Memory profiling code. Updates to reduce memory footprint.

.gitignore

@@ -1,4 +1,5 @@
 cmd/hello/hello
 cmd/cal/cal
 cmd/scroll/scroll
+cmd/grid/grid
 *.apk

cmd/cal/main.go

@@ -152,7 +152,7 @@ func eventloop() {
 			case app.DestroyEvent:
 				return
 			case app.UpdateEvent:
-				ctx.Reset(e)
+				ctx.Reset(&e)
 
 				mth.SetText(fmt.Sprintf("%s %d", sm.Month.String(), sm.Year))
 

cmd/hello/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"git.wow.st/gmp/giowrap"
 
+	"fmt"
 	"image"
 	"image/color"
 	"log"
@@ -27,12 +28,13 @@ import (
 )
 
 var (
-	FPS          int = 100
+	FPS           int = 100
-	frames       int64
+	frames        int64
-	frametime    int64 // nanoseconds
+	frametime     int64 // nanoseconds
-	maxframetime int64
+	maxframetime  int64
-	mux          sync.Mutex
+	mux           sync.Mutex
-	Profile      bool = false
+	Profile       bool = true
+	RecordMallocs bool = false
 )
 
 func NewButton(face text.Face, t string, c color.RGBA) giowrap.Clickable {
@@ -69,7 +71,7 @@ func main() {
 		fallthrough
 	default:
 		log.Fatal(`Usage:
-hello [main1|main2]
+hello [main1|main2|main3|main4]
 `)
 	case os.Args[1] == "main1":
 		log.Print("main1()")
@@ -77,10 +79,17 @@ hello [main1|main2]
 	case os.Args[1] == "main2":
 		log.Print("main2()")
 		go main2()
+	case os.Args[1] == "main3":
+		log.Print("main3()")
+		go main3()
+	case os.Args[1] == "main4":
+		log.Print("main4()")
+		go main4()
 	}
 	app.Main()
 }
 
+// Example with functional layout
 func main1() {
 	w := app.NewWindow()
 	regular, err := sfnt.Parse(goregular.TTF)
@@ -108,17 +117,156 @@ func main1() {
 	profiled := false
 	startTime := time.Now()
 
+	page := OuterInset(
+		f1(
+			e1,
+			giowrap.Flexible(0.33),
+			InnerInset(e2),
+			giowrap.Flexible(0.67),
+			f2(
+				InnerInset(btn1),
+				giowrap.Flexible(0.50),
+				InnerInset(btn2),
+			),
+		),
+	)
+
+	for {
+		select {
+		case <-t.C:
+			w.Invalidate()
+		case e := <-w.Events():
+			mux.Lock()
+			stime := time.Now()
+			switch e := e.(type) {
+			case app.DestroyEvent:
+				return
+			case app.UpdateEvent:
+				profileNow := false
+				var ms runtime.MemStats
+				if Profile && time.Since(startTime) > time.Second*2 {
+					startTime = time.Now()
+					profileNow = true
+				}
+				if profileNow {
+					if !profiled {
+						prof(0)
+					}
+					runtime.ReadMemStats(&ms)
+					if RecordMallocs {
+						giowrap.RecordMallocs()
+					}
+				}
+				giowrap.Mallocs("pre-reset")
+				ctx.Reset(&e)
+				giowrap.Mallocs("pre-layout")
+				page.Layout(ctx)
+				giowrap.Mallocs("post-layout")
+				ctx.Update()
+				giowrap.Mallocs("post-update")
+				if btn1.Clicked(ctx) {
+					log.Print("Clicked: " + e1.Text())
+				}
+				if btn2.Clicked(ctx) {
+					log.Print("Clicked: " + e2.Text())
+				}
+				giowrap.Mallocs("post-clicked()")
+				if profileNow {
+					for _, i := range giowrap.AllMallocs {
+						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
+					}
+					giowrap.AllMallocs = nil
+					mallocs := ms.Mallocs
+					runtime.ReadMemStats(&ms)
+					mallocs = ms.Mallocs - mallocs
+					log.Printf("Mallocs = %d\n", mallocs)
+					if !profiled {
+						prof(1)
+						profiled = true
+					}
+				}
+			}
+			dur := time.Since(stime).Nanoseconds()
+			frames = frames + 1
+			frametime = frametime + dur
+			if dur > maxframetime {
+				maxframetime = dur
+			}
+			mux.Unlock()
+		}
+	}
+}
+
+func prof(x int) {
+	names := []string{"memprofile-1.pprof", "memprofile-2.pprof"}
+	f1, err := os.Create(names[x])
+	if err != nil {
+		log.Fatal("could not create memory profile: ", err)
+	}
+	if err := pprof.WriteHeapProfile(f1); err != nil {
+		log.Fatal("could not write memory profile: ", err)
+	}
+	f1.Close()
+	log.Print("Memory profile written")
+}
+
+// Example showing use of WidgetCombinators in the main loop.
+func main2() {
+	w := app.NewWindow()
+	regular, err := sfnt.Parse(goregular.TTF)
+	if err != nil {
+		log.Fatal("Cannot parse font.")
+	}
+	ctx := giowrap.NewContext(w)
+	t := time.NewTicker(time.Second / time.Duration(FPS))
+	e1 := giowrap.NewEditor("text 1", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
+	e1.Focus()
+
+	e2 := giowrap.NewEditor("text 2", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
+
+	f1 := giowrap.NewFlex(giowrap.Axis(layout.Vertical))
+	OuterInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))
+	InnerInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))
+
+	f2 := giowrap.NewFlex(giowrap.Axis(layout.Horizontal))
+
+	btn1 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"push1", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+	btn2 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"push2", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+
+	profiled := false
+	startTime := time.Now()
+
 	for {
 		select {
 		case <-t.C:
 			w.Invalidate()
 		case e := <-w.Events():
+			mux.Lock()
 			stime := time.Now()
 			switch e := e.(type) {
 			case app.DestroyEvent:
 				return
 			case app.UpdateEvent:
-				ctx.Reset(e)
+				profileNow := false
+				var ms runtime.MemStats
+				if Profile && time.Since(startTime) > time.Second*2 {
+					startTime = time.Now()
+					profileNow = true
+				}
+				if profileNow {
+					if !profiled {
+						prof(0)
+					}
+					runtime.ReadMemStats(&ms)
+					if RecordMallocs {
+						giowrap.RecordMallocs()
+					}
+				}
+				giowrap.Mallocs("pre-reset")
+				ctx.Reset(&e)
+				giowrap.Mallocs("pre-layout")
 				OuterInset(
 					f1(
 						e1,
@@ -127,9 +275,107 @@ func main1() {
 						giowrap.Flexible(0.67),
 						f2(
 							InnerInset(btn1),
-							giowrap.Flexible(0.5),
+							giowrap.Flexible(0.50),
 							InnerInset(btn2),
 						),
+					),
+				).Layout(ctx)
+				giowrap.Mallocs("post-layout")
+				ctx.Update()
+				giowrap.Mallocs("post-update")
+				if btn1.Clicked(ctx) {
+					log.Print("Clicked: " + e1.Text())
+				}
+				if btn2.Clicked(ctx) {
+					log.Print("Clicked: " + e2.Text())
+				}
+				giowrap.Mallocs("post-clicked()")
+				if profileNow {
+					for _, i := range giowrap.AllMallocs {
+						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
+					}
+					giowrap.AllMallocs = nil
+					mallocs := ms.Mallocs
+					runtime.ReadMemStats(&ms)
+					mallocs = ms.Mallocs - mallocs
+					log.Printf("Mallocs = %d\n", mallocs)
+					if !profiled {
+						prof(1)
+						profiled = true
+					}
+				}
+			}
+			dur := time.Since(stime).Nanoseconds()
+			frames = frames + 1
+			frametime = frametime + dur
+			if dur > maxframetime {
+				maxframetime = dur
+			}
+			mux.Unlock()
+		}
+	}
+}
+
+// Example showing widget allocation within the main loop (causes unnecessary
+// memory allocations)
+func main3() {
+	w := app.NewWindow()
+	regular, err := sfnt.Parse(goregular.TTF)
+	if err != nil {
+		log.Fatal("Cannot parse font.")
+	}
+	ctx := giowrap.NewContext(w)
+	t := time.NewTicker(time.Second / time.Duration(FPS))
+	e1 := giowrap.NewEditor("text 1", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
+	e1.Focus()
+
+	e2 := giowrap.NewEditor("text 2", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
+
+	btn1 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"push1", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+	btn2 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"push2", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+
+	profiled := false
+	startTime := time.Now()
+
+	for {
+		select {
+		case <-t.C:
+			w.Invalidate()
+		case e := <-w.Events():
+			stime := time.Now()
+			switch e := e.(type) {
+			case app.DestroyEvent:
+				return
+			case app.UpdateEvent:
+				profileNow := false
+				var ms runtime.MemStats
+				if Profile && time.Since(startTime) > time.Second*2 {
+					profileNow = true
+					startTime = time.Now()
+				}
+				if profileNow {
+					if !profiled {
+						prof(0)
+					}
+					runtime.ReadMemStats(&ms)
+					if RecordMallocs {
+						giowrap.RecordMallocs()
+					}
+				}
+				ctx.Reset(&e)
+				giowrap.NewInset(giowrap.Size(ui.Dp(10)))(
+					giowrap.NewFlex(giowrap.Axis(layout.Vertical))(
+						e1,
+						//giowrap.Flexible(0.33),
+						giowrap.NewInset(giowrap.Size(ui.Dp(10)))(e2),
+						//giowrap.Flexible(0.67),
+						giowrap.NewFlex(giowrap.Axis(layout.Horizontal))(
+							giowrap.NewInset(giowrap.Size(ui.Dp(10)))(btn1),
+							//giowrap.Flexible(0.50),
+							giowrap.NewInset(giowrap.Size(ui.Dp(10)))(btn2),
+						),
 					)).Layout(ctx)
 				ctx.Update()
 				if btn1.Clicked(ctx) {
@@ -138,6 +384,20 @@ func main1() {
 				if btn2.Clicked(ctx) {
 					log.Print("Clicked: " + e2.Text())
 				}
+				if profileNow {
+					for _, i := range giowrap.AllMallocs {
+						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
+					}
+					giowrap.AllMallocs = nil
+					mallocs := ms.Mallocs
+					runtime.ReadMemStats(&ms)
+					mallocs = ms.Mallocs - mallocs
+					log.Printf("Mallocs = %d\n", mallocs)
+					if !profiled {
+						prof(1)
+						profiled = true
+					}
+				}
 			}
 			dur := time.Since(stime).Nanoseconds()
 			mux.Lock()
@@ -148,28 +408,11 @@ func main1() {
 			}
 			mux.Unlock()
 		}
-		if profiled {
-			continue
-		}
-		if time.Since(startTime) < time.Second*10 {
-			continue
-		}
-		if Profile {
-			profiled = true
-			f, err := os.Create("memprofile.pprof")
-			if err != nil {
-				log.Fatal("could not create memory profile: ", err)
-			}
-			if err := pprof.WriteHeapProfile(f); err != nil {
-				log.Fatal("could not write memory profile: ", err)
-			}
-			log.Print("Memory profile written")
-			f.Close()
-		}
 	}
 }
 
-func main2() {
+// Example using the base Gio API.
+func main4() {
 	w := app.NewWindow()
 	q := w.Queue()
 	ops := new(ui.Ops)
@@ -215,6 +458,18 @@ func main2() {
 			case app.DestroyEvent:
 				return
 			case app.UpdateEvent:
+				profileNow := false
+				var ms runtime.MemStats
+				if Profile && time.Since(startTime) > time.Second*2 {
+					profileNow = true
+					startTime = time.Now()
+				}
+				if profileNow {
+					if !profiled {
+						prof(0)
+					}
+					runtime.ReadMemStats(&ms)
+				}
 				c := &e.Config
 				ops.Reset()
 				faces.Reset(c)
@@ -257,6 +512,16 @@ func main2() {
 					dims = ins.End(f1.Layout(c1, c2, c3))
 				}
 				w.Update(ops)
+				if profileNow {
+					mallocs := ms.Mallocs
+					runtime.ReadMemStats(&ms)
+					mallocs = ms.Mallocs - mallocs
+					log.Printf("Mallocs = %d\n", mallocs)
+					if !profiled {
+						prof(1)
+						profiled = true
+					}
+				}
 			}
 			dur := time.Since(stime).Nanoseconds()
 			mux.Lock()
@@ -267,24 +532,6 @@ func main2() {
 			}
 			mux.Unlock()
 		}
-		if profiled {
-			continue
-		}
-		if time.Since(startTime) < time.Second*10 {
-			continue
-		}
-		if Profile {
-			profiled = true
-			f, err := os.Create("memprofile.pprof")
-			if err != nil {
-				log.Fatal("could not create memory profile: ", err)
-			}
-			if err := pprof.WriteHeapProfile(f); err != nil {
-				log.Fatal("could not write memory profile: ", err)
-			}
-			log.Print("Memory profile written")
-			f.Close()
-		}
 	}
 }
 

cmd/scroll/main.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"image/color"
 	"log"
+	"runtime"
+	"time"
 
 	gio "git.wow.st/gmp/giowrap"
 
@@ -99,18 +101,21 @@ func eventloop() {
 	lbar := gio.NewLabel("    ", gio.Face(face))
 	f2 := gio.NewFlex(gio.Axis(layout.Vertical))
 	topbar := gio.NewLabel("Scroll X and Y. Click to select", gio.Face(face))
+	f3 := gio.NewFlex(gio.Axis(layout.Horizontal))
+	f4 := gio.NewFlex(gio.Axis(layout.Vertical))
 
 	sh := gio.HScroll(gio.NewFlex(gio.Axis(layout.Horizontal)))
 	sv := gio.VScroll(gio.NewFlex(gio.Axis(layout.Vertical)))
 
-	numlabs := 50
+	numrows := 16
-	labs := make([][]gio.Widget, numlabs)
+	numcols := 50
-	sels := make([][]bool, numlabs)
+	labs := make([][]gio.Widget, numrows)
-	for i := 0; i < 16; i++ {
+	sels := make([][]bool, numrows)
-		labs[i] = make([]gio.Widget, numlabs)
+	for i := 0; i < numrows; i++ {
-		sels[i] = make([]bool, numlabs)
+		labs[i] = make([]gio.Widget, numcols)
-		for j := 0; j < numlabs; j++ {
+		sels[i] = make([]bool, numcols)
-			labs[i][j] = NewSLabel(fmt.Sprintf("%03d", i*16+j), &sels[i][j])
+		for j := 0; j < numcols; j++ {
+			labs[i][j] = NewSLabel(fmt.Sprintf("%03d", i+j*numrows), &sels[i][j])
 		}
 	}
 
@@ -120,8 +125,30 @@ func eventloop() {
 			gio.Left(x.Left), gio.Right(x.Right))
 	}
 
+	page := sysbg(sysinset(bg(margin(
+		f1(lbar, f2(topbar, sh(sv(f3(
+			f4(labs[0]...),
+			f4(labs[1]...),
+			f4(labs[2]...),
+			f4(labs[3]...),
+			f4(labs[4]...),
+			f4(labs[5]...),
+			f4(labs[6]...),
+			f4(labs[7]...),
+			f4(labs[8]...),
+			f4(labs[9]...),
+			f4(labs[10]...),
+			f4(labs[11]...),
+			f4(labs[12]...),
+			f4(labs[13]...),
+			f4(labs[14]...),
+			f4(labs[15]...),
+		)))))))))
+
 	var oldInsets app.Insets
 
+	stime := time.Now()
+	sm := runtime.MemStats{}
 	for {
 		select {
 		case e := <-w.Events():
@@ -129,32 +156,30 @@ func eventloop() {
 			case app.DestroyEvent:
 				return
 			case app.UpdateEvent:
-				ctx.Reset(e)
+				profileNow := time.Since(stime) > time.Second*2
+				if profileNow {
+					stime = time.Now()
+					//gio.RecordMallocs()
+					runtime.ReadMemStats(&sm)
+				}
+				gio.Mallocs("start")
+				ctx.Reset(&e)
 				if diffInsets(e.Insets, oldInsets) {
 					oldInsets = e.Insets
 					resetSysinset(e.Insets)
 				}
-
+				page.Layout(ctx)
-				sysbg(sysinset(bg(margin(
-					f1(lbar, f2(topbar, sh(
-						sv(labs[0]...),
-						sv(labs[1]...),
-						sv(labs[2]...),
-						sv(labs[3]...),
-						sv(labs[4]...),
-						sv(labs[5]...),
-						sv(labs[6]...),
-						sv(labs[7]...),
-						sv(labs[8]...),
-						sv(labs[9]...),
-						sv(labs[10]...),
-						sv(labs[11]...),
-						sv(labs[12]...),
-						sv(labs[13]...),
-						sv(labs[14]...),
-						sv(labs[15]...),
-					))))))).Layout(ctx)
 				ctx.Update()
+				gio.Mallocs("end")
+				if profileNow {
+					for _, m := range gio.AllMallocs {
+						fmt.Printf("Mallocs: %d (%s)\n", m.Value, m.Text)
+					}
+					gio.AllMallocs = nil
+					oldMallocs := sm.Mallocs
+					runtime.ReadMemStats(&sm)
+					fmt.Printf("Mallocs = %d\n", sm.Mallocs-oldMallocs)
+				}
 			}
 		}
 	}

grid.go

@@ -124,24 +124,34 @@ type HeightOpt struct{ height int }
 func Height(x int) HeightOpt             { return HeightOpt{x} }
 func (x HeightOpt) DoGridOption(g *Grid) { g.Height = x.height }
 
+type gridWidget struct {
+	g   Grid
+	gcs []GridChild
+	ws  []Widget
+}
+
 func NewGrid(cols int, gops ...GridOption) WidgetCombinator {
-	g := &Grid{Cols: cols}
+	ret := &gridWidget{}
+	ret.g = Grid{Cols: cols}
 	for _, gop := range gops {
-		gop.DoGridOption(g)
+		gop.DoGridOption(&ret.g)
 	}
-	gcs := make([]GridChild, 0)
+	ret.gcs = make([]GridChild, 0)
 	return func(ws ...Widget) Widget {
-		return NewfWidget(func(ctx *Context) {
+		ret.ws = ws
-			cs := g.Init(ctx.ops, ctx.cs)
+		return ret
-			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]
-		})
 	}
 }
+
+func (gw *gridWidget) Layout(ctx *Context) {
+	cs := gw.g.Init(ctx.ops, ctx.cs)
+	ctx.cs = cs
+	for _, w := range gw.ws {
+		gw.g.Begin()
+		w.Layout(ctx)
+		ctx.cs = cs // widget layout can modify constraints...
+		gw.gcs = append(gw.gcs, gw.g.End(ctx.dims))
+	}
+	ctx.dims = gw.g.Layout(gw.gcs...)
+	gw.gcs = gw.gcs[0:0]
+}

main.go

@@ -42,12 +42,13 @@ func (e *Extra) New() int {
 type Context struct {
 	Faces measure.Faces
 
-	w    *app.Window
+	w         *app.Window
-	c    *app.Config
+	c         *app.Config
-	q    input.Queue
+	q         input.Queue
-	ops  *ui.Ops
+	ops       *ui.Ops
-	cs   layout.Constraints
+	cs        layout.Constraints
-	dims layout.Dimens
+	dims      layout.Dimens
+	container Widget
 }
 
 func NewContext(w *app.Window) *Context {
@@ -58,11 +59,13 @@ func NewContext(w *app.Window) *Context {
 	}
 }
 
-func (ctx *Context) Reset(e app.UpdateEvent) {
+func (ctx *Context) Reset(e *app.UpdateEvent) {
+	Mallocs("ctx.Reset() ctx.c")
 	ctx.c = &e.Config
 	ctx.ops.Reset()
 	ctx.cs = layout.RigidConstraints(e.Size)
 	ctx.Faces.Reset(ctx.c)
+	Mallocs("ctx.Reset() done")
 }
 
 func (ctx *Context) Update() {
@@ -121,6 +124,7 @@ func NewLabel(t string, lops ...LabelOption) *Label {
 }
 
 func (l *Label) Layout(ctx *Context) {
+	Mallocs("Label.Layout()")
 	ctx.dims = l.l.Layout(ctx.ops, ctx.cs)
 }
 
@@ -157,6 +161,7 @@ func NewEditor(t string, eops ...EditorOption) *Editor {
 }
 
 func (e *Editor) Layout(ctx *Context) {
+	Mallocs("Editor.Layout()")
 	ctx.dims = e.e.Layout(ctx.c, ctx.q, ctx.ops, ctx.cs)
 }
 
@@ -164,38 +169,36 @@ func (e *Editor) Text() string     { return e.e.Text() }
 func (e *Editor) SetText(s string) { e.e.SetText(s) }
 func (e *Editor) Focus()           { e.e.Focus() }
 
-type fWidget struct {
-	l Layout
-}
-
-func NewfWidget(l Layout) fWidget {
-	return fWidget{l: l}
-}
-
-func (fw fWidget) Layout(ctx *Context) {
-	fw.l(ctx)
-}
-
 type Stack WidgetCombinator
 
+type stackWidget struct {
+	s   layout.Stack
+	scs []layout.StackChild
+	ws  []Widget
+}
+
 func NewStack() Stack {
-	s := layout.Stack{Alignment: layout.Center}
+	ret := &stackWidget{}
-	scs := make([]layout.StackChild, 0)
+	ret.s = layout.Stack{Alignment: layout.Center}
+	ret.scs = make([]layout.StackChild, 0)
 
 	return func(ws ...Widget) Widget {
-		return NewfWidget(func(ctx *Context) {
+		ret.ws = ws
-			s.Init(ctx.ops, ctx.cs)
+		return ret
-			for _, w := range ws {
-				ctx.cs = s.Rigid()
-				w.Layout(ctx)
-				scs = append(scs, s.End(ctx.dims))
-			}
-			ctx.dims = s.Layout(scs...)
-			scs = scs[0:0]
-		})
 	}
 }
 
+func (sw *stackWidget) Layout(ctx *Context) {
+	sw.s.Init(ctx.ops, ctx.cs)
+	for _, w := range sw.ws {
+		ctx.cs = sw.s.Rigid()
+		w.Layout(ctx)
+		sw.scs = append(sw.scs, sw.s.End(ctx.dims))
+	}
+	ctx.dims = sw.s.Layout(sw.scs...)
+	sw.scs = sw.scs[0:0]
+}
+
 type List = WidgetCombinator
 
 type AxisOpt struct{ axis layout.Axis }
@@ -209,24 +212,34 @@ type ListOption interface{ DoListOption(*ListOpts) }
 
 func (x AxisOpt) DoListOption(o *ListOpts) { o.axis = x.axis }
 
+type listWidget struct {
+	l  layout.List
+	ws []Widget
+}
+
 func NewList(los ...ListOption) List {
+	ret := &listWidget{}
 	opts := &ListOpts{}
 	for _, o := range los {
 		o.DoListOption(opts)
 	}
-	l := layout.List{Axis: opts.axis}
+	ret.l = layout.List{Axis: opts.axis}
+
 	return func(ws ...Widget) Widget {
-		return NewfWidget(func(ctx *Context) {
+		ret.ws = ws
-			for l.Init(ctx.c, ctx.q, ctx.ops, ctx.cs, len(ws)); l.More(); l.Next() {
+		return ret
-				ctx.cs = l.Constraints()
-				ws[l.Index()].Layout(ctx)
-				l.End(ctx.dims)
-			}
-			ctx.dims = l.Layout()
-		})
 	}
 }
 
+func (lw *listWidget) Layout(ctx *Context) {
+	for lw.l.Init(ctx.c, ctx.q, ctx.ops, ctx.cs, len(lw.ws)); lw.l.More(); lw.l.Next() {
+		ctx.cs = lw.l.Constraints()
+		lw.ws[lw.l.Index()].Layout(ctx)
+		lw.l.End(ctx.dims)
+	}
+	ctx.dims = lw.l.Layout()
+}
+
 func HScroll(c WidgetCombinator) WidgetCombinator {
 	return NewList(Axis(layout.Horizontal))
 }
@@ -237,19 +250,6 @@ func VScroll(c WidgetCombinator) WidgetCombinator {
 
 type Flex = WidgetCombinator
 
-// This "Widget" does nothing except set the Flexible field of a FlexOpts
-// struct within the Extra data structure
-func Flexible(v float32) Widget {
-	return NewfWidget(func(ctx *Context) {
-		extra.data[extra.cur].(*FlexOpts).flexible = v
-	})
-}
-func Rigid() Widget {
-	return NewfWidget(func(ctx *Context) {
-		extra.data[extra.cur].(*FlexOpts).flexible = 0
-	})
-}
-
 type AlignmentOpt struct{ alignment layout.Alignment }
 
 func Alignment(x layout.Alignment) AlignmentOpt { return AlignmentOpt{x} }
@@ -265,7 +265,35 @@ 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 }
 
+type flexWidget struct {
+	f        func(*Context)
+	flexible float32
+}
+
+type flexOptWidget struct {
+	flexible float32
+}
+
+func (fo flexOptWidget) Layout(ctx *Context) {
+	Mallocs("flexOptWidget.Layout()")
+	ctx.container.(*flexWidget).flexible = fo.flexible
+}
+
+// This "Widget" does nothing except set the Flexible field of a FlexOpts
+// struct within the Extra data structure
+func Flexible(v float32) Widget {
+	return flexOptWidget{v}
+}
+func Rigid() Widget {
+	return flexOptWidget{0}
+}
+
 // NewFlex returns a WidgetCombinator that wraps the layout.Flex element.
+
+func (fw *flexWidget) Layout(ctx *Context) {
+	fw.f(ctx)
+}
+
 func NewFlex(fos ...FlexOption) Flex {
 	opts := &FlexOpts{}
 	for _, o := range fos {
@@ -275,29 +303,23 @@ func NewFlex(fos ...FlexOption) Flex {
 		Axis:      opts.axis,
 		Alignment: opts.alignment,
 	}
-	index := extra.New()
-	extra.data[index] = opts
-	// do not call "make" inside the Layout function
 	fcs := make([]layout.FlexChild, 0)
-
 	return func(ws ...Widget) Widget {
-		return NewfWidget(func(ctx *Context) {
+		ret := &flexWidget{}
-			// ensure child widgets write options to the right place
+		ret.f = func(ctx *Context) {
-			extra.cur = index
+			oldContainer := ctx.container
-			opts := extra.data[index].(*FlexOpts)
+			ctx.container = ret
 			f.Init(ctx.ops, ctx.cs)
 			for _, w := range ws {
-				if opts.flexible != 0 {
+				ctx.cs = f.Rigid()
-					ctx.cs = f.Flexible(opts.flexible)
-				} else {
-					ctx.cs = f.Rigid()
-				}
 				w.Layout(ctx)
 				fcs = append(fcs, f.End(ctx.dims))
 			}
 			ctx.dims = f.Layout(fcs...)
-			fcs = fcs[0:0] // truncate
+			fcs = fcs[0:0]
-		})
+			ctx.container = oldContainer
+		}
+		return ret
 	}
 }
 
@@ -338,21 +360,34 @@ func (x SizeOpt) DoInsetOption(o *InsetOpts) {
 	o.left = x.size
 }
 
+type insetWidget func(*Context)
+
+func (iw insetWidget) Layout(ctx *Context) {
+	iw(ctx)
+}
+
 //NewInset returns a WidgetCombinator that wraps the layout.Inset element.
-func NewInset(insos ...InsetOption) WidgetCombinator {
+func NewInset(insos ...InsetOption) func(...Widget) Widget {
-	opts := &InsetOpts{}
+	opts := InsetOpts{}
 	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) {
+		Mallocs("NewInset() return")
+		var ret insetWidget
+		ret = func(ctx *Context) {
+			oldContainer := ctx.container
+			ctx.container = ret
 			ctx.cs = ins.Begin(ctx.c, ctx.ops, ctx.cs)
 			for _, w := range ws {
 				w.Layout(ctx)
 			}
 			ctx.dims = ins.End(ctx.dims)
-		})
+			ctx.container = oldContainer
+		}
+		return ret
 	}
 }
 
@@ -369,14 +404,24 @@ type Enclosure interface {
 	End(*Context)
 }
 
+type encloseWidget struct {
+	enc Enclosure
+	ws  []Widget
+}
+
 func Enclose(e Enclosure, ws ...Widget) Widget {
-	return NewfWidget(func(ctx *Context) {
+	return &encloseWidget{e, ws}
-		e.Begin(ctx)
+}
-		for _, w := range ws {
+
-			w.Layout(ctx)
+func (e *encloseWidget) Layout(ctx *Context) {
-		}
+	oldContainer := ctx.container
-		e.End(ctx)
+	ctx.container = e
-	})
+	e.enc.Begin(ctx)
+	for _, w := range e.ws {
+		w.Layout(ctx)
+	}
+	e.enc.End(ctx)
+	ctx.container = oldContainer
 }
 
 type BackgroundOpts struct {
@@ -412,11 +457,14 @@ func NewBackground(bos ...BackgroundOption) WidgetCombinator {
 }
 
 func (bg *Background) Begin(ctx *Context) {
+	Mallocs("Background.Begin()")
 	bg.macro.Record(ctx.ops)
 	ctx.cs = bg.Inset.Begin(ctx.c, ctx.ops, ctx.cs)
+	Mallocs("Background.Begin() done")
 }
 
 func (bg *Background) End(ctx *Context) {
+	Mallocs("Background.End()")
 	ctx.dims = bg.Inset.End(ctx.dims)
 	bg.macro.Stop()
 	var stack ui.StackOp
@@ -435,14 +483,19 @@ func (bg *Background) End(ctx *Context) {
 	paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: w, Y: h}}}.Add(ctx.ops)
 	bg.macro.Add(ctx.ops)
 	stack.Pop()
+	Mallocs("Background.End() done")
 }
 
 // https://pomax.github.io/bezierinfo/#circles_cubic.
 func Rrect(ops *ui.Ops, width, height, se, sw, nw, ne float32) {
+	Mallocs("Rrect() start")
 	w, h := float32(width), float32(height)
+	Mallocs("Rrect() const")
 	const c = 0.55228475 // 4*(sqrt(2)-1)/3
 	var b paint.PathBuilder
+	Mallocs("Rrect() init")
 	b.Init(ops)
+	Mallocs("Rrect() move")
 	b.Move(f32.Point{X: w, Y: h - se})
 	b.Cube(f32.Point{X: 0, Y: se * c}, f32.Point{X: -se + se*c, Y: se}, f32.Point{X: -se, Y: se}) // SE
 	b.Line(f32.Point{X: sw - w + se, Y: 0})
@@ -452,6 +505,7 @@ func Rrect(ops *ui.Ops, width, height, se, sw, nw, ne float32) {
 	b.Line(f32.Point{X: w - ne - nw, Y: 0})
 	b.Cube(f32.Point{X: ne * c, Y: 0}, f32.Point{X: ne, Y: ne - ne*c}, f32.Point{X: ne, Y: ne}) // NE
 	b.End()
+	Mallocs("Rrect() end")
 }
 
 type Clickable interface {
@@ -465,13 +519,15 @@ type cWidget struct {
 	click *gesture.Click
 }
 
-func (w cWidget) Layout(ctx *Context) {
+func (w *cWidget) Layout(ctx *Context) {
+	Mallocs("cWidget.Layout()")
 	w.w.Layout(ctx)
 	pointer.RectAreaOp{image.Rect(0, 0, ctx.dims.Size.X, ctx.dims.Size.Y)}.Add(ctx.ops)
 	w.click.Add(ctx.ops)
 }
 
 func (w cWidget) Clicked(ctx *Context) bool {
+	Mallocs("cWidget.Clicked()")
 	for e, ok := w.click.Next(ctx.q); ok; e, ok = w.click.Next(ctx.q) {
 		if e.Type == gesture.TypeClick {
 			ctx.w.Invalidate()
@@ -482,6 +538,6 @@ func (w cWidget) Clicked(ctx *Context) bool {
 }
 
 //Clickable converts any Widget into a clickable Widget.
-func AsClickable(w Widget) cWidget {
+func AsClickable(w Widget) *cWidget {
-	return cWidget{w: w, click: new(gesture.Click)}
+	return &cWidget{w: w, click: new(gesture.Click)}
 }

prof.go

@@ -0,0 +1,34 @@
+package giowrap
+
+import (
+	"runtime"
+)
+
+type AllocEntry struct {
+	Value uint64
+	Text  string
+}
+
+var (
+	memstats   runtime.MemStats
+	oldMallocs uint64
+	AllMallocs []AllocEntry
+)
+
+func RecordMallocs() {
+	if AllMallocs == nil {
+		AllMallocs = make([]AllocEntry, 0, 64)
+	} else {
+		AllMallocs = AllMallocs[0:0]
+	}
+	runtime.ReadMemStats(&memstats)
+	oldMallocs = memstats.Mallocs
+}
+
+func Mallocs(s string) {
+	if AllMallocs == nil {
+		return
+	}
+	runtime.ReadMemStats(&memstats)
+	AllMallocs = append(AllMallocs, AllocEntry{memstats.Mallocs - oldMallocs, s})
+}