Update code for layouts, objects

button.go

@@ -28,17 +28,16 @@ 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.SetText(text)
 	
-	box.CaptureDND(true)
+	box.CatchDND(true)
-	box.CaptureMouse(true)
+	box.CatchMouse(true)
-	box.CaptureScroll(true)
-	box.CaptureKeyboard(true)
 	
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
+	box.OnButtonUp(box.handleButtonUp)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
@@ -89,14 +88,19 @@ func (this *Button) applyLayout () {
 	}
 }
 
-func (this *Button) handleKeyUp (key input.Key, numberPad bool) {
+func (this *Button) handleKeyUp (catch func (), key input.Key, numberPad bool) {
 	if key != input.KeyEnter && key != input.Key(' ') { return }
 	this.on.click.Broadcast()
 }
 
-func (this *Button) handleMouseUp (button input.Button) {
+func (this *Button) handleButtonDown (catch func (), button input.Button) {
+	catch()
+}
+
+func (this *Button) handleButtonUp (catch func (), button input.Button) {
+	catch()
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.on.click.Broadcast()
 	}
 }

calendar.go

@@ -26,7 +26,7 @@ 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)
 	
 	prevButton := NewButton("")
@@ -42,10 +42,10 @@ func NewCalendar (tm time.Time) *Calendar {
 		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 (
 		true, true, true, true, true, true, true)())
 	calendar.Add(NewInnerContainer (
@@ -54,7 +54,6 @@ func NewCalendar (tm time.Time) *Calendar {
 	calendar.Add(calendar.grid)
 	
 	calendar.OnScroll(calendar.handleScroll)
-	calendar.CaptureScroll(true)
 	
 	calendar.refresh()
 	return calendar
@@ -98,9 +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)
 	}
 	
@@ -116,9 +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 {
@@ -127,7 +128,8 @@ func (this *Calendar) refresh () {
 	}
 }
 
-func (this *Calendar) handleScroll (x, y float64) {
+func (this *Calendar) handleScroll (catch func (), x, y float64) {
+	catch()
 	if y < 0 {
 		this.prevMonth()
 	} else {

checkbox.go

@@ -18,10 +18,11 @@ func NewCheckbox (value bool) *Checkbox {
 	box := &Checkbox {
 		Box: tomo.NewBox(),
 	}
-	box.SetRole(tomo.R("objects", "Checkbox", ""))
+	box.SetRole(tomo.R("objects", "Checkbox"))
 	box.SetValue(value)
 	
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
+	box.OnButtonUp(box.handleButtonUp)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
@@ -35,11 +36,9 @@ func (this *Checkbox) Value () bool {
 // SetValue sets the value of the checkbox.
 func (this *Checkbox) SetValue (value bool) {
 	this.value = value
-	if this.value {
+	// the theme shall decide what checked and unchecked states look like
-		this.SetTextureCenter(tomo.IconCheckboxChecked.Texture(tomo.IconSizeSmall))
+	this.SetTag("checked",    value)
-	} else {
+	this.SetTag("unchecked", !value)
-		this.SetTextureCenter(tomo.IconCheckboxUnchecked.Texture(tomo.IconSizeSmall))
-	}
 }
 
 // Toggle toggles the value of the checkbox between true and false.
@@ -53,14 +52,19 @@ 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) handleKeyUp (catch func (), key input.Key, numberPad bool) {
 	if key != input.KeyEnter && key != input.Key(' ') { return }
 	this.Toggle()
 }
 
-func (this *Checkbox) handleMouseUp (button input.Button) {
+func (this *Checkbox) handleButtonDown (catch func (), button input.Button) {
+	catch()
+}
+
+func (this *Checkbox) handleButtonUp (catch func (), button input.Button) {
+	catch()
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.Toggle()
 	}
 }

colorpicker.go

@@ -28,7 +28,7 @@ func NewColorPicker (value color.Color) *ColorPicker {
 	picker := &ColorPicker {
 		ContainerBox: tomo.NewContainerBox(),
 	}
-	picker.SetRole(tomo.R("objects", "ColorPicker", ""))
+	picker.SetRole(tomo.R("objects", "ColorPicker"))
 	picker.SetLayout(layouts.Row { true, false, false })
 	picker.pickerMap = newColorPickerMap(picker)
 	picker.Add(picker.pickerMap)
@@ -90,20 +90,20 @@ func newColorPickerMap (parent *ColorPicker) *colorPickerMap {
 		parent: parent,
 	}
 	picker.SetDrawer(picker)
-	picker.SetRole(tomo.R("objects", "ColorPickerMap", ""))
+	picker.SetRole(tomo.R("objects", "ColorPickerMap"))
-	picker.OnMouseUp(picker.handleMouseUp)
+	picker.OnButtonUp(picker.handleButtonUp)
-	picker.OnMouseDown(picker.handleMouseDown)
+	picker.OnButtonDown(picker.handleButtonDown)
 	picker.OnMouseMove(picker.handleMouseMove)
 	return picker
 }
 
-func (this *colorPickerMap) handleMouseDown (button input.Button) {
+func (this *colorPickerMap) handleButtonDown (catch func (), button input.Button) {
 	if button != input.ButtonLeft { return }
 	this.dragging = true
 	this.drag()
 }
 
-func (this *colorPickerMap) handleMouseUp (button input.Button) {
+func (this *colorPickerMap) handleButtonUp (catch func (), button input.Button) {
 	if button != input.ButtonLeft || !this.dragging { return }
 	this.dragging = false
 }
@@ -114,7 +114,7 @@ func (this *colorPickerMap) handleMouseMove () {
 }
 
 func (this *colorPickerMap) drag () {
-	pointer := this.MousePosition()
+	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())

container.go

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

heading.go

@@ -15,7 +15,8 @@ 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)
 	return this
 }

icon.go

@@ -1,6 +1,5 @@
 package objects
 
-import "image"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/tomo/data"
 import "git.tebibyte.media/tomo/tomo/canvas"
@@ -10,13 +9,22 @@ type Icon struct {
 	tomo.Box
 }
 
+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 {
 	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.SetTag(iconSizeString(size), true)
+	this.setTexture(id.Texture(size))
 	return this
 }
 
@@ -25,17 +33,20 @@ func NewMimeIcon (mime data.Mime, 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(tomo.MimeIcon(mime, size))
+	this.SetTag(iconSizeString(size), true)
+	this.setTexture(tomo.MimeIcon(mime, size))
 	return this
 }
 
-func (this *Icon) SetTexture (texture canvas.Texture) {
+func (this *Icon) setTexture (texture canvas.Texture) {
-	this.Box.SetTextureCenter(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)))
 	}
 }

label.go

@@ -10,8 +10,8 @@ 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.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	this.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
 	return this
 }

labelcheckbox.go

@@ -20,14 +20,14 @@ 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.Add(box.checkbox)
 	box.Add(box.label)
 	box.SetLayout(layouts.Row { false, true })
 
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
-	box.label.OnMouseUp(box.handleMouseUp)
+	box.OnButtonUp(box.handleButtonUp)
 	return box
 }
 
@@ -52,9 +52,14 @@ func (this *LabelCheckbox) OnValueChange (callback func ()) event.Cookie {
 	return this.checkbox.OnValueChange(callback)
 }
 
-func (this *LabelCheckbox) handleMouseUp (button input.Button) {
+func (this *LabelCheckbox) handleButtonDown (capture func (), button input.Button) {
+	capture()
+}
+
+func (this *LabelCheckbox) handleButtonUp (capture func (), button input.Button) {
+	capture()
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.checkbox.SetFocused(true)
 		this.checkbox.Toggle()
 	}

labelswatch.go

@@ -21,15 +21,15 @@ func NewLabelSwatch (value color.Color, text string) *LabelSwatch {
 		swatch:       NewSwatch(value),
 		label:        NewLabel(text),
 	}
-	box.SetRole(tomo.R("objects", "LabelSwatch", ""))
+	box.SetRole(tomo.R("objects", "LabelSwatch"))
 	box.swatch.label = text
-	box.label.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
+	box.label.SetAttr(tomo.AAlign(tomo.AlignStart, tomo.AlignMiddle))
 	box.Add(box.swatch)
 	box.Add(box.label)
 	box.SetLayout(layouts.Row { false, true })
 
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
-	box.label.OnMouseUp(box.handleMouseUp)
+	box.OnButtonUp(box.handleButtonUp)
 	return box
 }
 
@@ -60,9 +60,14 @@ func (this *LabelSwatch) OnConfirm (callback func ()) event.Cookie {
 	return this.swatch.OnConfirm(callback)
 }
 
-func (this *LabelSwatch) handleMouseUp (button input.Button) {
+func (this *LabelSwatch) handleButtonDown (catch func (), button input.Button) {
+	catch()
+}
+
+func (this *LabelSwatch) handleButtonUp (catch func (), button input.Button) {
+	catch()
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.swatch.SetFocused(true)
 		this.swatch.Choose()
 	}

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 +43,16 @@ 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
-		if stepIndexEnd > len(boxes) { stepIndexEnd = len(boxes) }
+		if stepIndexEnd > boxes.Len() { stepIndexEnd = boxes.Len() }
-		step := boxes[index:stepIndexEnd]
 		index += minorSteps
 		
 		// find a major size that will fit all boxes on this major step
 		majorSize := 0
-		for _, box := range step {
+		for index := index; 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 +61,9 @@ 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 := index; 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 +124,12 @@ 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

@@ -32,7 +32,7 @@ func NewGrid (columns ...bool) func (rows ...bool) *Grid {
 	}
 }
 
-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,
@@ -42,7 +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]
 	}
@@ -56,9 +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])),
 		})
@@ -71,13 +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
 		}
@@ -89,8 +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) {
@@ -116,10 +116,10 @@ func ceilDiv (x, y int) int {
 	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 {
 	return this.MinimumSize(hints, boxes).Y
 }
 
-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 {
 	return this.MinimumSize(hints, boxes).X
 }

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

@@ -40,15 +40,15 @@ func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
 
 	if !menu.torn {
 		menu.tearLine = tomo.NewBox()
-		menu.tearLine.SetRole(tomo.R("objects", "TearLine", ""))
+		menu.tearLine.SetRole(tomo.R("objects", "TearLine"))
 		menu.tearLine.SetFocusable(true)
-		menu.tearLine.OnKeyUp(func (key input.Key, numberPad bool) {
+		menu.tearLine.OnKeyUp(func (catch func (), key input.Key, numberPad bool) {
 			if key != input.KeyEnter && key != input.Key(' ') { return }
 			menu.TearOff()
 		})
-		menu.tearLine.OnMouseUp(func (button input.Button) {
+		menu.tearLine.OnButtonUp(func (catch func (), button input.Button) {
 			if button != input.ButtonLeft { return }
-			if menu.tearLine.MousePosition().In(menu.tearLine.Bounds()) {
+			if menu.tearLine.Window().MousePosition().In(menu.tearLine.Bounds()) {
 				menu.TearOff()
 			}
 		})
@@ -65,7 +65,8 @@ 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

menuitem.go

@@ -25,19 +25,18 @@ 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.Row { false, true })
 	
 	box.Add(box.icon)
 	box.Add(box.label)
 	
-	box.CaptureDND(true)
+	box.CatchDND(true)
-	box.CaptureMouse(true)
+	box.CatchMouse(true)
-	box.CaptureScroll(true)
-	box.CaptureKeyboard(true)
 	
-	box.OnMouseUp(box.handleMouseUp)
+	box.OnButtonDown(box.handleButtonDown)
+	box.OnButtonUp(box.handleButtonUp)
 	box.OnKeyUp(box.handleKeyUp)
 	box.SetFocusable(true)
 	return box
@@ -60,14 +59,19 @@ 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) handleKeyUp (catch func(), key input.Key, numberPad bool) {
 	if key != input.KeyEnter && key != input.Key(' ') { return }
 	this.on.click.Broadcast()
 }
 
-func (this *MenuItem) handleMouseUp (button input.Button) {
+func (this *MenuItem) handleButtonDown (catch func(), button input.Button) {
+	catch()
+}
+
+func (this *MenuItem) handleButtonUp (catch func(), button input.Button) {
+	catch()
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.on.click.Broadcast()
 	}
 }

numberinput.go

@@ -28,7 +28,7 @@ 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)
@@ -38,10 +38,8 @@ func NewNumberInput (value float64) *NumberInput {
 	
 	box.SetValue(value)
 	
-	box.CaptureScroll(true)
-	box.CaptureKeyboard(true)
-	
 	box.OnScroll(box.handleScroll)
+	box.OnKeyUp(box.handleKeyUp)
 	box.OnKeyDown(box.handleKeyDown)
 	box.input.OnConfirm(box.handleConfirm)
 	box.input.OnValueChange(box.on.valueChange.Broadcast)
@@ -78,19 +76,28 @@ func (this *NumberInput) shift (by int) {
 	this.on.valueChange.Broadcast()
 }
 
-func (this *NumberInput) handleKeyDown (key input.Key, numpad bool) {
+func (this *NumberInput) handleKeyDown (catch func (), key input.Key, numpad 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)
+		catch()
+	case input.KeyDown:
+		this.shift(-1)
+		catch()
 	}
 }
 
-func (this *NumberInput) handleScroll (x, y float64) {
+func (this *NumberInput) handleKeyUp (catch func (), key input.Key, numpad bool) {
+	switch key {
+	case input.KeyUp:   catch()
+	case input.KeyDown: catch()
+	}
+}
+
+func (this *NumberInput) handleScroll (catch func (), x, y float64) {
 	if x == 0 {
+		catch()
 		this.shift(-int(math.Round(y)))
-	} else {
-		this.input.handleScroll(x, y)
 	}
 }
 

scrollbar.go

@@ -35,19 +35,20 @@ func newScrollbar (orient string) *Scrollbar {
 	this.Add(this.handle)
 	this.SetFocusable(true)
 
-	this.CaptureDND(true)
+	this.CatchDND(true)
-	this.CaptureMouse(true)
+	this.CatchMouse(true)
-	this.CaptureScroll(true)
-	this.CaptureKeyboard(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
 }
 
@@ -120,22 +121,48 @@ 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.
+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()
+	}
+}
+
+// StepSize returns the scroll distance of a step.
+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 (catch func (), key input.Key, numpad bool) {
+	catch()
+}
+
+func (this *Scrollbar) handleKeyDown (catch func (), key input.Key, numpad bool) {
+	catch()
+	
 	var increment float64; if this.layout.vertical {
 		increment = -0.05
 	} else {
 		increment = 0.05
 	}
 
+	modifiers := this.Window().Modifiers()
+
 	switch key {
 	case input.KeyUp, input.KeyLeft:
-		if this.Modifiers().Alt {
+		if modifiers.Alt {
 			this.SetValue(0)
 		} else {
 			this.SetValue(this.Value() - increment)
 		}
 	case input.KeyDown, input.KeyRight:
-		if this.Modifiers().Alt {
+		if modifiers.Alt {
 			this.SetValue(1)
 		} else {
 			this.SetValue(this.Value() + increment)
@@ -147,8 +174,10 @@ func (this *Scrollbar) handleKeyDown (key input.Key, numpad bool) {
 	}
 }
 
-func (this *Scrollbar) handleMouseDown (button input.Button) {
+func (this *Scrollbar) handleButtonDown (catch func (), button input.Button) {
-	pointer := this.MousePosition()
+	catch()
+
+	pointer := this.Window().MousePosition()
 	handle  := this.handle.Bounds()
 
 	within := pointer.In(handle)
@@ -173,20 +202,21 @@ 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())
 		}
 	}
 }
 
-func (this *Scrollbar) handleMouseUp (button input.Button) {
+func (this *Scrollbar) handleButtonUp (catch func (), button input.Button) {
+	catch()
 	if button != input.ButtonLeft || !this.dragging { return }
 	this.dragging = false
 }
@@ -196,7 +226,8 @@ func (this *Scrollbar) handleMouseMove () {
 	this.drag()
 }
 
-func (this *Scrollbar) handleScroll (x, y float64) {
+func (this *Scrollbar) handleScroll (catch func(), x, y float64) {
+	catch()
 	if this.layout.linked == nil { return }
 	this.layout.linked.ScrollTo (
 		this.layout.linked.ContentBounds().Min.
@@ -204,7 +235,7 @@ func (this *Scrollbar) handleScroll (x, y float64) {
 }
 
 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 +260,6 @@ 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 {
@@ -283,14 +298,14 @@ 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 +326,7 @@ 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 +346,15 @@ 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 (
@@ -38,7 +40,10 @@ 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
@@ -52,22 +57,23 @@ type ScrollContainer struct {
 func NewScrollContainer (sides ScrollSide) *ScrollContainer {
 	this := &ScrollContainer {
 		ContainerBox: tomo.NewContainerBox(),
-		layout:       &scrollContainerLayout { },
 	}
 	if sides.Vertical() {
-		this.layout.vertical = NewVerticalScrollbar()
+		this.vertical = NewVerticalScrollbar()
-		this.layout.vertical.OnValueChange(this.handleValueChange)
+		this.vertical.OnValueChange(this.handleValueChange)
-		this.Add(this.layout.vertical)
+		this.Add(this.vertical)
 	}
 	if sides.Horizontal() {
-		this.layout.horizontal = NewHorizontalScrollbar()
+		this.horizontal = NewHorizontalScrollbar()
-		this.layout.horizontal.OnValueChange(this.handleValueChange)
+		this.horizontal.OnValueChange(this.handleValueChange)
-		this.Add(this.layout.horizontal)
+		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)
+	this.SetLayout(layouts.NewGrid(true, false)(true, false))
 	return this
 }
 
@@ -75,9 +81,9 @@ 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
@@ -87,24 +93,24 @@ 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)
 		}
 	}
 }
@@ -112,11 +118,11 @@ func (this *ScrollContainer) SetRoot (root tomo.ContentObject) {
 // 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
 }
@@ -124,11 +130,11 @@ func (this *ScrollContainer) Value () (x, y float64) {
 // 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 {
+	if this.horizontal != nil {
-		this.layout.horizontal.SetValue(x)
+		this.horizontal.SetValue(x)
 	}
-	if this.layout.vertical != nil {
+	if this.vertical != nil {
-		this.layout.vertical.SetValue(y)
+		this.vertical.SetValue(y)
 	}
 }
 
@@ -138,77 +144,74 @@ 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 {
+		page.X = this.horizontal.PageSize()
+	}
+	if this.vertical != nil {
+		page.Y = this.vertical.PageSize()
+	}
+	return page
+}
+
+// StepSize returns the scroll distance of a step.
+func (this *ScrollContainer) StepSize () image.Point {
+	page := image.Point { }
+	if this.horizontal != nil {
+		page.X = this.horizontal.StepSize()
+	}
+	if this.vertical != nil {
+		page.Y = this.vertical.StepSize()
+	}
+	return page
+}
+
 func (this *ScrollContainer) handleValueChange () {
 	this.on.valueChange.Broadcast()
 }
 
-func (this *ScrollContainer) handleScroll (x, y float64) {
+func (this *ScrollContainer) handleScroll (catch func (), x, y float64) {
-	if this.layout.root == nil { return }
+	catch()
-	this.layout.root.ScrollTo (
+	if this.root == nil { return }
-		this.layout.root.ContentBounds().Min.
+	this.scrollBy(image.Pt(int(x), int(y)))
-		Sub(image.Pt(int(x), int(y))))
 }
 
-// TODO: remove this and replace it with something from the layouts package
+func (this *ScrollContainer) scrollBy (vector image.Point) {
-type scrollContainerLayout struct {
+	if this.root == nil { return }
-	root       tomo.ContentObject
+	this.root.ScrollTo (
-	horizontal *Scrollbar
+		this.root.ContentBounds().Min.
-	vertical   *Scrollbar
+		Sub(vector))
 }
 
-func (this *scrollContainerLayout) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+func (this *ScrollContainer) handleKeyDown (catch func (), key input.Key, numpad bool) {
-	var minimum image.Point; if this.root != nil {
+	modifiers := this.Window().Modifiers()
-		minimum = this.root.GetBox().MinimumSize()
+	vector    := image.Point { }
+	switch key {
+	case input.KeyPageUp:
+		catch()
+		if modifiers.Shift {
+			vector.X -= this.PageSize().X
+		} else {
+			vector.Y -= this.PageSize().Y
+		}
+	case input.KeyPageDown:
+		catch()
+		if modifiers.Shift {
+			vector.X += this.PageSize().X
+		} else {
+			vector.Y += this.PageSize().Y
+		}
 	}
-	if this.horizontal != nil {
+	if vector != (image.Point { }) {
-		minimum.Y += this.horizontal.MinimumSize().Y
+		this.scrollBy(vector)
-	}
-	if this.vertical != nil {
-		minimum.X += this.vertical.MinimumSize().X
-		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) {
-	rootBounds := hints.Bounds
-	if this.horizontal != nil {
-		rootBounds.Max.Y -= this.horizontal.MinimumSize().Y
-	}
-	if this.vertical != nil {
-		rootBounds.Max.X -= this.vertical.MinimumSize().X
-	}
-	if this.root != nil {
-		this.root.GetBox().SetBounds(rootBounds)
-	}
-	if this.horizontal != nil {
-		this.horizontal.SetBounds(image.Rect (
-			hints.Bounds.Min.X,
-			rootBounds.Max.Y,
-			rootBounds.Max.X,
-			hints.Bounds.Max.Y))
-	}
-	if this.vertical != nil {
-		this.vertical.SetBounds(image.Rect (
-			rootBounds.Max.X,
-			hints.Bounds.Min.Y,
-			hints.Bounds.Max.X,
-			rootBounds.Max.Y))
 	}
 }
 
-func (this *scrollContainerLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+func (this *ScrollContainer) handleKeyUp (catch func (), key input.Key, numpad bool) {
-	return this.MinimumSize(hints, boxes).X
+	switch key {
-}
+	case input.KeyPageUp:   catch()
-
+	case input.KeyPageDown: catch()
-func (this *scrollContainerLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+	}
-	return this.MinimumSize(hints, boxes).Y
-}
-
-func max (x, y int) int {
-	if x > y { return x }
-	return y
 }

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

@@ -43,20 +43,21 @@ func newSlider (orient string, value float64) *Slider {
 	this.Add(this.handle)
 	this.SetFocusable(true)
 
-	this.CaptureDND(true)
+	this.CatchDND(true)
-	this.CaptureMouse(true)
+	this.CatchMouse(true)
-	this.CaptureScroll(true)
-	this.CaptureKeyboard(true)
 
 	this.SetValue(value)
+	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
 }
 
@@ -96,7 +97,9 @@ func (this *Slider) OnConfirm (callback func ()) event.Cookie {
 	return this.on.confirm.Connect(callback)
 }
 
-func (this *Slider) handleKeyDown (key input.Key, numpad bool) {
+func (this *Slider) handleKeyDown (catch func (), key input.Key, numpad bool) {
+	catch()
+	
 	var increment float64; if this.layout.vertical {
 		increment = -0.05
 	} else {
@@ -105,14 +108,14 @@ 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.valueChange.Broadcast()
 	case input.KeyDown, input.KeyRight:
-		if this.Modifiers().Alt {
+		if this.Window().Modifiers().Alt {
 			this.SetValue(1)
 		} else {
 			this.SetValue(this.Value() + increment)
@@ -127,8 +130,14 @@ func (this *Slider) handleKeyDown (key input.Key, numpad bool) {
 	}
 }
 
-func (this *Slider) handleMouseDown (button input.Button) {
+func (this *Slider) handleKeyUp (catch func (), key input.Key, numpad bool) {
-	pointer := this.MousePosition()
+	catch()
+}
+
+func (this *Slider) handleButtonDown (catch func (), button input.Button) {
+	catch()
+	
+	pointer := this.Window().MousePosition()
 	handle  := this.handle.Bounds()
 	
 	within := pointer.In(handle)
@@ -174,7 +183,8 @@ func (this *Slider) handleMouseDown (button input.Button) {
 	}
 }
 
-func (this *Slider) handleMouseUp (button input.Button) {
+func (this *Slider) handleButtonUp (catch func (), button input.Button) {
+	catch()
 	if button != input.ButtonLeft || !this.dragging { return }
 	this.dragging = false
 	this.on.confirm.Broadcast()
@@ -185,7 +195,7 @@ func (this *Slider) handleMouseMove () {
 	this.drag()
 }
 
-func (this *Slider) handleScroll (x, y float64) {
+func (this *Slider) handleScroll (catch func (), x, y float64) {
 	delta := (x + y) * 0.005
 	this.SetValue(this.Value() + delta)
 	this.on.valueChange.Broadcast()
@@ -193,7 +203,7 @@ func (this *Slider) handleScroll (x, y float64) {
 }
 
 func (this *Slider) drag () {
-	pointer := this.MousePosition().Sub(this.dragOffset)
+	pointer := this.Window().MousePosition().Sub(this.dragOffset)
 	gutter  := this.InnerBounds()
 	handle  := this.handle.Bounds()
 
@@ -225,39 +235,37 @@ 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

@@ -26,11 +26,11 @@ func NewSwatch (value color.Color) *Swatch {
 	swatch := &Swatch {
 		CanvasBox: tomo.NewCanvasBox(),
 	}
-	swatch.SetRole(tomo.R("objects", "Swatch", ""))
+	swatch.SetRole(tomo.R("objects", "Swatch"))
 	swatch.SetDrawer(swatch)
 	swatch.SetValue(value)
 	
-	swatch.OnMouseUp(swatch.handleMouseUp)
+	swatch.OnButtonUp(swatch.handleButtonUp)
 	swatch.OnKeyUp(swatch.handleKeyUp)
 	swatch.SetFocusable(true)
 	return swatch
@@ -114,7 +114,7 @@ func (this *Swatch) Choose () {
 		layouts.ContractHorizontal,
 		cancelButton,
 		okButton)
-	controlRow.SetAlign(tomo.AlignEnd, tomo.AlignMiddle)
+	controlRow.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignMiddle))
 	window.SetRoot(NewOuterContainer (
 		layouts.Column { true, false },
 		colorPicker,
@@ -155,14 +155,14 @@ func (this *Swatch) userSetValue (value color.Color) {
 	this.on.valueChange.Broadcast()
 }
 
-func (this *Swatch) handleKeyUp (key input.Key, numberPad bool) {
+func (this *Swatch) handleKeyUp (catch func (), key input.Key, numberPad bool) {
 	if key != input.KeyEnter && key != input.Key(' ') { return }
 	this.Choose()
 }
 
-func (this *Swatch) handleMouseUp (button input.Button) {
+func (this *Swatch) handleButtonUp (catch func (), button input.Button) {
 	if button != input.ButtonLeft { return }
-	if this.MousePosition().In(this.Bounds()) {
+	if this.Window().MousePosition().In(this.Bounds()) {
 		this.Choose()
 	}
 }

tabbedcontainer.go

@@ -18,17 +18,19 @@ func NewTabbedContainer () *TabbedContainer {
 	container := &TabbedContainer {
 		ContainerBox: tomo.NewContainerBox(),
 	}
-	container.SetRole(tomo.R("objects", "TabbedContainer", ""))
+	container.SetRole(tomo.R("objects", "TabbedContainer"))
 	container.SetLayout(layouts.Column { false, true } )
 	
 	container.tabsRow = tomo.NewContainerBox()
-	container.tabsRow.SetRole(tomo.R("objects", "TabRow", ""))
+	container.tabsRow.SetRole(tomo.R("objects", "TabRow"))
 	container.Add(container.tabsRow)
 	
 	container.leftSpacer = tomo.NewBox()
-	container.leftSpacer.SetRole(tomo.R("objects", "TabSpacer", "left"))
+	container.leftSpacer.SetRole(tomo.R("objects", "TabSpacer"))
+	container.leftSpacer.SetTag("left", true)
 	container.rightSpacer = tomo.NewBox()
-	container.rightSpacer.SetRole(tomo.R("objects", "TabSpacer", "right"))
+	container.rightSpacer.SetRole(tomo.R("objects", "TabSpacer"))
+	container.rightSpacer.SetTag("left", true)
 	
 	container.ClearTabs()
 	container.setTabRowLayout()
@@ -55,9 +57,9 @@ func (this *TabbedContainer) AddTab (name string, root tomo.Object) {
 		name:    name,
 		root:    root,
 	}
-	tab.SetRole(tomo.R("objects", "Tab", ""))
+	tab.SetRole(tomo.R("objects", "Tab"))
 	tab.SetText(name)
-	tab.OnMouseDown(func (button input.Button) {
+	tab.OnButtonDown(func (catch func (), button input.Button) {
 		if button != input.ButtonLeft { return }
 		this.Activate(name)
 	})
@@ -118,9 +120,11 @@ type tab struct {
 
 func (this *tab) setActive (active bool) {
 	if active {
-		this.SetRole(tomo.R("objects", "Tab", "active"))
+		this.SetRole(tomo.R("objects", "Tab"))
+		this.SetTag("active", false)
 	} else {
-		this.SetRole(tomo.R("objects", "Tab", ""))
+		this.SetRole(tomo.R("objects", "Tab"))
+		this.SetTag("active", true)
 	}
 }
 

textinput.go

@@ -19,8 +19,8 @@ type TextInput struct {
 // 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.SetText(text)
 	this.SetFocusable(true)
 	this.SetSelectable(true)
@@ -53,9 +53,9 @@ func (this *TextInput) OnValueChange (callback func ()) event.Cookie {
 	return this.on.valueChange.Connect(callback)
 }
 
-func (this *TextInput) handleKeyDown (key input.Key, numpad bool) {
+func (this *TextInput) handleKeyDown (catch func (), key input.Key, numpad bool) {
 	dot       := this.Dot()
-	modifiers := this.Modifiers()
+	modifiers := this.Window().Modifiers()
 	word      := modifiers.Control
 	sel       := modifiers.Shift
 	changed   := false
@@ -113,6 +113,6 @@ func (this *TextInput) Type (char rune) {
 	this.SetText(string(this.text))
 }
 
-func (this *TextInput) handleScroll (x, y float64) {
+func (this *TextInput) handleScroll (catch func (), x, y float64) {
 	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
 }

textview.go

@@ -11,7 +11,7 @@ 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)
@@ -21,6 +21,6 @@ func NewTextView (text string) *TextView {
 	return this
 }
 
-func (this *TextView) handleScroll (x, y float64) {
+func (this *TextView) handleScroll (catch func (), x, y float64) {
 	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
 }