Implement Insets.

main.go

@@ -10,13 +10,13 @@ import (
 	"gioui.org/ui/layout"
 	"gioui.org/ui/measure"
 	"gioui.org/ui/text"
-	//"gioui.org/ui/input"
 
 	"golang.org/x/image/font/gofont/goregular"
 	"golang.org/x/image/font/sfnt"
 )
 
 type Context struct {
+	w *app.Window
 	c *app.Config
 	q input.Queue
 	ops *ui.Ops
@@ -25,13 +25,15 @@ type Context struct {
 	faces measure.Faces
 }
 
-func NewContext() *Context {
+func NewContext(w *app.Window) *Context {
-	return &Context{ops: new(ui.Ops)}
+	return &Context{
+		ops: new(ui.Ops),
+		q: w.Queue(),
+	}
 }
 
-func (ctx *Context) Reset(w *app.Window, e app.DrawEvent) {
+func (ctx *Context) Reset(e app.DrawEvent) {
 	ctx.c = &e.Config
-	ctx.q = w.Queue()
 	ctx.ops.Reset()
 	ctx.cs = layout.RigidConstraints(e.Size)
 	ctx.faces.Reset(ctx.c)
@@ -53,12 +55,22 @@ type WidgetCombinator func(...Widget) Widget
 
 type Layout func(ui.Config, input.Queue, *ui.Ops, layout.Constraints) layout.Dimens
 
+type LayoutCombinator func(...Layout) Layout
+
 func (ctx *Context) Do(ls ...Layout) {
 	for _, l := range ls {
 		ctx.dims = l(ctx.c, ctx.q, ctx.ops, ctx.cs)
 	}
 }
 
+type Label struct {
+	l *text.Label
+}
+
+func (l *Label) Layout(c ui.Config, q input.Queue, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
+	return l.l.Layout(ops, cs)
+}
+
 func main() {
 	go func() {
 		w := app.NewWindow(nil)
@@ -66,7 +78,7 @@ func main() {
 		if err != nil {
 			log.Fatal("Cannot parse font.")
 		}
-		ctx := NewContext()
+		ctx := NewContext(w)
 		t := time.NewTicker(time.Second/30)
 		e1 := &text.Editor{
 			Face: ctx.faces.For(regular, ui.Sp(24)),
@@ -80,6 +92,16 @@ func main() {
 			SingleLine: true,
 		}
 		e2.SetText("ok bye")
+		f := Flex(layout.Vertical, layout.Start, layout.Start)
+		ins10a := Inset(ui.Dp(10),ui.Dp(10),ui.Dp(10),ui.Dp(10))
+		ins10b := Inset(ui.Dp(10),ui.Dp(10),ui.Dp(10),ui.Dp(10))
+
+		btn := &Label{}
+		btn.l = &text.Label{
+			Face: ctx.faces.For(regular, ui.Sp(24)),
+			Text: "centered",
+			Alignment: text.Center,
+		}
 
 		for {
 			select {
@@ -90,11 +112,13 @@ func main() {
 				case app.DestroyEvent:
 					return
 				case app.DrawEvent:
-					ctx.Reset(w,e)
+					ctx.Reset(e)
-
+					ctx.Do(
-					f := Flex(layout.Vertical, layout.Start, layout.Start)
+						ins10a(f(
-					//f(e1,e2).Layout(ctx.c, ctx.q, ctx.ops, ctx.cs)
+							FlexChild{10,e1},
-					ctx.Do(f(e1,e2).Layout)
+							FlexChild{5,ins10b(e2)},
+							FlexChild{1,btn},
+						)).Layout)
 					w.Draw(ctx.ops)
 				}
 			}
@@ -103,13 +127,18 @@ func main() {
 	app.Main()
 }
 
-func Flex(axis layout.Axis, mainAxisAlignment layout.MainAxisAlignment, crossAxisAlignment layout.CrossAxisAlignment) WidgetCombinator {
+type FlexChild struct {
+	x float32
+	w Widget
+}
+
+func Flex(axis layout.Axis, mainAxisAlignment layout.MainAxisAlignment, crossAxisAlignment layout.CrossAxisAlignment) func(...FlexChild) Widget {
 	f := layout.Flex{
 		Axis: axis,
 		MainAxisAlignment: mainAxisAlignment,
 		CrossAxisAlignment: crossAxisAlignment,
 	}
-	return func(ws ...Widget) Widget {
+	return func(ws ...FlexChild) Widget {
 		ret := fWidget{}
 		ret.l = func(c ui.Config, q input.Queue, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
 			f.Init(ops, cs)
@@ -118,9 +147,9 @@ func Flex(axis layout.Axis, mainAxisAlignment layout.MainAxisAlignment, crossAxi
 			fcs := make([]layout.FlexChild,len(ws))
 			for i, w := range ws {
 				if i > 0 {
-					cs = f.Flexible(1)
+					cs = f.Flexible(w.x)
 				}
-				dims = w.Layout(c, q, ops, cs)
+				dims = w.w.Layout(c, q, ops, cs)
 				fcs[i] = f.End(dims)
 			}
 			return f.Layout(fcs...)
@@ -129,3 +158,19 @@ func Flex(axis layout.Axis, mainAxisAlignment layout.MainAxisAlignment, crossAxi
 	}
 }
 
+func Inset(top, right, bottom, left ui.Value) WidgetCombinator {
+	ins := layout.Inset{ Top: top, Right: right, Bottom: bottom, Left: left }
+	return func(ws ...Widget) Widget {
+		ret := fWidget{}
+		ret.l = func(c ui.Config, q input.Queue, ops *ui.Ops, cs layout.Constraints) layout.Dimens {
+			cs = ins.Begin(c, ops, cs)
+			var dims layout.Dimens
+			for _, w := range ws {
+				dims = w.Layout(c, q, ops, cs)
+			}
+			return ins.End(dims)
+		}
+		return ret
+	}
+}
+