Add a BObjectList<BLayoutItem> to BView::fLayoutData that keeps track of any BLayoutItems that refer to this view that are part of a layout. BLayoutItem does the registering/deregistering of the items, and BView::Private proxies fLayoutData for us. Currently, this is not used anywhere, but there are many places where it will be used soon.

headers/private/interface/ViewPrivate.h

@@ -66,6 +66,11 @@ public:
 	bool	WillLayout();
 	bool	MinMaxValid();
 
+	BLayoutItem* LayoutItemAt(int32 index);
+	int32	CountLayoutItems();
+	void	RegisterLayoutItem(BLayoutItem* item);
+	void	DeregisterLayoutItem(BLayoutItem* item);
+
 	bool RemoveSelf()
 	{
 		return fView->_RemoveSelf();

src/kits/interface/Layout.cpp

@@ -238,7 +238,7 @@ BLayout::RemoveItem(int32 index)
 
 	BLayoutItem* item = (BLayoutItem*)fItems.RemoveItem(index);
 
-	// if the item refers to a BView, we make sure, it is removed from the
+	// if the item refers to a BView, we make sure it is removed from the
 	// parent view
 	BView* view = item->View();
 	if (view && view->fParent == fTarget)

src/kits/interface/LayoutItem.cpp

@@ -9,6 +9,7 @@
 #include <Layout.h>
 #include <LayoutUtils.h>
 #include <View.h>
+#include <ViewPrivate.h>
 
 #include <algorithm>
 
@@ -166,7 +167,15 @@ BLayoutItem::SetLayout(BLayout* layout)
 	std::swap(fLayout, layout);
 	if (layout)
 		DetachedFromLayout(layout);
-		
+
+	if (BView* view = View()) {
+		if (layout && !fLayout) {
+			BView::Private(view).DeregisterLayoutItem(this);
+		} else if (fLayout && !layout) {
+			BView::Private(view).RegisterLayoutItem(this);
+		}
+	}
+	
 	if (fLayout)
 		AttachedToLayout();
 }

src/kits/interface/View.cpp

@@ -34,6 +34,7 @@
 #include <MenuBar.h>
 #include <Message.h>
 #include <MessageQueue.h>
+#include <ObjectList.h>
 #include <Picture.h>
 #include <Point.h>
 #include <Polygon.h>
@@ -335,6 +336,7 @@ struct BView::LayoutData {
 		fLayoutInvalidationDisabled(0),
 		fLayout(NULL),
 		fLayoutContext(NULL),
+		fLayoutItems(5, false),
 		fLayoutValid(true),		// TODO: Rethink these initial values!
 		fMinMaxValid(true),		//
 		fLayoutInProgress(false),
@@ -375,6 +377,7 @@ struct BView::LayoutData {
 	int				fLayoutInvalidationDisabled;
 	BLayout*		fLayout;
 	BLayoutContext*	fLayoutContext;
+	BObjectList<BLayoutItem> fLayoutItems;
 	bool			fLayoutValid;
 	bool			fMinMaxValid;
 	bool			fLayoutInProgress;
@@ -5959,6 +5962,34 @@ BView::_PrintTree()
 // #pragma mark -
 
 
+BLayoutItem*
+BView::Private::LayoutItemAt(int32 index)
+{
+	return fView->fLayoutData->fLayoutItems.ItemAt(index);
+}
+
+
+int32
+BView::Private::CountLayoutItems()
+{
+	return fView->fLayoutData->fLayoutItems.CountItems();
+}
+
+
+void
+BView::Private::RegisterLayoutItem(BLayoutItem* item)
+{
+	fView->fLayoutData->fLayoutItems.AddItem(item);
+}
+
+
+void
+BView::Private::DeregisterLayoutItem(BLayoutItem* item)
+{
+	fView->fLayoutData->fLayoutItems.RemoveItem(item);
+}
+
+
 bool
 BView::Private::MinMaxValid()
 {