update gio

centering.go

@@ -16,38 +16,38 @@ func main() {
 	go func() {
 		w := app.NewWindow()
 		regular, _ := sfnt.Parse(goregular.TTF)
-		var cfg ui.Config
 		var faces measure.Faces
-		ops := new(ui.Ops)
+		gtx := &layout.Context{
+			Queue: w.Queue(),
+		}
 		for e := range w.Events() {
 			if e, ok := e.(app.UpdateEvent); ok {
-				cfg = &e.Config
-				cs := layout.RigidConstraints(e.Size)
-				ops.Reset()
-				faces.Reset(cfg)
+				gtx.Reset(&e.Config, layout.RigidConstraints(e.Size))
+				faces.Reset(gtx.Config)
 				f := faces.For(regular, ui.Sp(72))
-				drawLabels(f, ops, cs)
-				w.Update(ops)
+				drawLabels(gtx, f)
+				w.Update(gtx.Ops)
 			}
 		}
 	}()
 	app.Main()
 }
 
 // START OMIT
-func drawLabels(face text.Face, ops *ui.Ops, cs layout.Constraints) {
-	cs.Width.Min = 0
-	cs.Height.Min = 0
+func drawLabels(gtx *layout.Context, face text.Face) {
+	gtx.Constraints.Width.Min = 0
+	gtx.Constraints.Height.Min = 0
 	lbl := text.Label{Face: face, Text: "I'm centered!"}
-	var macro ui.MacroOp // HLcenter
-	macro.Record(ops)    // Start recording  // HLcenter
-	dimensions := lbl.Layout(ops, cs)
+	var macro ui.MacroOp  // HLcenter
+	macro.Record(gtx.Ops) // Start recording  // HLcenter
+	lbl.Layout(gtx)
+	dimensions := gtx.Dimensions
 	macro.Stop() // End recording // HLcenter
 	ui.TransformOp{}.Offset(f32.Point{
-		X: float32(cs.Width.Max-dimensions.Size.X) / 2,
-		Y: float32(cs.Height.Max-dimensions.Size.Y) / 2,
-	}).Add(ops)
-	macro.Add(ops) // Replay operations // HLcenter
+		X: float32(gtx.Constraints.Width.Max-dimensions.Size.X) / 2,
+		Y: float32(gtx.Constraints.Height.Max-dimensions.Size.Y) / 2,
+	}).Add(gtx.Ops)
+	macro.Add(gtx.Ops) // Replay operations // HLcenter
 }
 
 // END OMIT

editor.go

@@ -15,26 +15,24 @@ func main() {
 	go func() {
 		w := app.NewWindow()
 		regular, _ := sfnt.Parse(goregular.TTF) // HLdraw
-		var cfg ui.Config                       // HLdraw
-		ops := new(ui.Ops)                      // HLdraw
 		// START INIT OMIT
 		var faces measure.Faces // HLdraw
 		editor := &text.Editor{
 			Face: faces.For(regular, ui.Sp(52)),
 		}
 		editor.SetText("Hello, Gophercon! Edit me.")
+		gtx := &layout.Context{
+			Queue: w.Queue(),
+		}
 		// END INIT OMIT
 		for e := range w.Events() {
 			if e, ok := e.(app.UpdateEvent); ok {
-				cfg = &e.Config                       // HLdraw
-				cs := layout.RigidConstraints(e.Size) // HLdraw
-				ops.Reset()                           // HLdraw
-				faces.Reset(cfg)                      // HLdraw
-				queue := w.Queue()
+				gtx.Reset(&e.Config, layout.RigidConstraints(e.Size)) // HLdraw
+				faces.Reset(gtx.Config)                               // HLdraw
 				// START OMIT
-				editor.Layout(cfg, queue, ops, cs)
+				editor.Layout(gtx)
 				// END OMIT
-				w.Update(ops) // HLdraw
+				w.Update(gtx.Ops) // HLdraw
 			}
 		} // HLeventloop
 	}()

flex.go

@@ -4,7 +4,6 @@ import (
 	"image"
 	"image/color"
 
-	"gioui.org/ui"
 	"gioui.org/ui/app"
 	"gioui.org/ui/f32"
 	"gioui.org/ui/layout"
@@ -14,51 +13,51 @@ import (
 func main() {
 	go func() {
 		w := app.NewWindow()
-		var cfg app.Config
-		ops := new(ui.Ops)
+		gtx := &layout.Context{
+			Queue: w.Queue(),
+		}
 		for e := range w.Events() {
 			if e, ok := e.(app.UpdateEvent); ok {
-				cfg = e.Config
-				cs := layout.RigidConstraints(e.Size)
-				ops.Reset()
-				drawRects(&cfg, ops, cs)
-				w.Update(ops)
+				gtx.Reset(&e.Config, layout.RigidConstraints(e.Size))
+				drawRects(gtx)
+				w.Update(gtx.Ops)
 			}
 		}
 	}()
 	app.Main()
 }
 
 // START OMIT
-func drawRects(c ui.Config, ops *ui.Ops, cs layout.Constraints) {
+func drawRects(gtx *layout.Context) {
 	flex := layout.Flex{}
-	flex.Init(ops, cs)
+	flex.Init(gtx)
 
-	red := flex.Flexible(0.5, func(cs layout.Constraints) layout.Dimensions {
-		return drawRect(c, ops, color.RGBA{A: 0xff, R: 0xff}, cs)
+	red := flex.Flexible(0.5, func() {
+		drawRect(gtx, color.RGBA{A: 0xff, R: 0xff})
 	})
 
-	green := flex.Flexible(0.25, func(cs layout.Constraints) layout.Dimensions {
-		return drawRect(c, ops, color.RGBA{A: 0xff, G: 0xff}, cs)
+	green := flex.Flexible(0.25, func() {
+		drawRect(gtx, color.RGBA{A: 0xff, G: 0xff})
 	})
 
-	blue := flex.Flexible(0.25, func(cs layout.Constraints) layout.Dimensions {
-		return drawRect(c, ops, color.RGBA{A: 0xff, B: 0xff}, cs)
+	blue := flex.Flexible(0.25, func() {
+		drawRect(gtx, color.RGBA{A: 0xff, B: 0xff})
 	})
 
 	flex.Layout(red, green, blue)
 }
 
 // END OMIT
 
-func drawRect(c ui.Config, ops *ui.Ops, color color.RGBA, cs layout.Constraints) layout.Dimensions {
+func drawRect(gtx *layout.Context, color color.RGBA) {
+	cs := gtx.Constraints
 	square := f32.Rectangle{
 		Max: f32.Point{
 			X: float32(cs.Width.Max),
 			Y: float32(cs.Height.Max),
 		},
 	}
-	paint.ColorOp{Color: color}.Add(ops)
-	paint.PaintOp{Rect: square}.Add(ops)
-	return layout.Dimensions{Size: image.Point{X: cs.Width.Max, Y: cs.Height.Max}}
+	paint.ColorOp{Color: color}.Add(gtx.Ops)
+	paint.PaintOp{Rect: square}.Add(gtx.Ops)
+	gtx.Dimensions = layout.Dimensions{Size: image.Point{X: cs.Width.Max, Y: cs.Height.Max}}
 }

go.mod

@@ -3,6 +3,6 @@ module gophercon2019
 go 1.13
 
 require (
-	gioui.org/ui v0.0.0-20190918182616-7ca1d7a3fee0
+	gioui.org/ui v0.0.0-20190925074315-9c33550644a7
 	golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9
 )

go.sum

@@ -1,5 +1,5 @@
-gioui.org/ui v0.0.0-20190918182616-7ca1d7a3fee0 h1:1popnecUCpLbiELuAfx0id4JtlN2xehC6QRLITvug30=
-gioui.org/ui v0.0.0-20190918182616-7ca1d7a3fee0/go.mod h1:PssKPKlqVIeyaed+0w492Xc2NgX5M3n6oZKOAj5rxoE=
+gioui.org/ui v0.0.0-20190925074315-9c33550644a7 h1:l/WdLfRQnDRjipqy7NP9iJcq/zXABhsCd7vGX8oapYo=
+gioui.org/ui v0.0.0-20190925074315-9c33550644a7/go.mod h1:PssKPKlqVIeyaed+0w492Xc2NgX5M3n6oZKOAj5rxoE=
 golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9 h1:uc17S921SPw5F2gJo7slQ3aqvr2RwpL7eb3+DZncu3s=
 golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a h1:aYOabOQFp6Vj6W1F80affTUvO9UxmJRx8K0gsfABByQ=

gophercon-2019.slide

@@ -381,16 +381,17 @@ Dimensions are output
 
 * Constraints and dimensions
 
-Widgets accept constraints, output dimensions
+Widgets accept constraints, output dimensions, stored in
+layout.Context.
 
 	package text // import gioui.org/ui/text
 
-	func (l Label) Layout(ops *ui.Ops, cs layout.Constraints) layout.Dimensions
-	func (e *Editor) Layout(ops *ui.Ops, cs layout.Constraints) layout.Dimensions
+	func (l Label) Layout(gtx *layout.Context)
+	func (e *Editor) Layout(gtx *layout.Context)
 
 	package widget // import gioui.org/ui/widget
 
-	func (im Image) Layout(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimensions
+	func (im Image) Layout(gtx *layout.Context)
 
 
 : Gio borrows Constraints and Dimensions from the Flutter framework.
@@ -424,25 +425,21 @@ Widgets accept constraints, output dimensions
 
 Aligning
 
-	var ops *ui.Ops
-	var cs layout.Constraints
+	var gtx *layout.Context
 
-	align := layout.Align{Alignment: layout.Center}
-	cs = align.Begin(ops, cs)
-	...
-	dimensions := someWidget.Layout(..., cs) // Draw widget
-	...
-	dimensions = align.End(dimensions)
+	align := layout.Align(layout.Center)
+	align.Layout(gtx, func() {
+		someWidget.Layout(gtx, ...) // Draw widget
+	})
+	dimensions := gtx.Dimensions
 
 Insetting
 
-	var c ui.Config
 	inset := layout.Inset{Top: ui.Dp(8), ...} // 8dp top inset
-	cs = inset.Begin(c, ops, cs)
-	...
-	dimensions := anotherWidget.Layout(..., cs) // Draw widget
-	...
-	dimensions = inset.End(dimensions)
+	inset.Layout(gtx, func() {
+		anotherWidget.Layout(gtx, ...) // Draw widget
+	})
+	dimensions := gtx.Dimensions
 
 : Centering is a special case of aligning widgets. Aligning and insetting widgets are so common that Gio provides two helper
 : types in the layout package, Align and Inset.
@@ -551,9 +548,9 @@ Lay out widgets on an axis.
 
 
 
-* Window input queue
+* Window event queue
 
-The Window's Queue method returns an input.Queue for OS events.
+The Window's Queue method returns an ui.Queue for OS events.
 
 	package app // import gioui.org/ui/app
 
@@ -565,11 +562,10 @@ The Window's Queue method returns an input.Queue for OS events.
 
 	import "gioui.org/ui"
 	import "gioui.org/ui/gesture"
-	import "gioui.org/ui/input"
 
 Detect clicks
 
-	var queue input.Queue
+	var queue ui.Queue
 	var c gesture.Click
 	for event, ok := c.Next(queue); ok; event, ok = c.Next(queue) {
 		// event is a gesture.ClickEvent, not a raw pointer.Event.

helloworld.go

@@ -16,20 +16,19 @@ func main() {
 	go func() {
 		w := app.NewWindow()
 		regular, _ := sfnt.Parse(goregular.TTF)
-		var cfg ui.Config
 		var faces measure.Faces
-		ops := new(ui.Ops)
+		gtx := &layout.Context{
+			Queue: w.Queue(),
+		}
 		for e := range w.Events() {
 			if e, ok := e.(app.UpdateEvent); ok {
-				cfg = &e.Config
-				cs := layout.RigidConstraints(e.Size)
-				ops.Reset()
-				faces.Reset(cfg)
+				gtx.Reset(&e.Config, layout.RigidConstraints(e.Size))
+				faces.Reset(gtx.Config)
 
 				lbl := text.Label{Face: faces.For(regular, ui.Sp(72)), Text: "Hello, World!"} // HLdraw
-				lbl.Layout(ops, cs)                                                           // HLdraw
+				lbl.Layout(gtx)                                                               // HLdraw
 
-				w.Update(ops)
+				w.Update(gtx.Ops)
 			}
 		} // HLeventloop
 	}()

list.go

@@ -5,7 +5,6 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/app"
-	"gioui.org/ui/input"
 	"gioui.org/ui/layout"
 	"gioui.org/ui/measure"
 	"gioui.org/ui/text"
@@ -18,37 +17,36 @@ func main() {
 	go func() {
 		w := app.NewWindow()
 		regular, _ := sfnt.Parse(goregular.TTF)
-		var cfg ui.Config
 		var faces measure.Faces
-		ops := new(ui.Ops)
 		// START INIT OMIT
 		list := &layout.List{
 			Axis: layout.Vertical,
 		}
+		gtx := &layout.Context{
+			Queue: w.Queue(),
+		}
 		// END INIT OMIT
 		for e := range w.Events() {
 			if e, ok := e.(app.UpdateEvent); ok {
-				cfg = &e.Config
-				cs := layout.RigidConstraints(e.Size)
-				ops.Reset()
-				faces.Reset(cfg)
+				gtx.Reset(&e.Config, layout.RigidConstraints(e.Size))
+				faces.Reset(gtx.Config)
 				f := faces.For(regular, ui.Sp(42))
-				drawList(cfg, w.Queue(), list, f, ops, cs)
-				w.Update(ops)
+				drawList(gtx, list, f)
+				w.Update(gtx.Ops)
 			}
 		}
 	}()
 	app.Main()
 }
 
 // START OMIT
-func drawList(c ui.Config, q input.Queue, list *layout.List, face text.Face, ops *ui.Ops, cs layout.Constraints) {
+func drawList(gtx *layout.Context, list *layout.List, face text.Face) {
 	const n = 1e6
-	list.Layout(c, q, ops, cs, n, func(cs layout.Constraints, i int) layout.Dimensions {
+	list.Layout(gtx, n, func(i int) {
 		txt := fmt.Sprintf("List element #%d", i)
 
 		lbl := text.Label{Face: face, Text: txt}
-		return lbl.Layout(ops, cs)
+		lbl.Layout(gtx)
 	})
 }
 

pointer.go

@@ -7,7 +7,6 @@ import (
 	"gioui.org/ui"
 	"gioui.org/ui/app"
 	"gioui.org/ui/f32"
-	"gioui.org/ui/input"
 	"gioui.org/ui/paint"
 	"gioui.org/ui/pointer"
 )
@@ -37,7 +36,7 @@ type Button struct {
 }
 
 // START OMIT
-func (b *Button) Layout(queue input.Queue, ops *ui.Ops) {
+func (b *Button) Layout(queue ui.Queue, ops *ui.Ops) {
 	for e, ok := queue.Next(b); ok; e, ok = queue.Next(b) { // HLevent
 		if e, ok := e.(pointer.Event); ok { // HLevent
 			switch e.Type { // HLevent