall:  return "small"
+	case IconSizeMedium: return "medium"
+	case IconSizeLarge:  return "large"
+	default:             return "unknown"
+	}
+}
+
+// Icon represents an icon ID.
+type Icon string
+
+// A list of standard icon IDs.
+const (
+	IconUnknown                      Icon = ""
+
+	// objects: files
+	IconFile                         Icon = "File" // generic
+	IconDirectory                    Icon = "Directory"
+	IconDirectoryFull                Icon = "DirectoryFull"
+
+	// objects: places
+	IconPlaceHome                    Icon = "PlaceHome"
+	IconPlaceDownloads               Icon = "PlaceDownloads"
+	IconPlacePhotos                  Icon = "PlacePhotos"
+	IconPlaceBooks                   Icon = "PlaceBooks"
+	IconPlaceDocuments               Icon = "PlaceDocuments"
+	IconPlaceRepositories            Icon = "PlaceRepositories"
+	IconPlaceMusic                   Icon = "PlaceMusic"
+	IconPlaceArchives                Icon = "PlaceArchives"
+	IconPlaceFonts                   Icon = "PlaceFonts"
+	IconPlaceBinaries                Icon = "PlaceBinaries"
+	IconPlaceVideos                  Icon = "PlaceVideos"
+	IconPlace3DObjects               Icon = "Place3DObjects"
+	IconPlaceHistory                 Icon = "PlaceHistory"
+	IconPlacePreferences             Icon = "PlacePreferences"
+
+	// objects: storage
+	IconStorage                      Icon = "Storage" // generic
+	IconStorageMagneticTape          Icon = "StorageMagneticTape"
+	IconStorageFloppyDisk            Icon = "StorageFloppyDisk"
+	IconStorageHardDisk              Icon = "StorageHardDisk"
+	IconStorageSolidStateDisk        Icon = "StorageSolidState"
+	IconStorageFlashStick            Icon = "StorageFlashStick"
+	IconStorageFlashCard             Icon = "StorageFlashCard"
+	IconStorageROM                   Icon = "StorageROM"
+	IconStorageRAM                   Icon = "StorageRAM"
+	IconStorageCD                    Icon = "StorageCD"
+	IconStorageDVD                   Icon = "StorageDVD"
+
+	// objects: applications
+	// Keep these in sync with nasin.ApplicationRole!
+	IconApplication                  Icon = "Application" // generic
+	IconApplicationWebBrowser        Icon = "ApplicationWebBrowser"
+	IconApplicationMesssanger        Icon = "ApplicationMesssanger"
+	IconApplicationPhone             Icon = "ApplicationPhone"
+	IconApplicationMail              Icon = "ApplicationMail"
+	IconApplicationTerminalEmulator  Icon = "ApplicationTerminalEmulator"
+	IconApplicationFileBrowser       Icon = "ApplicationFileBrowser"
+	IconApplicationTextEditor        Icon = "ApplicationTextEditor"
+	IconApplicationDocumentViewer    Icon = "ApplicationDocumentViewer"
+	IconApplicationWordProcessor     Icon = "ApplicationWordProcessor"
+	IconApplicationSpreadsheet       Icon = "ApplicationSpreadsheet"
+	IconApplicationSlideshow         Icon = "ApplicationSlideshow"
+	IconApplicationCalculator        Icon = "ApplicationCalculator"
+	IconApplicationPreferences       Icon = "ApplicationPreferences"
+	IconApplicationProcessManager    Icon = "ApplicationProcessManager"
+	IconApplicationSystemInformation Icon = "ApplicationSystemInformation"
+	IconApplicationManual            Icon = "ApplicationManual"
+	IconApplicationCamera            Icon = "ApplicationCamera"
+	IconApplicationImageViewer       Icon = "ApplicationImageViewer"
+	IconApplicationMediaPlayer       Icon = "ApplicationMediaPlayer"
+	IconApplicationImageEditor       Icon = "ApplicationImageEditor"
+	IconApplicationAudioEditor       Icon = "ApplicationAudioEditor"
+	IconApplicationVideoEditor       Icon = "ApplicationVideoEditor"
+	IconApplicationClock             Icon = "ApplicationClock"
+	IconApplicationCalendar          Icon = "ApplicationCalendar"
+	IconApplicationChecklist         Icon = "ApplicationChecklist"
+
+	// objects: networks
+	IconNetwork                      Icon = "Network" // generic
+	IconNetworkLocal                 Icon = "NetworkLocal"
+	IconNetworkInternet              Icon = "NetworkInternet"
+	IconNetworkEthernet              Icon = "NetworkEthernet"
+	IconNetworkWireless              Icon = "NetworkWireless"
+	IconNetworkCell                  Icon = "NetworkCell"
+	IconNetworkBluetooth             Icon = "NetworkBluetooth"
+	IconNetworkRadio                 Icon = "NetworkRadio"
+
+	// objects: devices
+	IconDevice                       Icon = "Device" // generic
+	IconDeviceRouter                 Icon = "DeviceRouter"
+	IconDeviceServer                 Icon = "DeviceServer"
+	IconDeviceDesktop                Icon = "DeviceDesktop"
+	IconDeviceLaptop                 Icon = "DeviceLaptop"
+	IconDeviceTablet                 Icon = "DeviceTablet"
+	IconDevicePhone                  Icon = "DevicePhone"
+	IconDeviceWatch                  Icon = "DeviceWatch"
+	IconDeviceCamera                 Icon = "DeviceCamera"
+
+	// objects: peripherals
+	IconPeripheral                   Icon = "Peripheral" // generic
+	IconPeripheralKeyboard           Icon = "PeripheralKeyboard"
+	IconPeripheralMouse              Icon = "PeripheralMouse"
+	IconPeripheralMonitor            Icon = "PeripheralMonitor"
+	IconPeripheralWebcam             Icon = "PeripheralWebcam"
+	IconPeripheralMicrophone         Icon = "PeripheralMicrophone"
+	IconPeripheralSpeaker            Icon = "PeripheralSpeaker"
+	IconPeripheralPenTablet          Icon = "PeripheralPenTablet"
+	IconPeripheralTrackpad           Icon = "PeripheralTrackpad"
+	IconPeripheralController         Icon = "PeripheralController"
+
+	// objects: i/o
+	IconPort                         Icon = "Port" // generic
+	IconPortEthernet                 Icon = "PortEthernet"
+	IconPortUSB                      Icon = "PortUSB"
+	IconPortParallel                 Icon = "PortParallel"
+	IconPortSerial                   Icon = "PortSerial"
+	IconPortPS2                      Icon = "PortPS2"
+	IconPortDisplay                  Icon = "PortDisplay"
+	IconPortCGA                      Icon = "PortCGA"
+	IconPortVGA                      Icon = "PortVGA"
+	IconPortHDMI                     Icon = "PortHDMI"
+	IconPortDisplayPort              Icon = "PortDisplayPort"
+	IconPortInfrared                 Icon = "PortInfrared"
+
+	// actions: files
+	IconActionOpen                   Icon = "ActionOpen"
+	IconActionOpenIn                 Icon = "ActionOpenIn"
+	IconActionSave                   Icon = "ActionSave"
+	IconActionSaveAs                 Icon = "ActionSaveAs"
+	IconActionPrint                  Icon = "ActionPrint"
+	IconActionNew                    Icon = "ActionNew"
+	IconActionNewDirectory           Icon = "ActionNewDirectory"
+	IconActionDelete                 Icon = "ActionDelete"
+	IconActionRename                 Icon = "ActionRename"
+	IconActionGetInformation         Icon = "ActionGetInformation"
+	IconActionChangePermissions      Icon = "ActionChangePermissions"
+	IconActionRevert                 Icon = "ActionRevert"
+
+	// actions: list management
+	IconActionAdd                    Icon = "ActionAdd"
+	IconActionRemove                 Icon = "ActionRemove"
+	IconActionAddBookmark            Icon = "ActionAddBookmark"
+	IconActionRemoveBookmark         Icon = "ActionRemoveBookmark"
+	IconActionAddFavorite            Icon = "ActionAddFavorite"
+	IconActionRemoveFavorite         Icon = "ActionRemoveFavorite"
+
+	// actions: media
+	IconActionPlay                   Icon = "ActionPlay"
+	IconActionPause                  Icon = "ActionPause"
+	IconActionStop                   Icon = "ActionStop"
+	IconActionFastForward            Icon = "ActionFastForward"
+	IconActionRewind                 Icon = "ActionRewind"
+	IconActionToBeginning            Icon = "ActionToBeginning"
+	IconActionToEnd                  Icon = "ActionToEnd"
+	IconActionRecord                 Icon = "ActionRecord"
+	IconActionVolumeUp               Icon = "ActionVolumeUp"
+	IconActionVolumeDown             Icon = "ActionVolumeDown"
+	IconActionMute                   Icon = "ActionMute"
+
+	// actions: editing
+	IconActionUndo                   Icon = "ActionUndo"
+	IconActionRedo                   Icon = "ActionRedo"
+	IconActionCut                    Icon = "ActionCut"
+	IconActionCopy                   Icon = "ActionCopy"
+	IconActionPaste                  Icon = "ActionPaste"
+	IconActionFind                   Icon = "ActionFind"
+	IconActionReplace                Icon = "ActionReplace"
+	IconActionSelectAll              Icon = "ActionSelectAll"
+	IconActionSelectNone             Icon = "ActionSelectNone"
+	IconActionIncrement              Icon = "ActionIncrement"
+	IconActionDecrement              Icon = "ActionDecrement"
+
+	// actions: window management
+	IconActionClose                  Icon = "ActionClose"
+	IconActionQuit                   Icon = "ActionQuit"
+	IconActionIconify                Icon = "ActionIconify"
+	IconActionShade                  Icon = "ActionShade"
+	IconActionMaximize               Icon = "ActionMaximize"
+	IconActionFullScreen             Icon = "ActionFullScreen"
+	IconActionRestore                Icon = "ActionRestore"
+
+	// actions: view
+	IconActionExpand                 Icon = "ActionExpand"
+	IconActionContract               Icon = "ActionContract"
+	IconActionBack                   Icon = "ActionBack"
+	IconActionForward                Icon = "ActionForward"
+	IconActionUp                     Icon = "ActionUp"
+	IconActionDown                   Icon = "ActionDown"
+	IconActionReload                 Icon = "ActionReload"
+	IconActionZoomIn                 Icon = "ActionZoomIn"
+	IconActionZoomOut                Icon = "ActionZoomOut"
+	IconActionZoomReset              Icon = "ActionZoomReset"
+	IconActionMove                   Icon = "ActionMove"
+	IconActionResize                 Icon = "ActionResize"
+	IconActionGoTo                   Icon = "ActionGoTo"
+
+	// actions: tools
+	IconActionTransform              Icon = "ActionTransform"
+	IconActionTranslate              Icon = "ActionTranslate"
+	IconActionRotate                 Icon = "ActionRotate"
+	IconActionScale                  Icon = "ActionScale"
+	IconActionWarp                   Icon = "ActionWarp"
+	IconActionCornerPin              Icon = "ActionCornerPin"
+	IconActionSelectRectangle        Icon = "ActionSelectRectangle"
+	IconActionSelectEllipse          Icon = "ActionSelectEllipse"
+	IconActionSelectLasso            Icon = "ActionSelectLasso"
+	IconActionSelectGeometric        Icon = "ActionSelectGeometric"
+	IconActionSelectAuto             Icon = "ActionSelectAuto"
+	IconActionCrop                   Icon = "ActionCrop"
+	IconActionFill                   Icon = "ActionFill"
+	IconActionGradient               Icon = "ActionGradient"
+	IconActionPencil                 Icon = "ActionPencil"
+	IconActionBrush                  Icon = "ActionBrush"
+	IconActionEraser                 Icon = "ActionEraser"
+	IconActionText                   Icon = "ActionText"
+	IconActionEyedropper             Icon = "ActionEyedropper"
+
+	// status: dialog
+	IconStatusInformation            Icon = "StatusInformation"
+	IconStatusQuestion               Icon = "StatusQuestion"
+	IconStatusWarning                Icon = "StatusWarning"
+	IconStatusError                  Icon = "StatusError"
+	IconStatusCancel                 Icon = "StatusCancel"
+	IconStatusOkay                   Icon = "StatusOkay"
+
+	// status: network
+	IconStatusCellSignal0            Icon = "StatusCellSignal0"
+	IconStatusCellSignal1            Icon = "StatusCellSignal1"
+	IconStatusCellSignal2            Icon = "StatusCellSignal2"
+	IconStatusCellSignal3            Icon = "StatusCellSignal3"
+	IconStatusWirelessSignal0        Icon = "StatusWirelessSignal0"
+	IconStatusWirelessSignal1        Icon = "StatusWirelessSignal1"
+	IconStatusWirelessSignal2        Icon = "StatusWirelessSignal2"
+	IconStatusWirelessSignal3        Icon = "StatusWirelessSignal3"
+
+	// status: power
+	IconStatusBattery0               Icon = "StatusBattery0"
+	IconStatusBattery1               Icon = "StatusBattery1"
+	IconStatusBattery2               Icon = "StatusBattery2"
+	IconStatusBattery3               Icon = "StatusBattery3"
+	IconStatusBrightness0            Icon = "StatusBrightness0"
+	IconStatusBrightness1            Icon = "StatusBrightness1"
+	IconStatusBrightness2            Icon = "StatusBrightness2"
+	IconStatusBrightness3            Icon = "StatusBrightness3"
+
+	// status: media
+	IconStatusVolume0                Icon = "StatusVolume0"
+	IconStatusVolume1                Icon = "StatusVolume1"
+	IconStatusVolume2                Icon = "StatusVolume2"
+	IconStatusVolume3                Icon = "StatusVolume3"
+)
+
+// Texture returns a texture of the corresponding icon ID.
+func (id Icon) Texture (size IconSize) canvas.Texture {
+	if current == nil { return nil }
+	return current.Icon(id, size)
+}
+
+// MimeIcon returns an icon corresponding to a MIME type.
+func MimeIcon (mime data.Mime, size IconSize) canvas.Texture {
+	if current == nil { return nil }
+	return current.MimeIcon(mime, size)
+}

theme/theme.go

@@ -1,14 +1,17 @@
 package theme
 
+import "fmt"
 import "git.tebibyte.media/tomo/tomo"
+import "git.tebibyte.media/tomo/tomo/data"
 import "git.tebibyte.media/tomo/tomo/event"
+import "git.tebibyte.media/tomo/tomo/canvas"
 
 // Role describes the role of an object.
 type Role struct {
 	// Package is an optional namespace field. If specified, it should be
 	// the package name or module name the object is from.
 	Package string
-	
+
 	// Object specifies what type of object it is. For example:
 	//   - TextInput
 	//   - Table
@@ -16,12 +19,24 @@ type Role struct {
 	//   - Dial
 	// This should correspond directly to the type name of the object.
 	Object string
+
+	// Variant is an optional field to be used when an object has one or
+	// more soft variants under one type. For example, an object "Slider"
+	// may have variations "horizontal" and "vertical".
+	Variant string
+}
+
+// String satisfies the fmt.Stringer interface.
+// It follows the format of:
+// Package.Object[Variant]
+func (r Role) String () string {
+	return fmt.Sprintf("%s.%s[%s]", r.Package, r.Object, r.Variant)
 }
 
 // R is shorthand for creating a Role structure.
-func R (pack, object string) Role {
-	return Role { Package: pack, Object: object }
-} 
+func R (pack, object, variant string) Role {
+	return Role { Package: pack, Object: object, Variant: variant }
+}
 
 // Color represents a color ID.
 type Color int; const (
@@ -32,21 +47,50 @@ type Color int; const (
 	ColorAccent
 )
 
+// String satisfies the fmt.Stringer interface.
+func (c Color) String () string {
+	switch c {
+	case ColorBackground: return "background"
+	case ColorForeground: return "foreground"
+	case ColorRaised:     return "raised"
+	case ColorSunken:     return "sunken"
+	case ColorAccent:     return "accent"
+	default:              return "unknown"
+	}
+}
+
 // RGBA satisfies the color.Color interface.
 func (id Color) RGBA () (r, g, b, a uint32) {
 	if current == nil { return }
 	return current.RGBA(id)
 }
 
-// Theme is an object that can apply a visual style to different objects.
+// Theme can apply a visual style to different objects.
 type Theme interface {
+	// A word on textures:
+	//
+	// Because textures can be linked to some resource that is outside of
+	// the control of Go's garbage collector, methods of Theme must not
+	// allocate new copies of a texture each time they are called. It is
+	// fine to lazily load textures and save them for later use, but the
+	// same texture must never be allocated multiple times as this could
+	// cause a memory leak.
+	//
+	// As such, textures returned by these methods must be protected.
+	
 	// Apply applies the theme to the given object, according to the given
 	// role. This may register event listeners with the given object;
-	// closing the returned cookie will remove them.
+	// closing the returned cookie must remove them.
 	Apply (tomo.Object, Role) event.Cookie
-	
+
 	// RGBA returns the RGBA values of the corresponding color ID.
 	RGBA (Color) (r, g, b, a uint32)
+
+	// Icon returns a texture of the corresponding icon ID.
+	Icon (Icon, IconSize) canvas.Texture
+
+	// MimeIcon returns an icon corresponding to a MIME type.
+	MimeIcon (data.Mime, IconSize) canvas.Texture
 }
 
 var current Theme
@@ -63,4 +107,3 @@ func Apply (object tomo.Object, role Role) event.Cookie {
 	if current == nil { return event.NoCookie { } }
 	return current.Apply(object, role)
 }
-

tomo.go

@@ -3,6 +3,7 @@ package tomo
 import "sync"
 import "image"
 import "errors"
+import "git.tebibyte.media/tomo/tomo/canvas"
 
 var backendLock sync.Mutex
 var backend Backend
@@ -11,8 +12,6 @@ var backend Backend
 // event loop in that order. This function blocks until Stop is called, or the
 // backend experiences a fatal error.
 func Run (callback func ()) error {
-	loadPlugins()
-
 	if backend != nil {
 		return errors.New("there is already a backend running")
 	}
@@ -56,6 +55,14 @@ func NewWindow (bounds image.Rectangle) (MainWindow, error) {
 	return backend.NewWindow(bounds)
 }
 
+// NewPlainWindow is like NewWindow, but it creates an undecorated window that
+// does not appear in window lists. It is intended for creating things like
+// docks, panels, etc.
+func NewPlainWindow (bounds image.Rectangle) (MainWindow, error) {
+	assertBackend()
+	return backend.NewPlainWindow(bounds)
+}
+
 // NewBox creates and returns a basic Box.
 func NewBox () Box {
 	assertBackend()
@@ -79,3 +86,10 @@ func NewContainerBox () ContainerBox {
 	assertBackend()
 	return backend.NewContainerBox()
 }
+
+// NewTexture creates a new texture from an image. When no longer in use, it
+// must be freed using Close().
+func NewTexture (source image.Image) canvas.TextureCloser {
+	assertBackend()
+	return backend.NewTexture(source)
+}

unix.go

@@ -1,22 +0,0 @@
-//go:build linux || darwin || freebsd
-
-package tomo
-
-import "os"
-import "strings"
-import "path/filepath"
-
-func init () {
-	pathVariable := os.Getenv("TOMO_PLUGIN_PATH")
-	pluginPaths = strings.Split(pathVariable, ":")
-	pluginPaths = append (
-		pluginPaths,
-		"/usr/lib/tomo/plugins",
-		"/usr/local/lib/tomo/plugins")
-	homeDir, err := os.UserHomeDir()
-	if err == nil {
-		pluginPaths = append (
-			pluginPaths,
-			filepath.Join(homeDir, ".local/lib/tomo/plugins"))
-	}
-}