/*
 * Copyright 2006-2010, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef _LAYOUT_H
#define _LAYOUT_H


#include <Alignment.h>
#include <Archivable.h>
#include <LayoutItem.h>
#include <List.h>
#include <Size.h>


class BLayoutContext;
class BLayoutItem;
class BView;


class BLayout : public BLayoutItem {
public:
                                                                BLayout();
                                                                BLayout(BMessage* archive);
        virtual                                         ~BLayout();

                        BView*                          Owner() const;
                        BView*                          TargetView() const;
        virtual BView*                          View(); // from BLayoutItem

        // methods dealing with items
        virtual BLayoutItem*            AddView(BView* child);
        virtual BLayoutItem*            AddView(int32 index, BView* child);

        virtual bool                            AddItem(BLayoutItem* item);
        virtual bool                            AddItem(int32 index, BLayoutItem* item);

        virtual bool                            RemoveView(BView* child);
        virtual bool                            RemoveItem(BLayoutItem* item);
        virtual BLayoutItem*            RemoveItem(int32 index);

                        BLayoutItem*            ItemAt(int32 index) const;
                        int32                           CountItems() const;
                        int32                           IndexOfItem(const BLayoutItem* item) const;
                        int32                           IndexOfView(BView* child) const;

                        bool                            AncestorsVisible() const;

        // Layouting related methods

        virtual void                            InvalidateLayout(bool children = false);
        virtual void                            Relayout(bool immediate = false);
                                                                        // from BLayoutItem
                        void                            RequireLayout();
                        bool                            IsValid();
                        void                            EnableLayoutInvalidation();
                        void                            DisableLayoutInvalidation();

                        void                            LayoutItems(bool force = false);
                        BRect                           LayoutArea();
                        BLayoutContext*         LayoutContext() const;

        virtual status_t                        Archive(BMessage* into, bool deep = true) const;

        virtual status_t                        Perform(perform_code d, void* arg);

protected:
        // Archiving hook methods
        virtual status_t                        AllArchived(BMessage* archive) const;
        virtual status_t                        AllUnarchived(const BMessage* from);

        virtual status_t                        ItemArchived(BMessage* into, BLayoutItem* item,
                                                                        int32 index) const;
        virtual status_t                        ItemUnarchived(const BMessage* from,
                                                                        BLayoutItem* item, int32 index);
        // BLayout hook methods
        virtual bool                            ItemAdded(BLayoutItem* item, int32 atIndex);
        virtual void                            ItemRemoved(BLayoutItem* item, int32 fromIndex);
        virtual void                            LayoutInvalidated(bool children);
        virtual void                            DoLayout() = 0;
        virtual void                            OwnerChanged(BView* was);

        // BLayoutItem hook methods
        virtual void                            AttachedToLayout();
        virtual void                            DetachedFromLayout(BLayout* layout);
        virtual void                            AncestorVisibilityChanged(bool shown);

        // To be called by sub-classes in SetVisible().
                        void                            VisibilityChanged(bool show);
        // To be called when layout data is known to be good
                        void                            ResetLayoutInvalidation();

private:

        // FBC padding
        virtual void                            _ReservedLayout1();
        virtual void                            _ReservedLayout2();
        virtual void                            _ReservedLayout3();
        virtual void                            _ReservedLayout4();
        virtual void                            _ReservedLayout5();
        virtual void                            _ReservedLayout6();
        virtual void                            _ReservedLayout7();
        virtual void                            _ReservedLayout8();
        virtual void                            _ReservedLayout9();
        virtual void                            _ReservedLayout10();

        // forbidden methods
                                                                BLayout(const BLayout&);
                        void                            operator =(const BLayout&);

                        friend class BView;

                        void                            SetOwner(BView* owner);
                        void                            SetTarget(BView* target);

                        void                            _LayoutWithinContext(bool force,
                                                                        BLayoutContext* context);

                        uint32                          fState;
                        bool                            fAncestorsVisible;
                        int32                           fInvalidationDisabled;
                        BLayoutContext*         fContext;
                        BView*                          fOwner;
                        BView*                          fTarget;
                        BList                           fItems;
                        BList                           fNestedLayouts;

                        uint32                          _reserved[10];
};


#endif  //      _LAYOUT_H