Actually use layouts

internal/system/box.go

@@ -484,9 +484,6 @@ func (this *box) calculateMinimumSize () image.Point {
 		minSize.Y = userMinSize.Y
 	}
 	
-	if this.parent != nil {
-		this.parent.notifyMinimumSizeChange(this)
-	}
 	return minSize
 }
 
@@ -564,6 +561,9 @@ func (this *box) invalidateDraw () {
 
 func (this *box) invalidateMinimum () {
 	this.minSize.Invalidate()
+	if this.parent != nil {
+		this.parent.notifyMinimumSizeChange(this)
+	}
 }
 
 func (this *box) recursiveReApply () {

internal/system/containerbox.go

@@ -20,7 +20,6 @@ type containerBox struct {
 	attrLayout   attrHierarchy[tomo.AttrLayout]
 
 	children []anyBox
-	layout   tomo.Layout
 
 	on struct {
 		contentBoundsChange event.FuncBroadcaster
@@ -187,19 +186,21 @@ func (this *containerBox) setAttr (attr tomo.Attr, user bool) {
 }
 
 func (this *containerBox) recommendedHeight (width int) int {
-	if this.layout == nil || this.attrOverflow.Value().Y {
+	layout := this.attrLayout.Value().Layout
+	if layout == nil || this.attrOverflow.Value().Y {
 		return this.minSize.Value().Y
 	} else {
-		return this.layout.RecommendedHeight(this.layoutHints(), this.boxQuerier(), width) +
+		return layout.RecommendedHeight(this.layoutHints(), this.boxQuerier(), width) +
 			this.borderAndPaddingSum().Vertical()
 	}
 }
 
 func (this *containerBox) recommendedWidth (height int) int {
-	if this.layout == nil || this.attrOverflow.Value().X {
+	layout := this.attrLayout.Value().Layout
+	if layout == nil || this.attrOverflow.Value().X {
 		return this.minSize.Value().X
 	} else {
-		return this.layout.RecommendedWidth(this.layoutHints(), this.boxQuerier(), height) +
+		return layout.RecommendedWidth(this.layoutHints(), this.boxQuerier(), height) +
 			this.borderAndPaddingSum().Horizontal()
 	}
 }
@@ -274,8 +275,9 @@ func (this *containerBox) layoutHints () tomo.LayoutHints {
 func (this *containerBox) contentMinimum () image.Point {
 	overflow := this.attrOverflow.Value()
 	minimum  := this.box.contentMinimum()
-	if this.layout != nil {
+	layout := this.attrLayout.Value().Layout
-		layoutMinimum := this.layout.MinimumSize (
+	if layout != nil {
+		layoutMinimum := layout.MinimumSize (
 			this.layoutHints(),
 			this.boxQuerier())
 		if overflow.X { layoutMinimum.X = 0 }