diff --git a/redo/windows/child.c b/redo/windows/child.c
index 4090ce01..8f871234 100644
--- a/redo/windows/child.c
+++ b/redo/windows/child.c
@@ -7,11 +7,13 @@ struct child {
 	uiControl *c;
 	HWND hwnd;
 
-	HWND parent;
+	// This is a helper for uiTab pages.
+	// For visual accuracy of tab page backgrounds, margins are also handled here, applied to the child only (rather than applied to the whole tab page).
+	HWND tabpage;
+	int margined;
 
 	// This flag is for users of these functions.
 	// For uiBox, this is "spaced".
-	// For uiTab, this is "margined". (uiGroup and uiWindow have to maintain their margined state themselves, since the margined state is independent of whether there is a child for those two.)
 	int flag;
 };
 
@@ -28,15 +30,27 @@ struct child *newChild(uiControl *child, uiControl *parent, HWND parentHWND)
 
 	uiControlSetParent(c->c, parent);
 	uiWindowsEnsureSetParent(c->hwnd, parentHWND);
-	c->parent = parentHWND;
 
 	return c;
 }
 
+struct child *newChildWithTabPage(uiControl *child, uiControl *parent, HWND parentHWND)
+{
+	struct child *c;
+	HWND tabpage;
+
+	tabpage = newTabPage();
+	c = newChild(child, parent, tabpage);
+	uiWindowsEnsureSetParent(tabpage, parentHWND);
+	return c;
+}
+
 void childRemove(struct child *c)
 {
 	uiWindowsEnsureSetParent(c->hwnd, utilwin);
 	uiControlSetParent(c->c, NULL);
+	if (c->tabpage != NULL)
+		uiWindowsEnsureDestroyWindow(c->tabpage);
 	uiFree(c);
 }
 
@@ -57,15 +71,34 @@ HWND childHWND(struct child *c)
 void childMinimumSize(struct child *c, uiWindowsSizing *d, intmax_t *width, intmax_t *height)
 {
 	uiWindowsControl *wc;
+	intmax_t left, top, right, bottom
 
 	wc = uiWindowsControl(c->c);
 	(*(wc->MinimumSize))(wc, d, width, height);
+	if (c->tabpage != NULL && c->margined) {
+		tabPageMargins(c->tabpage, &left, &top, &right, &bottom);
+		*width += left + right;
+		*height += top + bottom;
+	}
 }
 
 void childRelayout(struct child *c, intmax_t x, intmax_t y, intmax_t width, intmax_t height)
 {
 	uiWindowsControl *wc;
+	intmax_t left, top, right, bottom;
 
+	if (c->tabpage != NULL) {
+		uiWindowsEnsureMoveWindow(c->tabpage, x, y, width, height);
+		x = 0;		// and make relative to the client rect of the tab page
+		y = 0;
+		if (c->margined) {
+			tabPageMargins(c->tabpage, &left, &top, &right, &bottom);
+			x += left;
+			y += top;
+			width -= left + right;
+			height -= top + bottom;
+		}
+	}
 	wc = uiWindowsControl(c->c);
 	(*(wc->Relayout))(wc, x, y, width, height);
 }
@@ -75,6 +108,22 @@ void childUpdateState(struct child *c)
 	controlUpdateState(c->c);
 }
 
+HWND childTabPage(struct child *c)
+{
+	return c->tabpage;
+}
+
+int childMargined(struct child *c)
+{
+	return c->margined;
+}
+
+void childSetMargined(struct child *c)
+{
+	c->margined = margined;
+	uiControlQueueResize(c->c);
+}
+
 int childFlag(struct child *c)
 {
 	return c->flag;
diff --git a/redo/windows/tabpage.c b/redo/windows/tabpage.c
new file mode 100644
index 00000000..c3675f12
--- /dev/null
+++ b/redo/windows/tabpage.c
@@ -0,0 +1,62 @@
+// 30 may 2015
+#include "uipriv_windows.h"
+
+// This just defines the implementation of the tab page HWND itself.
+// The actual work of hosting a tab page's control is in child.c.
+
+// from http://msdn.microsoft.com/en-us/library/windows/desktop/bb226818%28v=vs.85%29.aspx
+#define tabMargin 7
+
+static void tabPageMargins(HWND hwnd, intmax_t *left, intmax_t *right, intmax_t *right, intmax_t *bottom)
+{
+	uiWindowsSizing *d;
+
+	d = uiWindowsNewSizing(hwnd);
+	*left = uiWindowsDlgUnitsToX(tabMargin, d->BaseX);
+	*top = uiWindowsDlgUnitsToY(tabMargin, d->BaseY);
+	*right = *left;
+	*bottom = *top;
+	uiWindowsFreeSizing(d);
+}
+
+// dummy dialog procedure; see below for details
+// let's handle parent messages here to avoid needing to subclass
+static INT_PTR CALLBACK dlgproc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+	LRESULT lResult;
+
+	if (handleParentMessages(hwnd, uMsg, wParam, lParam, &lResult) != FALSE) {
+		SetWindowLongPtrW(hwnd, DWLP_MSGRESULT, (LONG_PTR) lResult);
+		return TRUE;
+	}
+	// unthemed dialogs don't respond to WM_PRINTCLIENT
+	// fortunately they don't have any special painting
+	if (uMsg == WM_PRINTCLIENT) {
+		// don't worry about the return value; hopefully DefWindowProcW() caught it (if not the dialog procedure itself)
+		// we COULD paint the dialog background brush ourselves but meh, it works
+		SendMessageW(hwnd, WM_ERASEBKGND, wParam, lParam);
+		// and pretend we did nothing just so the themed dialog can still paint its content
+		return FALSE;
+	}
+	if (uMsg == WM_INITDIALOG)
+		return TRUE;
+	return FALSE;
+}
+
+HWND newTabPage(void)
+{
+	HWND hwnd;
+	HRESULT hr;
+
+	// unfortunately this needs to be a proper dialog for EnableThemeDialogTexture() to work; CreateWindowExW() won't suffice
+	hwnd = CreateDialogW(hInstance, MAKEINTRESOURCE(rcTabPageDialog),
+		utilWindow, dlgproc);
+	if (t->hwnd == NULL)
+		logLastError("error creating tab page in newTabPage()");
+
+	hr = EnableThemeDialogTexture(t->hwnd, ETDT_ENABLE | ETDT_USETABTEXTURE | ETDT_ENABLETAB);
+	if (hr != S_OK)
+		logHRESULT("error setting tab page background in newTabPage()", hr);
+
+	return hwnd;
+}
diff --git a/windows/tabpage.c b/windows/tabpage.c
deleted file mode 100644
index 47f8ed11..00000000
--- a/windows/tabpage.c
+++ /dev/null
@@ -1,169 +0,0 @@
-// 30 may 2015
-#include "uipriv_windows.h"
-
-// This is a special internal control type that handles tab pages.
-// This doesn't use the container class, but rather a subclassed WC_DIALOG, as that supports tab textures properly.
-// The standard property sheet control does the same thing.
-
-struct tabPage {
-	uiControl c;
-	HWND hwnd;
-	uiControl *child;
-	int margined;
-	void (*baseResize)(uiControl *, intmax_t, intmax_t, intmax_t, intmax_t, uiSizing *);
-};
-
-uiDefineControlType(tabPage, tabPageType, struct tabPage)
-
-// don't override CommitDestroy(); we destroy the child with a separate function
-
-static uintptr_t tabPageHandle(uiControl *c)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	return (uintptr_t) (t->hwnd);
-}
-
-// from http://msdn.microsoft.com/en-us/library/windows/desktop/bb226818%28v=vs.85%29.aspx
-#define tabMargin 7
-
-static void tabPagePreferredSize(uiControl *c, uiSizing *d, intmax_t *width, intmax_t *height)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	*width = 0;
-	*height = 0;
-	if (t->child != NULL)
-		uiControlPreferredSize(t->child, d, width, height);
-	if (t->margined) {
-		*width += 2 * uiWindowsDlgUnitsToX(tabMargin, d->Sys->BaseX);
-		*height += 2 * uiWindowsDlgUnitsToY(tabMargin, d->Sys->BaseY);
-	}
-}
-
-static void tabPageResize(uiControl *c, intmax_t x, intmax_t y, intmax_t width, intmax_t height, uiSizing *d)
-{
-	struct tabPage *t = (struct tabPage *) c;
-	RECT r;
-	uiSizing *dchild;
-
-	(*(t->baseResize))(uiControl(t), x, y, width, height, d);
-
-	if (t->child == NULL)
-		return;
-
-	dchild = uiControlSizing(uiControl(t));
-
-	if (GetClientRect(t->hwnd, &r) == 0)
-		logLastError("error getting tab page client rect in tabPageResize()");
-	if (t->margined) {
-		r.left += uiWindowsDlgUnitsToX(tabMargin, d->Sys->BaseX);
-		r.top += uiWindowsDlgUnitsToY(tabMargin, d->Sys->BaseY);
-		r.right -= uiWindowsDlgUnitsToX(tabMargin, d->Sys->BaseX);
-		r.bottom -= uiWindowsDlgUnitsToY(tabMargin, d->Sys->BaseY);
-	}
-	// this rect is in client coordinates; we need toplevel window coordinates
-	mapWindowRect(t->hwnd, dchild->Sys->CoordFrom, &r);
-
-	uiControlResize(t->child, r.left, r.top, r.right - r.left, r.bottom - r.top, dchild);
-
-	uiFreeSizing(dchild);
-}
-
-static void tabPageContainerUpdateState(uiControl *c)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	if (t->child != NULL)
-		uiControlUpdateState(t->child);
-}
-
-// dummy dialog procedure; see below for details
-// let's handle parent messages here to avoid needing to subclass
-static INT_PTR CALLBACK dlgproc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
-{
-	LRESULT lResult;
-
-	if (handleParentMessages(hwnd, uMsg, wParam, lParam, &lResult) != FALSE) {
-		SetWindowLongPtrW(hwnd, DWLP_MSGRESULT, (LONG_PTR) lResult);
-		return TRUE;
-	}
-	// unthemed dialogs don't respond to WM_PRINTCLIENT
-	// fortunately they don't have any special painting
-	if (uMsg == WM_PRINTCLIENT) {
-		// don't worry about the return value; hopefully DefWindowProcW() caught it (if not the dialog procedure itself)
-		// we COULD paint the dialog background brush ourselves but meh, it works
-		SendMessageW(hwnd, WM_ERASEBKGND, wParam, lParam);
-		// and pretend we did nothing just so the themed dialog can still paint its content
-		return FALSE;
-	}
-	if (uMsg == WM_INITDIALOG)
-		return TRUE;
-	return FALSE;
-}
-
-uiControl *newTabPage(void)
-{
-	struct tabPage *t;
-	HRESULT hr;
-
-	t = (struct tabPage *) uiWindowsNewSingleHWNDControl(tabPageType());
-
-	// unfortunately this needs to be a proper dialog for EnableThemeDialogTexture() to work; CreateWindowExW() won't suffice
-	t->hwnd = CreateDialogW(hInstance, MAKEINTRESOURCE(rcTabPageDialog),
-		utilWindow, dlgproc);
-	if (t->hwnd == NULL)
-		logLastError("error creating tab page in newTabPage()");
-
-	hr = EnableThemeDialogTexture(t->hwnd, ETDT_ENABLE | ETDT_USETABTEXTURE | ETDT_ENABLETAB);
-	if (hr != S_OK)
-		logHRESULT("error setting tab page background in newTabPage()", hr);
-
-	uiControl(t)->Handle = tabPageHandle;
-	uiControl(t)->PreferredSize = tabPagePreferredSize;
-	t->baseResize = uiControl(t)->Resize;
-	uiControl(t)->Resize = tabPageResize;
-	uiControl(t)->ContainerUpdateState = tabPageContainerUpdateState;
-
-	return uiControl(t);
-}
-
-int tabPageMargined(uiControl *c)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	return t->margined;
-}
-
-void tabPageSetMargined(uiControl *c, int margined)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	t->margined = margined;
-}
-
-void tabPageDestroyChild(uiControl *c)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	uiControlSetParent(t->child, NULL);
-	uiControlDestroy(t->child);
-	t->child = NULL;
-}
-
-void tabPagePreserveChild(uiControl *c)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	uiControlSetParent(t->child, NULL);
-	t->child = NULL;
-}
-
-void tabPageSetChild(uiControl *c, uiControl *child)
-{
-	struct tabPage *t = (struct tabPage *) c;
-
-	t->child = child;
-	t->child = child;
-	uiControlSetParent(t->child, uiControl(t));
-}