diff --git a/redo/containerctrls_darwin.go b/redo/containerctrls_darwin.go
index 7249134..4c70cce 100644
--- a/redo/containerctrls_darwin.go
+++ b/redo/containerctrls_darwin.go
@@ -12,7 +12,7 @@ import "C"
 type tab struct {
 	*controlbase
 
-	containers	[]*container
+	tabs			[]*sizer
 }
 
 func newTab() Tab {
@@ -23,14 +23,13 @@ func newTab() Tab {
 }
 
 func (t *tab) Append(name string, control Control) {
-	// TODO isolate and standardize
-	c := new(container)
-	t.containers = append(t.containers, c)
+	s := new(sizer)
+	t.tabs = append(t.tabs, s)
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
 	tabview := C.tabAppend(t.id, cname)
-	c.child = control
-	c.child.setParent(&controlParent{tabview})
+	s.child = control
+	s.child.setParent(&controlParent{tabview})
 }
 
 // no need to override Control.allocate() as only prepared the tabbed control; its children will be reallocated when that one is resized
@@ -38,8 +37,8 @@ func (t *tab) Append(name string, control Control) {
 //export tabResized
 func tabResized(data unsafe.Pointer, width C.intptr_t, height C.intptr_t) {
 	t := (*tab)(unsafe.Pointer(data))
-	for _, c := range t.containers {
+	for _, s := range t.tabs {
 		// the tab area's coordinate system is localized, so the origin is (0, 0)
-		c.resize(0, 0, int(width), int(height))
+		s.resize(0, 0, int(width), int(height))
 	}
 }
diff --git a/redo/sizing_darwin.go b/redo/sizer_darwin.go
similarity index 94%
rename from redo/sizing_darwin.go
rename to redo/sizer_darwin.go
index 6eb29b2..1aa345a 100644
--- a/redo/sizing_darwin.go
+++ b/redo/sizer_darwin.go
@@ -24,7 +24,7 @@ const (
 	macYPadding = 12
 )
 
-func (c *container) beginResize() (d *sizing) {
+func (s *sizer) beginResize() (d *sizing) {
 	d = new(sizing)
 	if spaced {
 		d.xmargin = macXMargin
@@ -35,7 +35,7 @@ func (c *container) beginResize() (d *sizing) {
 	return d
 }
 
-func (c *container) translateAllocationCoords(allocations []*allocation, winwidth, winheight int) {
+func (s *sizer) translateAllocationCoords(allocations []*allocation, winwidth, winheight int) {
 	for _, a := range allocations {
 		// winheight - y because (0,0) is the bottom-left corner of the window and not the top-left corner
 		// (winheight - y) - height because (x, y) is the bottom-left corner of the control and not the top-left
diff --git a/redo/window_darwin.go b/redo/window_darwin.go
index 80d1a51..8393cf7 100644
--- a/redo/window_darwin.go
+++ b/redo/window_darwin.go
@@ -15,7 +15,7 @@ type window struct {
 
 	closing	*event
 
-	*container
+	*sizer
 }
 
 func newWindow(title string, width int, height int, control Control) *window {
@@ -26,7 +26,7 @@ func newWindow(title string, width int, height int, control Control) *window {
 	w := &window{
 		id:			id,
 		closing:		newEvent(),
-		container:		new(container),
+		sizer:		new(sizer),
 	}
 	C.windowSetDelegate(id, unsafe.Pointer(w))
 	w.child = control