Change icon on dropdown

Major progress on #4

.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

button.go

@@ -69,6 +69,7 @@ func (this *Button) SetIcon (id tomo.Icon) {
 	if this.icon != nil {
 		this.Insert(this.icon, this.label)
 	}
+	this.SetTag("icon", this.icon != nil)
 	this.applyLayout()
 }
 
@@ -88,23 +89,23 @@ func (this *Button) applyLayout () {
 }
 
 func (this *Button) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	return true
-}
-
-func (this *Button) handleKeyUp (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false }
+	if !isClickingKey(key) { return false }
 	this.on.click.Broadcast()
 	return true
 }
 
+func (this *Button) handleKeyUp (key input.Key, numberPad bool) bool {
+	if !isClickingKey(key) { return false }
+	return true
+}
+
 func (this *Button) handleButtonDown (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	return true
 }
 
 func (this *Button) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	if this.Window().MousePosition().In(this.Bounds()) {
 		this.on.click.Broadcast()
 	}

checkbox.go

@@ -54,23 +54,23 @@ func (this *Checkbox) OnValueChange (callback func ()) event.Cookie {
 }
 
 func (this *Checkbox) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false }
+	if !isClickingKey(key) { return false }
 	this.Toggle()
 	return true
 }
 
 func (this *Checkbox) handleKeyUp (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false}
+	if !isClickingKey(key) { return false}
 	return true
 }
 
 func (this *Checkbox) handleButtonDown (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	return true
 }
 
 func (this *Checkbox) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	if this.Window().MousePosition().In(this.Bounds()) {
 		this.Toggle()
 	}

colorpicker.go

@@ -8,13 +8,13 @@ import "git.tebibyte.media/tomo/tomo/canvas"
 import "git.tebibyte.media/tomo/objects/layouts"
 import "git.tebibyte.media/tomo/objects/internal"
 
-// ColorPicker allows the user to pick a color by controlling its HSBA
+// HSVAColorPicker allows the user to pick a color by controlling its HSVA
 // parameters.
-type ColorPicker struct {
+type HSVAColorPicker struct {
 	tomo.ContainerBox
 	value internal.HSVA
 	
-	pickerMap   *colorPickerMap
+	pickerMap   *hsvaColorPickerMap
 	hueSlider   *Slider
 	alphaSlider *Slider
 	
@@ -23,14 +23,14 @@ type ColorPicker struct {
 	}
 }
 
-// NewColorPicker creates a new color picker with the specified color.
-func NewColorPicker (value color.Color) *ColorPicker {
-	picker := &ColorPicker {
+// NewHSVAColorPicker creates a new color picker with the specified color.
+func NewHSVAColorPicker (value color.Color) *HSVAColorPicker {
+	picker := &HSVAColorPicker {
 		ContainerBox: tomo.NewContainerBox(),
 	}
 	picker.SetRole(tomo.R("objects", "ColorPicker"))
 	picker.SetAttr(tomo.ALayout(layouts.Row { true, false, false }))
-	picker.pickerMap = newColorPickerMap(picker)
+	picker.pickerMap = newHsvaColorPickerMap(picker)
 	picker.Add(picker.pickerMap)
 	
 	picker.hueSlider = NewVerticalSlider(0.0)
@@ -44,7 +44,7 @@ func NewColorPicker (value color.Color) *ColorPicker {
 	picker.alphaSlider = NewVerticalSlider(0.0)
 	picker.Add(picker.alphaSlider)
 	picker.alphaSlider.OnValueChange(func () {
-		picker.value.A = uint8(picker.alphaSlider.Value() * 255)
+		picker.value.A = uint16(picker.alphaSlider.Value() * 0xFFFF)
 		picker.on.valueChange.Broadcast()
 		picker.pickerMap.Invalidate()
 	})
@@ -55,37 +55,38 @@ func NewColorPicker (value color.Color) *ColorPicker {
 }
 
 // Value returns the color of the picker.
-func (this *ColorPicker) Value () color.Color {
+func (this *HSVAColorPicker) Value () color.Color {
 	return this.value
 }
 
 // SetValue sets the color of the picker.
-func (this *ColorPicker) SetValue (value color.Color) {
+func (this *HSVAColorPicker) SetValue (value color.Color) {
 	if value == nil { value = color.Transparent }
-	this.value = internal.RGBAToHSVA(value.RGBA())
+	this.value = internal.HSVAModel.Convert(value).(internal.HSVA)
 	this.hueSlider.SetValue(this.value.H)
-	this.alphaSlider.SetValue(float64(this.value.A) / 255)
+	this.alphaSlider.SetValue(float64(this.value.A) / 0xFFFF)
+	this.pickerMap.Invalidate()
 }
 
 // OnValueChange specifies a function to be called when the user changes the
 // swatch's color.
-func (this *ColorPicker) OnValueChange (callback func ()) event.Cookie {
+func (this *HSVAColorPicker) OnValueChange (callback func ()) event.Cookie {
 	return this.on.valueChange.Connect(callback)
 }
 
 // RGBA satisfies the color.Color interface
-func (this *ColorPicker) RGBA () (r, g, b, a uint32) {
+func (this *HSVAColorPicker) RGBA () (r, g, b, a uint32) {
 	return this.value.RGBA()
 }
 
-type colorPickerMap struct {
+type hsvaColorPickerMap struct {
 	tomo.CanvasBox
 	dragging bool
-	parent *ColorPicker
+	parent *HSVAColorPicker
 }
 
-func newColorPickerMap (parent *ColorPicker) *colorPickerMap {
-	picker := &colorPickerMap {
+func newHsvaColorPickerMap (parent *HSVAColorPicker) *hsvaColorPickerMap {
+	picker := &hsvaColorPickerMap {
 		CanvasBox: tomo.NewCanvasBox(),
 		parent: parent,
 	}
@@ -97,26 +98,26 @@ func newColorPickerMap (parent *ColorPicker) *colorPickerMap {
 	return picker
 }
 
-func (this *colorPickerMap) handleButtonDown (button input.Button) bool {
+func (this *hsvaColorPickerMap) handleButtonDown (button input.Button) bool {
 	if button != input.ButtonLeft { return false }
 	this.dragging = true
 	this.drag()
 	return true
 }
 
-func (this *colorPickerMap) handleButtonUp (button input.Button) bool {
+func (this *hsvaColorPickerMap) handleButtonUp (button input.Button) bool {
 	if button != input.ButtonLeft { return false }
 	this.dragging = false
 	return true
 }
 
-func (this *colorPickerMap) handleMouseMove () bool {
+func (this *hsvaColorPickerMap) handleMouseMove () bool {
 	if !this.dragging { return false }
 	this.drag()
 	return true
 }
 
-func (this *colorPickerMap) drag () {
+func (this *hsvaColorPickerMap) drag () {
 	pointer := this.Window().MousePosition()
 	bounds  := this.InnerBounds()
 	this.parent.value.S =     float64(pointer.X - bounds.Min.X) / float64(bounds.Dx())
@@ -126,7 +127,7 @@ func (this *colorPickerMap) drag () {
 	this.Invalidate()
 }
 
-func (this *colorPickerMap) Draw (can canvas.Canvas) {
+func (this *hsvaColorPickerMap) Draw (can canvas.Canvas) {
 	bounds := can.Bounds()
 	for y := bounds.Min.Y; y < bounds.Max.Y; y ++ {
 	for x := bounds.Min.X; x < bounds.Max.X; x ++ {
@@ -137,7 +138,7 @@ func (this *colorPickerMap) Draw (can canvas.Canvas) {
 			H: this.parent.value.H,
 			S:     float64(xx) / float64(bounds.Dx()),
 			V: 1 - float64(yy) / float64(bounds.Dy()),
-			A: 255,
+			A: 0xFFFF,
 		}
 		
 		sPos := int(     this.parent.value.S  * float64(bounds.Dx()))

dialog.go

@@ -63,7 +63,7 @@ func NewDialog (kind DialogKind, parent tomo.Window, title, message string, opti
 		}
 	}
 	dialog.controlRow = NewInnerContainer(layouts.ContractHorizontal, options...)
-	messageText.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignEnd))
+	dialog.controlRow.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignEnd))
 
 	dialog.SetRoot(NewOuterContainer (
 		layouts.Column { true, false },

dropdown.go

@@ -0,0 +1,114 @@
+package objects
+
+// import "image"
+import "git.tebibyte.media/tomo/tomo"
+import "git.tebibyte.media/tomo/tomo/input"
+import "git.tebibyte.media/tomo/tomo/event"
+import "git.tebibyte.media/tomo/objects/layouts"
+
+// Dropdown is a non-editable text input that allows the user to pick a value
+// from a list.
+type Dropdown struct {
+	tomo.ContainerBox
+	label *Label
+
+	value string
+	items []string
+	menu  *Menu
+
+	on struct {
+		valueChange event.FuncBroadcaster
+	}
+}
+
+// NewDropdown creates a new dropdown input with the specified items
+func NewDropdown (items ...string) *Dropdown {
+	dropdown := &Dropdown {
+		ContainerBox: tomo.NewContainerBox(),
+		label:        NewLabel(""),
+	}
+	dropdown.SetRole(tomo.R("objects", "Dropdown"))
+	dropdown.SetAttr(tomo.ALayout(layouts.Row { true, false }))
+	dropdown.Add(dropdown.label)
+	dropdown.Add(NewIcon(tomo.IconListChoose, tomo.IconSizeSmall))
+	
+	dropdown.SetItems(items...)
+	if len(items) > 0 {
+		dropdown.SetValue(items[0])
+	}
+	
+	dropdown.SetInputMask(true)
+	dropdown.OnButtonDown(dropdown.handleButtonDown)
+	dropdown.OnButtonUp(dropdown.handleButtonUp)
+	dropdown.OnKeyDown(dropdown.handleKeyDown)
+	dropdown.OnKeyUp(dropdown.handleKeyUp)
+	dropdown.SetFocusable(true)
+	return dropdown
+}
+
+// Value returns the value of the dropdown. This does not necissarily have to be
+// in the list of items.
+func (this *Dropdown) Value () string {
+	return this.value
+}
+
+// SetValue sets the value of the dropdown. This does not necissarily have to be
+// in the list of items.
+func (this *Dropdown) SetValue (value string) {
+	this.value = value
+	this.label.SetText(value)
+}
+
+// SetItems sets the items from which the user is able to pick.
+func (this *Dropdown) SetItems (items ...string) {
+	this.items = items
+}
+
+// Choose creates a menu that allows the user to pick a value.
+func (this *Dropdown) Choose () {
+	if this.menu != nil {
+		this.menu.Close()
+	}
+	menu, err := NewAnchoredMenu(this, this.itemList()...)
+	if err != nil { return }
+	this.menu = menu
+	menu.SetVisible(true)
+}
+
+func (this *Dropdown) itemList () []tomo.Object {
+	items := make([]tomo.Object, len(this.items))
+	for index, value := range this.items {
+		value := value
+		item := NewMenuItem(value)
+		item.OnClick(func () {
+			this.SetValue(value)
+			this.on.valueChange.Broadcast()
+		})
+		items[index] = item
+	}
+	return items
+}
+
+func (this *Dropdown) handleKeyDown (key input.Key, numberPad bool) bool {
+	if !isClickingKey(key) { return false }
+	this.Choose()
+	return true
+}
+
+func (this *Dropdown) handleKeyUp (key input.Key, numberPad bool) bool {
+	if !isClickingKey(key) { return false }
+	return true
+}
+
+func (this *Dropdown) handleButtonDown (button input.Button) bool {
+	if !isClickingButton(button) { return false }
+	return true
+}
+
+func (this *Dropdown) handleButtonUp (button input.Button) bool {
+	if !isClickingButton(button) { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
+		this.Choose()
+	}
+	return true
+}

go.mod

@@ -2,6 +2,4 @@ module git.tebibyte.media/tomo/objects
 
 go 1.20
 
-require git.tebibyte.media/tomo/tomo v0.41.0
-
-require golang.org/x/image v0.11.0 // indirect
+require git.tebibyte.media/tomo/tomo v0.46.1

go.sum

@@ -1,35 +1,2 @@
-git.tebibyte.media/tomo/tomo v0.41.0 h1:Z+7FHhbGiKjs+kQNvuJOfz47xIct5qxvSJqyDuoNIOs=
-git.tebibyte.media/tomo/tomo v0.41.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
-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=
-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=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-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 v0.12.0/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=
-golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+git.tebibyte.media/tomo/tomo v0.46.1 h1:/8fT6I9l4TK529zokrThbNDHGRvUsNgif1Zs++0PBSQ=
+git.tebibyte.media/tomo/tomo v0.46.1/go.mod h1:WrtilgKB1y8O2Yu7X4mYcRiqOlPR8NuUnoA/ynkQWrs=

heading.go

@@ -18,6 +18,14 @@ func NewHeading (level int, text string) *Heading {
 	this.SetRole(tomo.R("objects", "Heading"))
 	this.SetTag(fmt.Sprint(level), true)
 	this.SetText(text)
+	this.SetSelectable(true)
+	this.SetFocusable(true)
 	return this
 }
 
+// NewMenuHeading creatss a new heading for use in menus.
+func NewMenuHeading (text string) *Heading {
+	heading := NewHeading(0, text)
+	heading.SetTag("menu", true)
+	return heading
+}

icon.go

@@ -1,12 +1,13 @@
 package objects
 
 import "git.tebibyte.media/tomo/tomo"
-import "git.tebibyte.media/tomo/tomo/data"
 import "git.tebibyte.media/tomo/tomo/canvas"
 
 // Icon displays a single icon.
 type Icon struct {
 	tomo.Box
+	icon tomo.Icon
+	size tomo.IconSize
 }
 
 func iconSizeString (size tomo.IconSize) string {
@@ -18,29 +19,29 @@ func iconSizeString (size tomo.IconSize) string {
 }
 
 // NewIcon creates a new icon from an icon ID.
-func NewIcon (id tomo.Icon, size tomo.IconSize) *Icon {
+func NewIcon (icon tomo.Icon, size tomo.IconSize) *Icon {
 	this := &Icon {
 		Box: tomo.NewBox(),
 	}
 	this.SetRole(tomo.R("objects", "Icon"))
-	this.SetTag(iconSizeString(size), true)
-	this.setTexture(id.Texture(size))
+	this.SetIcon(icon, size)
+	this.OnIconSetChange(this.handleIconSetChange)
 	return this
 }
 
-// NewMimeIcon creates a new icon from a MIME type.
-func NewMimeIcon (mime data.Mime, size tomo.IconSize) *Icon {
-	this := &Icon {
-		Box: tomo.NewBox(),
-	}
-	this.SetRole(tomo.R("objects", "Icon"))
-	this.SetTag(iconSizeString(size), true)
-	this.setTexture(tomo.MimeIcon(mime, size))
-	return this
+// SetIcon sets the icon.
+func (this *Icon) SetIcon (icon tomo.Icon, size tomo.IconSize) {
+	if this.icon == icon { return }
+	this.icon = icon
+	this.size = size
+	this.setTexture(icon.Texture(size))
+}
+
+func (this *Icon) handleIconSetChange () {
+	this.setTexture(this.icon.Texture(this.size))
 }
 
 func (this *Icon) setTexture (texture canvas.Texture) {
-	
 	this.SetAttr(tomo.ATexture(texture))
 	this.SetAttr(tomo.ATextureMode(tomo.TextureModeCenter))
 	if texture == nil {

input.go

@@ -0,0 +1,19 @@
+package objects
+
+import "git.tebibyte.media/tomo/tomo/input"
+
+func isClickingKey (key input.Key) bool {
+	return key == input.KeyEnter || key == input.Key(' ')
+}
+
+func isConfirmationKey (key input.Key) bool {
+	return key == input.KeyEnter
+}
+
+func isClickingButton (button input.Button) bool {
+	return button == input.ButtonLeft
+}
+
+func isMenuButton (button input.Button) bool {
+	return button == input.ButtonLeft
+}

internal/color.go

@@ -1,13 +1,32 @@
 package internal
 
+import "fmt"
+import "image/color"
+
+// HSV represents a color with hue, saturation, and value components. Each
+// component C is in range 0 <= C <= 1.
+type HSV struct {
+	H float64
+	S float64
+	V float64
+}
+
+// HSVA is an HSV color with an added 8-bit alpha component. The alpha component
+// ranges from 0x0000 (fully transparent) to 0xFFFF (opaque), and has no bearing
+// on the other components.
 type HSVA struct {
 	H float64
 	S float64
 	V float64
-	A uint8
+	A uint16
 }
 
-func (hsva HSVA) RGBA () (r, g, b, a uint32) {
+var (
+	HSVModel  color.Model = color.ModelFunc(hsvModel)
+	HSVAModel color.Model = color.ModelFunc(hsvaModel)
+)
+
+func (hsv HSV) RGBA () (r, g, b, a uint32) {
 	// Adapted from:
 	// https://www.cs.rit.edu/~ncs/color/t_convert.html
 	
@@ -15,34 +34,57 @@ func (hsva HSVA) RGBA () (r, g, b, a uint32) {
 		return uint32(float64(0xFFFF) * x)
 	}
 
-	ca := uint32(hsva.A) << 8
-	s := clamp01(hsva.S)
-	v := clamp01(hsva.V)
+	s := clamp01(hsv.S)
+	v := clamp01(hsv.V)
 	if s == 0 {
 		light := component(v)
-		return light, light, light, ca
+		return light, light, light, 0xFFFF
 	}
 	
-	h := clamp01(hsva.H) * 360
+	h := clamp01(hsv.H) * 360
 	sector := int(h / 60)
+	// otherwise when given 1.0 for H, sector would overflow to 6
+	if sector > 5 { sector = 5 }
 	offset := (h / 60) - float64(sector)
 	
-	fac := float64(hsva.A) / 255
-	p  := component(fac * v * (1 - s))
-	q  := component(fac * v * (1 - s * offset))
-	t  := component(fac * v * (1 - s * (1 - offset)))
+	p  := component(v * (1 - s))
+	q  := component(v * (1 - s * offset))
+	t  := component(v * (1 - s * (1 - offset)))
 	va := component(v)
 	
 	switch sector {
-	case 0:  return va, t,  p,  ca
-	case 1:  return q,  va, p,  ca
-	case 2:  return p,  va, t,  ca
-	case 3:  return p,  q,  va, ca
-	case 4:  return t,  p,  va, ca
-	default: return va, p,  q,  ca
+	case 0:  return va, t,  p,  0xFFFF
+	case 1:  return q,  va, p,  0xFFFF
+	case 2:  return p,  va, t,  0xFFFF
+	case 3:  return p,  q,  va, 0xFFFF
+	case 4:  return t,  p,  va, 0xFFFF
+	default: return va, p,  q,  0xFFFF
 	}
 }
 
+func (hsva HSVA) RGBA () (r, g, b, a uint32) {
+	r, g, b, a = HSV {
+		H: hsva.H,
+		S: hsva.S,
+		V: hsva.V,
+	}.RGBA()
+	a = uint32(hsva.A)
+	// alpha premultiplication
+	r = (r * a) / 0xFFFF
+	g = (g * a) / 0xFFFF
+	b = (b * a) / 0xFFFF
+	return
+}
+
+// Canon returns the color but with the H, S, and V fields are constrained to
+// the range 0.0-1.0
+func (hsv HSV) Canon () HSV {
+	hsv.H = clamp01(hsv.H)
+	hsv.S = clamp01(hsv.S)
+	hsv.V = clamp01(hsv.V)
+	return hsv
+}
+
 // Canon returns the color but with the H, S, and V fields are constrained to
 // the range 0.0-1.0
 func (hsva HSVA) Canon () HSVA {
@@ -58,7 +100,38 @@ func clamp01 (x float64) float64 {
 	return x
 }
 
-func RGBAToHSVA (r, g, b, a uint32) HSVA {
+func hsvModel (c color.Color) color.Color {
+	switch c := c.(type) {
+	case HSV:  return c
+	case HSVA: return HSV { H: c.H, S: c.S, V: c.V }
+	default:
+		r, g, b, a := c.RGBA()
+		// alpha unpremultiplication
+		r = (r / a) * 0xFFFF
+		g = (g / a) * 0xFFFF
+		b = (b / a) * 0xFFFF
+		return rgbToHSV(r, g, b)
+	}
+}
+
+func hsvaModel (c color.Color) color.Color {
+	switch c := c.(type) {
+	case HSV:  return HSVA { H: c.H, S: c.S, V: c.V, A: 0xFFFF }
+	case HSVA: return c
+	default:
+		r, g, b, a := c.RGBA()
+		hsv := rgbToHSV(r, g, b)
+
+		return HSVA {
+			H: hsv.H,
+			S: hsv.S,
+			V: hsv.V,
+			A: uint16(a),
+		}
+	}
+}
+
+func rgbToHSV (r, g, b uint32) HSV {
 	// Adapted from:
 	// https://www.cs.rit.edu/~ncs/color/t_convert.html
 	
@@ -78,27 +151,81 @@ func RGBAToHSVA (r, g, b, a uint32) HSVA {
 	if cg < minComponent { minComponent = cg }
 	if cb < minComponent { minComponent = cb }
 	
-	hsva := HSVA {
+	hsv := HSV {
 		V: maxComponent,
-		A: uint8(a >> 8),
 	}
 	
 	delta := maxComponent - minComponent
 	if delta == 0 {
 		// hsva.S is undefined, so hue doesn't matter
-		return hsva
+		return hsv
 	}
-	hsva.S = delta / maxComponent
+	hsv.S = delta / maxComponent
 	
 	switch {
-	case cr == maxComponent: hsva.H =     (cg - cb) / delta
-	case cg == maxComponent: hsva.H = 2 + (cb - cr) / delta
-	case cb == maxComponent: hsva.H = 4 + (cr - cg) / delta
+	case cr == maxComponent: hsv.H =     (cg - cb) / delta
+	case cg == maxComponent: hsv.H = 2 + (cb - cr) / delta
+	case cb == maxComponent: hsv.H = 4 + (cr - cg) / delta
 	}
 	
-	hsva.H *= 60
-	if hsva.H < 0 { hsva.H += 360 }
-	hsva.H /= 360
+	hsv.H *= 60
+	if hsv.H < 0 { hsv.H += 360 }
+	hsv.H /= 360
 	
-	return hsva
+	return hsv
+}
+
+// FormatNRGBA formats an NRGBA value into a hex string.
+func FormatNRGBA (nrgba color.NRGBA) string {
+	return fmt.Sprintf("%02X%02X%02X%02X", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
+}
+
+// ParseNRGBA parses an NRGBA value from a hex string. It can be of the format:
+//   - RGB
+//   - RGBA
+//   - RRGGBB
+//   - RRGGBBAA
+// If none of these are specified, this function will return an opaque black
+// color. Hex digits may either be upper case or lower case.
+func ParseNRGBA (str string) color.NRGBA {
+	runes := []rune(str)
+	c := color.NRGBA { A: 255 }
+	switch len(runes) {
+	case 3:
+		c.R = fillOctet(hexDigit(runes[0]))
+		c.G = fillOctet(hexDigit(runes[1]))
+		c.B = fillOctet(hexDigit(runes[2]))
+	case 4:
+		c.R = fillOctet(hexDigit(runes[0]))
+		c.G = fillOctet(hexDigit(runes[1]))
+		c.B = fillOctet(hexDigit(runes[2]))
+		c.A = fillOctet(hexDigit(runes[3]))
+	case 6:
+		c.R = hexOctet(runes[0], runes[1])
+		c.G = hexOctet(runes[2], runes[3])
+		c.B = hexOctet(runes[4], runes[5])
+	case 8:
+		c.R = hexOctet(runes[0], runes[1])
+		c.G = hexOctet(runes[2], runes[3])
+		c.B = hexOctet(runes[4], runes[5])
+		c.A = hexOctet(runes[6], runes[7])
+	}
+	return c
+}
+
+func hexDigit (r rune) uint8 {
+	switch {
+	case r >= '0' && r <= '9': return uint8(r - '0')
+	case r >= 'A' && r <= 'F': return uint8(r - 'A') + 10
+	case r >= 'a' && r <= 'f': return uint8(r - 'a') + 10
+	default: return 0
+	}
+}
+
+func fillOctet (low uint8) uint8 {
+	return low << 4 | low
+}
+
+func hexOctet (high, low rune) uint8 {
+	return hexDigit(high) << 4 | hexDigit(low)
 }

label.go

@@ -13,5 +13,7 @@ func NewLabel (text string) *Label {
 	this.SetRole(tomo.R("objects", "Label"))
 	this.SetText(text)
 	this.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
+	this.SetSelectable(true)
+	this.SetFocusable(true)
 	return this
 }

labelcheckbox.go

@@ -22,6 +22,8 @@ func NewLabelCheckbox (value bool, text string) *LabelCheckbox {
 	}
 	box.SetRole(tomo.R("objects", "LabelCheckbox"))
 	box.label.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
+	box.label.SetSelectable(false)
+	box.label.SetFocusable(false)
 	box.Add(box.checkbox)
 	box.Add(box.label)
 	box.SetAttr(tomo.ALayout(layouts.Row { false, true }))
@@ -53,12 +55,12 @@ func (this *LabelCheckbox) OnValueChange (callback func ()) event.Cookie {
 }
 
 func (this *LabelCheckbox) handleButtonDown (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	return true
 }
 
 func (this *LabelCheckbox) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	if this.Window().MousePosition().In(this.Bounds()) {
 		this.checkbox.SetFocused(true)
 		this.checkbox.Toggle()

layouts/flow.go

@@ -45,13 +45,14 @@ func (flow Flow) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	index := 0
 	for index < boxes.Len() {
 		// get a slice of boxes for this major step
-		stepIndexEnd := index + minorSteps
+		stepIndexStart := index
+		stepIndexEnd   := index + minorSteps
 		if stepIndexEnd > boxes.Len() { stepIndexEnd = boxes.Len() }
 		index += minorSteps
 		
 		// find a major size that will fit all boxes on this major step
 		majorSize := 0
-		for index := index; index < stepIndexEnd; index ++ {
+		for index := stepIndexStart; index < stepIndexEnd; index ++ {
 			boxSize := flow.major(boxes.MinimumSize(index))
 			if boxSize > majorSize { majorSize = boxSize }
 		}
@@ -61,7 +62,7 @@ func (flow Flow) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 		var size image.Point
 		size = flow.incrMajor(size, majorSize)
 		size = flow.incrMinor(size, minorSize)
-		for index := index; index < stepIndexEnd; index ++ {
+		for index := stepIndexStart; index < stepIndexEnd; index ++ {
 			bounds := image.Rectangle { Min: point, Max: point.Add(size) }
 			boxes.SetBounds(index, bounds)
 

layouts/rowcol.go

@@ -50,7 +50,7 @@ func (column Column) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	if !hints.OverflowY {
 		gaps       := boxes.Len() - 1
 		freeSpace  := float64(hints.Bounds.Dy() - hints.Gap.Y * gaps)
-		nExpanding := 0;
+		nExpanding := 0
 		for index := 0; index < boxes.Len(); index ++ {
 			if expands(index) {
 				nExpanding ++
@@ -121,7 +121,7 @@ func (row Row) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	if !hints.OverflowY {
 		gaps       := boxes.Len() - 1
 		freeSpace  := float64(hints.Bounds.Dx() - hints.Gap.X * gaps)
-		nExpanding := 0;
+		nExpanding := 0
 		for index := 0; index < boxes.Len(); index ++ {
 			if expands(index) {
 				nExpanding ++

menu.go

@@ -18,23 +18,28 @@ type Menu struct {
 }
 
 // NewMenu creates a new menu with the specified items. The menu will appear
-// directly under the anchor Object. If the anchor is nil, it will appear
-// directly under the mouse pointer instead.
-func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
-	menu := &Menu { }
-	if anchor == nil {
-		// TODO: *actually* put it under the mouse
-		window, err := tomo.NewWindow(menu.bounds)
-		if err != nil { return nil, err }
-		menu.Window = window
-	} else {
-		menu.bounds = menuBoundsFromAnchor(anchor)
-		menu.parent = anchor.GetBox().Window()
-		window, err := menu.parent.NewMenu(menu.bounds)
-		if err != nil { return nil, err }
-		menu.Window = window
-	}
+// directly under the mouse pointer.
+func NewMenu (parent tomo.Window, items ...tomo.Object) (*Menu, error) {
+	bounds := (image.Rectangle { }).Add(parent.MousePosition())
+	return newMenu(parent, bounds, items...)
+}
 
+// NewAnchoredMenu creates a new menu with the specified items. The menu will
+// appear directly under the anchor.
+func NewAnchoredMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
+	parent := anchor.GetBox().Window()
+	bounds := menuBoundsFromAnchor(anchor)
+	return newMenu(parent, bounds, items...)
+}
+
+func newMenu (parent tomo.Window, bounds image.Rectangle, items ...tomo.Object) (*Menu, error) {
+	menu := &Menu { }
+	menu.bounds = bounds
+	menu.parent = parent
+	window, err := menu.parent.NewMenu(menu.bounds)
+	if err != nil { return nil, err }
+	menu.Window = window
+	
 	menu.rootContainer = tomo.NewContainerBox()
 	menu.rootContainer.SetAttr(tomo.ALayout(layouts.ContractVertical))
 
@@ -74,6 +79,7 @@ func (this *Menu) TearOff () {
 	this.Window.Close()
 
 	this.rootContainer.Remove(this.tearLine)
+	this.rootContainer.SetTag("torn", true)
 	
 	this.Window = window
 	this.Window.SetRoot(this.rootContainer)

menuitem.go

@@ -20,10 +20,15 @@ type MenuItem struct {
 
 // NewMenuItem creates a new menu item with the specified text.
 func NewMenuItem (text string) *MenuItem {
+	return NewIconMenuItem(tomo.IconUnknown, text)
+}
+
+// NewIconMenuItem creates a new menu item with the specified icon and text.
+func NewIconMenuItem (icon tomo.Icon, text string) *MenuItem {
 	box := &MenuItem {
 		ContainerBox: tomo.NewContainerBox(),
 		label:        NewLabel(text),
-		icon:         NewIcon("", tomo.IconSizeSmall),
+		icon:         NewIcon(icon, tomo.IconSizeSmall),
 	}
 	box.SetRole(tomo.R("objects", "MenuItem"))
 	box.label.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
@@ -49,8 +54,7 @@ func (this *MenuItem) SetText (text string) {
 // SetIcon sets an icon for this item. Setting the icon to IconUnknown will
 // remove it.
 func (this *MenuItem) SetIcon (id tomo.Icon) {
-	if this.icon != nil { this.Remove(this.icon) }
-	this.Insert(NewIcon(id, tomo.IconSizeSmall), this.label)
+	this.icon.SetIcon(id, tomo.IconSizeSmall)
 }
 
 // OnClick specifies a function to be called when the menu item is clicked.

mimeicon.go

@@ -0,0 +1,46 @@
+package objects
+
+import "git.tebibyte.media/tomo/tomo"
+import "git.tebibyte.media/tomo/tomo/data"
+import "git.tebibyte.media/tomo/tomo/canvas"
+
+// MimeIcon displays an icon of a MIME type.
+type MimeIcon struct {
+	tomo.Box
+	mime data.Mime
+	size tomo.IconSize
+}
+
+// NewMimeIcon creates a new icon from a MIME type.
+func NewMimeIcon (mime data.Mime, size tomo.IconSize) *MimeIcon {
+	this := &MimeIcon {
+		Box: tomo.NewBox(),
+	}
+	this.SetRole(tomo.R("objects", "MimeIcon"))
+	this.SetIcon(mime, size)
+	this.OnIconSetChange(this.handleIconSetChange)
+	return this
+}
+
+// SetIcon sets the MIME type and size of the icon.
+func (this *MimeIcon) SetIcon (mime data.Mime, size tomo.IconSize) {
+	if this.mime == mime && this.size == size { return }
+	this.mime = mime
+	this.size = size
+	this.setTexture(tomo.MimeIconTexture(mime, size))
+}
+
+func (this *MimeIcon) handleIconSetChange () {
+	this.setTexture(tomo.MimeIconTexture(this.mime, this.size))
+}
+
+func (this *MimeIcon) setTexture (texture canvas.Texture) {
+	this.SetAttr(tomo.ATexture(texture))
+	this.SetAttr(tomo.ATextureMode(tomo.TextureModeCenter))
+	if texture == nil {
+		this.SetAttr(tomo.AMinimumSize(0, 0))
+	} else {
+		bounds := texture.Bounds()
+		this.SetAttr(tomo.AttrMinimumSize(bounds.Max.Sub(bounds.Min)))
+	}
+}

scrollbar.go

@@ -141,19 +141,15 @@ func (this *Scrollbar) handleKeyUp (key input.Key, numpad bool) bool {
 	switch key {
 	case input.KeyUp,   input.KeyLeft:  return true
 	case input.KeyDown, input.KeyRight: return true
-	case input.KeyHome: return true
-	case input.KeyEnd:  return true
+	case input.KeyPageUp:   return true
+	case input.KeyPageDown: return true
+	case input.KeyHome:     return true
+	case input.KeyEnd:      return true
 	}
 	return false
 }
 
 func (this *Scrollbar) handleKeyDown (key input.Key, numpad bool) bool {
-	var increment float64; if this.layout.vertical {
-		increment = -0.05
-	} else {
-		increment = 0.05
-	}
-
 	modifiers := this.Window().Modifiers()
 
 	switch key {
@@ -161,15 +157,20 @@ func (this *Scrollbar) handleKeyDown (key input.Key, numpad bool) bool {
 		if modifiers.Alt {
 			this.SetValue(0)
 		} else {
-			this.SetValue(this.Value() - increment)
+			this.scrollBy(this.StepSize())
 		}
 		return true
 	case input.KeyDown, input.KeyRight:
 		if modifiers.Alt {
 			this.SetValue(1)
 		} else {
-			this.SetValue(this.Value() + increment)
+			this.scrollBy(-this.StepSize())
 		}
+	case input.KeyPageUp:
+		this.scrollBy(this.PageSize())
+		return true
+	case input.KeyPageDown:
+		this.scrollBy(-this.PageSize())
 		return true
 	case input.KeyHome:
 		this.SetValue(0)
@@ -229,11 +230,22 @@ func (this *Scrollbar) handleButtonUp (button input.Button) bool {
 
 func (this *Scrollbar) handleMouseMove () bool {
 	if !this.dragging { return false }
+	this.drag()
 	return true
 }
 
 func (this *Scrollbar) handleScroll (x, y float64) bool {
 	if this.layout.linked == nil { return false }
+	
+	delta := (x + y)
+	if this.layout.vertical {
+		x = 0
+		y = delta
+	} else {
+		x = delta
+		y = 0
+	}
+	
 	this.layout.linked.ScrollTo (
 		this.layout.linked.ContentBounds().Min.
 		Sub(image.Pt(int(x), int(y))))

scrollcontainer.go

@@ -73,7 +73,11 @@ func NewScrollContainer (sides ScrollSide) *ScrollContainer {
 	this.OnKeyUp(this.handleKeyUp)
 	this.SetRole(tomo.R("objects", "ScrollContainer"))
 	this.SetTag(sides.String(), true)
-	this.SetAttr(tomo.ALayout(layouts.NewGrid(true, false)(true, false)))
+	if sides == ScrollHorizontal {
+		this.SetAttr(tomo.ALayout(layouts.NewGrid(true)(true, false)))
+	} else {
+		this.SetAttr(tomo.ALayout(layouts.NewGrid(true, false)(true, false)))
+	}
 	return this
 }
 
@@ -196,6 +200,7 @@ func (this *ScrollContainer) handleKeyDown (key input.Key, numpad bool) bool {
 		} else {
 			vector.Y -= this.PageSize().Y
 		}
+		this.scrollBy(vector)
 		return true
 	case input.KeyPageDown:
 		if modifiers.Shift {
@@ -203,6 +208,23 @@ func (this *ScrollContainer) handleKeyDown (key input.Key, numpad bool) bool {
 		} else {
 			vector.Y += this.PageSize().Y
 		}
+		this.scrollBy(vector)
+		return true
+	case input.KeyUp:
+		if modifiers.Shift {
+			vector.X -= this.StepSize().X
+		} else {
+			vector.Y -= this.StepSize().Y
+		}
+		this.scrollBy(vector)
+		return true
+	case input.KeyDown:
+		if modifiers.Shift {
+			vector.X += this.StepSize().X
+		} else {
+			vector.Y += this.StepSize().Y
+		}
+		this.scrollBy(vector)
 		return true
 	}
 	return false

swatch.go

@@ -8,6 +8,7 @@ import "git.tebibyte.media/tomo/tomo/input"
 import "git.tebibyte.media/tomo/tomo/event"
 import "git.tebibyte.media/tomo/tomo/canvas"
 import "git.tebibyte.media/tomo/objects/layouts"
+import "git.tebibyte.media/tomo/objects/internal"
 
 // Swatch displays a color, allowing the user to edit it by clicking on it.
 type Swatch struct {
@@ -91,26 +92,38 @@ func (this *Swatch) Choose () {
 	
 	committed := false
 	
-	colorPicker := NewColorPicker(this.Value())
-	colorPicker.OnValueChange(func () {
-		this.userSetValue(colorPicker.Value())
-	})
-	
-	hexInput := NewTextInput("TODO")
-	
+	colorPicker  := NewHSVAColorPicker(this.Value())
 	colorMemory  := this.value
+	hexInput     := NewTextInput("")
+	hexInput.SetFocused(true)
 	cancelButton := NewButton("Cancel")
 	cancelButton.SetIcon(tomo.IconDialogCancel)
+	okButton     := NewButton("OK")
+	okButton.SetIcon(tomo.IconDialogOkay)
+	
+	updateHexInput := func () {
+		nrgba := color.NRGBAModel.Convert(colorPicker.Value()).(color.NRGBA)
+		hexInput.SetValue(internal.FormatNRGBA(nrgba))
+	}
+	updateHexInput()
+	commit := func () {
+		committed = true
+		window.Close()
+	}
+	colorPicker.OnValueChange(func () {
+		this.userSetValue(colorPicker.Value())
+		updateHexInput()
+	})
+	hexInput.OnConfirm(commit)
+	hexInput.OnValueChange(func () {
+		nrgba := internal.ParseNRGBA(hexInput.Value())
+		this.userSetValue(nrgba)
+		colorPicker.SetValue(nrgba)
+	})
 	cancelButton.OnClick(func () {
 		window.Close()
 	})
-	okButton := NewButton("OK")
-	okButton.SetFocused(true)
-	okButton.SetIcon(tomo.IconDialogOkay)
-	okButton.OnClick(func () {
-		committed = true
-		window.Close()
-	})
+	okButton.OnClick(commit)
 	
 	controlRow := NewInnerContainer (
 		layouts.ContractHorizontal,
@@ -158,23 +171,23 @@ func (this *Swatch) userSetValue (value color.Color) {
 }
 
 func (this *Swatch) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	return true
-}
-
-func (this *Swatch) handleKeyUp (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return false }
+	if !isClickingKey(key) { return false }
 	this.Choose()
 	return true
 }
 
+func (this *Swatch) handleKeyUp (key input.Key, numberPad bool) bool {
+	if !isClickingKey(key) { return false }
+	return true
+}
+
 func (this *Swatch) handleButtonDown (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	return true
 }
 
 func (this *Swatch) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft { return false }
+	if !isClickingButton(button) { return false }
 	if this.Window().MousePosition().In(this.Bounds()) {
 		this.Choose()
 	}

tabbedcontainer.go

@@ -126,10 +126,10 @@ type tab struct {
 func (this *tab) setActive (active bool) {
 	if active {
 		this.SetRole(tomo.R("objects", "Tab"))
-		this.SetTag("active", false)
+		this.SetTag("active", true)
 	} else {
 		this.SetRole(tomo.R("objects", "Tab"))
-		this.SetTag("active", true)
+		this.SetTag("active", false)
 	}
 }
 

textinput.go

@@ -31,15 +31,25 @@ func NewTextInput (text string) *TextInput {
 	return this
 }
 
-// SetText sets the text content of the input.
-func (this *TextInput) SetText (text string) {
+// SetValue sets the text content of the input.
+func (this *TextInput) SetValue (text string) {
 	this.text = []rune(text)
 	this.TextBox.SetText(text)
 }
 
+// Value returns the text content of the input.
+func (this *TextInput) Value () string {
+	return string(this.text)
+}
+
+// SetText sets the text content of the input.
+func (this *TextInput) SetText (text string) {
+	this.SetValue(text)
+}
+
 // Text returns the text content of the input.
 func (this *TextInput) Text () string {
-	return string(this.text)
+	return this.Value()
 }
 
 // OnConfirm specifies a function to be called when the user presses enter
@@ -66,60 +76,55 @@ func (this *TextInput) handleKeyDown (key input.Key, numpad bool) bool {
 	dot       := this.Dot()
 	modifiers := this.Window().Modifiers()
 	word      := modifiers.Control
-	sel       := modifiers.Shift
 	changed   := false
 
-	// TODO all dot control (movement, selection, etc) should be done in the
-	// backend. (editing should be done here, though)
+	defer func () {
+		this.Select(dot)
+		if changed {
+			this.SetText(string(this.text))
+			this.on.valueChange.Broadcast()
+		}
+	} ()
 
 	switch {
-	case key == input.KeyEnter:
+	case isConfirmationKey(key):
 		this.on.confirm.Broadcast()
-	case key == input.KeyHome || (modifiers.Alt && key == input.KeyLeft):
-		dot.End = 0
-		if !sel { dot.Start = dot.End }
-	case key == input.KeyEnd || (modifiers.Alt && key == input.KeyRight):
-		dot.End = len(this.text)
-		if !sel { dot.Start = dot.End }
-	case key == input.KeyLeft:
-		if sel {
-			dot = text.SelectLeft(this.text, dot, word)
-		} else {
-			dot = text.MoveLeft(this.text, dot, word)
-		}
-	case key == input.KeyRight:
-		if sel {
-			dot = text.SelectRight(this.text, dot, word)
-		} else {
-			dot = text.MoveRight(this.text, dot, word)
-		}
+		return true
 	case key == input.KeyBackspace:
 		this.text, dot = text.Backspace(this.text, dot, word)
 		changed = true
+		return true
 	case key == input.KeyDelete:
 		this.text, dot = text.Delete(this.text, dot, word)
 		changed = true
-	case key == input.Key('a') && modifiers.Control:
-		dot.Start = 0
-		dot.End   = len(this.text)
-	case key.Printable():
+		return true
+	case key.Printable() && !modifiers.Control:
 		this.text, dot = text.Type(this.text, dot, rune(key))
 		changed = true
+		return true
+	default:
+		return false
 	}
-
-	this.Select(dot)
-	if changed {
-		this.SetText(string(this.text))
-		this.on.valueChange.Broadcast()
-	}
-	return true
 }
 
 func (this *TextInput) handleKeyUp (key input.Key, numpad bool) bool {
-	return true
+	modifiers := this.Window().Modifiers()
+	switch {
+	case isConfirmationKey(key):
+		return true
+	case key == input.KeyBackspace:
+		return true
+	case key == input.KeyDelete:
+		return true
+	case key.Printable() && !modifiers.Control:
+		return true
+	default:
+		return false
+	}
 }
 
 func (this *TextInput) handleScroll (x, y float64) bool {
-	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
+	if x == 0 { return false }
+	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
 	return true
 }

textview.go

@@ -22,6 +22,6 @@ func NewTextView (text string) *TextView {
 }
 
 func (this *TextView) handleScroll (x, y float64) bool {
-	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
+	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
 	return true
 }