op: rename StackOp/Push/Pop to StateOp/Save/Load

The semantics were relaxed in a previous commit; this change renames
to operations accordingly.

API change. Use gofmt to adjust your code accordingly:

gofmt -r 'op.Push(a).Pop() -> op.Save(a).Load()'
gofmt -r 'op.Push(a) -> op.Save(a)'
gofmt -r 'v.Pop() -> v.Load()'
gofmt -r 'op.StackOp -> op.StateOp'

Signed-off-by: Elias Naur <mail@eliasnaur.com>

layout/flex.go

@@ -181,10 +181,10 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 				cross = maxBaseline - b
 			}
 		}
-		stack := op.Push(gtx.Ops)
+		stack := op.Save(gtx.Ops)
 		op.Offset(FPt(f.Axis.point(mainSize, cross))).Add(gtx.Ops)
 		child.call.Add(gtx.Ops)
-		stack.Pop()
+		stack.Load()
 		mainSize += f.Axis.Main(dims.Size)
 		if i < len(children)-1 {
 			switch f.Spacing {

layout/layout.go

@@ -141,11 +141,11 @@ func (in Inset) Layout(gtx Context, w Widget) Dimensions {
 	if mcs.Min.Y > mcs.Max.Y {
 		mcs.Min.Y = mcs.Max.Y
 	}
-	stack := op.Push(gtx.Ops)
+	stack := op.Save(gtx.Ops)
 	op.Offset(FPt(image.Point{X: left, Y: top})).Add(gtx.Ops)
 	gtx.Constraints = mcs
 	dims := w(gtx)
-	stack.Pop()
+	stack.Load()
 	return Dimensions{
 		Size:     dims.Size.Add(image.Point{X: right + left, Y: top + bottom}),
 		Baseline: dims.Baseline + bottom,
@@ -186,10 +186,10 @@ func (d Direction) Layout(gtx Context, w Widget) Dimensions {
 	case SW, S, SE:
 		p.Y = sz.Y - dims.Size.Y
 	}
-	stack := op.Push(gtx.Ops)
+	stack := op.Save(gtx.Ops)
 	op.Offset(FPt(p)).Add(gtx.Ops)
 	call.Add(gtx.Ops)
-	stack.Pop()
+	stack.Load()
 	return Dimensions{
 		Size:     sz,
 		Baseline: dims.Baseline + sz.Y - dims.Size.Y - p.Y,

layout/list.go

@@ -253,11 +253,11 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 			Min: l.Axis.point(min, -inf),
 			Max: l.Axis.point(max, inf),
 		}
-		stack := op.Push(ops)
+		stack := op.Save(ops)
 		clip.Rect(r).Add(ops)
 		op.Offset(FPt(l.Axis.point(pos, cross))).Add(ops)
 		child.call.Add(ops)
-		stack.Pop()
+		stack.Load()
 		pos += childSize
 	}
 	atStart := l.Position.First == 0 && l.Position.Offset <= 0
@@ -274,7 +274,7 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 	}
 	dims := l.Axis.point(pos, maxCross)
 	call := macro.Stop()
-	defer op.Push(ops).Pop()
+	defer op.Save(ops).Load()
 	pointer.Rect(image.Rectangle{Max: dims}).Add(ops)
 	l.scroll.Add(ops)
 	call.Add(ops)

layout/stack.go

@@ -104,10 +104,10 @@ func (s Stack) Layout(gtx Context, children ...StackChild) Dimensions {
 		case SW, S, SE:
 			p.Y = maxSZ.Y - sz.Y
 		}
-		stack := op.Push(gtx.Ops)
+		stack := op.Save(gtx.Ops)
 		op.Offset(FPt(p)).Add(gtx.Ops)
 		ch.call.Add(gtx.Ops)
-		stack.Pop()
+		stack.Load()
 		if baseline == 0 {
 			if b := ch.dims.Baseline; b != 0 {
 				baseline = b + maxSZ.Y - sz.Y - p.Y