Add FillWidth and FillHeight enclosures.

.gitignore

@@ -3,3 +3,4 @@ cmd/cal/cal
 cmd/scroll/scroll
 cmd/grid/grid
 *.apk
+memprofile*

cmd/cal/main.go

@@ -20,7 +20,6 @@ import (
 )
 
 var (
-	sel  int32
 	face text.Face
 )
 

main.go

@@ -204,6 +204,7 @@ type List = WidgetCombinator
 type AxisOpt struct{ axis layout.Axis }
 
 func Axis(x layout.Axis) AxisOpt { return AxisOpt{x} }
+
 var Horizontal = AxisOpt{layout.Horizontal}
 var Vertical = AxisOpt{layout.Vertical}
 
@@ -510,6 +511,29 @@ func Rrect(ops *ui.Ops, width, height, se, sw, nw, ne float32) {
 	Mallocs("Rrect() end")
 }
 
+type fillWidget struct {
+	axis layout.Axis
+}
+
+func FillWidth(ws ...Widget) Widget {
+	return Enclose(fillWidget{layout.Horizontal}, ws...)
+}
+func FillHeight(ws ...Widget) Widget {
+	return Enclose(fillWidget{layout.Vertical}, ws...)
+}
+
+func (fw fillWidget) Begin(ctx *Context) {
+	switch fw.axis {
+	case layout.Horizontal:
+		ctx.cs.Width.Min = ctx.cs.Width.Max
+	case layout.Vertical:
+		ctx.cs.Height.Min = ctx.cs.Height.Max
+	}
+}
+
+func (fw fillWidget) End(*Context) {
+}
+
 type Clickable interface {
 	Widget
 	Clicked(*Context) bool