Various improvements to Icon, MimeIcon

Full remediation of #6

.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

@@ -28,17 +28,15 @@ func NewButton (text string) *Button {
 		ContainerBox: tomo.NewContainerBox(),
 		label:        NewLabel(text),
 	}
-	box.SetRole(tomo.R("objects", "Button", ""))
+	box.SetRole(tomo.R("objects", "Button"))
-	box.label.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
+	box.label.SetAttr(tomo.AAlign(tomo.AlignMiddle, tomo.AlignMiddle))
-	box.SetLayout(buttonLayout)
+	box.SetAttr(tomo.ALayout(buttonLayout))
 	box.SetText(text)
 	
-	box.CaptureDND(true)
+	box.SetInputMask(true)
-	box.CaptureMouse(true)
+	box.OnButtonDown(box.handleButtonDown)
-	box.CaptureScroll(true)
+	box.OnButtonUp(box.handleButtonUp)
-	box.CaptureKeyboard(true)
+	box.OnKeyDown(box.handleKeyDown)
-	
-	box.OnMouseUp(box.handleMouseUp)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
@@ -71,6 +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()
 }
 
@@ -81,22 +80,34 @@ func (this *Button) OnClick (callback func ()) event.Cookie {
 
 func (this *Button) applyLayout () {
 	if this.labelActive && this.icon == nil {
-		this.SetLayout(buttonLayout)
+		this.SetAttr(tomo.ALayout(buttonLayout))
 	} else if !this.labelActive && this.icon != nil {
-		this.SetLayout(iconButtonLayout)
+		this.SetAttr(tomo.ALayout(iconButtonLayout))
 	} else {
-		this.SetLayout(bothButtonLayout)
+		this.SetAttr(tomo.ALayout(bothButtonLayout))
 	}
 }
 
-func (this *Button) handleKeyUp (key input.Key, numberPad bool) {
+func (this *Button) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	this.on.click.Broadcast()
+	return true
 }
 
-func (this *Button) handleMouseUp (button input.Button) {
+func (this *Button) handleKeyUp (key input.Key, numberPad bool) bool {
-	if button != input.ButtonLeft { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	if this.MousePosition().In(this.Bounds()) {
+	this.on.click.Broadcast()
+	return true
+}
+
+func (this *Button) handleButtonDown (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	return true
+}
+
+func (this *Button) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.on.click.Broadcast()
 	}
+	return true
 }

calendar.go

@@ -16,7 +16,7 @@ type Calendar struct {
 	monthLabel *Label
 	
 	on struct {
-		edit event.FuncBroadcaster
+		valueChange event.FuncBroadcaster
 	}
 }
 
@@ -26,61 +26,64 @@ func NewCalendar (tm time.Time) *Calendar {
 		ContainerBox: tomo.NewContainerBox(),
 		time:         tm,
 	}
-	calendar.SetRole(tomo.R("objects", "Calendar", ""))
+	calendar.SetRole(tomo.R("objects", "Calendar"))
-	calendar.SetLayout(layouts.ContractVertical)
+	calendar.SetAttr(tomo.ALayout(layouts.ContractVertical))
 	
 	prevButton := NewButton("")
 	prevButton.SetIcon(tomo.IconGoPrevious)
 	prevButton.OnClick(func () {
 		calendar.prevMonth()
-		calendar.on.edit.Broadcast()
+		calendar.on.valueChange.Broadcast()
 	})
 	nextButton := NewButton("")
 	nextButton.SetIcon(tomo.IconGoNext)
 	nextButton.OnClick(func () {
 		calendar.nextMonth()
-		calendar.on.edit.Broadcast()
+		calendar.on.valueChange.Broadcast()
 	})
 	calendar.monthLabel = NewLabel("")
-	calendar.monthLabel.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
+	calendar.monthLabel.SetAttr(tomo.AAlign(tomo.AlignMiddle, tomo.AlignMiddle))
 	
 	calendar.grid = tomo.NewContainerBox()
-	calendar.grid.SetRole(tomo.R("objects", "CalendarGrid", ""))
+	calendar.grid.SetRole(tomo.R("objects", "CalendarGrid"))
-	calendar.grid.SetLayout(layouts.NewGrid (
+	calendar.grid.SetAttr(tomo.ALayout(layouts.NewGrid (
-		[]bool { true, true, true, true, true, true, true },
+		true, true, true, true, true, true, true)()))
-		[]bool { }))
 	calendar.Add(NewInnerContainer (
 		layouts.Row { false, true, false },
 		prevButton, calendar.monthLabel, nextButton))
 	calendar.Add(calendar.grid)
 	
 	calendar.OnScroll(calendar.handleScroll)
-	calendar.CaptureScroll(true)
 	
 	calendar.refresh()
 	return calendar
 }
 
-// SetTime sets the date the calendar will display.
+// Value returns the time this calendar is displaying.
-func (this *Calendar) SetTime (tm time.Time) {
+func (this *Calendar) Value () time.Time {
+	return this.time
+}
+
+// SetValue sets the date the calendar will display.
+func (this *Calendar) SetValue (tm time.Time) {
 	if this.time == tm { return }
 	this.time = tm
 	this.refresh()
 }
 
-// OnEdit sets a function to be called when the user changes the date on the
+// OnValueChange sets a function to be called when the user changes the date on
-// calendar.
+// the calendar.
-func (this *Calendar) OnEdit (callback func ()) {
+func (this *Calendar) OnValueChange (callback func ()) {
-	this.on.edit.Connect(callback)
+	this.on.valueChange.Connect(callback)
 }
 
 func (this *Calendar) prevMonth () {
-	this.time = firstOfMonth(this.time.Add(24 * time.Hour * 40))
+	this.time = firstOfMonth(this.time.Add(24 * time.Hour * -20))
 	this.refresh()
 }
 
 func (this *Calendar) nextMonth () {
-	this.time = firstOfMonth(this.time.Add(24 * time.Hour * -20))
+	this.time = firstOfMonth(this.time.Add(24 * time.Hour * 40))
 	this.refresh()
 }
 
@@ -94,9 +97,9 @@ func (this *Calendar) refresh () {
 	this.grid.Clear()
 	for _, day := range weekdayAbbreviations {
 		dayLabel := tomo.NewTextBox()
-		dayLabel.SetRole(tomo.R("objects", "CalendarWeekdayHeader", ""))
+		dayLabel.SetRole(tomo.R("objects", "CalendarWeekdayHeader"))
 		dayLabel.SetText(day)
-		dayLabel.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
+		dayLabel.SetAttr(tomo.AAlign(tomo.AlignMiddle, tomo.AlignMiddle))
 		this.grid.Add(dayLabel)
 	}
 	
@@ -112,9 +115,11 @@ func (this *Calendar) refresh () {
 			day := tomo.NewTextBox()
 			day.SetText(fmt.Sprint(dayIter))
 			if weekday == 1 || weekday == 0 {
-				day.SetRole(tomo.R("objects", "CalendarDay", "weekend"))
+				day.SetRole(tomo.R("objects", "CalendarDay"))
+				day.SetTag("weekend", true)
 			} else {
-				day.SetRole(tomo.R("objects", "CalendarDay", "weekday"))
+				day.SetRole(tomo.R("objects", "CalendarDay"))
+				day.SetTag("weekday", true)
 			}
 			this.grid.Add(day)
 		} else {
@@ -123,12 +128,13 @@ func (this *Calendar) refresh () {
 	}
 }
 
-func (this *Calendar) handleScroll (x, y float64) {
+func (this *Calendar) handleScroll (x, y float64) bool {
 	if y < 0 {
-		this.nextMonth()
-	} else {
 		this.prevMonth()
+	} else {
+		this.nextMonth()
 	}
+	return true
 }
 
 func firstOfMonth (tm time.Time) time.Time {

checkbox.go

@@ -18,49 +18,61 @@ func NewCheckbox (value bool) *Checkbox {
 	box := &Checkbox {
 		Box: tomo.NewBox(),
 	}
-	box.SetRole(tomo.R("objects", "Checkbox", ""))
+	box.SetRole(tomo.R("objects", "Checkbox"))
-	box.SetValue(false)
+	box.SetValue(value)
 	
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
+	box.OnButtonUp(box.handleButtonUp)
+	box.OnKeyDown(box.handleKeyDown)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
 }
 
-// SetValue sets the value of the checkbox.
-func (this *Checkbox) SetValue (value bool) {
-	this.value = value
-	if this.value {
-		this.SetTextureCenter(tomo.IconCheckboxChecked.Texture(tomo.IconSizeSmall))
-	} else {
-		this.SetTextureCenter(tomo.IconCheckboxUnchecked.Texture(tomo.IconSizeSmall))
-	}
-}
-
-// Toggle toggles the value of the checkbox between true and false.
-func (this *Checkbox) Toggle () {
-	this.SetValue(!this.Value())
-}
-
 // Value returns the value of the checkbox.
 func (this *Checkbox) Value () bool {
 	return this.value
 }
 
-// OnValueChange specifies a function to be called when the checkbox's value
+// SetValue sets the value of the checkbox.
-// changes.
+func (this *Checkbox) SetValue (value bool) {
+	this.value = value
+	// the theme shall decide what checked and unchecked states look like
+	this.SetTag("checked",    value)
+	this.SetTag("unchecked", !value)
+}
+
+// Toggle toggles the value of the checkbox between true and false.
+func (this *Checkbox) Toggle () {
+	this.SetValue(!this.Value())
+}
+
+// OnValueChange specifies a function to be called when the user checks or
+// unchecks the checkbox.
 func (this *Checkbox) OnValueChange (callback func ()) event.Cookie {
 	return this.on.valueChange.Connect(callback)
 }
 
-func (this *Checkbox) handleKeyUp (key input.Key, numberPad bool) {
+func (this *Checkbox) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false }
 	this.Toggle()
+	return true
 }
 
-func (this *Checkbox) handleMouseUp (button input.Button) {
+func (this *Checkbox) handleKeyUp (key input.Key, numberPad bool) bool {
-	if button != input.ButtonLeft { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false}
-	if this.MousePosition().In(this.Bounds()) {
+	return true
+}
+
+func (this *Checkbox) handleButtonDown (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	return true
+}
+
+func (this *Checkbox) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.Toggle()
 	}
+	return true
 }

colorpicker.go

@@ -0,0 +1,159 @@
+package objects
+
+import "image/color"
+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/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
+// parameters.
+type ColorPicker struct {
+	tomo.ContainerBox
+	value internal.HSVA
+	
+	pickerMap   *colorPickerMap
+	hueSlider   *Slider
+	alphaSlider *Slider
+	
+	on struct {
+		valueChange event.FuncBroadcaster
+	}
+}
+
+// NewColorPicker creates a new color picker with the specified color.
+func NewColorPicker (value color.Color) *ColorPicker {
+	picker := &ColorPicker {
+		ContainerBox: tomo.NewContainerBox(),
+	}
+	picker.SetRole(tomo.R("objects", "ColorPicker"))
+	picker.SetAttr(tomo.ALayout(layouts.Row { true, false, false }))
+	picker.pickerMap = newColorPickerMap(picker)
+	picker.Add(picker.pickerMap)
+	
+	picker.hueSlider = NewVerticalSlider(0.0)
+	picker.Add(picker.hueSlider)
+	picker.hueSlider.OnValueChange(func () {
+		picker.value.H = picker.hueSlider.Value()
+		picker.on.valueChange.Broadcast()
+		picker.pickerMap.Invalidate()
+	})
+	
+	picker.alphaSlider = NewVerticalSlider(0.0)
+	picker.Add(picker.alphaSlider)
+	picker.alphaSlider.OnValueChange(func () {
+		picker.value.A = uint8(picker.alphaSlider.Value() * 255)
+		picker.on.valueChange.Broadcast()
+		picker.pickerMap.Invalidate()
+	})
+	
+	if value == nil { value = color.Transparent }
+	picker.SetValue(value)
+	return picker
+}
+
+// Value returns the color of the picker.
+func (this *ColorPicker) Value () color.Color {
+	return this.value
+}
+
+// SetValue sets the color of the picker.
+func (this *ColorPicker) SetValue (value color.Color) {
+	if value == nil { value = color.Transparent }
+	this.value = internal.RGBAToHSVA(value.RGBA())
+	this.hueSlider.SetValue(this.value.H)
+	this.alphaSlider.SetValue(float64(this.value.A) / 255)
+}
+
+// OnValueChange specifies a function to be called when the user changes the
+// swatch's color.
+func (this *ColorPicker) 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) {
+	return this.value.RGBA()
+}
+
+type colorPickerMap struct {
+	tomo.CanvasBox
+	dragging bool
+	parent *ColorPicker
+}
+
+func newColorPickerMap (parent *ColorPicker) *colorPickerMap {
+	picker := &colorPickerMap {
+		CanvasBox: tomo.NewCanvasBox(),
+		parent: parent,
+	}
+	picker.SetDrawer(picker)
+	picker.SetRole(tomo.R("objects", "ColorPickerMap"))
+	picker.OnButtonUp(picker.handleButtonUp)
+	picker.OnButtonDown(picker.handleButtonDown)
+	picker.OnMouseMove(picker.handleMouseMove)
+	return picker
+}
+
+func (this *colorPickerMap) 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 {
+	if button != input.ButtonLeft { return false }
+	this.dragging = false
+	return true
+}
+
+func (this *colorPickerMap) handleMouseMove () bool {
+	if !this.dragging { return false }
+	this.drag()
+	return true
+}
+
+func (this *colorPickerMap) drag () {
+	pointer := this.Window().MousePosition()
+	bounds  := this.InnerBounds()
+	this.parent.value.S =     float64(pointer.X - bounds.Min.X) / float64(bounds.Dx())
+	this.parent.value.V = 1 - float64(pointer.Y - bounds.Min.Y) / float64(bounds.Dy())
+	this.parent.value = this.parent.value.Canon()
+	this.parent.on.valueChange.Broadcast()
+	this.Invalidate()
+}
+
+func (this *colorPickerMap) 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 ++ {
+		xx := x - bounds.Min.X
+		yy := y - bounds.Min.Y
+		
+		pixel := internal.HSVA {
+			H: this.parent.value.H,
+			S:     float64(xx) / float64(bounds.Dx()),
+			V: 1 - float64(yy) / float64(bounds.Dy()),
+			A: 255,
+		}
+		
+		sPos := int(     this.parent.value.S  * float64(bounds.Dx()))
+		vPos := int((1 - this.parent.value.V) * float64(bounds.Dy()))
+		sDist := sPos - xx
+		vDist := vPos - yy
+		crosshair :=
+			(sDist == 0 || vDist == 0) &&
+			-8 < sDist && sDist < 8 &&
+			-8 < vDist && vDist < 8
+		if crosshair {
+			pixel.S = 1 - pixel.S
+			pixel.V = 1 - pixel.V
+		}
+		
+		can.Set(x, y, pixel)
+	}}
+}
+

container.go

@@ -15,7 +15,7 @@ func newContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := &Container {
 		ContainerBox: tomo.NewContainerBox(),
 	}
-	this.SetLayout(layout)
+	this.SetAttr(tomo.ALayout(layout))
 	for _, child := range children {
 		this.Add(child)
 	}
@@ -27,7 +27,8 @@ func newContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 // window, tab pane, etc.
 func NewOuterContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
-	this.SetRole(tomo.R("objects", "Container", "outer"))
+	this.SetRole(tomo.R("objects", "Container"))
+	this.SetTag("outer", true)
 	return this
 }
 
@@ -35,14 +36,16 @@ func NewOuterContainer (layout tomo.Layout, children ...tomo.Object) *Container
 // around it. It is meant to be used as a root container for a ScrollContainer.
 func NewSunkenContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
-	this.SetRole(tomo.R("objects", "Container", "sunken"))
+	this.SetRole(tomo.R("objects", "Container"))
+	this.SetTag("sunken", true)
 	return this
 }
 
 // NewInnerContainer creates a new container that has no padding around it.
 func NewInnerContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
-	this.SetRole(tomo.R("objects", "Container", "inner"))
+	this.SetRole(tomo.R("objects", "Container"))
+	this.SetTag("inner", true)
 	return this
 }
 

dialog.go

@@ -55,7 +55,7 @@ func NewDialog (kind DialogKind, parent tomo.Window, title, message string, opti
 	dialog.SetTitle(title)
 	icon := NewIcon(iconId, tomo.IconSizeLarge)
 	messageText := NewLabel(message)
-	messageText.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	messageText.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
 
 	for _, option := range options {
 		if option, ok := option.(clickable); ok {
@@ -63,10 +63,10 @@ func NewDialog (kind DialogKind, parent tomo.Window, title, message string, opti
 		}
 	}
 	dialog.controlRow = NewInnerContainer(layouts.ContractHorizontal, options...)
-	dialog.controlRow.SetAlign(tomo.AlignEnd, tomo.AlignEnd)
+	dialog.controlRow.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignEnd))
 
 	dialog.SetRoot(NewOuterContainer (
-		layouts.NewGrid([]bool { true }, []bool { true, false }),
+		layouts.Column { true, false },
 		NewInnerContainer(layouts.ContractHorizontal, icon, messageText),
 		dialog.controlRow))
 	return dialog, nil

go.mod

@@ -2,6 +2,4 @@ module git.tebibyte.media/tomo/objects
 
 go 1.20
 
-require git.tebibyte.media/tomo/tomo v0.38.0
+require git.tebibyte.media/tomo/tomo v0.45.0
-
-require golang.org/x/image v0.11.0 // indirect

go.sum

@@ -1,35 +1,2 @@
-git.tebibyte.media/tomo/tomo v0.38.0 h1:K5TP67RxnszudeNfmGZiU5cFTRjFueXiI3NCsgw+05U=
+git.tebibyte.media/tomo/tomo v0.45.0 h1:fQH0WIPidW275hOq9dE6R7p064xG1RGx2QU68Avlr84=
-git.tebibyte.media/tomo/tomo v0.38.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
+git.tebibyte.media/tomo/tomo v0.45.0/go.mod h1:WrtilgKB1y8O2Yu7X4mYcRiqOlPR8NuUnoA/ynkQWrs=
-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=

heading.go

@@ -15,8 +15,11 @@ func NewHeading (level int, text string) *Heading {
 	if level < 0 { level = 0 }
 	if level > 2 { level = 2 }
 	this := &Heading { TextBox: tomo.NewTextBox() }
-	this.SetRole(tomo.R("objects", "Heading", fmt.Sprint(level)))
+	this.SetRole(tomo.R("objects", "Heading"))
+	this.SetTag(fmt.Sprint(level), true)
 	this.SetText(text)
+	this.SetSelectable(true)
+	this.SetFocusable(true)
 	return this
 }
 

icon.go

@@ -1,41 +1,52 @@
 package objects
 
-import "image"
 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 {
+	switch size {
+	case tomo.IconSizeLarge:  return "large"
+	case tomo.IconSizeMedium: return "medium"
+	default:                  return "small"
+	}
 }
 
 // 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", size.String()))
+	this.SetRole(tomo.R("objects", "Icon"))
-	this.SetTexture(id.Texture(size))
+	this.SetIcon(icon, size)
+	this.OnIconSetChange(this.handleIconSetChange)
 	return this
 }
 
-// NewMimeIcon creates a new icon from a MIME type.
+// SetIcon sets the icon.
-func NewMimeIcon (mime data.Mime, size tomo.IconSize) *Icon {
+func (this *Icon) SetIcon (icon tomo.Icon, size tomo.IconSize) {
-	this := &Icon {
+	if this.icon == icon { return }
-		Box: tomo.NewBox(),
+	this.icon = icon
-	}
+	this.setTexture(icon.Texture(size))
-	this.SetRole(tomo.R("objects", "Icon", size.String()))
-	this.SetTexture(tomo.MimeIcon(mime, size))
-	return this
 }
 
-func (this *Icon) SetTexture (texture canvas.Texture) {
+func (this *Icon) handleIconSetChange () {
-	this.Box.SetTextureCenter(texture)
+	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 {
-		this.SetMinimumSize(image.Pt(0, 0))
+		this.SetAttr(tomo.AMinimumSize(0, 0))
 	} else {
 		bounds := texture.Bounds()
-		this.SetMinimumSize(bounds.Max.Sub(bounds.Min))
+		this.SetAttr(tomo.AttrMinimumSize(bounds.Max.Sub(bounds.Min)))
 	}
 }

internal/color.go

@@ -0,0 +1,104 @@
+package internal
+
+type HSVA struct {
+	H float64
+	S float64
+	V float64
+	A uint8
+}
+
+func (hsva HSVA) RGBA () (r, g, b, a uint32) {
+	// Adapted from:
+	// https://www.cs.rit.edu/~ncs/color/t_convert.html
+	
+	component := func (x float64) uint32 {
+		return uint32(float64(0xFFFF) * x)
+	}
+
+	ca := uint32(hsva.A) << 8
+	s := clamp01(hsva.S)
+	v := clamp01(hsva.V)
+	if s == 0 {
+		light := component(v)
+		return light, light, light, ca
+	}
+	
+	h := clamp01(hsva.H) * 360
+	sector := int(h / 60)
+	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)))
+	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
+	}
+}
+
+// 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 {
+	hsva.H = clamp01(hsva.H)
+	hsva.S = clamp01(hsva.S)
+	hsva.V = clamp01(hsva.V)
+	return hsva
+}
+
+func clamp01 (x float64) float64 {
+	if x > 1.0 { return 1.0 }
+	if x < 0.0 { return 0.0 }
+	return x
+}
+
+func RGBAToHSVA (r, g, b, a uint32) HSVA {
+	// Adapted from:
+	// https://www.cs.rit.edu/~ncs/color/t_convert.html
+	
+	component := func (x uint32) float64 {
+		return clamp01(float64(x) / 0xFFFF)
+	}
+	cr := component(r)
+	cg := component(g)
+	cb := component(b)
+	
+	var maxComponent float64
+	if cr > maxComponent { maxComponent = cr }
+	if cg > maxComponent { maxComponent = cg }
+	if cb > maxComponent { maxComponent = cb }
+	var minComponent = 1.0
+	if cr < minComponent { minComponent = cr }
+	if cg < minComponent { minComponent = cg }
+	if cb < minComponent { minComponent = cb }
+	
+	hsva := HSVA {
+		V: maxComponent,
+		A: uint8(a >> 8),
+	}
+	
+	delta := maxComponent - minComponent
+	if delta == 0 {
+		// hsva.S is undefined, so hue doesn't matter
+		return hsva
+	}
+	hsva.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
+	}
+	
+	hsva.H *= 60
+	if hsva.H < 0 { hsva.H += 360 }
+	hsva.H /= 360
+	
+	return hsva
+}

label.go

@@ -10,7 +10,10 @@ type Label struct {
 // NewLabel creates a new text label.
 func NewLabel (text string) *Label {
 	this := &Label { TextBox: tomo.NewTextBox() }
-	this.SetRole(tomo.R("objects", "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

@@ -20,17 +20,24 @@ func NewLabelCheckbox (value bool, text string) *LabelCheckbox {
 		checkbox:     NewCheckbox(value),
 		label:        NewLabel(text),
 	}
-	box.SetRole(tomo.R("objects", "LabelCheckbox", ""))
+	box.SetRole(tomo.R("objects", "LabelCheckbox"))
-	box.label.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	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.SetLayout(layouts.NewGrid([]bool { false, true }, []bool { false }))
+	box.SetAttr(tomo.ALayout(layouts.Row { false, true }))
 
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
-	box.label.OnMouseUp(box.handleMouseUp)
+	box.OnButtonUp(box.handleButtonUp)
 	return box
 }
 
+// Value returns the value of the checkbox.
+func (this *LabelCheckbox) Value () bool {
+	return this.checkbox.Value()
+}
+
 // SetValue sets the value of the checkbox.
 func (this *LabelCheckbox) SetValue (value bool) {
 	this.checkbox.SetValue(value)
@@ -41,21 +48,22 @@ func (this *LabelCheckbox) Toggle () {
 	this.checkbox.Toggle()
 }
 
-// Value returns the value of the checkbox.
+// OnValueChange specifies a function to be called when the user checks or
-func (this *LabelCheckbox) Value () bool {
+// unchecks the checkbox.
-	return this.checkbox.Value()
-}
-
-// OnValueChange specifies a function to be called when the checkbox's value
-// changes.
 func (this *LabelCheckbox) OnValueChange (callback func ()) event.Cookie {
 	return this.checkbox.OnValueChange(callback)
 }
 
-func (this *LabelCheckbox) handleMouseUp (button input.Button) {
+func (this *LabelCheckbox) handleButtonDown (button input.Button) bool {
-	if button != input.ButtonLeft { return }
+	if button != input.ButtonLeft { return false }
-	if this.MousePosition().In(this.Bounds()) {
+	return true
+}
+
+func (this *LabelCheckbox) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.checkbox.SetFocused(true)
 		this.checkbox.Toggle()
 	}
+	return true
 }

labelswatch.go

@@ -0,0 +1,75 @@
+package objects
+
+import "image/color"
+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"
+
+// LabelSwatch is a swatch with a label.
+type LabelSwatch struct {
+	tomo.ContainerBox
+	swatch  *Swatch
+	label   *Label
+}
+
+// NewLabelSwatch creates a new labeled swatch with the specified color and
+// label text.
+func NewLabelSwatch (value color.Color, text string) *LabelSwatch {
+	box := &LabelSwatch {
+		ContainerBox: tomo.NewContainerBox(),
+		swatch:       NewSwatch(value),
+		label:        NewLabel(text),
+	}
+	box.SetRole(tomo.R("objects", "LabelSwatch"))
+	box.swatch.label = text
+	box.label.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
+	box.Add(box.swatch)
+	box.Add(box.label)
+	box.SetAttr(tomo.ALayout(layouts.Row { false, true }))
+
+	box.OnButtonDown(box.handleButtonDown)
+	box.OnButtonUp(box.handleButtonUp)
+	return box
+}
+
+// Value returns the color of the swatch.
+func (this *LabelSwatch) Value () color.Color {
+	return this.swatch.Value()
+}
+
+// SetValue sets the color of the swatch.
+func (this *LabelSwatch) SetValue (value color.Color) {
+	this.swatch.SetValue(value)
+}
+
+// OnValueChange specifies a function to be called when the swatch's color
+// is changed by the user.
+func (this *LabelSwatch) OnValueChange (callback func ()) event.Cookie {
+	return this.swatch.OnValueChange(callback)
+}
+
+// RGBA satisfies the color.Color interface
+func (this *LabelSwatch) RGBA () (r, g, b, a uint32) {
+	return this.swatch.RGBA()
+}
+
+// OnConfirm specifies a function to be called when the user selects "OK" in the
+// color picker.
+func (this *LabelSwatch) OnConfirm (callback func ()) event.Cookie {
+	return this.swatch.OnConfirm(callback)
+}
+
+func (this *LabelSwatch) handleButtonDown (button input.Button) bool {
+	if button != input.ButtonLeft { return true }
+	return true
+}
+
+func (this *LabelSwatch) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return true }
+	if this.Window().MousePosition().In(this.Bounds()) {
+		this.swatch.SetFocused(true)
+		this.swatch.Choose()
+	}
+	return true
+}

layouts/contract.go

@@ -15,19 +15,19 @@ const ContractVertical Contract = true
 // ContractHorizontal is a horizontal contracted layout.
 const ContractHorizontal Contract = false
 
-func (contract Contract) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (contract Contract) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
 	return contract.fallback().MinimumSize(hints, boxes)
 }
 
-func (contract Contract) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (contract Contract) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	contract.fallback().Arrange(hints, boxes)
 }
 
-func (contract Contract) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (contract Contract) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
 	return contract.fallback().RecommendedHeight(hints, boxes, width)
 }
 
-func (contract Contract) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (contract Contract) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
 	return contract.fallback().RecommendedWidth(hints, boxes, height)
 }
 

layouts/flow.go

@@ -17,21 +17,21 @@ const FlowVertical Flow = true
 // FlowHorizontal is a horizontal flow layout.
 const FlowHorizontal Flow = false
 
-func (flow Flow) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (flow Flow) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
 	// TODO: write down somewhere that layout minimums aren't taken into
 	// account when the respective direction is overflowed
 	return flow.fallback().MinimumSize(hints, boxes)
 }
 
-func (flow Flow) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (flow Flow) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	if flow.v() && !hints.OverflowY || flow.h() && !hints.OverflowX {
 		flow.fallback().Arrange(hints, boxes)
 	}
 
 	// find a minor size value that will fit all boxes
 	minorSize := 0
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		boxSize := flow.minor(box.MinimumSize())
+		boxSize := flow.minor(boxes.MinimumSize(index))
 		if boxSize > minorSize { minorSize = boxSize }
 	}
 	if minorSize == 0 { return }
@@ -43,17 +43,17 @@ func (flow Flow) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	// arrange
 	point := hints.Bounds.Min
 	index := 0
-	for index < len(boxes) {
+	for index < boxes.Len() {
 		// get a slice of boxes for this major step
-		stepIndexEnd := index + minorSteps
+		stepIndexStart := index
-		if stepIndexEnd > len(boxes) { stepIndexEnd = len(boxes) }
+		stepIndexEnd   := index + minorSteps
-		step := boxes[index:stepIndexEnd]
+		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 _, box := range step {
+		for index := stepIndexStart; index < stepIndexEnd; index ++ {
-			boxSize := flow.major(box.MinimumSize())
+			boxSize := flow.major(boxes.MinimumSize(index))
 			if boxSize > majorSize { majorSize = boxSize }
 		}
 		if majorSize == 0 { continue }
@@ -62,9 +62,9 @@ func (flow Flow) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 		var size image.Point
 		size = flow.incrMajor(size, majorSize)
 		size = flow.incrMinor(size, minorSize)
-		for _, box := range step {
+		for index := stepIndexStart; index < stepIndexEnd; index ++ {
 			bounds := image.Rectangle { Min: point, Max: point.Add(size) }
-			box.SetBounds(bounds)
+			boxes.SetBounds(index, bounds)
 
 			point = flow.incrMinor(point, minorSize + flow.minor(hints.Gap))
 		}
@@ -125,12 +125,12 @@ func (flow Flow) fallback () tomo.Layout {
 	return Contract(flow)
 }
 
-func (flow Flow) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (flow Flow) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
 	// TODO
 	return 0
 }
 
-func (flow Flow) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (flow Flow) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
 	// TODO
 	return 0
 }

layouts/grid.go

@@ -18,15 +18,21 @@ type Grid struct {
 // will contract. Boxes are laid out left to right, then top to bottom. Boxes
 // that go beyond the lengh of rows will be laid out according to columns, but
 // they will not expand vertically.
-func NewGrid (columns, rows []bool) *Grid {
+//
-	this := &Grid {
+// If you aren't sure how to use this constructor, here is an example:
-		xExpand: columns,
+//
-		yExpand: rows,
+//            X0     X1    X2     Y0    Y1    Y2
+//   NewGrid(true, false, true)(false, true, true)
+func NewGrid (columns ...bool) func (rows ...bool) *Grid {
+	return func (rows ...bool) *Grid {
+		return &Grid {
+			xExpand: columns,
+			yExpand: rows,
+		}
 	}
-	return this
 }
 
-func (this *Grid) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (this *Grid) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
 	cols, rows := this.minimums(boxes)
 	size := image.Pt (
 		(len(cols) - 1) * hints.Gap.X,
@@ -36,7 +42,7 @@ func (this *Grid) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.P
 	return size
 }
 
-func (this *Grid) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (this *Grid) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	xExpand := func (index int) bool {
 		return this.xExpand[index]
 	}
@@ -50,9 +56,9 @@ func (this *Grid) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	expand(hints, rows, hints.Bounds.Dy(), yExpand)
 
 	position := hints.Bounds.Min
-	for index, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
 		col, row := index % len(cols), index / len(cols)
-		box.SetBounds(image.Rectangle {
+		boxes.SetBounds(index, image.Rectangle {
 			Min: position,
 			Max: position.Add(image.Pt(cols[col], rows[row])),
 		})
@@ -65,13 +71,13 @@ func (this *Grid) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	}
 }
 
-func (this *Grid) minimums (boxes []tomo.Box) ([]int, []int) {
+func (this *Grid) minimums (boxes tomo.BoxQuerier) ([]int, []int) {
 	nCols, nRows := this.dimensions(boxes)
 	cols,  rows  := make([]int, nCols), make([]int, nRows)
 
-	for index, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
 		col, row := index % len(cols), index / len(cols)
-		minimum := box.MinimumSize()
+		minimum := boxes.MinimumSize(index)
 		if cols[col] < minimum.X {
 			cols[col] = minimum.X
 		}
@@ -83,8 +89,8 @@ func (this *Grid) minimums (boxes []tomo.Box) ([]int, []int) {
 	return cols, rows
 }
 
-func (this *Grid) dimensions (boxes []tomo.Box) (int, int) {
+func (this *Grid) dimensions (boxes tomo.BoxQuerier) (int, int) {
-	return len(this.xExpand), ceilDiv(len(boxes), len(this.xExpand)) 
+	return len(this.xExpand), ceilDiv(boxes.Len(), len(this.xExpand)) 
 }
 
 func expand (hints tomo.LayoutHints, sizes []int, space int, expands func (int) bool) {
@@ -106,15 +112,14 @@ func expand (hints tomo.LayoutHints, sizes []int, space int, expands func (int)
 }
 
 func ceilDiv (x, y int) int {
+	if y == 0 { return 0 }
 	return int(math.Ceil(float64(x) / float64(y)))
 }
 
-func (this *Grid) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (this *Grid) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
-	// TODO
+	return this.MinimumSize(hints, boxes).Y
-	return 0
 }
 
-func (this *Grid) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (this *Grid) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
-	// TODO
+	return this.MinimumSize(hints, boxes).X
-	return 0
 }

layouts/rowcol.go

@@ -13,33 +13,33 @@ type Row []bool
 // value will expand, and others will contract.
 type Column []bool
 
-func (column Column) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (column Column) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
 	dot := image.Point { }
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		minimum := box.MinimumSize()
+		minimum := boxes.MinimumSize(index)
 		dot.Y += minimum.Y
 		if dot.X < minimum.X {
 			dot.X = minimum.X
 		}
 	}
-	dot.Y += hints.Gap.Y * (len(boxes) - 1)
+	dot.Y += hints.Gap.Y * (boxes.Len() - 1)
 	return dot
 }
 
-func (row Row) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (row Row) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
 	dot := image.Point { }
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		minimum := box.MinimumSize()
+		minimum := boxes.MinimumSize(index)
 		dot.X += minimum.X
 		if dot.Y < minimum.Y {
 			dot.Y = minimum.Y
 		}
 	}
-	dot.X += hints.Gap.X * (len(boxes) - 1)
+	dot.X += hints.Gap.X * (boxes.Len() - 1)
 	return dot
 }
 
-func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (column Column) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	expands := func (index int) bool {
 		if index >= len(column) { return false }
 		return column[index]
@@ -48,13 +48,14 @@ func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	// determine expanding box size
 	expandingSize := 0.0
 	if !hints.OverflowY {
-		gaps       := len(boxes) - 1
+		gaps       := boxes.Len() - 1
 		freeSpace  := float64(hints.Bounds.Dy() - hints.Gap.Y * gaps)
-		nExpanding := 0; for index, box := range boxes {
+		nExpanding := 0
+		for index := 0; index < boxes.Len(); index ++ {
 			if expands(index) {
 				nExpanding ++
 			} else {
-				freeSpace -= float64(box.MinimumSize().Y)
+				freeSpace -= float64(boxes.MinimumSize(index).Y)
 			}
 		}
 		expandingSize = freeSpace / float64(nExpanding)
@@ -63,8 +64,8 @@ func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	// determine width
 	width := 0
 	if hints.OverflowX {
-		for _, box := range boxes {
+		for index := 0; index < boxes.Len(); index ++ {
-			minimum := box.MinimumSize()
+			minimum := boxes.MinimumSize(index)
 			if width < minimum.X { width = minimum.X }
 		}
 	} else {
@@ -73,44 +74,43 @@ func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 
 	// arrange
 	dot := hints.Bounds.Min
-	for index, box := range boxes {
+	bounds := make([]image.Rectangle, boxes.Len())
+	for index := 0; index < boxes.Len(); index ++ {
 		if index > 0 { dot.Y += hints.Gap.Y }
 
 		// determine height
-		height := box.MinimumSize().Y
+		height := boxes.MinimumSize(index).Y
 		if hints.OverflowY {
-			if box, ok := box.(tomo.ContentBox); ok {
+			height = boxes.RecommendedHeight(index, width)
-				height = box.RecommendedHeight(width)
-			}
 		} else {
 			if expands(index) {
 				height = int(expandingSize)
 			}
 		}
 
-		// set bounds
+		// store bounds of this box
-		box.SetBounds(image.Rectangle {
+		bounds[index] = image.Rectangle {
 			Min: dot,
 			Max: dot.Add(image.Pt(width, height)),
-		})
+		}
 		dot.Y += height
 	}
-	
+
+	// align
 	height := dot.Y - hints.Bounds.Min.Y
 	offset := 0
-	
 	switch hints.AlignY {
 	case tomo.AlignMiddle:
 		offset = (hints.Bounds.Dy() - height) / 2
 	case tomo.AlignEnd:
 		offset = hints.Bounds.Dy() - height
 	}
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		box.SetBounds(box.Bounds().Add(image.Pt(0, offset)))
+		boxes.SetBounds(index, bounds[index].Add(image.Pt(0, offset)))
 	}
 }
 
-func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (row Row) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
 	expands := func (index int) bool {
 		if index >= len(row) { return false }
 		return row[index]
@@ -119,13 +119,14 @@ func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	// determine expanding box size
 	expandingSize := 0.0
 	if !hints.OverflowY {
-		gaps       := len(boxes) - 1
+		gaps       := boxes.Len() - 1
 		freeSpace  := float64(hints.Bounds.Dx() - hints.Gap.X * gaps)
-		nExpanding := 0; for index, box := range boxes {
+		nExpanding := 0
+		for index := 0; index < boxes.Len(); index ++ {
 			if expands(index) {
 				nExpanding ++
 			} else {
-				freeSpace -= float64(box.MinimumSize().X)
+				freeSpace -= float64(boxes.MinimumSize(index).X)
 			}
 		}
 		expandingSize = freeSpace / float64(nExpanding)
@@ -134,8 +135,8 @@ func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	// determine height
 	height := 0
 	if hints.OverflowY {
-		for _, box := range boxes {
+		for index := 0; index < boxes.Len(); index ++ {
-			minimum := box.MinimumSize()
+			minimum := boxes.MinimumSize(index)
 			if height < minimum.Y { height = minimum.Y }
 		}
 	} else {
@@ -144,95 +145,76 @@ func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 
 	// arrange
 	dot := hints.Bounds.Min
-	for index, box := range boxes {
+	bounds := make([]image.Rectangle, boxes.Len())
+	for index := 0; index < boxes.Len(); index ++ {
 		if index > 0 { dot.X += hints.Gap.X }
 
 		// determine width
-		width := box.MinimumSize().X
+		width := boxes.MinimumSize(index).X
 		if hints.OverflowY {
-			if box, ok := box.(tomo.ContentBox); ok {
+			width = boxes.RecommendedHeight(index, height)
-				width = box.RecommendedHeight(height)
-			}
 		} else {
 			if expands(index) {
 				width = int(expandingSize)
 			}
 		}
 
-		// set bounds
+		// store bounds
-		box.SetBounds(image.Rectangle {
+		bounds[index] = image.Rectangle {
 			Min: dot,
 			Max: dot.Add(image.Pt(width, height)),
-		})
+		}
 		dot.X += width
 	}
 
+	// align
 	width  := dot.X - hints.Bounds.Min.X
 	offset := 0
-	
 	switch hints.AlignX {
 	case tomo.AlignMiddle:
 		offset = (hints.Bounds.Dx() - width) / 2
 	case tomo.AlignEnd:
 		offset = hints.Bounds.Dx() - width
 	}
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		box.SetBounds(box.Bounds().Add(image.Pt(offset, 0)))
+		boxes.SetBounds(index, bounds[index].Add(image.Pt(offset, 0)))
 	}
 }
 
-func (column Column) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (column Column) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
 	height := 0
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		if box, ok := box.(tomo.ContentBox); ok {
+		height += boxes.RecommendedHeight(index, width)
-			height += box.RecommendedHeight(width) 
-		} else {
-			height += box.MinimumSize().Y
-		}
 	}
-	height += hints.Gap.Y * (len(boxes) - 1)
+	height += hints.Gap.Y * (boxes.Len() - 1)
 	return height
 }
 
-func (row Row) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (row Row) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
 	height := 0
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		minimum   := box.MinimumSize()
+		minimum   := boxes.MinimumSize(index)
-		boxHeight := 0
+		boxHeight := boxes.RecommendedHeight(index, minimum.X)
-		if box, ok := box.(tomo.ContentBox); ok {
-			boxHeight = box.RecommendedHeight(minimum.X)
-		} else {
-			boxHeight = minimum.Y
-		}
 		if boxHeight > height { height = boxHeight }
 	}
 	return height
 }
 
-func (column Column) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (column Column) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
 	width := 0
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		minimum   := box.MinimumSize()
+		minimum  := boxes.MinimumSize(index)
-		boxWidth := 0
+		boxWidth := boxes.RecommendedWidth(index, minimum.Y)
-		if box, ok := box.(tomo.ContentBox); ok {
-			boxWidth = box.RecommendedHeight(minimum.Y)
-		} else {
-			boxWidth = minimum.X
-		}
 		if boxWidth > width { width = boxWidth }
 	}
 	return width
 }
 
-func (row Row) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (row Row) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
 	width := 0
-	for _, box := range boxes {
+	for index := 0; index < boxes.Len(); index ++ {
-		if box, ok := box.(tomo.ContentBox); ok {
+		width += boxes.RecommendedWidth(index, height)
-			width += box.RecommendedWidth(height)
-		} else {
-			width += box.MinimumSize().X
-		}
 	}
-	width += hints.Gap.X * (len(boxes) - 1)
+	width += hints.Gap.X * (boxes.Len() - 1)
 	return width
 }

menu.go

@@ -13,7 +13,7 @@ type Menu struct {
 	parent        tomo.Window
 	bounds        image.Rectangle
 	rootContainer tomo.ContainerBox
-	tearLine      tomo.Box
+	tearLine      tomo.Object
 	torn          bool
 }
 
@@ -36,22 +36,10 @@ func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
 	}
 
 	menu.rootContainer = tomo.NewContainerBox()
-	menu.rootContainer.SetLayout(layouts.ContractVertical)
+	menu.rootContainer.SetAttr(tomo.ALayout(layouts.ContractVertical))
 
 	if !menu.torn {
-		menu.tearLine = tomo.NewBox()
+		menu.tearLine = menu.newTearLine()
-		menu.tearLine.SetRole(tomo.R("objects", "TearLine", ""))
-		menu.tearLine.SetFocusable(true)
-		menu.tearLine.OnKeyUp(func (key input.Key, numberPad bool) {
-			if key != input.KeyEnter && key != input.Key(' ') { return }
-			menu.TearOff()
-		})
-		menu.tearLine.OnMouseUp(func (button input.Button) {
-			if button != input.ButtonLeft { return }
-			if menu.tearLine.MousePosition().In(menu.tearLine.Bounds()) {
-				menu.TearOff()
-			}
-		})
 		menu.rootContainer.Add(menu.tearLine)
 	}
 	
@@ -65,7 +53,8 @@ func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
 			})
 		}
 	}
-	menu.rootContainer.SetRole(tomo.R("objects", "Container", "menu"))
+	menu.rootContainer.SetRole(tomo.R("objects", "Container"))
+	menu.rootContainer.SetTag("menu", true)
 
 	menu.Window.SetRoot(menu.rootContainer)
 	return menu, nil
@@ -91,6 +80,33 @@ func (this *Menu) TearOff () {
 	this.Window.SetVisible(visible)
 }
 
+func (this *Menu) newTearLine () tomo.Object {
+	tearLine := tomo.NewBox()
+	tearLine.SetRole(tomo.R("objects", "TearLine"))
+	tearLine.SetFocusable(true)
+	tearLine.OnKeyDown(func (key input.Key, numberPad bool) bool {
+		if key != input.KeyEnter && key != input.Key(' ') { return false }
+		return true
+	})
+	tearLine.OnKeyUp(func (key input.Key, numberPad bool) bool {
+		if key != input.KeyEnter && key != input.Key(' ') { return false }
+		this.TearOff()
+		return true
+	})
+	tearLine.OnButtonDown(func (button input.Button) bool {
+		if button != input.ButtonLeft { return false }
+		return true
+	})
+	tearLine.OnButtonUp(func (button input.Button) bool {
+		if button != input.ButtonLeft { return false }
+		if tearLine.Window().MousePosition().In(tearLine.Bounds()) {
+			this.TearOff()
+		}
+		return true
+	})
+	return tearLine
+}
+
 func menuBoundsFromAnchor (anchor tomo.Object) image.Rectangle {
 	bounds := anchor.GetBox().Bounds()
 	return image.Rect (

menuitem.go

@@ -5,7 +5,7 @@ import "git.tebibyte.media/tomo/tomo/input"
 import "git.tebibyte.media/tomo/tomo/event"
 import "git.tebibyte.media/tomo/objects/layouts"
 
-// MenuItem is a clickable button.
+// MenuItem is a selectable memu item.
 type MenuItem struct {
 	tomo.ContainerBox
 
@@ -25,19 +25,17 @@ func NewMenuItem (text string) *MenuItem {
 		label:        NewLabel(text),
 		icon:         NewIcon("", tomo.IconSizeSmall),
 	}
-	box.SetRole(tomo.R("objects", "MenuItem", ""))
+	box.SetRole(tomo.R("objects", "MenuItem"))
-	box.label.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	box.label.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
-	box.SetLayout(layouts.NewGrid([]bool { false, true }, []bool { true }))
+	box.SetAttr(tomo.ALayout(layouts.Row { false, true }))
 	
 	box.Add(box.icon)
 	box.Add(box.label)
 	
-	box.CaptureDND(true)
+	box.SetInputMask(true)
-	box.CaptureMouse(true)
+	box.OnButtonDown(box.handleButtonDown)
-	box.CaptureScroll(true)
+	box.OnButtonUp(box.handleButtonUp)
-	box.CaptureKeyboard(true)
+	box.OnKeyDown(box.handleKeyDown)
-	
-	box.OnMouseUp(box.handleMouseUp)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
@@ -60,14 +58,26 @@ func (this *MenuItem) OnClick (callback func ()) event.Cookie {
 	return this.on.click.Connect(callback)
 }
 
-func (this *MenuItem) handleKeyUp (key input.Key, numberPad bool) {
+func (this *MenuItem) handleKeyDown (key input.Key, numberPad bool) bool {
-	if key != input.KeyEnter && key != input.Key(' ') { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	this.on.click.Broadcast()
+	return true
 }
 
-func (this *MenuItem) handleMouseUp (button input.Button) {
+func (this *MenuItem) handleKeyUp (key input.Key, numberPad bool) bool {
-	if button != input.ButtonLeft { return }
+	if key != input.KeyEnter && key != input.Key(' ') { return false }
-	if this.MousePosition().In(this.Bounds()) {
+	this.on.click.Broadcast()
+	return true
+}
+
+func (this *MenuItem) handleButtonDown (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	return true
+}
+
+func (this *MenuItem) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.on.click.Broadcast()
 	}
+	return true
 }

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)))
+	}
+}

numberinput.go

@@ -15,8 +15,8 @@ type NumberInput struct {
 	increment *Button
 	decrement *Button
 	on struct {
-		enter event.FuncBroadcaster
+		valueChange event.FuncBroadcaster
-		edit  event.FuncBroadcaster
+		confirm     event.FuncBroadcaster
 	}
 }
 
@@ -28,72 +28,83 @@ func NewNumberInput (value float64) *NumberInput {
 		increment:    NewButton(""),
 		decrement:    NewButton(""),
 	}
-	box.SetRole(tomo.R("objects", "NumberInput", ""))
+	box.SetRole(tomo.R("objects", "NumberInput"))
 	box.Add(box.input)
 	box.Add(box.decrement)
 	box.Add(box.increment)
-	box.SetLayout(layouts.NewGrid([]bool { true, false, false }, []bool { true }))
+	box.SetAttr(tomo.ALayout(layouts.Row { true, false, false }))
 	box.increment.SetIcon(tomo.IconValueIncrement)
 	box.decrement.SetIcon(tomo.IconValueDecrement)
 	
 	box.SetValue(value)
 	
-	box.CaptureScroll(true)
-	box.CaptureKeyboard(true)
-	
 	box.OnScroll(box.handleScroll)
 	box.OnKeyDown(box.handleKeyDown)
-	box.input.OnEnter(box.handleEnter)
+	box.OnKeyUp(box.handleKeyUp)
-	box.input.OnEdit(box.on.edit.Broadcast)
+	box.input.OnConfirm(box.handleConfirm)
+	box.input.OnValueChange(box.on.valueChange.Broadcast)
 	box.increment.OnClick(func () { box.shift(1)  })
 	box.decrement.OnClick(func () { box.shift(-1) })
 	return box
 }
 
-// SetValue sets the value of the input.
-func (this *NumberInput) SetValue (value float64) {
-	this.input.SetText(strconv.FormatFloat(value, 'g', -1, 64))
-}
-
 // Value returns the value of the input.
 func (this *NumberInput) Value () float64 {
 	value, _ := strconv.ParseFloat(this.input.Text(), 64)
 	return value
 }
 
-// OnEnter specifies a function to be called when the user presses enter within
+// SetValue sets the value of the input.
-// the text input.
+func (this *NumberInput) SetValue (value float64) {
-func (this *NumberInput) OnEnter (callback func ()) event.Cookie {
+	this.input.SetText(strconv.FormatFloat(value, 'g', -1, 64))
-	return this.on.enter.Connect(callback)
 }
 
-// OnEdit specifies a function to be called when the user edits the input value.
+// OnValueChange specifies a function to be called when the user edits the input
-func (this *NumberInput) OnEdit (callback func ()) event.Cookie {
+// value.
-	return this.on.edit.Connect(callback)
+func (this *NumberInput) OnValueChange (callback func ()) event.Cookie {
+	return this.on.valueChange.Connect(callback)
+}
+
+// OnConfirm specifies a function to be called when the user presses enter within
+// the number input.
+func (this *NumberInput) OnConfirm (callback func ()) event.Cookie {
+	return this.on.confirm.Connect(callback)
 }
 
 func (this *NumberInput) shift (by int) {
 	this.SetValue(this.Value() + float64(by))
-	this.on.edit.Broadcast()
+	this.on.valueChange.Broadcast()
 }
 
-func (this *NumberInput) handleKeyDown (key input.Key, numpad bool) {
+func (this *NumberInput) handleKeyDown (key input.Key, numpad bool) bool {
 	switch key {
-	case input.KeyUp:   this.shift(1)
+	case input.KeyUp:
-	case input.KeyDown: this.shift(-1)
+		this.shift(1)
-	default:            this.input.handleKeyDown(key, numpad)
+		return true
+	case input.KeyDown:
+		this.shift(-1)
+		return true
 	}
+	return false
 }
 
-func (this *NumberInput) handleScroll (x, y float64) {
+func (this *NumberInput) handleKeyUp (key input.Key, numpad bool) bool {
+	switch key {
+	case input.KeyUp:   return true
+	case input.KeyDown: return true
+	}
+	return false
+}
+
+func (this *NumberInput) handleScroll (x, y float64) bool {
 	if x == 0 {
 		this.shift(-int(math.Round(y)))
-	} else {
+		return true
-		this.input.handleScroll(x, y)
 	}
+	return false
 }
 
-func (this *NumberInput) handleEnter () {
+func (this *NumberInput) handleConfirm () {
 	this.SetValue(this.Value())
-	this.on.enter.Broadcast()
+	this.on.confirm.Broadcast()
 }

scrollbar.go

@@ -33,21 +33,20 @@ func newScrollbar (orient string) *Scrollbar {
 	}
 
 	this.Add(this.handle)
+
 	this.SetFocusable(true)
-
+	this.SetInputMask(true)
-	this.CaptureDND(true)
+	this.OnKeyUp(this.handleKeyUp)
-	this.CaptureMouse(true)
-	this.CaptureScroll(true)
-	this.CaptureKeyboard(true)
-
 	this.OnKeyDown(this.handleKeyDown)
-	this.OnMouseDown(this.handleMouseDown)
+	this.OnButtonDown(this.handleButtonDown)
-	this.OnMouseUp(this.handleMouseUp)
+	this.OnButtonUp(this.handleButtonUp)
 	this.OnMouseMove(this.handleMouseMove)
 	this.OnScroll(this.handleScroll)
 	
-	this.handle.SetRole(tomo.R("objects", "SliderHandle", orient))
+	this.handle.SetRole(tomo.R("objects", "SliderHandle"))
-	this.SetRole(tomo.R("objects", "Slider", orient))
+	this.handle.SetTag(orient, true)
+	this.SetRole(tomo.R("objects", "Slider"))
+	this.SetTag(orient, true)
 	return this
 }
 
@@ -67,7 +66,7 @@ func (this *Scrollbar) Link (box tomo.ContentObject) event.Cookie {
 	this.layout.linked = box
 	this.linkCookie = this.newLinkCookie (
 		box.OnContentBoundsChange(this.handleLinkedContentBoundsChange))
-	this.SetLayout(this.layout)
+	this.SetAttr(tomo.ALayout(this.layout))
 	return this.linkCookie
 }
 
@@ -80,12 +79,20 @@ func (this *Scrollbar) handleLinkedContentBoundsChange () {
 	} else {
 		this.layout.value = this.layout.contentPos() / trackLength
 	}
-	this.SetLayout(this.layout)
+	this.SetAttr(tomo.ALayout(this.layout))
 	if this.layout.value != previousValue {
 		this.on.valueChange.Broadcast()
 	}
 }
 
+// Value returns the value of the scrollbar between 0 and 1 where 0 is scrolled
+// all the way to the left/top, and 1 is scrolled all the way to the
+// right/bottom.
+func (this *Scrollbar) Value () float64 {
+	if this.layout.linked == nil { return 0 }
+	return this.layout.value
+}
+
 // SetValue sets the value of the scrollbar between 0 and 1, where 0 is scrolled
 // all the way to the left/top, and 1 is scrolled all the way to the
 // right/bottom.
@@ -106,49 +113,77 @@ func (this *Scrollbar) SetValue (value float64) {
 	
 }
 
-// Value returns the value of the scrollbar between 0 and 1 where 0 is scrolled
+// OnValueChange specifies a function to be called when the user changes the
-// all the way to the left/top, and 1 is scrolled all the way to the
+// position of the scrollbar.
-// right/bottom.
-func (this *Scrollbar) Value () float64 {
-	if this.layout.linked == nil { return 0 }
-	return this.layout.value
-}
-
-// OnValueChange specifies a function to be called when the position of the
-// scrollbar changes.
 func (this *Scrollbar) OnValueChange (callback func ()) event.Cookie {
 	return this.on.valueChange.Connect(callback)
 }
 
-func (this *Scrollbar) handleKeyDown (key input.Key, numpad bool) {
+// PageSize returns the scroll distance of a page.
-	var increment float64; if this.layout.vertical {
+func (this *Scrollbar) PageSize () int {
-		increment = -0.05
+	if this.layout.linked == nil { return 0 }
+	viewport := this.layout.linked.GetBox().InnerBounds()
+	if this.layout.vertical {
+		return viewport.Dy()
 	} else {
-		increment = 0.05
+		return viewport.Dx()
-	}
-
-	switch key {
-	case input.KeyUp, input.KeyLeft:
-		if this.Modifiers().Alt {
-			this.SetValue(0)
-		} else {
-			this.SetValue(this.Value() - increment)
-		}
-	case input.KeyDown, input.KeyRight:
-		if this.Modifiers().Alt {
-			this.SetValue(1)
-		} else {
-			this.SetValue(this.Value() + increment)
-		}
-	case input.KeyHome:
-		this.SetValue(0)
-	case input.KeyEnd:
-		this.SetValue(1)
 	}
 }
 
-func (this *Scrollbar) handleMouseDown (button input.Button) {
+// StepSize returns the scroll distance of a step.
-	pointer := this.MousePosition()
+func (this *Scrollbar) StepSize () int {
+	// FIXME: this should not be hardcoded, need to get base font metrics
+	// from tomo somehow. should be (emspace, lineheight)
+	return 16
+}
+
+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.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 {
+	modifiers := this.Window().Modifiers()
+
+	switch key {
+	case input.KeyUp, input.KeyLeft:
+		if modifiers.Alt {
+			this.SetValue(0)
+		} else {
+			this.scrollBy(this.StepSize())
+		}
+		return true
+	case input.KeyDown, input.KeyRight:
+		if modifiers.Alt {
+			this.SetValue(1)
+		} else {
+			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)
+		return true
+	case input.KeyEnd:
+		this.SetValue(1)
+		return true
+	}
+	return false
+}
+
+func (this *Scrollbar) handleButtonDown (button input.Button) bool {
+	pointer := this.Window().MousePosition()
 	handle  := this.handle.Bounds()
 
 	within := pointer.In(handle)
@@ -173,38 +208,52 @@ func (this *Scrollbar) handleMouseDown (button input.Button) {
 		}
 	case input.ButtonMiddle:
 		if above {
-			this.scrollBy(this.pageSize())
+			this.scrollBy(this.PageSize())
 		} else {
-			this.scrollBy(-this.pageSize())
+			this.scrollBy(-this.PageSize())
 		}
 	case input.ButtonRight:
 		if above {
-			this.scrollBy(this.stepSize())
+			this.scrollBy(this.StepSize())
 		} else {
-			this.scrollBy(-this.stepSize())
+			this.scrollBy(-this.StepSize())
 		}
 	}
+	return true
 }
 
-func (this *Scrollbar) handleMouseUp (button input.Button) {
+func (this *Scrollbar) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft || !this.dragging { return }
+	if button != input.ButtonLeft || !this.dragging { return true }
 	this.dragging = false
+	return true
 }
 
-func (this *Scrollbar) handleMouseMove () {
+func (this *Scrollbar) handleMouseMove () bool {
-	if !this.dragging { return }
+	if !this.dragging { return false }
 	this.drag()
+	return true
 }
 
-func (this *Scrollbar) handleScroll (x, y float64) {
+func (this *Scrollbar) handleScroll (x, y float64) bool {
-	if this.layout.linked == nil { return }
+	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))))
+	return true
 }
 
 func (this *Scrollbar) drag () {
-	pointer := this.MousePosition().Sub(this.dragOffset)
+	pointer := this.Window().MousePosition().Sub(this.dragOffset)
 	gutter  := this.InnerBounds()
 	handle  := this.handle.Bounds()
 
@@ -229,22 +278,6 @@ func (this *Scrollbar) fallbackDragOffset () image.Point {
 	}
 }
 
-func (this *Scrollbar) pageSize () int {
-	if this.layout.linked == nil { return 0 }
-	viewport := this.layout.linked.GetBox().InnerBounds()
-	if this.layout.vertical {
-		return viewport.Dy()
-	} else {
-		return viewport.Dx()
-	}
-}
-
-func (this *Scrollbar) stepSize () int {
-	// FIXME: this should not be hardcoded, need to get base font metrics
-	// from tomo.somehow. should be (emspace, lineheight)
-	return 16
-}
-
 func (this *Scrollbar) scrollBy (distance int) {
 	if this.layout.linked == nil { return }
 	var vector image.Point; if this.layout.vertical {
@@ -274,7 +307,7 @@ func (this *scrollbarCookie) Close () {
 		cookie.Close()
 	}
 	this.owner.layout.linked = nil
-	this.owner.SetLayout(this.owner.layout)
+	this.owner.SetAttr(tomo.ALayout(this.owner.layout))
 }
 
 type scrollbarLayout struct {
@@ -283,14 +316,14 @@ type scrollbarLayout struct {
 	linked   tomo.ContentObject
 }
 
-func (scrollbarLayout) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (scrollbarLayout) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
-	if len(boxes) != 1 { return image.Pt(0, 0) }
+	if boxes.Len() != 1 { return image.Pt(0, 0) }
-	return boxes[0].MinimumSize()
+	return boxes.MinimumSize(0)
 }
 
-func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
-	if len(boxes) != 1 { return }
+	if boxes.Len() != 1 { return }
-	handle := image.Rectangle { Max: boxes[0].MinimumSize() }
+	handle := image.Rectangle { Max: boxes.MinimumSize(0) }
 	gutter := hints.Bounds
 
 	var gutterLength float64;
@@ -311,7 +344,7 @@ func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 		// and we shouldn't be adding and removing boxes, so this is
 		// really the only good way to hide things.
 		// TODO perhaps have a "Hidden" rectangle in the Tomo API?
-		boxes[0].SetBounds(image.Rect(-16, -16, 0, 0))
+		boxes.SetBounds(0, image.Rect(-32, -32, -16, -16))
 		return
 	}
 	if this.vertical {
@@ -331,15 +364,15 @@ func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	handle = handle.Sub(handleOffset).Add(gutter.Min)
 	
 	// place handle
-	boxes[0].SetBounds(handle)
+	boxes.SetBounds(0, handle)
 	
 }
 
-func (this scrollbarLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (this scrollbarLayout) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
 	return this.MinimumSize(hints, boxes).X
 }
 
-func (this scrollbarLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (this scrollbarLayout) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
 	return this.MinimumSize(hints, boxes).Y
 }
 

scrollcontainer.go

@@ -2,7 +2,9 @@ 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"
 
 // ScrollSide determines which Scrollbars are active in a ScrollContainer.
 type ScrollSide int; const (
@@ -38,30 +40,44 @@ func (sides ScrollSide) String () string {
 // ScrollContainer couples a ContentBox with one or two Scrollbars.
 type ScrollContainer struct {
 	tomo.ContainerBox
-	layout *scrollContainerLayout
 
+	root       tomo.ContentObject
+	horizontal *Scrollbar
+	vertical   *Scrollbar
+	
 	horizontalCookie event.Cookie
 	verticalCookie   event.Cookie
+
+	on struct {
+		valueChange event.FuncBroadcaster
+	}
 }
 
 // NewScrollContainer creates a new scroll container.
 func NewScrollContainer (sides ScrollSide) *ScrollContainer {
 	this := &ScrollContainer {
 		ContainerBox: tomo.NewContainerBox(),
-		layout:       &scrollContainerLayout { },
 	}
 	if sides.Vertical() {
-		this.layout.vertical = NewVerticalScrollbar()
+		this.vertical = NewVerticalScrollbar()
-		this.Add(this.layout.vertical)
+		this.vertical.OnValueChange(this.handleValueChange)
+		this.Add(this.vertical)
 	}
 	if sides.Horizontal() {
-		this.layout.horizontal = NewHorizontalScrollbar()
+		this.horizontal = NewHorizontalScrollbar()
-		this.Add(this.layout.horizontal)
+		this.horizontal.OnValueChange(this.handleValueChange)
+		this.Add(this.horizontal)
 	}
-	this.CaptureScroll(true)
 	this.OnScroll(this.handleScroll)
-	this.SetRole(tomo.R("objects", "ScrollContainer", sides.String()))
+	this.OnKeyDown(this.handleKeyDown)
-	this.SetLayout(this.layout)
+	this.OnKeyUp(this.handleKeyUp)
+	this.SetRole(tomo.R("objects", "ScrollContainer"))
+	this.SetTag(sides.String(), true)
+	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
 }
 
@@ -69,9 +85,9 @@ func NewScrollContainer (sides ScrollSide) *ScrollContainer {
 // a time, and setting it will remove and unlink the current child if there is
 // one.
 func (this *ScrollContainer) SetRoot (root tomo.ContentObject) {
-	if this.layout.root != nil {
+	if this.root != nil {
 		// remove root and close cookies
-		this.Remove(this.layout.root)
+		this.Remove(this.root)
 		if this.horizontalCookie != nil {
 			this.horizontalCookie.Close()
 			this.horizontalCookie = nil
@@ -81,118 +97,143 @@ func (this *ScrollContainer) SetRoot (root tomo.ContentObject) {
 			this.verticalCookie = nil
 		}
 	}
-	this.layout.root = root
+	this.root = root
 	if root != nil {
 		// insert root at the beginning (for keynav)
 		switch {
-		case this.layout.vertical != nil:
+		case this.vertical != nil:
-			this.Insert(root, this.layout.vertical)
+			this.Insert(root, this.vertical)
-		case this.layout.horizontal != nil:
+		case this.horizontal != nil:
-			this.Insert(root, this.layout.horizontal)
+			this.Insert(root, this.horizontal)
 		default:
 			this.Add(root)
 		}
 		
 		// link root and remember cookies
-		if this.layout.horizontal != nil {
+		if this.horizontal != nil {
-			this.horizontalCookie = this.layout.horizontal.Link(root)
+			this.horizontalCookie = this.horizontal.Link(root)
 		}
-		if this.layout.vertical != nil {
+		if this.vertical != nil {
-			this.verticalCookie =  this.layout.vertical.Link(root)
+			this.verticalCookie =  this.vertical.Link(root)
 		}
 	}
 }
 
-// SetValue sets the horizontal and vertical scrollbar values where 0 is all the
-// way to the left/top, and 1 is all the way to the right/bottom.
-func (this *ScrollContainer) SetValue (x, y float64) {
-	if this.layout.horizontal != nil {
-		this.layout.horizontal.SetValue(x)
-	}
-	if this.layout.vertical != nil {
-		this.layout.vertical.SetValue(y)
-	}
-}
-
 // Value returns the horizontal and vertical scrollbar values where 0 is all the
 // way to the left/top, and 1 is all the way to the right/bottom.
 func (this *ScrollContainer) Value () (x, y float64) {
-	if this.layout.horizontal != nil {
+	if this.horizontal != nil {
-		x = this.layout.horizontal.Value()
+		x = this.horizontal.Value()
 	}
-	if this.layout.vertical != nil {
+	if this.vertical != nil {
-		y = this.layout.vertical.Value()
+		y = this.vertical.Value()
 	}
 	return x, y
 }
 
-func (this *ScrollContainer) handleScroll (x, y float64) {
+// SetValue sets the horizontal and vertical scrollbar values where 0 is all the
-	if this.layout.root == nil { return }
+// way to the left/top, and 1 is all the way to the right/bottom.
-	this.layout.root.ScrollTo (
+func (this *ScrollContainer) SetValue (x, y float64) {
-		this.layout.root.ContentBounds().Min.
-		Sub(image.Pt(int(x), int(y))))
-}
-
-// TODO: remove this and replace it with something from the layouts package
-type scrollContainerLayout struct {
-	root       tomo.ContentObject
-	horizontal *Scrollbar
-	vertical   *Scrollbar
-}
-
-func (this *scrollContainerLayout) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
-	var minimum image.Point; if this.root != nil {
-		minimum = this.root.GetBox().MinimumSize()
-	}
 	if this.horizontal != nil {
-		minimum.Y += this.horizontal.MinimumSize().Y
+		this.horizontal.SetValue(x)
 	}
 	if this.vertical != nil {
-		minimum.X += this.vertical.MinimumSize().X
+		this.vertical.SetValue(y)
-		minimum.Y = max(minimum.Y, this.vertical.MinimumSize().Y)
 	}
-	if this.horizontal != nil {
-		minimum.X = max(minimum.X, this.horizontal.MinimumSize().X)
-	}
-	return minimum
 }
 
-func (this *scrollContainerLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+// OnValueChange specifies a function to be called when the user changes the
-	rootBounds := hints.Bounds
+// position of the horizontal or vertical scrollbars.
+func (this *ScrollContainer) OnValueChange (callback func ()) event.Cookie {
+	return this.on.valueChange.Connect(callback)
+}
+
+// PageSize returns the scroll distance of a page.
+func (this *ScrollContainer) PageSize () image.Point {
+	page := image.Point { }
 	if this.horizontal != nil {
-		rootBounds.Max.Y -= this.horizontal.MinimumSize().Y
+		page.X = this.horizontal.PageSize()
 	}
 	if this.vertical != nil {
-		rootBounds.Max.X -= this.vertical.MinimumSize().X
+		page.Y = this.vertical.PageSize()
-	}
-	if this.root != nil {
-		this.root.GetBox().SetBounds(rootBounds)
 	}
+	return page
+}
+
+// StepSize returns the scroll distance of a step.
+func (this *ScrollContainer) StepSize () image.Point {
+	page := image.Point { }
 	if this.horizontal != nil {
-		this.horizontal.SetBounds(image.Rect (
+		page.X = this.horizontal.StepSize()
-			hints.Bounds.Min.X,
-			rootBounds.Max.Y,
-			rootBounds.Max.X,
-			hints.Bounds.Max.Y))
 	}
 	if this.vertical != nil {
-		this.vertical.SetBounds(image.Rect (
+		page.Y = this.vertical.StepSize()
-			rootBounds.Max.X,
-			hints.Bounds.Min.Y,
-			hints.Bounds.Max.X,
-			rootBounds.Max.Y))
 	}
+	return page
 }
 
-func (this *scrollContainerLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (this *ScrollContainer) handleValueChange () {
-	return this.MinimumSize(hints, boxes).X
+	this.on.valueChange.Broadcast()
 }
 
-func (this *scrollContainerLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+func (this *ScrollContainer) scrollBy (vector image.Point) {
-	return this.MinimumSize(hints, boxes).Y
+	if this.root == nil               { return }
+	if vector    == (image.Point { }) { return }
+	this.root.ScrollTo (
+		this.root.ContentBounds().Min.
+		Sub(vector))
 }
 
-func max (x, y int) int {
+func (this *ScrollContainer) handleScroll (x, y float64) bool {
-	if x > y { return x }
+	if this.root == nil { return false }
-	return y
+	this.scrollBy(image.Pt(int(x), int(y)))
+	return true
+}
+
+func (this *ScrollContainer) handleKeyDown (key input.Key, numpad bool) bool {
+	modifiers := this.Window().Modifiers()
+	vector    := image.Point { }
+	switch key {
+	case input.KeyPageUp:
+		if modifiers.Shift {
+			vector.X -= this.PageSize().X
+		} else {
+			vector.Y -= this.PageSize().Y
+		}
+		this.scrollBy(vector)
+		return true
+	case input.KeyPageDown:
+		if modifiers.Shift {
+			vector.X += this.PageSize().X
+		} 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
+}
+
+func (this *ScrollContainer) handleKeyUp (key input.Key, numpad bool) bool {
+	switch key {
+	case input.KeyPageUp:   return true
+	case input.KeyPageDown: return true
+	}
+	return false
 }

separator.go

@@ -12,6 +12,6 @@ func NewSeparator () *Separator {
 	this := &Separator {
 		Box: tomo.NewBox(),
 	}
-	this.SetRole(tomo.R("objects", "Separator", ""))
+	this.SetRole(tomo.R("objects", "Separator"))
 	return this
 }

slider.go

@@ -1,5 +1,6 @@
 package objects
 
+import "math"
 import "image"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/tomo/input"
@@ -15,7 +16,8 @@ type Slider struct {
 	step       float64
 
 	on struct {
-		slide event.FuncBroadcaster
+		valueChange event.FuncBroadcaster
+		confirm     event.FuncBroadcaster
 	}
 }
 
@@ -33,27 +35,27 @@ func newSlider (orient string, value float64) *Slider {
 		},
 		layout: sliderLayout {
 			vertical: orient == "vertical",
+			value:    math.NaN(),
 		},
 		step: 0.05,
 	}
 
 	this.Add(this.handle)
 	this.SetFocusable(true)
-
-	this.CaptureDND(true)
-	this.CaptureMouse(true)
-	this.CaptureScroll(true)
-	this.CaptureKeyboard(true)
-
 	this.SetValue(value)
+
+	this.SetInputMask(true)
+	this.OnKeyUp(this.handleKeyUp)
 	this.OnKeyDown(this.handleKeyDown)
-	this.OnMouseDown(this.handleMouseDown)
+	this.OnButtonDown(this.handleButtonDown)
-	this.OnMouseUp(this.handleMouseUp)
+	this.OnButtonUp(this.handleButtonUp)
 	this.OnMouseMove(this.handleMouseMove)
 	this.OnScroll(this.handleScroll)
 	
-	this.handle.SetRole(tomo.R("objects", "SliderHandle", orient))
+	this.handle.SetRole(tomo.R("objects", "SliderHandle"))
-	this.SetRole(tomo.R("objects", "Slider", orient))
+	this.handle.SetTag(orient, true)
+	this.SetRole(tomo.R("objects", "Slider"))
+	this.SetTag(orient, true)
 	return this
 }
 
@@ -73,7 +75,7 @@ func (this *Slider) SetValue (value float64) {
 	if value > 1 { value = 1 }
 	if value == this.layout.value { return }
 	this.layout.value = value
-	this.SetLayout(this.layout)
+	this.SetAttr(tomo.ALayout(this.layout))
 }
 
 // Value returns the value of the slider between 0 and 1.
@@ -83,11 +85,17 @@ func (this *Slider) Value () float64 {
 
 // OnValueChange specifies a function to be called when the user moves the
 // slider.
-func (this *Slider) OnSlide (callback func ()) event.Cookie {
+func (this *Slider) OnValueChange (callback func ()) event.Cookie {
-	return this.on.slide.Connect(callback)
+	return this.on.valueChange.Connect(callback)
 }
 
-func (this *Slider) handleKeyDown (key input.Key, numpad bool) {
+// OnConfirm specifies a function to be called when the user stops moving the
+// slider.
+func (this *Slider) OnConfirm (callback func ()) event.Cookie {
+	return this.on.confirm.Connect(callback)
+}
+
+func (this *Slider) handleKeyDown (key input.Key, numpad bool) bool {
 	var increment float64; if this.layout.vertical {
 		increment = -0.05
 	} else {
@@ -96,30 +104,45 @@ func (this *Slider) handleKeyDown (key input.Key, numpad bool) {
 
 	switch key {
 	case input.KeyUp, input.KeyLeft:
-		if this.Modifiers().Alt {
+		if this.Window().Modifiers().Alt {
 			this.SetValue(0)
 		} else {
 			this.SetValue(this.Value() - increment)
 		}
-		this.on.slide.Broadcast()
+		this.on.valueChange.Broadcast()
+		return true
 	case input.KeyDown, input.KeyRight:
-		if this.Modifiers().Alt {
+		if this.Window().Modifiers().Alt {
 			this.SetValue(1)
 		} else {
 			this.SetValue(this.Value() + increment)
 		}
-		this.on.slide.Broadcast()
+		this.on.valueChange.Broadcast()
+		return true
 	case input.KeyHome:
 		this.SetValue(0)
-		this.on.slide.Broadcast()
+		this.on.valueChange.Broadcast()
+		return true
 	case input.KeyEnd:
 		this.SetValue(1)
-		this.on.slide.Broadcast()
+		this.on.valueChange.Broadcast()
+		return true
 	}
+	return false
 }
 
-func (this *Slider) handleMouseDown (button input.Button) {
+func (this *Slider) handleKeyUp (key input.Key, numpad bool) bool {
-	pointer := this.MousePosition()
+	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
+	}
+	return false
+}
+
+func (this *Slider) handleButtonDown (button input.Button) bool {
+	pointer := this.Window().MousePosition()
 	handle  := this.handle.Bounds()
 	
 	within := pointer.In(handle)
@@ -145,40 +168,50 @@ func (this *Slider) handleMouseDown (button input.Button) {
 	case input.ButtonMiddle:
 		if above {
 			this.SetValue(0)
-			this.on.slide.Broadcast()
+			this.on.valueChange.Broadcast()
+			this.on.confirm.Broadcast()
 		} else {
 			this.SetValue(1)
-			this.on.slide.Broadcast()
+			this.on.valueChange.Broadcast()
+			this.on.confirm.Broadcast()
 		}
 	case input.ButtonRight:
 		if above {
 			this.SetValue(this.Value() - this.step)
-			this.on.slide.Broadcast()
+			this.on.valueChange.Broadcast()
+			this.on.confirm.Broadcast()
 		} else {
 			this.SetValue(this.Value() + this.step)
-			this.on.slide.Broadcast()
+			this.on.valueChange.Broadcast()
+			this.on.confirm.Broadcast()
 		}
 	}
+	return true
 }
 
-func (this *Slider) handleMouseUp (button input.Button) {
+func (this *Slider) handleButtonUp (button input.Button) bool {
-	if button != input.ButtonLeft || !this.dragging { return }
+	if button != input.ButtonLeft || !this.dragging { return true }
 	this.dragging = false
+	this.on.confirm.Broadcast()
+	return true
 }
 
-func (this *Slider) handleMouseMove () {
+func (this *Slider) handleMouseMove () bool {
-	if !this.dragging { return }
+	if !this.dragging { return false }
 	this.drag()
+	return true
 }
 
-func (this *Slider) handleScroll (x, y float64) {
+func (this *Slider) handleScroll (x, y float64) bool {
 	delta := (x + y) * 0.005
 	this.SetValue(this.Value() + delta)
-	this.on.slide.Broadcast()
+	this.on.valueChange.Broadcast()
+	this.on.confirm.Broadcast()
+	return true
 }
 
 func (this *Slider) drag () {
-	pointer := this.MousePosition().Sub(this.dragOffset)
+	pointer := this.Window().MousePosition().Sub(this.dragOffset)
 	gutter  := this.InnerBounds()
 	handle  := this.handle.Bounds()
 
@@ -192,7 +225,7 @@ func (this *Slider) drag () {
 			float64(pointer.X) /
 			float64(gutter.Dx() - handle.Dx()))
 	}
-	this.on.slide.Broadcast()
+	this.on.valueChange.Broadcast()
 }
 
 func (this *Slider) fallbackDragOffset () image.Point {
@@ -210,39 +243,37 @@ type sliderLayout struct {
 	value    float64
 }
 
-func (sliderLayout) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (sliderLayout) MinimumSize (hints tomo.LayoutHints, boxes tomo.BoxQuerier) image.Point {
-	if len(boxes) != 1 { return image.Pt(0, 0) }
+	if boxes.Len() != 1 { return image.Pt(0, 0) }
-	return boxes[0].MinimumSize()
+	return boxes.MinimumSize(0)
 }
 
-func (this sliderLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+func (this sliderLayout) Arrange (hints tomo.LayoutHints, boxes tomo.BoxArranger) {
-	if len(boxes) != 1 { return }
+	if boxes.Len() != 1 { return }
-	handle := image.Rectangle { Max: boxes[0].MinimumSize() }
+	handle := image.Rectangle { Max: boxes.MinimumSize(0) }
 	gutter := hints.Bounds
 
 	if this.vertical {
 		height := gutter.Dy() - handle.Dy()
 		offset := int(float64(height) * (1 - this.value))
 		handle.Max.X = gutter.Dx()
-		boxes[0].SetBounds (
+		boxes.SetBounds (
-			handle.
+			0,
-			Add(image.Pt(0, offset)).
+			handle.Add(image.Pt(0, offset)).Add(gutter.Min))
-			Add(gutter.Min))
 	} else {
 		width  := gutter.Dx() - handle.Dx()
 		offset := int(float64(width) * this.value)
 		handle.Max.Y = gutter.Dy()
-		boxes[0].SetBounds (
+		boxes.SetBounds (
-			handle.
+			0,
-			Add(image.Pt(offset, 0)).
+			handle.Add(image.Pt(offset, 0)).Add(gutter.Min))
-			Add(gutter.Min))
 	}
 }
 
-func (this sliderLayout) RecommendedHeight (tomo.LayoutHints, []tomo.Box, int) int {
+func (this sliderLayout) RecommendedHeight (hints tomo.LayoutHints, boxes tomo.BoxQuerier, width int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).X
 }
 
-func (this sliderLayout) RecommendedWidth (tomo.LayoutHints, []tomo.Box, int) int {
+func (this sliderLayout) RecommendedWidth (hints tomo.LayoutHints, boxes tomo.BoxQuerier, height int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).Y
 }

swatch.go

@@ -0,0 +1,182 @@
+package objects
+
+import "log"
+import "image"
+import "image/color"
+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/tomo/canvas"
+import "git.tebibyte.media/tomo/objects/layouts"
+
+// Swatch displays a color, allowing the user to edit it by clicking on it.
+type Swatch struct {
+	tomo.CanvasBox
+	value color.Color
+	editing bool
+	label string
+	on struct {
+		valueChange event.FuncBroadcaster
+		confirm     event.FuncBroadcaster
+	}
+}
+
+// NewSwatch creates a new swatch with the given color.
+func NewSwatch (value color.Color) *Swatch {
+	swatch := &Swatch {
+		CanvasBox: tomo.NewCanvasBox(),
+	}
+	swatch.SetRole(tomo.R("objects", "Swatch"))
+	swatch.SetDrawer(swatch)
+	swatch.SetValue(value)
+	
+	swatch.OnButtonDown(swatch.handleButtonDown)
+	swatch.OnButtonUp(swatch.handleButtonUp)
+	swatch.OnKeyDown(swatch.handleKeyDown)
+	swatch.OnKeyUp(swatch.handleKeyUp)
+	swatch.SetFocusable(true)
+	return swatch
+}
+
+// Value returns the color of the swatch.
+func (this *Swatch) Value () color.Color {
+	return this.value
+}
+
+// SetValue sets the color of the swatch.
+func (this *Swatch) SetValue (value color.Color) {
+	this.value = value
+	if value == nil { value = color.Transparent }
+	this.Invalidate()
+}
+
+// OnValueChange specifies a function to be called when the swatch's color
+// is changed by the user.
+func (this *Swatch) OnValueChange (callback func ()) event.Cookie {
+	return this.on.valueChange.Connect(callback)
+}
+
+// RGBA satisfies the color.Color interface
+func (this *Swatch) RGBA () (r, g, b, a uint32) {
+	if this.value == nil { return }
+	return this.value.RGBA()
+}
+
+// OnConfirm specifies a function to be called when the user selects "OK" in the
+// color picker.
+func (this *Swatch) OnConfirm (callback func ()) event.Cookie {
+	return this.on.confirm.Connect(callback)
+}
+
+// Choose creates a modal that allows the user to edit the color of the swatch.
+func (this *Swatch) Choose () {
+	if this.editing { return }
+
+	var err    error
+	var window tomo.Window
+	if parent := this.Window(); parent != nil {
+		window, err = parent.NewChild(image.Rectangle { })
+	} else {
+		window, err = tomo.NewWindow(image.Rectangle { })
+	}
+	if err != nil {
+		log.Println("objects: could not create swatch modal:", err)
+		return
+	}
+	if this.label == "" {
+		window.SetTitle("Select Color")
+	} else {
+		window.SetTitle(this.label)
+	}
+	
+	committed := false
+	
+	colorPicker := NewColorPicker(this.Value())
+	colorPicker.OnValueChange(func () {
+		this.userSetValue(colorPicker.Value())
+	})
+	
+	hexInput := NewTextInput("TODO")
+	
+	colorMemory  := this.value
+	cancelButton := NewButton("Cancel")
+	cancelButton.SetIcon(tomo.IconDialogCancel)
+	cancelButton.OnClick(func () {
+		window.Close()
+	})
+	okButton := NewButton("OK")
+	okButton.SetFocused(true)
+	okButton.SetIcon(tomo.IconDialogOkay)
+	okButton.OnClick(func () {
+		committed = true
+		window.Close()
+	})
+	
+	controlRow := NewInnerContainer (
+		layouts.ContractHorizontal,
+		cancelButton,
+		okButton)
+	controlRow.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignMiddle))
+	window.SetRoot(NewOuterContainer (
+		layouts.Column { true, false },
+		colorPicker,
+		NewInnerContainer(layouts.Row { false, true },
+			NewLabel("Hex"),
+			hexInput),
+		controlRow))
+	window.OnClose(func () {
+		if committed {
+			this.on.confirm.Broadcast()
+		} else {
+			this.userSetValue(colorMemory)
+		}
+		this.editing = false
+	})
+	this.editing = true
+	window.SetVisible(true)
+}
+
+func (this *Swatch) Draw (can canvas.Canvas) {
+	pen := can.Pen()
+	
+	// transparency slash
+	pen.Stroke(color.RGBA { R: 255, A: 255 })
+	pen.StrokeWeight(1)
+	pen.Path(this.Bounds().Min, this.Bounds().Max)
+	
+	// color
+	if this.value != nil {
+		pen.StrokeWeight(0)
+		pen.Fill(this.value)
+		pen.Rectangle(this.Bounds())
+	}
+}
+
+func (this *Swatch) userSetValue (value color.Color) {
+	this.SetValue(value)
+	this.on.valueChange.Broadcast()
+}
+
+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 }
+	this.Choose()
+	return true
+}
+
+func (this *Swatch) handleButtonDown (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	return true
+}
+
+func (this *Swatch) handleButtonUp (button input.Button) bool {
+	if button != input.ButtonLeft { return false }
+	if this.Window().MousePosition().In(this.Bounds()) {
+		this.Choose()
+	}
+	return true
+}

tabbedcontainer.go

@@ -0,0 +1,135 @@
+package objects
+
+import "git.tebibyte.media/tomo/tomo"
+import "git.tebibyte.media/tomo/tomo/input"
+import "git.tebibyte.media/tomo/objects/layouts"
+
+type TabbedContainer struct {
+	tomo.ContainerBox
+	
+	leftSpacer  tomo.Box
+	rightSpacer tomo.Box
+	tabsRow tomo.ContainerBox
+	active string
+	tabs []*tab
+}
+
+func NewTabbedContainer () *TabbedContainer {
+	container := &TabbedContainer {
+		ContainerBox: tomo.NewContainerBox(),
+	}
+	container.SetRole(tomo.R("objects", "TabbedContainer"))
+	container.SetAttr(tomo.ALayout(layouts.Column { false, true }))
+	
+	container.tabsRow = tomo.NewContainerBox()
+	container.tabsRow.SetRole(tomo.R("objects", "TabRow"))
+	container.Add(container.tabsRow)
+	
+	container.leftSpacer = tomo.NewBox()
+	container.leftSpacer.SetRole(tomo.R("objects", "TabSpacer"))
+	container.leftSpacer.SetTag("left", true)
+	container.rightSpacer = tomo.NewBox()
+	container.rightSpacer.SetRole(tomo.R("objects", "TabSpacer"))
+	container.rightSpacer.SetTag("left", true)
+	
+	container.ClearTabs()
+	container.setTabRowLayout()
+	return container
+}
+
+func (this *TabbedContainer) Activate (name string) {
+	if _, tab := this.findTab(this.active); tab != nil {
+		tab.setActive(false)
+		this.Remove(tab.root)
+	}
+	if _, tab := this.findTab(name); tab != nil {
+		tab.setActive(true)
+		this.Add(tab.root)
+	} else {
+		name = ""
+	}
+	this.active = name
+}
+
+func (this *TabbedContainer) AddTab (name string, root tomo.Object) {
+	tab := &tab {
+		TextBox: tomo.NewTextBox(),
+		name:    name,
+		root:    root,
+	}
+	tab.SetRole(tomo.R("objects", "Tab"))
+	tab.SetText(name)
+	tab.OnButtonDown(func (button input.Button) bool {
+		if button != input.ButtonLeft { return false }
+		this.Activate(name)
+		return true
+	})
+	tab.OnButtonUp(func (button input.Button) bool {
+		if button != input.ButtonLeft { return false }
+		return true
+	})
+	
+	this.tabs = append(this.tabs, tab)
+	this.tabsRow.Insert(tab, this.rightSpacer)
+	this.setTabRowLayout()
+	
+	// if the row was empty before, activate this tab
+	if len(this.tabs) == 1 {
+		this.Activate(name)	
+	}
+}
+
+func (this *TabbedContainer) RemoveTab (name string) {
+	index, tab := this.findTab(name)
+	if index < 0 { return }
+	nextIndex := index - 1
+	
+	this.tabsRow.Remove(tab)
+	this.tabs = append(this.tabs[:index], this.tabs[index - 1:]...)
+	this.setTabRowLayout()
+	
+	if nextIndex < 0               { nextIndex = 0 }
+	if nextIndex >= len(this.tabs) { nextIndex = len(this.tabs) - 1 }
+	if nextIndex < 0 {
+		this.Activate("")
+	} else {
+		this.Activate(this.tabs[nextIndex].name)
+	}
+}
+
+func (this *TabbedContainer) ClearTabs () {
+	this.tabs = nil
+	this.tabsRow.Clear()
+	this.tabsRow.Add(this.leftSpacer)
+	this.tabsRow.Add(this.rightSpacer)
+}
+
+func (this *TabbedContainer) setTabRowLayout () {
+	row := make(layouts.Row, 1 + len(this.tabs) + 1)
+	row[len(row) - 1] = true
+	this.tabsRow.SetAttr(tomo.ALayout(row))
+}
+
+func (this *TabbedContainer) findTab (name string) (int, *tab) {
+	for index, tab := range this.tabs {
+		if tab.name == name { return index, tab }
+	}
+	return -1, nil
+}
+
+type tab struct {
+	tomo.TextBox
+	name string
+	root tomo.Object
+}
+
+func (this *tab) setActive (active bool) {
+	if active {
+		this.SetRole(tomo.R("objects", "Tab"))
+		this.SetTag("active", false)
+	} else {
+		this.SetRole(tomo.R("objects", "Tab"))
+		this.SetTag("active", true)
+	}
+}
+

textinput.go

@@ -11,21 +11,22 @@ type TextInput struct {
 	tomo.TextBox
 	text []rune
 	on struct {
-		enter event.FuncBroadcaster
+		valueChange event.FuncBroadcaster
-		edit  event.FuncBroadcaster
+		confirm     event.FuncBroadcaster
 	}
 }
 
 // NewTextInput creates a new text input containing the specified text.
 func NewTextInput (text string) *TextInput {
 	this := &TextInput { TextBox: tomo.NewTextBox() }
-	this.SetRole(tomo.R("objects", "TextInput", ""))
+	this.SetRole(tomo.R("objects", "TextInput"))
-	this.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	this.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
+	this.SetAttr(tomo.AOverflow(true, false))
 	this.SetText(text)
 	this.SetFocusable(true)
 	this.SetSelectable(true)
-	this.SetOverflow(true, false)
 	this.OnKeyDown(this.handleKeyDown)
+	this.OnKeyUp(this.handleKeyUp)
 	this.OnScroll(this.handleScroll)
 	return this
 }
@@ -41,67 +42,16 @@ func (this *TextInput) Text () string {
 	return string(this.text)
 }
 
-// OnEnter specifies a function to be called when the user presses enter within
+// OnConfirm specifies a function to be called when the user presses enter
-// the text input.
+// within the text input.
-func (this *TextInput) OnEnter (callback func ()) event.Cookie {
+func (this *TextInput) OnConfirm (callback func ()) event.Cookie {
-	return this.on.enter.Connect(callback)
+	return this.on.confirm.Connect(callback)
 }
 
-// OnEdit specifies a function to be called when the user edits the input text.
+// OnValueChange specifies a function to be called when the user edits the input
-func (this *TextInput) OnEdit (callback func ()) event.Cookie {
+// text.
-	return this.on.edit.Connect(callback)
+func (this *TextInput) OnValueChange (callback func ()) event.Cookie {
-}
+	return this.on.valueChange.Connect(callback)
-
-func (this *TextInput) handleKeyDown (key input.Key, numpad bool) {
-	dot       := this.Dot()
-	modifiers := this.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)
-
-	switch {
-	case key == input.KeyEnter:
-		this.on.enter.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)
-		}
-	case key == input.KeyBackspace:
-		this.text, dot = text.Backspace(this.text, dot, word)
-		changed = 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():
-		this.text, dot = text.Type(this.text, dot, rune(key))
-		changed = true
-	}
-
-	this.Select(dot)
-	if changed {
-		this.SetText(string(this.text))
-		this.on.edit.Broadcast()
-	}
 }
 
 // Type types a character at the current dot position.
@@ -112,6 +62,65 @@ func (this *TextInput) Type (char rune) {
 	this.SetText(string(this.text))
 }
 
-func (this *TextInput) handleScroll (x, y float64) {
+func (this *TextInput) handleKeyDown (key input.Key, numpad bool) bool {
-	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
+	dot       := this.Dot()
+	modifiers := this.Window().Modifiers()
+	word      := modifiers.Control
+	changed   := false
+
+	defer func () {
+		this.Select(dot)
+		if changed {
+			this.SetText(string(this.text))
+			this.on.valueChange.Broadcast()
+		}
+	} ()
+
+	switch {
+	case key == input.KeyEnter:
+		this.on.confirm.Broadcast()
+		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
+		return true
+	case key == input.Key('a') && modifiers.Control:
+		dot.Start = 0
+		dot.End   = len(this.text)
+		return true
+	case key.Printable():
+		this.text, dot = text.Type(this.text, dot, rune(key))
+		changed = true
+		return true
+	default:
+		return false
+	}
+}
+
+func (this *TextInput) handleKeyUp (key input.Key, numpad bool) bool {
+	modifiers := this.Window().Modifiers()
+	switch {
+	case key == input.KeyEnter:
+		return true
+	case key == input.KeyBackspace:
+		return true
+	case key == input.KeyDelete:
+		return true
+	case key == input.Key('a') && modifiers.Control:
+		return true
+	case key.Printable():
+		return true
+	default:
+		return false
+	}
+}
+
+func (this *TextInput) handleScroll (x, y float64) bool {
+	if x == 0 { return false }
+	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
+	return true
 }

textview.go

@@ -11,16 +11,17 @@ type TextView struct {
 // NewTextView creates a new text view.
 func NewTextView (text string) *TextView {
 	this := &TextView { TextBox: tomo.NewTextBox() }
-	this.SetRole(tomo.R("objects", "TextView", ""))
+	this.SetRole(tomo.R("objects", "TextView"))
 	this.SetFocusable(true)
 	this.SetSelectable(true)
 	this.SetText(text)
-	this.SetOverflow(false, true)
+	this.SetAttr(tomo.AOverflow(false, true))
-	this.SetWrap(true)
+	this.SetAttr(tomo.AWrap(true))
 	this.OnScroll(this.handleScroll)
 	return this
 }
 
-func (this *TextView) handleScroll (x, y float64) {
+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
 }