Add form example, add /examples directory.

.gitignore

@@ -2,5 +2,6 @@ cmd/hello/hello
 cmd/cal/cal
 cmd/scroll/scroll
 cmd/grid/grid
+cmd/form/form
 *.apk
 memprofile*

cmd/form/main.go

@@ -0,0 +1,227 @@
+package main
+
+import (
+	"git.wow.st/gmp/giowrap"
+
+	"fmt"
+	//"image"
+	"image/color"
+	"log"
+	"os"
+	"runtime"
+	"runtime/pprof"
+	"sync"
+	"time"
+
+	"gioui.org/ui"
+	"gioui.org/ui/app"
+	"gioui.org/ui/text"
+
+	"golang.org/x/image/font/gofont/goregular"
+	"golang.org/x/image/font/sfnt"
+)
+
+var (
+	FPS           int = 100
+	frames        int64
+	frametime     int64 // nanoseconds
+	maxframetime  int64
+	mux           sync.Mutex
+	Profile       bool = true
+	RecordMallocs bool = false
+)
+
+func NewButton(face text.Face, t string, c color.RGBA) giowrap.Clickable {
+	lbl := giowrap.NewLabel(t, giowrap.Face(face), giowrap.Align(text.Middle))
+	bg := giowrap.NewBackground(giowrap.Color(c), giowrap.Radius(ui.Dp(4)))
+	ins := giowrap.NewInset(giowrap.Size(ui.Dp(4)))
+	return giowrap.AsClickable(ins(bg(lbl)))
+}
+
+func main() {
+	go func() {
+		ms := &runtime.MemStats{}
+		var a1 uint64
+		for {
+			time.Sleep(time.Second * 3)
+			mux.Lock()
+			if frames == 0 {
+				mux.Unlock()
+				continue
+			}
+			runtime.ReadMemStats(ms)
+			a1 = ms.Alloc
+			runtime.GC()
+			runtime.ReadMemStats(ms)
+			log.Printf("Alloc: %d - %d = %d (%d per frame)", a1, ms.Alloc, a1-ms.Alloc, (a1-ms.Alloc)/(3*uint64(FPS)))
+			log.Printf("Frametime: %d max Frametime: %d us\n", frametime/(frames*1000), maxframetime/1000)
+			frames = 0
+			frametime = 0
+			maxframetime = 0
+			mux.Unlock()
+		}
+	}()
+	go main1()
+	app.Main()
+}
+
+func main1() {
+	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))
+
+	graybg := giowrap.NewBackground(
+		giowrap.Color(color.RGBA{A: 0xff, R: 0xd0, G: 0xd0, B: 0xd0}), 
+		giowrap.Radius(ui.Dp(4)))
+	whitebg := giowrap.NewBackground(
+		giowrap.Color(color.RGBA{A: 0xff, R: 0xff, G: 0xff, B: 0xff}), 
+		giowrap.Radius(ui.Dp(4)))
+	margin := giowrap.NewInset(giowrap.Size(ui.Dp(10)))
+	buffer := giowrap.NewInset(giowrap.Bottom(ui.Dp(10)))
+	f1 := giowrap.NewFlex(giowrap.Vertical)
+	row := giowrap.NewFlex(giowrap.Horizontal)
+
+	more := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"more", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+	submit := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"submit", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+	back := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
+		"back", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
+
+	numfields := 5
+	eds := make([]*giowrap.Editor,0)
+	btns := make([]giowrap.Clickable,0)
+	entryrows := make([]giowrap.Widget,0)
+	submitrows := make([]giowrap.Widget,0)
+
+	var entryPage giowrap.Widget
+	var submitPage giowrap.Widget
+
+	newRow := func(i int) {
+		eds = append(eds, giowrap.NewEditor(fmt.Sprintf("text %d",i), giowrap.Face(ctx.Faces.For(regular, ui.Sp(24)))))
+		btns = append(btns, NewButton(ctx.Faces.For(regular, ui.Sp(18)), "X",
+			color.RGBA{A: 0xff, R: 0x80, G: 0x80, B: 0x80}))
+	}
+
+	for i := 0; i < numfields; i++ {
+		newRow(i)
+	}
+	updatePages := func() {
+		entryrows = entryrows[0:0]
+		entryrows = append(entryrows, buffer(row(more, submit)))
+		for i := 0; i < len(btns); i++ {
+			entryrows = append(entryrows, row(btns[i], giowrap.FillWidth(whitebg(eds[i]))))
+		}
+		entryPage = graybg(margin(giowrap.VScroll(f1)(entryrows...)))
+
+		submitrows = submitrows[0:0]
+		submitrows = append(submitrows, buffer(row(back)))
+		for i := 0; i < len(btns); i++ {
+			submitrows = append(submitrows, giowrap.NewLabel(eds[i].Text(), giowrap.Face(ctx.Faces.For(regular, ui.Sp(24)))))
+		}
+		submitPage = graybg(margin(giowrap.VScroll(f1)(submitrows...)))
+	}
+	updatePages()
+
+	page := &entryPage
+
+	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:
+				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()
+					}
+				}
+				ctx = ctx.Reset(&e)
+				giowrap.Mallocs("pre-layout")
+				ctx = (*page).Layout(ctx)
+				giowrap.Mallocs("post-layout")
+				ctx.Update()
+				for i, w := range btns {
+					if w.Clicked(ctx) {
+						log.Printf("%d clicked\n",i)
+						btns = append(btns[:i], btns[i+1:]...)
+						eds = append(eds[:i], eds[i+1:]...)
+						entryrows = append(entryrows[:i], entryrows[i+1:]...)
+						numfields--
+						updatePages()
+					}
+				}
+				if more.Clicked(ctx) {
+					log.Print("More")
+					newRow(len(btns))
+					updatePages()
+				}
+				if submit.Clicked(ctx) {
+					log.Print("Submit")
+					updatePages()
+					page = &submitPage
+				}
+				if back.Clicked(ctx) {
+					page = &entryPage
+				}
+				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")
+}
+

examples/ctx.go

@@ -0,0 +1,36 @@
+{
+	ctx.Reset(&e) // ctx keeps a pointer to e.Config, so we can do...
+	ctx.RigidConstraints()
+	{
+		f1 := layout.Flex{Axis: layout.Vertical} // maybe pass ctx in here?
+		ins := layout.UniformInset(ui.Dp(10))
+		ins.Begin(ctx) // containers like Insets and Flex keep a pointer to ctx
+		f1.Init(ctx)
+		f1.Rigid()
+		editor1.Layout(ctx)
+		f1.End()
+		{
+			f1.Flexible(0.33)
+			ins := layout.UniformInset(ui.Dp(10))
+			ins.Begin(ctx)
+			editor2.Layout(ctx)
+			ins.End()
+		}
+		f1.End()
+		{
+			f1.Flexible(0.67)
+			f2 := layout.Flex{Axis: layout.Horizontal}
+			f2.Init(ctx)
+			f2.Rigid()
+			button1.Layout(ctx)
+			c1 := f2.End()
+			f2.Flexible(0.5)
+			button2.Layout(ctx)
+			c2 := f2.End()
+			f2.Layout(c1, c2)
+		}
+		c3 := f1.End()
+		f1.Layout(c1, c2, c3)
+		ins.End()
+	}
+}