Move Grid{} to a new file. Run go fmt.

cmd/cal/datetime.go

@@ -103,7 +103,9 @@ func (sm *SelectableMonth) Weekdays() int {
 	for w := 0; w <= 6; w++ {
 		for d := 1; d < 6; d++ {
 			x := w*7 + d + 1 - sm.Pad
-			if x < 0 || x >= sm.DaysIn { break }
+			if x < 0 || x >= sm.DaysIn {
+				break
+			}
 			if sm.S[x] {
 				i++
 			}
@@ -116,12 +118,22 @@ func (sm *SelectableMonth) Weekends() int {
 	var i int
 	for w := 0; w <= 6; w++ {
 		x := w*7 + 1 - sm.Pad
-		if x < 0 { continue }
+		if x < 0 {
-		if x >= sm.DaysIn { break }
+			continue
-		if sm.S[x] { i++ }
+		}
+		if x >= sm.DaysIn {
+			break
+		}
+		if sm.S[x] {
+			i++
+		}
 		x = w*7 + 6 + 1 - sm.Pad
-		if x < 0 || x >= sm.DaysIn { break }
+		if x < 0 || x >= sm.DaysIn {
-		if sm.S[x] { i++ }
+			break
+		}
+		if sm.S[x] {
+			i++
+		}
 	}
 	return i
 }

cmd/cal/main.go

@@ -4,8 +4,8 @@ package main
 
 import (
 	"fmt"
-	"log"
 	"image/color"
+	"log"
 	"time"
 
 	gio "git.wow.st/gmp/giowrap"
@@ -15,8 +15,8 @@ import (
 	"gioui.org/ui/layout"
 	"gioui.org/ui/text"
 
-	"golang.org/x/image/font/sfnt"
 	"golang.org/x/image/font/gofont/goregular"
+	"golang.org/x/image/font/sfnt"
 )
 
 var (
@@ -104,7 +104,9 @@ func eventloop() {
 
 	regular, err := sfnt.Parse(goregular.TTF)
 	face = ctx.Faces.For(regular, ui.Sp(20))
-	if err != nil { log.Fatal("Cannot parse font.") }
+	if err != nil {
+		log.Fatal("Cannot parse font.")
+	}
 
 	bg := gio.NewBackground(
 		gio.Color(color.RGBA{A: 0xff, R: 0xf0, G: 0xf0, B: 0xe0}))
@@ -143,7 +145,8 @@ func eventloop() {
 	}
 	resetCal()
 
-	for { select {
+	for {
+		select {
 		case e := <-w.Events():
 			switch e := e.(type) {
 			case app.DestroyEvent:
@@ -193,6 +196,6 @@ func eventloop() {
 				}
 				sm.CheckSel()
 			}
-	}}
 		}
-
+	}
+}

cmd/grid/grid.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"image"
+
+	"gioui.org/ui"
+	"gioui.org/ui/app"
+	"gioui.org/ui/f32"
+	"gioui.org/ui/layout"
+	"gioui.org/ui/paint"
+
+	gio "git.wow.st/gmp/giowrap"
+)
+
+func main() {
+	go func() {
+		w := app.NewWindow()
+		ops := new(ui.Ops)
+		gcs := make([]gio.GridChild, 0)
+
+		for e := range w.Events() {
+			if e, ok := e.(app.UpdateEvent); ok {
+				ops.Reset()
+				c := &e.Config
+				cs := layout.RigidConstraints(e.Size)
+				nrows := 5
+				ncols := 10
+				grid := gio.Grid{Cols: ncols}
+				cs = grid.Init(ops, cs)
+
+				for i := 0; i < nrows*ncols; i++ {
+					grid.Begin()
+					dims := layoutRect(c, ops, cs)
+					gcs = append(gcs, grid.End(dims))
+				}
+
+				grid.Layout(gcs...)
+				w.Update(ops)
+				gcs = gcs[0:0]
+			}
+		}
+	}()
+	app.Main()
+}
+
+func layoutRect(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
+	ins := layout.UniformInset(ui.Px(10))
+	cs = ins.Begin(c, ops, cs)
+	paint.PaintOp{Rect: f32.Rectangle{
+		Max: f32.Point{
+			X: float32(cs.Width.Max),
+			Y: float32(cs.Width.Max),
+		},
+	}}.Add(ops)
+	dims := layout.Dimens{
+		Size: image.Point{
+			X: cs.Width.Max,
+			Y: cs.Width.Max,
+		},
+	}
+	return ins.End(dims)
+}

cmd/hello/main.go

@@ -14,16 +14,16 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/app"
-	"gioui.org/ui/paint"
 	"gioui.org/ui/f32"
 	"gioui.org/ui/gesture"
 	"gioui.org/ui/layout"
 	"gioui.org/ui/measure"
+	"gioui.org/ui/paint"
 	"gioui.org/ui/pointer"
 	"gioui.org/ui/text"
 
-	"golang.org/x/image/font/sfnt"
 	"golang.org/x/image/font/gofont/goregular"
+	"golang.org/x/image/font/sfnt"
 )
 
 var (
@@ -64,6 +64,7 @@ func main() {
 			mux.Unlock()
 		}
 	}()
+	if len(os.Args) > 1 {
 		switch os.Args[1] {
 		case "", "main1":
 			log.Print("main1()")
@@ -76,6 +77,7 @@ func main() {
 hello [main1|main2]
 `)
 		}
+	}
 	app.Main()
 }
 
@@ -141,11 +143,17 @@ func main1() {
 			mux.Lock()
 			frames = frames + 1
 			frametime = frametime + dur
-			if dur > maxframetime { maxframetime = dur }
+			if dur > maxframetime {
+				maxframetime = dur
+			}
 			mux.Unlock()
 		}
-		if profiled { continue }
+		if profiled {
-		if time.Since(startTime) < time.Second * 10 { continue }
+			continue
+		}
+		if time.Since(startTime) < time.Second*10 {
+			continue
+		}
 		if Profile {
 			profiled = true
 			f, err := os.Create("memprofile.pprof")
@@ -287,11 +295,17 @@ func main2() {
 			mux.Lock()
 			frames = frames + 1
 			frametime = frametime + dur
-			if dur > maxframetime { maxframetime = dur }
+			if dur > maxframetime {
+				maxframetime = dur
+			}
 			mux.Unlock()
 		}
-		if profiled { continue }
+		if profiled {
-		if time.Since(startTime) < time.Second * 10 { continue }
+			continue
+		}
+		if time.Since(startTime) < time.Second*10 {
+			continue
+		}
 		if Profile {
 			profiled = true
 			f, err := os.Create("memprofile.pprof")
@@ -306,4 +320,3 @@ func main2() {
 		}
 	}
 }
-

cmd/scroll/main.go

@@ -1,8 +1,8 @@
 package main
 
 import (
-	"image/color"
 	"fmt"
+	"image/color"
 	"log"
 
 	gio "git.wow.st/gmp/giowrap"
@@ -12,15 +12,15 @@ import (
 	"gioui.org/ui/layout"
 	"gioui.org/ui/text"
 
-	"golang.org/x/image/font/sfnt"
 	"golang.org/x/image/font/gofont/goregular"
+	"golang.org/x/image/font/sfnt"
 )
 
 var (
 	face  text.Face
 	black color.RGBA = color.RGBA{A: 0xff, R: 0x00, G: 0x00, B: 0x00}
-	gray2 color.RGBA = color.RGBA{ A: 0xff, R: 0x70, G: 0x70, B: 0x70 }
+	gray2 color.RGBA = color.RGBA{A: 0xff, R: 0xc0, G: 0xc0, B: 0xc0}
-	gray1 color.RGBA = color.RGBA{ A: 0xff, R: 0x50, G: 0x50, B: 0x50 }
+	gray1 color.RGBA = color.RGBA{A: 0xff, R: 0x70, G: 0x70, B: 0x70}
 )
 
 type SLabel struct {
@@ -87,7 +87,9 @@ func eventloop() {
 
 	regular, err := sfnt.Parse(goregular.TTF)
 	face = ctx.Faces.For(regular, ui.Sp(16))
-	if err != nil { log.Fatal("Cannot parse font.") }
+	if err != nil {
+		log.Fatal("Cannot parse font.")
+	}
 
 	sysbg := gio.NewBackground(gio.Color(black))
 	bg := gio.NewBackground(gio.Color(gray2))
@@ -108,7 +110,7 @@ func eventloop() {
 		labs[i] = make([]gio.Widget, numlabs)
 		sels[i] = make([]bool, numlabs)
 		for j := 0; j < numlabs; j++ {
-			labs[i][j] = NewSLabel(fmt.Sprintf("%03d",i * j), &sels[i][j])
+			labs[i][j] = NewSLabel(fmt.Sprintf("%03d", i*16+j), &sels[i][j])
 		}
 	}
 
@@ -120,7 +122,8 @@ func eventloop() {
 
 	var oldInsets app.Insets
 
-	for { select {
+	for {
+		select {
 		case e := <-w.Events():
 			switch e := e.(type) {
 			case app.DestroyEvent:
@@ -153,6 +156,6 @@ func eventloop() {
 					))))))).Layout(ctx)
 				ctx.Update()
 			}
-	}}
 		}
-
+	}
+}

grid.go

@@ -0,0 +1,147 @@
+package giowrap
+
+import (
+	"image"
+
+	"gioui.org/ui"
+	"gioui.org/ui/f32"
+	"gioui.org/ui/layout"
+)
+
+type Grid struct {
+	Cols          int
+	Height, Width int
+
+	macro    ui.MacroOp
+	ops      *ui.Ops
+	cs       layout.Constraints
+	mode     gridMode
+	row, col int
+}
+
+type GridChild struct {
+	dims  layout.Dimens
+	macro ui.MacroOp
+}
+
+type gridMode uint8
+
+const (
+	modeNone gridMode = iota
+	modeBegun
+)
+
+func (g *Grid) Init(ops *ui.Ops, cs layout.Constraints) layout.Constraints {
+	g.mode = modeBegun
+	g.ops = ops
+	g.cs = cs
+	g.row, g.col = 0, 0
+
+	cs.Height.Min = 0
+
+	if g.Height != 0 {
+		g.cs.Height.Max = g.Height
+	}
+	if g.Width != 0 {
+		g.cs.Width.Max = g.Width
+	}
+
+	cs.Width.Max = g.cs.Width.Max / g.Cols
+	if g.Cols > 1 {
+		cs.Width.Min = cs.Width.Max
+	}
+	return cs
+}
+
+func (g *Grid) Begin() {
+	g.macro.Record(g.ops)
+}
+
+func (g *Grid) End(dims layout.Dimens) GridChild {
+	if g.mode != modeBegun {
+		panic("Must call Grid.Begin() before adding children.")
+	}
+	g.macro.Stop()
+	return GridChild{dims: dims, macro: g.macro}
+}
+
+func (g *Grid) Layout(cs ...GridChild) layout.Dimens {
+	rowheight := 0
+	height := 0
+	var width float32
+	var maxwidth float32
+	for _, c := range cs {
+		var stack ui.StackOp
+		stack.Push(g.ops)
+		c.macro.Add(g.ops)
+		stack.Pop()
+		if c.dims.Size.Y > rowheight {
+			rowheight = c.dims.Size.Y
+		}
+		g.col = g.col + 1
+		var x float32
+		if g.Cols == 1 {
+			x = float32(c.dims.Size.X)
+			if x > maxwidth {
+				maxwidth = x
+			}
+		} else {
+			x = float32(g.cs.Width.Max / g.Cols)
+		}
+		if g.col < g.Cols {
+			ui.TransformOp{}.Offset(f32.Point{X: x}).Add(g.ops)
+			width = width + x
+		} else {
+			g.col = 0
+			ui.TransformOp{}.Offset(f32.Point{X: -width, Y: float32(rowheight)}).Add(g.ops)
+			g.row = g.row + 1
+			height = height + rowheight
+			width = 0
+			rowheight = 0
+		}
+	}
+	if height == 0 {
+		height = rowheight
+	}
+	g.mode = modeNone
+	var dwidth int
+	if g.Cols == 1 {
+		dwidth = int(maxwidth)
+	} else {
+		dwidth = g.cs.Width.Max
+	}
+	return layout.Dimens{Size: image.Point{dwidth, height}}
+}
+
+func toPointF(p image.Point) f32.Point {
+	return f32.Point{X: float32(p.X), Y: float32(p.Y)}
+}
+
+type GridOption interface{ DoGridOption(*Grid) }
+
+type HeightOpt struct{ height int }
+
+func Height(x int) HeightOpt             { return HeightOpt{x} }
+func (x HeightOpt) DoGridOption(g *Grid) { g.Height = x.height }
+
+func NewGrid(cols int, gops ...GridOption) WidgetCombinator {
+	g := &Grid{Cols: cols}
+	for _, gop := range gops {
+		gop.DoGridOption(g)
+	}
+	gcs := make([]GridChild, 0)
+	return func(ws ...Widget) Widget {
+		return NewfWidget(func(ctx *Context) {
+			cs := g.Init(ctx.ops, ctx.cs)
+			ctx.cs = cs
+			for _, w := range ws {
+				g.Begin()
+				w.Layout(ctx)
+				ctx.cs = cs // widget layout can modify constraints...
+				gcs = append(gcs, g.End(ctx.dims))
+			}
+			ctx.dims = g.Layout(gcs...)
+			gcs = gcs[0:0]
+		})
+	}
+}

main.go

@@ -14,8 +14,8 @@ import (
 	"gioui.org/ui/text"
 
 	"gioui.org/ui/f32"
-	"gioui.org/ui/paint"
 	"gioui.org/ui/gesture"
+	"gioui.org/ui/paint"
 	"gioui.org/ui/pointer"
 )
 
@@ -29,7 +29,9 @@ var extra Extra
 
 func (e *Extra) New() int {
 	e.Lock()
-	if e.data == nil { e.data = make([]interface{},0) }
+	if e.data == nil {
+		e.data = make([]interface{}, 0)
+	}
 	ret := e.max
 	e.max = e.max + 1
 	e.data = append(e.data, nil)
@@ -80,8 +82,11 @@ type Label struct {
 }
 
 type FaceOpt struct{ face text.Face }
+
 func Face(x text.Face) FaceOpt { return FaceOpt{x} }
+
 type AlignOpt struct{ alignment text.Alignment }
+
 func Align(x text.Alignment) AlignOpt { return AlignOpt{x} }
 
 type LabelOpts struct {
@@ -90,14 +95,17 @@ type LabelOpts struct {
 	AlignOpt
 }
 type LabelOption interface{ DoLabelOption(*LabelOpts) }
+
 func (x FaceOpt) DoLabelOption(o *LabelOpts)  { o.face = x.face }
 func (x AlignOpt) DoLabelOption(o *LabelOpts) { o.alignment = x.alignment }
-func (x ColorOpt) DoLabelOption(o *LabelOpts) { o.c = &x.c; }
+func (x ColorOpt) DoLabelOption(o *LabelOpts) { o.c = &x.c }
 
 func NewLabel(t string, lops ...LabelOption) *Label {
 	ret := &Label{}
 	opts := &LabelOpts{}
-	for _,o := range lops { o.DoLabelOption(opts) }
+	for _, o := range lops {
+		o.DoLabelOption(opts)
+	}
 	ret.l = &text.Label{
 		Face:      opts.face,
 		Text:      t,
@@ -125,6 +133,7 @@ type Editor struct {
 }
 
 type SinglelineOpt struct{ singleline bool }
+
 func Singleline(x bool) SinglelineOpt { return SinglelineOpt{x} }
 
 type EditorOpts struct {
@@ -132,13 +141,16 @@ type EditorOpts struct {
 	SinglelineOpt
 }
 type EditorOption interface{ DoEditorOption(*EditorOpts) }
+
 func (x FaceOpt) DoEditorOption(o *EditorOpts)       { o.face = x.face }
 func (x SinglelineOpt) DoEditorOption(o *EditorOpts) { o.singleline = x.singleline }
 
 func NewEditor(t string, eops ...EditorOption) *Editor {
 	ret := &Editor{}
 	opts := &EditorOpts{}
-	for _,o := range eops { o.DoEditorOption(opts) }
+	for _, o := range eops {
+		o.DoEditorOption(opts)
+	}
 	ret.e = &text.Editor{Face: opts.face, SingleLine: opts.singleline}
 	ret.SetText(t)
 	return ret
@@ -187,17 +199,21 @@ func NewStack() Stack {
 type List = WidgetCombinator
 
 type AxisOpt struct{ axis layout.Axis }
+
 func Axis(x layout.Axis) AxisOpt { return AxisOpt{x} }
 
 type ListOpts struct {
 	AxisOpt
 }
 type ListOption interface{ DoListOption(*ListOpts) }
+
 func (x AxisOpt) DoListOption(o *ListOpts) { o.axis = x.axis }
 
 func NewList(los ...ListOption) List {
 	opts := &ListOpts{}
-	for _,o := range los { o.DoListOption(opts) }
+	for _, o := range los {
+		o.DoListOption(opts)
+	}
 	l := layout.List{Axis: opts.axis}
 	return func(ws ...Widget) Widget {
 		return NewfWidget(func(ctx *Context) {
@@ -235,6 +251,7 @@ func Rigid() Widget {
 }
 
 type AlignmentOpt struct{ alignment layout.Alignment }
+
 func Alignment(x layout.Alignment) AlignmentOpt { return AlignmentOpt{x} }
 
 type FlexOpts struct {
@@ -244,13 +261,16 @@ type FlexOpts struct {
 }
 
 type FlexOption interface{ DoFlexOption(*FlexOpts) }
+
 func (x AxisOpt) DoFlexOption(o *FlexOpts)      { o.axis = x.axis }
 func (x AlignmentOpt) DoFlexOption(o *FlexOpts) { o.alignment = x.alignment }
 
 // NewFlex returns a WidgetCombinator that wraps the layout.Flex element.
 func NewFlex(fos ...FlexOption) Flex {
 	opts := &FlexOpts{}
-	for _,o := range fos { o.DoFlexOption(opts) }
+	for _, o := range fos {
+		o.DoFlexOption(opts)
+	}
 	f := layout.Flex{
 		Axis:      opts.axis,
 		Alignment: opts.alignment,
@@ -288,12 +308,19 @@ type InsetOpts struct {
 type InsetOption interface{ DoInsetOption(*InsetOpts) }
 
 type TopOpt struct{ top ui.Value }
+
 func Top(x ui.Value) TopOpt { return TopOpt{x} }
+
 type RightOpt struct{ right ui.Value }
+
 func Right(x ui.Value) RightOpt { return RightOpt{x} }
+
 type BottomOpt struct{ bottom ui.Value }
+
 func Bottom(x ui.Value) BottomOpt { return BottomOpt{x} }
+
 type LeftOpt struct{ left ui.Value }
+
 func Left(x ui.Value) LeftOpt { return LeftOpt{x} }
 
 func (x TopOpt) DoInsetOption(o *InsetOpts)    { o.top = x.top }
@@ -302,6 +329,7 @@ func (x BottomOpt) DoInsetOption(o *InsetOpts) { o.bottom = x.bottom }
 func (x LeftOpt) DoInsetOption(o *InsetOpts)   { o.left = x.left }
 
 type SizeOpt struct{ size ui.Value }
+
 func Size(x ui.Value) SizeOpt { return SizeOpt{x} }
 func (x SizeOpt) DoInsetOption(o *InsetOpts) {
 	o.top = x.size
@@ -313,7 +341,9 @@ func (x SizeOpt) DoInsetOption(o *InsetOpts) {
 //NewInset returns a WidgetCombinator that wraps the layout.Inset element.
 func NewInset(insos ...InsetOption) WidgetCombinator {
 	opts := &InsetOpts{}
-	for _,o := range insos { o.DoInsetOption(opts) }
+	for _, o := range insos {
+		o.DoInsetOption(opts)
+	}
 	ins := layout.Inset{Top: opts.top, Right: opts.right, Bottom: opts.bottom, Left: opts.left}
 	return func(ws ...Widget) Widget {
 		return NewfWidget(func(ctx *Context) {
@@ -357,16 +387,20 @@ type BackgroundOpts struct {
 type BackgroundOption interface{ DoBackgroundOption(*BackgroundOpts) }
 
 type ColorOpt struct{ c color.RGBA }
+
 func Color(x color.RGBA) ColorOpt                       { return ColorOpt{x} }
 func (x ColorOpt) DoBackgroundOption(o *BackgroundOpts) { o.c = x.c }
 
 type RadiusOpt struct{ radius ui.Value }
+
 func Radius(x ui.Value) RadiusOpt                        { return RadiusOpt{x} }
 func (x RadiusOpt) DoBackgroundOption(o *BackgroundOpts) { o.radius = x.radius }
 
 func NewBackground(bos ...BackgroundOption) WidgetCombinator {
 	opts := &BackgroundOpts{}
-	for _,o := range bos { o.DoBackgroundOption(opts) }
+	for _, o := range bos {
+		o.DoBackgroundOption(opts)
+	}
 	bg := &Background{
 		Color:  opts.c,
 		Radius: opts.radius,
@@ -451,131 +485,3 @@ func (w cWidget) Clicked(ctx *Context) bool {
 func AsClickable(w Widget) cWidget {
 	return cWidget{w: w, click: new(gesture.Click)}
 }
-
-type Grid struct {
-	Cols int
-	Height, Width int
-
-	macro ui.MacroOp
-	ops *ui.Ops
-	cs layout.Constraints
-	mode gridMode
-	row, col int
-}
-
-type GridChild struct {
-	dims layout.Dimens
-	macro ui.MacroOp
-}
-
-type gridMode uint8
-const (
-	modeNone gridMode = iota
-	modeBegun
-)
-
-func (g *Grid) Init(ops *ui.Ops, cs layout.Constraints) layout.Constraints {
-	g.mode = modeBegun
-	g.ops = ops
-	g.cs = cs
-	g.row, g.col = 0, 0
-
-	cs.Height.Min = 0
-
-	if g.Height != 0 { g.cs.Height.Max = g.Height }
-	if g.Width != 0 { g.cs.Width.Max = g.Width }
-
-	cs.Width.Max = g.cs.Width.Max / g.Cols
-	if g.Cols > 1 {
-		cs.Width.Min = cs.Width.Max
-	}
-	return cs
-}
-
-func (g *Grid) Begin() {
-	g.macro.Record(g.ops)
-}
-
-func (g *Grid) End(dims layout.Dimens) GridChild {
-	if g.mode != modeBegun {
-		panic("Must call Grid.Begin() before adding children.")
-	}
-	g.macro.Stop()
-	return GridChild{ dims: dims, macro: g.macro }
-}
-
-func (g *Grid) Layout(cs ...GridChild) layout.Dimens {
-	rowheight := 0
-	height := 0
-	var width float32
-	var maxwidth float32
-	for _,c := range cs {
-		var stack ui.StackOp
-		stack.Push(g.ops)
-		c.macro.Add(g.ops)
-		stack.Pop()
-		if c.dims.Size.Y > rowheight {
-			rowheight = c.dims.Size.Y
-		}
-		g.col = g.col+1
-		var x float32
-		if g.Cols == 1 {
-			x = float32(c.dims.Size.X)
-			if x > maxwidth { maxwidth = x }
-		} else {
-			x = float32(g.cs.Width.Max / g.Cols)
-		}
-		if g.col < g.Cols {
-			ui.TransformOp{}.Offset(f32.Point{X: x}).Add(g.ops)
-			width = width + x
-		} else {
-			g.col = 0
-			ui.TransformOp{}.Offset(f32.Point{ X: -width, Y: float32(rowheight) }).Add(g.ops)
-			g.row = g.row + 1
-			height = height + rowheight
-			width = 0
-			rowheight = 0
-		}
-	}
-	if height == 0 { height = rowheight }
-	g.mode = modeNone
-	var dwidth int
-	if g.Cols == 1 {
-		dwidth = int(maxwidth)
-	} else {
-		dwidth = g.cs.Width.Max
-	}
-	return layout.Dimens{ Size: image.Point{ dwidth, height } }
-}
-
-func toPointF(p image.Point) f32.Point {
-	return f32.Point{X: float32(p.X), Y: float32(p.Y)}
-}
-
-type GridOption interface { DoGridOption(*Grid) }
-
-type HeightOpt struct { height int }
-func Height(x int) HeightOpt { return HeightOpt{ x } }
-func (x HeightOpt) DoGridOption(g *Grid) { g.Height = x.height }
-
-func NewGrid(cols int, gops ...GridOption) WidgetCombinator {
-	g := &Grid{ Cols: cols }
-	for _, gop := range gops {
-		gop.DoGridOption(g)
-	}
-	gcs := make([]GridChild,0)
-	return func(ws ...Widget) Widget {
-		return NewfWidget(func(ctx *Context) {
-			cs := g.Init(ctx.ops, ctx.cs)
-			ctx.cs = cs
-			for _,w := range ws {
-				g.Begin()
-				w.Layout(ctx)
-				ctx.cs = cs // widget layout can modify constraints...
-				gcs = append(gcs,g.End(ctx.dims))
-			}
-			ctx.dims = g.Layout(gcs...)
-			gcs = gcs[0:0]
-		})
-	}
-}