Some internal layouts return recommended sizes

Not a very good implementation

button.go

@@ -5,9 +5,9 @@ import "git.tebibyte.media/tomo/tomo/input"
 import "git.tebibyte.media/tomo/tomo/event"
 import "git.tebibyte.media/tomo/objects/layouts"
 
-var buttonLayout     = layouts.NewGrid([]bool { true        }, []bool { true })
-var iconButtonLayout = layouts.NewGrid([]bool { true        }, []bool { true })
-var bothButtonLayout = layouts.NewGrid([]bool { false, true }, []bool { true })
+var buttonLayout     = layouts.Row { true        }
+var iconButtonLayout = layouts.Row { true        }
+var bothButtonLayout = layouts.Row { false, true }
 
 // Button is a clickable button.
 type Button struct {
@@ -29,7 +29,6 @@ func NewButton (text string) *Button {
 		label:        NewLabel(text),
 	}
 	box.SetRole(tomo.R("objects", "Button", ""))
-	tomo.Apply(box)
 	box.label.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
 	box.SetLayout(buttonLayout)
 	box.SetText(text)

checkbox.go

@@ -19,7 +19,6 @@ func NewCheckbox (value bool) *Checkbox {
 		Box: tomo.NewBox(),
 	}
 	box.SetRole(tomo.R("objects", "Checkbox", ""))
-	tomo.Apply(box)
 	box.SetValue(false)
 	
 	box.OnMouseUp(box.handleMouseUp)

container.go

@@ -28,7 +28,6 @@ func newContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 func NewOuterContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
 	this.SetRole(tomo.R("objects", "Container", "outer"))
-	tomo.Apply(this)
 	return this
 }
 
@@ -37,7 +36,6 @@ func NewOuterContainer (layout tomo.Layout, children ...tomo.Object) *Container
 func NewSunkenContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
 	this.SetRole(tomo.R("objects", "Container", "sunken"))
-	tomo.Apply(this)
 	return this
 }
 
@@ -45,7 +43,6 @@ func NewSunkenContainer (layout tomo.Layout, children ...tomo.Object) *Container
 func NewInnerContainer (layout tomo.Layout, children ...tomo.Object) *Container {
 	this := newContainer(layout, children...)
 	this.SetRole(tomo.R("objects", "Container", "inner"))
-	tomo.Apply(this)
 	return this
 }
 

go.mod

@@ -2,6 +2,6 @@ module git.tebibyte.media/tomo/objects
 
 go 1.20
 
-require git.tebibyte.media/tomo/tomo v0.36.0
+require git.tebibyte.media/tomo/tomo v0.38.0
 
 require golang.org/x/image v0.11.0 // indirect

go.sum

@@ -1,5 +1,5 @@
-git.tebibyte.media/tomo/tomo v0.36.0 h1:V9vyPYb4kpUceBhcDF/XyLDACzE5lY8kYEGHAkIsqs0=
-git.tebibyte.media/tomo/tomo v0.36.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
+git.tebibyte.media/tomo/tomo v0.38.0 h1:K5TP67RxnszudeNfmGZiU5cFTRjFueXiI3NCsgw+05U=
+git.tebibyte.media/tomo/tomo v0.38.0/go.mod h1:C9EzepS9wjkTJjnZaPBh22YvVPyA4hbBAJVU20Rdmps=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=

heading.go

@@ -16,7 +16,6 @@ func NewHeading (level int, text string) *Heading {
 	if level > 2 { level = 2 }
 	this := &Heading { TextBox: tomo.NewTextBox() }
 	this.SetRole(tomo.R("objects", "Heading", fmt.Sprint(level)))
-	tomo.Apply(this)
 	this.SetText(text)
 	return this
 }

icon.go

@@ -16,7 +16,6 @@ func NewIcon (id tomo.Icon, size tomo.IconSize) *Icon {
 		Box: tomo.NewBox(),
 	}
 	this.SetRole(tomo.R("objects", "Icon", size.String()))
-	tomo.Apply(this)
 	this.SetTexture(id.Texture(size))
 	return this
 }
@@ -27,7 +26,6 @@ func NewMimeIcon (mime data.Mime, size tomo.IconSize) *Icon {
 		Box: tomo.NewBox(),
 	}
 	this.SetRole(tomo.R("objects", "Icon", size.String()))
-	tomo.Apply(this)
 	this.SetTexture(tomo.MimeIcon(mime, size))
 	return this
 }

label.go

@@ -11,7 +11,6 @@ type Label struct {
 func NewLabel (text string) *Label {
 	this := &Label { TextBox: tomo.NewTextBox() }
 	this.SetRole(tomo.R("objects", "Label", ""))
-	tomo.Apply(this)
 	this.SetText(text)
 	return this
 }

labelcheckbox.go

@@ -21,7 +21,6 @@ func NewLabelCheckbox (value bool, text string) *LabelCheckbox {
 		label:        NewLabel(text),
 	}
 	box.SetRole(tomo.R("objects", "LabelCheckbox", ""))
-	tomo.Apply(box)
 	box.label.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
 	box.Add(box.checkbox)
 	box.Add(box.label)

layouts/contract.go

@@ -0,0 +1,40 @@
+package layouts
+
+import "image"
+import "git.tebibyte.media/tomo/tomo"
+
+var _ tomo.Layout = ContractVertical
+
+// Contract is a layout that arranges boxes in a simple row or column according
+// to their minimum sizes.
+type Contract bool
+
+// ContractVertical is a vertical contracted layout.
+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 {
+	return contract.fallback().MinimumSize(hints, boxes)
+}
+
+func (contract Contract) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+	contract.fallback().Arrange(hints, boxes)
+}
+
+func (contract Contract) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	return contract.fallback().RecommendedHeight(hints, boxes, width)
+}
+
+func (contract Contract) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+	return contract.fallback().RecommendedWidth(hints, boxes, height)
+}
+
+func (contract Contract) fallback () tomo.Layout {
+	if contract == ContractVertical {
+		return Column { }
+	} else {
+		return Row { }
+	}
+}

layouts/cut.go

@@ -1,173 +0,0 @@
-package layouts
-
-import "image"
-import "git.tebibyte.media/tomo/tomo"
-
-// Cut is a layout that can be divided into smaller and smaller sections.
-type Cut struct {
-	branches []*Cut
-	expand   []bool
-	vertical bool
-}
-
-// NewCut creates and returns a new Cut layout.
-func NewCut () *Cut {
-	return new(Cut)
-}
-
-// Vertical divides the layout vertically. Sections are specified using
-// booleans. If a section is true, it will expand. If false, it will contract.
-func (this *Cut) Vertical (expand ...bool) {
-	this.expand   = expand
-	this.vertical = true
-	this.fill()
-}
-
-// Horizontal divides the layout horizontally. Sections are specified using
-// booleans. If a section is true, it will expand. If false, it will contract.
-func (this *Cut) Horizontal (expand ...bool) {
-	this.expand   = expand
-	this.vertical = false
-	this.fill()
-}
-
-// At returns the section of this layout at the specified index.
-func (this *Cut) At (index int) *Cut {
-	return this.branches[index]
-}
-
-func (this *Cut) real () bool {
-	return this != nil && this.branches != nil
-}
-
-func (this *Cut) fill () {
-	this.branches = make([]*Cut, len(this.expand))
-	for index := range this.branches {
-		this.branches[index] = new(Cut)
-	}
-}
-
-func (this *Cut) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
-	size, _ := this.minimumSize(hints, boxes)
-	return size
-}
-
-func (this *Cut) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
-	this.arrange(hints, boxes)
-}
-
-func (this *Cut) minimumSize (hints tomo.LayoutHints, boxes []tomo.Box) (image.Point, []tomo.Box) {
-	size := image.Point { }
-
-	for index, branch := range this.branches {
-		if len(boxes) == 0 { break }
-
-		var point image.Point
-		if branch.real() {
-			point, boxes = branch.minimumSize(hints, boxes)
-		} else {
-			point = boxes[0].MinimumSize()
-			boxes = boxes[1:]
-		}
-
-		if this.vertical {
-			if point.X > size.X { size.X  = point.X     }
-			if index   > 0      { size.Y += hints.Gap.Y }
-			size.Y += point.Y
-		} else {
-			if point.Y > size.Y { size.Y  = point.Y     }
-			if index   > 0      { size.X += hints.Gap.X }
-			size.X += point.X
-		}
-	}
-
-	return size, boxes
-}
-
-func (this *Cut) arrange (hints tomo.LayoutHints, boxes []tomo.Box) []tomo.Box {
-	nChildren := len(this.branches)
-
-	// collect minimum sizes and physical endpoints
-	var minimums = make([]image.Point,  nChildren)
-	var leaves   = make([]tomo.Box,     nChildren)
-	var nBranches int
-	remaining := boxes
-	for index, branch := range this.branches {
-		if branch.real() {
-			minimums[index], remaining = branch.minimumSize(hints, remaining)
-		} else {
-			if len(remaining) == 0 { break }
-			leaves[index]   = remaining[0]
-			minimums[index] = remaining[0].MinimumSize()
-			remaining       = remaining[1:]
-		}
-		nBranches ++
-	}
-
-	// determine the amount of space to divide among expanding branches
-	gaps := nBranches - 1
-	var freeSpace float64; if this.vertical {
-		freeSpace = float64(hints.Bounds.Dy() - hints.Gap.Y * gaps)
-	} else {
-		freeSpace = float64(hints.Bounds.Dx() - hints.Gap.X * gaps)
-	}
-	var nExpanding float64
-	for index, minimum := range minimums {
-		if this.expand[index] {
-			nExpanding ++
-		} else if this.vertical {
-			freeSpace -= float64(minimum.Y)
-		} else {
-			freeSpace -= float64(minimum.X)
-		}
-	}
-	expandingSize := freeSpace / nExpanding
-
-	// calculate the size and position of branches
-	var bounds = make([]image.Rectangle, nChildren)
-	x := float64(hints.Bounds.Min.X)
-	y := float64(hints.Bounds.Min.Y)
-	for index, minimum := range minimums {
-		// get size along significant axis
-		var size float64; if this.expand[index] {
-			size = expandingSize
-		} else if this.vertical {
-			size = float64(minimum.Y)
-		} else {
-			size = float64(minimum.X)
-		}
-
-		// figure out bounds from size
-		if this.vertical {
-			bounds[index].Max = image.Pt (
-				int(hints.Bounds.Dx()),
-				int(size))
-		} else {
-			bounds[index].Max = image.Pt (
-				int(size),
-				int(hints.Bounds.Dy()))
-		}
-		bounds[index] = bounds[index].Add(image.Pt(int(x), int(y)))
-
-		// move along
-		if this.vertical {
-			y += float64(hints.Gap.Y) + size
-		} else {
-			x += float64(hints.Gap.X) + size
-		}
-	}
-
-	// apply the size and position
-	for index, bound := range bounds {
-		if leaves[index] != nil {
-			leaves[index].SetBounds(bound)
-			boxes = boxes[1:]
-		} else if this.branches[index] != nil {
-			newHints := hints
-			newHints.Bounds = bound
-			boxes = this.branches[index].arrange(newHints, boxes)
-		}
-	}
-	
-	return boxes
-}

layouts/flow.go

@@ -3,6 +3,8 @@ package layouts
 import "image"
 import "git.tebibyte.media/tomo/tomo"
 
+var _ tomo.Layout = FlowVertical
+
 // Flow is a grid layout where the number of rows and columns changes depending
 // on the size of the container. It is designed to be used with an overflowing
 // container. If the container does not overflow in the correct direction, the
@@ -121,3 +123,13 @@ func (flow Flow) deltaMinor (rectangle image.Rectangle) int {
 func (flow Flow) fallback () tomo.Layout {
 	return Contract(flow)
 }
+
+func (flow Flow) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	// TODO
+	return 0
+}
+
+func (flow Flow) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+	// TODO
+	return 0
+}

layouts/grid.go

@@ -4,6 +4,8 @@ import "math"
 import "image"
 import "git.tebibyte.media/tomo/tomo"
 
+var _ tomo.Layout = new(Grid)
+
 // Grid is a layout that arranges boxes in a grid formation with distinct rows
 // and columns. It is great for creating forms.
 type Grid struct {
@@ -106,3 +108,13 @@ func expand (hints tomo.LayoutHints, sizes []int, space int, expands func (int)
 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 {
+	// TODO
+	return 0
+}
+
+func (this *Grid) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+	// TODO
+	return 0
+}

layouts/layouts.go

@@ -1,95 +0,0 @@
-package layouts
-
-import "image"
-import "git.tebibyte.media/tomo/tomo"
-
-// Contract is a layout that arranges boxes in a simple row or column according
-// to their minimum sizes.
-type Contract bool
-
-// ContractVertical is a vertical contracted layout.
-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 {
-	if contract.v() {
-		dot := image.Point { }
-		for _, box := range boxes {
-			minimum := box.MinimumSize()
-			dot.Y += minimum.Y
-			if dot.X < minimum.X {
-				dot.X = minimum.X
-			}
-		}
-		dot.Y += hints.Gap.Y * (len(boxes) - 1)
-		return dot
-	} else {
-		dot := image.Point { }
-		for _, box := range boxes {
-			minimum := box.MinimumSize()
-			dot.X += minimum.X
-			if dot.Y < minimum.Y {
-				dot.Y = minimum.Y
-			}
-		}
-		dot.X += hints.Gap.X * (len(boxes) - 1)
-		return dot
-	}
-}
-
-func (contract Contract) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
-	if contract.v() {
-		dot := hints.Bounds.Min
-		for index, box := range boxes {
-			if index > 0 { dot.Y += hints.Gap.Y }
-			minimum := box.MinimumSize()
-			box.SetBounds(image.Rectangle {
-				Min: dot,
-				Max: dot.Add(image.Pt(hints.Bounds.Dx(), minimum.Y)),
-			})
-			dot.Y += minimum.Y
-		}
-		
-		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 {
-			box.SetBounds(box.Bounds().Add(image.Pt(0, offset)))
-		}
-	} else {
-		dot := hints.Bounds.Min
-		for index, box := range boxes {
-			if index > 0 { dot.X += hints.Gap.X }
-			minimum := box.MinimumSize()
-			box.SetBounds(image.Rectangle {
-				Min: dot,
-				Max: dot.Add(image.Pt(minimum.X, hints.Bounds.Dy())),
-			})
-			dot.X += minimum.X
-		}
-
-		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 {
-			box.SetBounds(box.Bounds().Add(image.Pt(offset, 0)))
-		}
-	}
-}
-
-func (contract Contract) v () bool { return contract == ContractVertical   }
-func (contract Contract) h () bool { return contract == ContractHorizontal }

layouts/rowcol.go

@@ -0,0 +1,238 @@
+package layouts
+
+import "image"
+import "git.tebibyte.media/tomo/tomo"
+
+var _ tomo.Layout = ContractVertical
+
+// Row arranges boxes in a row. Boxes that share an index with a true value will
+// expand, and others will contract.
+type Row []bool
+
+// Column arranges boxes in a column. Boxes that share an index with a true
+// value will expand, and others will contract.
+type Column []bool
+
+func (column Column) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+	dot := image.Point { }
+	for _, box := range boxes {
+		minimum := box.MinimumSize()
+		dot.Y += minimum.Y
+		if dot.X < minimum.X {
+			dot.X = minimum.X
+		}
+	}
+	dot.Y += hints.Gap.Y * (len(boxes) - 1)
+	return dot
+}
+
+func (row Row) MinimumSize (hints tomo.LayoutHints, boxes []tomo.Box) image.Point {
+	dot := image.Point { }
+	for _, box := range boxes {
+		minimum := box.MinimumSize()
+		dot.X += minimum.X
+		if dot.Y < minimum.Y {
+			dot.Y = minimum.Y
+		}
+	}
+	dot.X += hints.Gap.X * (len(boxes) - 1)
+	return dot
+}
+
+func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+	expands := func (index int) bool {
+		if index >= len(column) { return false }
+		return column[index]
+	}
+
+	// determine expanding box size
+	expandingSize := 0.0
+	if !hints.OverflowY {
+		gaps       := len(boxes) - 1
+		freeSpace  := float64(hints.Bounds.Dy() - hints.Gap.Y * gaps)
+		nExpanding := 0; for index, box := range boxes {
+			if expands(index) {
+				nExpanding ++
+			} else {
+				freeSpace -= float64(box.MinimumSize().Y)
+			}
+		}
+		expandingSize = freeSpace / float64(nExpanding)
+	}
+
+	// determine width
+	width := 0
+	if hints.OverflowX {
+		for _, box := range boxes {
+			minimum := box.MinimumSize()
+			if width < minimum.X { width = minimum.X }
+		}
+	} else {
+		width = hints.Bounds.Dx()
+	}
+
+	// arrange
+	dot := hints.Bounds.Min
+	for index, box := range boxes {
+		if index > 0 { dot.Y += hints.Gap.Y }
+
+		// determine height
+		height := box.MinimumSize().Y
+		if hints.OverflowY {
+			if box, ok := box.(tomo.ContentBox); ok {
+				height = box.RecommendedHeight(width)
+			}
+		} else {
+			if expands(index) {
+				height = int(expandingSize)
+			}
+		}
+
+		// set bounds
+		box.SetBounds(image.Rectangle {
+			Min: dot,
+			Max: dot.Add(image.Pt(width, height)),
+		})
+		dot.Y += height
+	}
+	
+	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 {
+		box.SetBounds(box.Bounds().Add(image.Pt(0, offset)))
+	}
+}
+
+func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
+	expands := func (index int) bool {
+		if index >= len(row) { return false }
+		return row[index]
+	}
+
+	// determine expanding box size
+	expandingSize := 0.0
+	if !hints.OverflowY {
+		gaps       := len(boxes) - 1
+		freeSpace  := float64(hints.Bounds.Dx() - hints.Gap.X * gaps)
+		nExpanding := 0; for index, box := range boxes {
+			if expands(index) {
+				nExpanding ++
+			} else {
+				freeSpace -= float64(box.MinimumSize().X)
+			}
+		}
+		expandingSize = freeSpace / float64(nExpanding)
+	}
+
+	// determine height
+	height := 0
+	if hints.OverflowY {
+		for _, box := range boxes {
+			minimum := box.MinimumSize()
+			if height < minimum.Y { height = minimum.Y }
+		}
+	} else {
+		height = hints.Bounds.Dy()
+	}
+
+	// arrange
+	dot := hints.Bounds.Min
+	for index, box := range boxes {
+		if index > 0 { dot.X += hints.Gap.X }
+
+		// determine width
+		width := box.MinimumSize().X
+		if hints.OverflowY {
+			if box, ok := box.(tomo.ContentBox); ok {
+				width = box.RecommendedHeight(height)
+			}
+		} else {
+			if expands(index) {
+				width = int(expandingSize)
+			}
+		}
+
+		// set bounds
+		box.SetBounds(image.Rectangle {
+			Min: dot,
+			Max: dot.Add(image.Pt(width, height)),
+		})
+		dot.X += width
+	}
+
+	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 {
+		box.SetBounds(box.Bounds().Add(image.Pt(offset, 0)))
+	}
+}
+
+func (column Column) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	height := 0
+	for _, box := range boxes {
+		if box, ok := box.(tomo.ContentBox); ok {
+			height += box.RecommendedHeight(width) 
+		} else {
+			height += box.MinimumSize().Y
+		}
+	}
+	height += hints.Gap.Y * (len(boxes) - 1)
+	return height
+}
+
+func (row Row) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	height := 0
+	for _, box := range boxes {
+		minimum   := box.MinimumSize()
+		boxHeight := 0
+		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 {
+	width := 0
+	for _, box := range boxes {
+		minimum   := box.MinimumSize()
+		boxWidth := 0
+		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 {
+	width := 0
+	for _, box := range boxes {
+		if box, ok := box.(tomo.ContentBox); ok {
+			width += box.RecommendedWidth(height)
+		} else {
+			width += box.MinimumSize().X
+		}
+	}
+	width += hints.Gap.X * (len(boxes) - 1)
+	return width
+}

menu.go

@@ -41,7 +41,6 @@ func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
 	if !menu.torn {
 		menu.tearLine = tomo.NewBox()
 		menu.tearLine.SetRole(tomo.R("objects", "TearLine", ""))
-		tomo.Apply(menu.tearLine)
 		menu.tearLine.SetFocusable(true)
 		menu.tearLine.OnKeyUp(func (key input.Key, numberPad bool) {
 			if key != input.KeyEnter && key != input.Key(' ') { return }
@@ -67,7 +66,6 @@ func NewMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
 		}
 	}
 	menu.rootContainer.SetRole(tomo.R("objects", "Container", "menu"))
-	tomo.Apply(menu.rootContainer)
 
 	menu.Window.SetRoot(menu.rootContainer)
 	return menu, nil

menuitem.go

@@ -26,7 +26,6 @@ func NewMenuItem (text string) *MenuItem {
 		icon:         NewIcon("", tomo.IconSizeSmall),
 	}
 	box.SetRole(tomo.R("objects", "MenuItem", ""))
-	tomo.Apply(box)
 	box.label.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
 	box.SetLayout(layouts.NewGrid([]bool { false, true }, []bool { true }))
 	

numberinput.go

@@ -29,7 +29,6 @@ func NewNumberInput (value float64) *NumberInput {
 		decrement:    NewButton(""),
 	}
 	box.SetRole(tomo.R("objects", "NumberInput", ""))
-	tomo.Apply(box)
 	box.Add(box.input)
 	box.Add(box.decrement)
 	box.Add(box.increment)

scrollbar.go

@@ -47,9 +47,7 @@ func newScrollbar (orient string) *Scrollbar {
 	this.OnScroll(this.handleScroll)
 	
 	this.handle.SetRole(tomo.R("objects", "SliderHandle", orient))
-	tomo.Apply(this.handle)
 	this.SetRole(tomo.R("objects", "Slider", orient))
-	tomo.Apply(this)
 	return this
 }
 
@@ -337,6 +335,14 @@ func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	
 }
 
+func (this scrollbarLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	return this.MinimumSize(hints, boxes).X
+}
+
+func (this scrollbarLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
+	return this.MinimumSize(hints, boxes).Y
+}
+
 func (this scrollbarLayout) viewportContentRatio () float64 {
 	if this.linked == nil { return 0 }
 	return this.viewportLength() / this.contentLength()

scrollcontainer.go

@@ -61,7 +61,6 @@ func NewScrollContainer (sides ScrollSide) *ScrollContainer {
 	this.CaptureScroll(true)
 	this.OnScroll(this.handleScroll)
 	this.SetRole(tomo.R("objects", "ScrollContainer", sides.String()))
-	tomo.Apply(this)
 	this.SetLayout(this.layout)
 	return this
 }
@@ -134,6 +133,7 @@ func (this *ScrollContainer) handleScroll (x, y float64) {
 		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
@@ -184,6 +184,14 @@ func (this *scrollContainerLayout) Arrange (hints tomo.LayoutHints, boxes []tomo
 	}
 }
 
+func (this *scrollContainerLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
+	return this.MinimumSize(hints, boxes).X
+}
+
+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

@@ -13,6 +13,5 @@ func NewSeparator () *Separator {
 		Box: tomo.NewBox(),
 	}
 	this.SetRole(tomo.R("objects", "Separator", ""))
-	tomo.Apply(this)
 	return this
 }

slider.go

@@ -53,9 +53,7 @@ func newSlider (orient string, value float64) *Slider {
 	this.OnScroll(this.handleScroll)
 	
 	this.handle.SetRole(tomo.R("objects", "SliderHandle", orient))
-	tomo.Apply(this.handle)
 	this.SetRole(tomo.R("objects", "Slider", orient))
-	tomo.Apply(this)
 	return this
 }
 
@@ -240,3 +238,11 @@ func (this sliderLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 			Add(gutter.Min))
 	}
 }
+
+func (this sliderLayout) RecommendedHeight (tomo.LayoutHints, []tomo.Box, int) int {
+	return 0
+}
+
+func (this sliderLayout) RecommendedWidth (tomo.LayoutHints, []tomo.Box, int) int {
+	return 0
+}

textinput.go

@@ -20,7 +20,6 @@ type TextInput struct {
 func NewTextInput (text string) *TextInput {
 	this := &TextInput { TextBox: tomo.NewTextBox() }
 	this.SetRole(tomo.R("objects", "TextInput", ""))
-	tomo.Apply(this)
 	this.SetAlign(tomo.AlignStart, tomo.AlignMiddle)
 	this.SetText(text)
 	this.SetFocusable(true)

textview.go

@@ -12,7 +12,6 @@ type TextView struct {
 func NewTextView (text string) *TextView {
 	this := &TextView { TextBox: tomo.NewTextBox() }
 	this.SetRole(tomo.R("objects", "TextView", ""))
-	tomo.Apply(this)
 	this.SetFocusable(true)
 	this.SetSelectable(true)
 	this.SetText(text)