/*
 * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */
#ifndef LIST_SELECTION_MODEL_H
#define LIST_SELECTION_MODEL_H


#include <SupportDefs.h>

#include <Array.h>
#include <ObjectList.h>


class ListSelectionModel {
public:
                        class Listener;

public:
                                                                ListSelectionModel();
                                                                ListSelectionModel(
                                                                        const ListSelectionModel& other);
                                                                ~ListSelectionModel();

                        int32                           CountSelectedItems() const
                                                                        { return fSelectedItems.Count(); }
                        int32                           SelectedItemAt(int32 index) const;
                        bool                            IsItemSelected(int32 itemIndex) const;

                        void                            Clear();
                        bool                            SelectItem(int32 itemIndex,
                                                                        bool extendSelection);
                        bool                            SelectItems(int32 itemIndex, int32 count,
                                                                        bool extendSelection);
                        void                            DeselectItem(int32 itemIndex);
                        void                            DeselectItems(int32 itemIndex, int32 count);

                        void                            ItemsAdded(int32 itemIndex, int32 count);
                        void                            ItemsRemoved(int32 itemIndex, int32 count);

                        bool                            AddListener(Listener* listener);
                        void                            RemoveListener(Listener* listener);

                        ListSelectionModel&     operator=(const ListSelectionModel& other);

private:
                        typedef BObjectList<Listener> ListenerList;

private:
                        int32                           _FindItem(int32 itemIndex) const;
                        int32                           _CountSelectedItemsInRange(int32 index,
                                                                        int32 endItemIndex) const;

                        void                            _NotifyItemsSelected(int32 index, int32 count);
                        void                            _NotifyItemsDeselected(int32 index,
                                                                        int32 count);

private:
                        Array<int32>            fSelectedItems;
                        ListenerList            fListeners;
};


class ListSelectionModel::Listener {
public:
        virtual                                         ~Listener();

        virtual void                            ItemsSelected(ListSelectionModel* model,
                                                                        int32 index, int32 count);
        virtual void                            ItemsDeselected(ListSelectionModel* model,
                                                                        int32 index, int32 count);
};


inline bool
ListSelectionModel::IsItemSelected(int32 itemIndex) const
{
        int32 index = _FindItem(itemIndex);
        return index < fSelectedItems.Count() && fSelectedItems[index] == itemIndex;
}


inline int32
ListSelectionModel::SelectedItemAt(int32 index) const
{
        return index >= 0 && index < fSelectedItems.Count()
                ? fSelectedItems[index] : -1;
}


inline bool
ListSelectionModel::SelectItem(int32 itemIndex, bool extendSelection)
{
        return SelectItems(itemIndex, 1, extendSelection);
}


inline void
ListSelectionModel::DeselectItem(int32 itemIndex)
{
        DeselectItems(itemIndex, 1);
}


#endif  // LIST_SELECTION_MODEL_H