Merge from layout management branch.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18649 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/GroupLayoutBuilder.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2006, Haiku Inc.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef	_GROUP_LAYOUT_BUILDER_H
+#define	_GROUP_LAYOUT_BUILDER_H
+
+#include <GroupLayout.h>
+#include <GroupView.h>
+#include <List.h>
+
+class BGroupLayoutBuilder {
+public:
+								BGroupLayoutBuilder(
+									enum orientation orientation = B_HORIZONTAL,
+									float spacing = 0.0f);
+								BGroupLayoutBuilder(BGroupLayout* layout);
+								BGroupLayoutBuilder(BGroupView* view);
+
+			BGroupLayout*		RootLayout() const;
+			BGroupLayout*		TopLayout() const;
+			BGroupLayoutBuilder& GetTopLayout(BGroupLayout** _layout);
+			BGroupLayoutBuilder& GetTopView(BView** _view);
+
+			BGroupLayoutBuilder& Add(BView* view);
+			BGroupLayoutBuilder& Add(BView* view, float weight);
+			BGroupLayoutBuilder& Add(BLayoutItem* item);
+			BGroupLayoutBuilder& Add(BLayoutItem* item, float weight);
+
+			BGroupLayoutBuilder& AddGroup(enum orientation orientation,
+									float spacing = 0.0f, float weight = 1.0f);
+			BGroupLayoutBuilder& End();
+
+			BGroupLayoutBuilder& AddGlue(float weight = 1.0f);
+			BGroupLayoutBuilder& AddStrut(float size);
+
+								operator BGroupLayout*();
+								operator BView*();
+
+private:
+			bool				_PushLayout(BGroupLayout* layout);
+			void				_PopLayout();
+
+private:
+			BGroupLayout*		fRootLayout;
+			BList				fLayoutStack;
+};
+
+#endif	// _GROUP_LAYOUT_BUILDER_H