Some internal layouts return recommended sizes

layouts/rowcol.go

@@ -54,7 +54,7 @@ func (column Column) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 			if expands(index) {
 				nExpanding ++
 			} else {
-				freeSpace -= float64(box.MinimumSize().X)
+				freeSpace -= float64(box.MinimumSize().Y)
 			}
 		}
 		expandingSize = freeSpace / float64(nExpanding)
@@ -125,7 +125,7 @@ func (row Row) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 			if expands(index) {
 				nExpanding ++
 			} else {
-				freeSpace -= float64(box.MinimumSize().Y)
+				freeSpace -= float64(box.MinimumSize().X)
 			}
 		}
 		expandingSize = freeSpace / float64(nExpanding)

scrollbar.go

@@ -335,12 +335,12 @@ func (this scrollbarLayout) Arrange (hints tomo.LayoutHints, boxes []tomo.Box) {
 	
 }
 
-func (this scrollbarLayout) RecommendedHeight (tomo.LayoutHints, []tomo.Box, int) int {
+func (this scrollbarLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).X
 }
 
-func (this scrollbarLayout) RecommendedWidth (tomo.LayoutHints, []tomo.Box, int) int {
+func (this scrollbarLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).Y
 }
 
 func (this scrollbarLayout) viewportContentRatio () float64 {

scrollcontainer.go

@@ -184,12 +184,12 @@ func (this *scrollContainerLayout) Arrange (hints tomo.LayoutHints, boxes []tomo
 	}
 }
 
-func (this *scrollContainerLayout) RecommendedHeight (tomo.LayoutHints, []tomo.Box, int) int {
+func (this *scrollContainerLayout) RecommendedHeight (hints tomo.LayoutHints, boxes []tomo.Box, width int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).X
 }
 
-func (this *scrollContainerLayout) RecommendedWidth (tomo.LayoutHints, []tomo.Box, int) int {
+func (this *scrollContainerLayout) RecommendedWidth (hints tomo.LayoutHints, boxes []tomo.Box, height int) int {
-	return 0
+	return this.MinimumSize(hints, boxes).Y
 }
 
 func max (x, y int) int {