cmd/cal/datetime.go

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

cmd/cal/main.go

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

cmd/grid/grid.go

@@ -1,62 +0,0 @@
-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/gofont/goregular"
 	"golang.org/x/image/font/sfnt"
+	"golang.org/x/image/font/gofont/goregular"
 )
 
 var (
@@ -64,19 +64,17 @@ func main() {
 			mux.Unlock()
 		}
 	}()
-	switch {
+	switch os.Args[1] {
-	case len(os.Args) < 2:
+	case "", "main1":
-		fallthrough
+		log.Print("main1()")
+		go main1()
+	case "main2":
+		log.Print("main2()")
+		go main2()
 	default:
 		log.Fatal(`Usage:
 hello [main1|main2]
 `)
-	case os.Args[1] == "main1":
-		log.Print("main1()")
-		go main1()
-	case os.Args[1] == "main2":
-		log.Print("main2()")
-		go main2()
 	}
 	app.Main()
 }
@@ -122,9 +120,9 @@ func main1() {
 				OuterInset(
 					    f1(
 						e1,
-						giowrap.Flexible(0.33),
+						giowrap.Flexible(5),
 						InnerInset(e2),
-						giowrap.Flexible(0.67),
+						giowrap.Flexible(10),
 						f2(
 							InnerInset(btn1),
 							giowrap.Flexible(0.5),
@@ -143,17 +141,11 @@ func main1() {
 			mux.Lock()
 			frames = frames + 1
 			frametime = frametime + dur
-			if dur > maxframetime {
+			if dur > maxframetime { maxframetime = dur }
-				maxframetime = dur
-			}
 			mux.Unlock()
 		}
-		if profiled {
+		if profiled { continue }
-			continue
+		if time.Since(startTime) < time.Second * 10 { continue }
-		}
-		if time.Since(startTime) < time.Second*10 {
-			continue
-		}
 		if Profile {
 			profiled = true
 			f, err := os.Create("memprofile.pprof")
@@ -193,14 +185,25 @@ func main2() {
 	e2.Focus()
 	e2.SetText("text 2")
 
-	btn1 := &Button{
+	f1 := layout.Flex{ Axis: layout.Vertical }
+	OuterInset := layout.UniformInset(ui.Dp(10))
+	InnerInset := layout.UniformInset(ui.Dp(10))
+
+	f2 := layout.Flex{ Axis: layout.Horizontal }
+
+	btn1 := text.Label{
 		Face: faces.For(regular, ui.Sp(24)),
-		Label: "push1",
+		Text: "push1",
 	}
-	btn2 := &Button{
+	b1ins := layout.UniformInset(ui.Dp(4))
+	btn2 := text.Label{
 		Face: faces.For(regular, ui.Sp(24)),
-		Label: "push2",
+		Text: "push2",
 	}
+	b2ins := layout.UniformInset(ui.Dp(4))
+	var bg1, bg2 ui.MacroOp
+	click1 := new(gesture.Click)
+	click2 := new(gesture.Click)
 
 	profiled := false
 	startTime := time.Now()
@@ -218,61 +221,77 @@ func main2() {
 				c := &e.Config
 				ops.Reset()
 				faces.Reset(c)
-				for ev, ok := btn1.Click.Next(q); ok; ev, ok = btn1.Click.Next(q) {
+				cs := layout.RigidConstraints(e.Size)
+				cs = OuterInset.Begin(c, ops, cs)
+				f1.Init(ops, cs)
+				cs = f1.Rigid()
+				dims := e1.Layout(c, q, ops, cs)
+				f1c1 := f1.End(dims)
+				cs = f1.Flexible(5)
+				cs = InnerInset.Begin(c, ops, cs)
+				dims = e2.Layout(c, q, ops, cs)
+				dims = InnerInset.End(dims)
+				f1c2 := f1.End(dims)
+				cs = f1.Flexible(10)
+				f2.Init(ops, cs)
+				cs = f2.Rigid()
+				cs = InnerInset.Begin(c, ops, cs)
+				bg1.Record(ops)
+				cs = b1ins.Begin(c, ops, cs)
+				dims = btn1.Layout(ops, cs)
+				dims = b1ins.End(dims)
+				pointer.RectAreaOp{image.Rect(0,0,dims.Size.X,dims.Size.Y)}.Add(ops)
+				click1.Add(ops)
+				bg1.Stop()
+				wi, h := float32(dims.Size.X), float32(dims.Size.Y)
+				r := float32(c.Px(ui.Dp(4)))
+				giowrap.Rrect(ops, wi, h, r, r, r, r)
+				paint.ColorOp{Color: color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6}}.Add(ops)
+				paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: wi, Y: h}}}.Add(ops)
+				bg1.Add(ops)
+				dims = InnerInset.End(dims)
+				f2c1 := f2.End(dims)
+				cs = f2.Flexible(0.5)
+				cs = InnerInset.Begin(c, ops, cs)
+				bg2.Record(ops)
+				cs = b2ins.Begin(c, ops, cs)
+				dims = btn2.Layout(ops, cs)
+				dims = b2ins.End(dims)
+				pointer.RectAreaOp{image.Rect(0,0,dims.Size.X,dims.Size.Y)}.Add(ops)
+				click2.Add(ops)
+				bg2.Stop()
+				wi, h = float32(dims.Size.X), float32(dims.Size.Y)
+				giowrap.Rrect(ops, wi, h, r, r, r, r)
+				paint.ColorOp{Color: color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6}}.Add(ops)
+				paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: wi, Y: h}}}.Add(ops)
+				bg2.Add(ops)
+				dims = InnerInset.End(dims)
+				f2c2 := f2.End(dims)
+				dims = f2.Layout(f2c1, f2c2)
+				f1c3 := f1.End(dims)
+				dims = f1.Layout(f1c1, f1c2, f1c3)
+				dims = OuterInset.End(dims)
+				w.Update(ops)
+				for ev, ok := click1.Next(q); ok; ev, ok = click1.Next(q) {
 					if ev.Type == gesture.TypeClick {
 						log.Print("Clicked: " + e1.Text() )
 					}
 				}
-				for ev, ok := btn2.Click.Next(q); ok; ev, ok = btn2.Click.Next(q) {
+				for ev, ok := click2.Next(q); ok; ev, ok = click2.Next(q) {
 					if ev.Type == gesture.TypeClick {
 						log.Print("Clicked: " + e2.Text() )
 					}
 				}
-
-				var dims layout.Dimens
-				cs := layout.RigidConstraints(e.Size)
-				{
-					f1 := layout.Flex{Axis: layout.Vertical}
-					ins := layout.UniformInset(ui.Dp(10))
-					f1.Init(ops, ins.Begin(c, ops, cs))
-					c1 := f1.End(e1.Layout(c, q, ops, f1.Rigid()))
-					{
-						cs = f1.Flexible(0.33)
-						ins := layout.UniformInset(ui.Dp(10))
-						dims = ins.End(e2.Layout(c, q, ops, ins.Begin(c, ops, cs)))
-					}
-					c2 := f1.End(dims)
-					{
-						cs = f1.Flexible(0.67)
-						f2 := layout.Flex{Axis: layout.Horizontal}
-						f2.Init(ops, cs)
-
-						c1 := f2.End(btn1.Layout(c, ops, f2.Rigid()))
-
-						c2 := f2.End(btn2.Layout(c, ops, f2.Flexible(0.5)))
-
-						dims = f2.Layout(c1, c2)
-					}
-					c3 := f1.End(dims)
-					dims = ins.End(f1.Layout(c1, c2, c3))
-				}
-				w.Update(ops)
 			}
 			dur := time.Since(stime).Nanoseconds()
 			mux.Lock()
 			frames = frames + 1
 			frametime = frametime + dur
-			if dur > maxframetime {
+			if dur > maxframetime { maxframetime = dur }
-				maxframetime = dur
-			}
 			mux.Unlock()
 		}
-		if profiled {
+		if profiled { continue }
-			continue
+		if time.Since(startTime) < time.Second * 10 { continue }
-		}
-		if time.Since(startTime) < time.Second*10 {
-			continue
-		}
 		if Profile {
 			profiled = true
 			f, err := os.Create("memprofile.pprof")
@@ -288,41 +307,3 @@ func main2() {
 	}
 }
 
-func layoutRRect(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
-	r := float32(c.Px(ui.Dp(4)))
-	sz := image.Point{X: cs.Width.Min, Y: cs.Height.Min}
-	w, h := float32(sz.X), float32(sz.Y)
-	giowrap.Rrect(ops, w, h, r, r, r, r)
-	paint.ColorOp{Color: color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6}}.Add(ops)
-	paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: w, Y: h}}}.Add(ops)
-	return layout.Dimens{Size: sz}
-}
-
-type Button struct {
-	Face  text.Face
-	Label string
-	Click gesture.Click
-}
-
-func (b *Button) Layout(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
-	ins := layout.UniformInset(ui.Dp(10))
-	cs = ins.Begin(c, ops, cs)
-	var dims layout.Dimens
-	st := layout.Stack{}
-	st.Init(ops, cs)
-	{
-		cs = st.Rigid()
-		l := text.Label{
-			Face: b.Face,
-			Text: b.Label,
-		}
-		ins := layout.UniformInset(ui.Dp(4))
-		dims = ins.End(l.Layout(ops, ins.Begin(c, ops, cs)))
-		pointer.RectAreaOp{image.Rect(0, 0, dims.Size.X, dims.Size.Y)}.Add(ops)
-		b.Click.Add(ops)
-	}
-	c2 := st.End(dims)
-	c1 := st.End(layoutRRect(c, ops, st.Expand()))
-	dims = st.Layout(c1, c2)
-	return ins.End(dims)
-}

cmd/scroll/main.go

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

grid.go

@@ -1,147 +0,0 @@
-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/gesture"
 	"gioui.org/ui/paint"
+	"gioui.org/ui/gesture"
 	"gioui.org/ui/pointer"
 )
 
@@ -29,9 +29,7 @@ var extra Extra
 
 func (e *Extra) New() int {
 	e.Lock()
-	if e.data == nil {
+	if e.data == nil { e.data = make([]interface{},0) }
-		e.data = make([]interface{}, 0)
-	}
 	ret := e.max
 	e.max = e.max + 1
 	e.data = append(e.data,nil)
@@ -82,11 +80,8 @@ 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 {
@@ -95,17 +90,14 @@ 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 {
+	for _,o := range lops { o.DoLabelOption(opts) }
-		o.DoLabelOption(opts)
-	}
 	ret.l = &text.Label{
 		Face: opts.face,
 		Text: t,
@@ -133,7 +125,6 @@ type Editor struct {
 }
 
 type SinglelineOpt struct { singleline bool }
-
 func Singleline(x bool) SinglelineOpt { return SinglelineOpt{ x } }
 
 type EditorOpts struct {
@@ -141,16 +132,13 @@ 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 {
+	for _,o := range eops { o.DoEditorOption(opts) }
-		o.DoEditorOption(opts)
-	}
 	ret.e = &text.Editor{ Face: opts.face, SingleLine: opts.singleline }
 	ret.SetText(t)
 	return ret
@@ -199,21 +187,17 @@ 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 {
+	for _,o := range los { o.DoListOption(opts) }
-		o.DoListOption(opts)
-	}
 	l := layout.List { Axis: opts.axis }
 	return func(ws ...Widget) Widget {
 		return NewfWidget(func(ctx *Context) {
@@ -251,7 +235,6 @@ func Rigid() Widget {
 }
 
 type AlignmentOpt struct { alignment layout.Alignment }
-
 func Alignment(x layout.Alignment) AlignmentOpt { return AlignmentOpt{ x } }
 
 type FlexOpts struct {
@@ -261,16 +244,13 @@ 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 {
+	for _,o := range fos { o.DoFlexOption(opts) }
-		o.DoFlexOption(opts)
-	}
 	f := layout.Flex{
 		Axis: opts.axis,
 		Alignment: opts.alignment,
@@ -308,19 +288,12 @@ 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 }
@@ -329,7 +302,6 @@ 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
@@ -341,9 +313,7 @@ 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 {
+	for _,o := range insos { o.DoInsetOption(opts) }
-		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) {
@@ -387,20 +357,16 @@ 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 {
+	for _,o := range bos { o.DoBackgroundOption(opts) }
-		o.DoBackgroundOption(opts)
-	}
 	bg := &Background{
 		Color: opts.c,
 		Radius: opts.radius,
@@ -485,3 +451,131 @@ 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]
+		})
+	}
+}