px_list.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * Additional copyright for this file:
 * Copyright (C) 1999-2000 Revolution Software Ltd.
 * This code is based on source code created by Revolution Software,
 * used with permission.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ICB_PX_LIBRARY_LIST_TEMPLATE
#define ICB_PX_LIBRARY_LIST_TEMPLATE

namespace ICB {

template <class Type> class pxList {
protected:
    Type m_item;          // The item at this node
    pxList<Type> *m_tail; // The tail of the list

public:
    pxList() {
        m_tail = NULL; // Construct an empty list
    }
    ~pxList() {
        if (!IsEmpty())
            delete Tail(); // Destruct the array
    }

    Type &Head() {
        return m_item; // The lists' head
    }
    pxList<Type> *Tail() {
        return m_tail; // The lists' tail
    }
    bool IsEmpty() {
        return (m_tail == NULL); // Is the list empty ?
    }
    void Append(const Type &);        // Append item to the end of the list
    void Insert(const Type &);        // Inserts an item after the current item
    pxList<Type> *Find(const Type &); // Returns the list whose head == entry (NULL if not found)
    int32 Length();                     // Returns the length of the list
};

template <class Type> class rcSortedList {
protected:
    Type m_item;                // The item at this node
    rcSortedList<Type> *m_tail; // The tail of the list

public:
    rcSortedList() {
        m_tail = NULL; // Construct an empty list
    }
    ~rcSortedList() {
        if (!IsEmpty())
            delete Tail(); // Destruct the array
    }

public:
    Type &Head();               // The lists' head
    rcSortedList<Type> *Tail(); // The lists' tail
    bool IsEmpty();             // Is the list empty ?
    int32 Length();               // Returns the length of the list

public:
    rcSortedList<Type> *Insert(const Type &); // Inserts an item in the correct place
    rcSortedList<Type> *Find(const Type &);   // Returns the list whose head == entry (NULL if not found)
};

template <class Type> void pxList<Type>::Append(const Type &entry) {
    if (IsEmpty()) {
        m_item = entry;
        m_tail = new pxList<Type>;
    } else {
        Tail()->Append(entry);
    }
}

template <class Type> void pxList<Type>::Insert(const Type &entry) {
    pxList<Type> *newNode = new pxList<Type>;

    if (IsEmpty()) { // Is the list is empty, insert the item at the start of the list
        m_item = entry;
    } else { // Else put the item before this node
        newNode->m_item = m_item;
        m_item = entry;
        newNode->m_tail = Tail();
    }
    m_tail = newNode;
}

template <class Type> pxList<Type> *pxList<Type>::Find(const Type &entry) {
    // If this is the end of list marker we haven't found it
    if (IsEmpty())
        return NULL;

    if (Head() == entry)
        return this;

    return (Tail()->Find(entry));
}

template <class Type> int32 pxList<Type>::Length() {
    if (IsEmpty())
        return 0;

    return (1 + Tail()->Length());
}

template <class Type> Type &rcSortedList<Type>::Head() { // The lists' head
    return m_item;
}

template <class Type> rcSortedList<Type> *rcSortedList<Type>::Tail() { // The lists' tail
    return m_tail;
}

template <class Type> bool rcSortedList<Type>::IsEmpty() { // Is the list empty ?
    return (m_tail == NULL);
}

template <class Type> rcSortedList<Type> *rcSortedList<Type>::Insert(const Type &entry) {
    if (IsEmpty()) {
        // End of the list so add the entry here
        m_item = entry;
        m_tail = new rcSortedList<Type>;
        return this;
    }
    // The class being listed must have a '>' Operator defined
    else if (m_item > entry) {
        // The new item comes before the current one
        rcSortedList<Type> *newNode = new rcSortedList<Type>;
        newNode->m_tail = m_tail;
        newNode->m_item = m_item;
        m_item = entry;
        m_tail = newNode;
        return this;
    } else {
        // Keep going
        return Tail()->Insert(entry);
    }
}

template <class Type> rcSortedList<Type> *rcSortedList<Type>::Find(const Type &entry) {
    // If this is the end of list marker we haven't found it
    if (IsEmpty())
        return NULL;

    // this list is sorted, so we can stop when we have a higher value than entry
    if (Head() > entry)
        return NULL;

    if (Head() == entry)
        return this;

    return (Tail()->Find(entry));
}

template <class Type> int32 rcSortedList<Type>::Length() {
    if (IsEmpty())
        return 0;

    return (1 + Tail()->Length());
}

} // End of namespace ICB

#endif // #ifndef _PX_LIBRARY_LIST_TEMPLATE