michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef TRANSFRMX_LIST_H
michael@0: #define TRANSFRMX_LIST_H
michael@0: 
michael@0: #include "txCore.h"
michael@0: 
michael@0: class txListIterator;
michael@0: 
michael@0: /**
michael@0:  * Represents an ordered list of Object pointers. Modeled after a Java 2 List.
michael@0: **/
michael@0: class txList : public txObject {
michael@0: 
michael@0: friend class txListIterator;
michael@0: 
michael@0: public:
michael@0: 
michael@0:     /**
michael@0:     * Creates an empty txList
michael@0:     **/
michael@0:     txList();
michael@0: 
michael@0:     /**
michael@0:      * txList destructor, object references will not be deleted.
michael@0:     **/
michael@0:     ~txList();
michael@0: 
michael@0:     /**
michael@0:      * Returns the number of items in this txList
michael@0:     **/
michael@0:     int32_t getLength();
michael@0: 
michael@0:     /**
michael@0:      * Returns true if there are no items in this txList
michael@0:      */
michael@0:     inline bool isEmpty()
michael@0:     {
michael@0:         return itemCount == 0;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Adds the given Object to the list
michael@0:     **/
michael@0:     nsresult add(void* objPtr);
michael@0: 
michael@0:     /*
michael@0:      * Removes all the objects from the list
michael@0:      */
michael@0:     void clear();
michael@0: 
michael@0: protected:
michael@0: 
michael@0:     struct ListItem {
michael@0:         ListItem* nextItem;
michael@0:         ListItem* prevItem;
michael@0:         void* objPtr;
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      * Removes the given ListItem pointer from the list
michael@0:     **/
michael@0:     ListItem* remove(ListItem* sItem);
michael@0: 
michael@0: private:
michael@0:       txList(const txList& aOther); // not implemented
michael@0: 
michael@0:       ListItem* firstItem;
michael@0:       ListItem* lastItem;
michael@0:       int32_t itemCount;
michael@0: 
michael@0:       nsresult insertAfter(void* objPtr, ListItem* sItem);
michael@0:       nsresult insertBefore(void* objPtr, ListItem* sItem);
michael@0: };
michael@0: 
michael@0: 
michael@0: 
michael@0: /**
michael@0:  * An Iterator for the txList Class
michael@0: **/
michael@0: class txListIterator {
michael@0: 
michael@0: public:
michael@0:     /**
michael@0:      * Creates a new txListIterator for the given txList
michael@0:      * @param list, the txList to create an Iterator for
michael@0:     **/
michael@0:     txListIterator(txList* list);
michael@0: 
michael@0:     /**
michael@0:      * Adds the Object pointer to the txList pointed to by this txListIterator.
michael@0:      * The Object pointer is inserted as the next item in the txList
michael@0:      * based on the current position within the txList
michael@0:      * @param objPtr the Object pointer to add to the list
michael@0:     **/
michael@0:     nsresult addAfter(void* objPtr);
michael@0: 
michael@0:     /**
michael@0:      * Adds the Object pointer to the txList pointed to by this txListIterator.
michael@0:      * The Object pointer is inserted as the previous item in the txList
michael@0:      * based on the current position within the txList
michael@0:      * @param objPtr the Object pointer to add to the list
michael@0:     **/
michael@0:     nsresult addBefore(void* objPtr);
michael@0: 
michael@0:     /**
michael@0:      * Returns true if a successful call to the next() method can be made
michael@0:      * @return true if a successful call to the next() method can be made,
michael@0:      * otherwise false
michael@0:     **/
michael@0:     bool  hasNext();
michael@0: 
michael@0:     /**
michael@0:      * Returns the next Object pointer from the list
michael@0:     **/
michael@0:     void* next();
michael@0: 
michael@0:     /**
michael@0:      * Returns the previous Object pointer from the list
michael@0:     **/
michael@0:     void* previous();
michael@0:     
michael@0:     /**
michael@0:      * Returns the current Object
michael@0:     **/
michael@0:     void* current();
michael@0:     
michael@0:     /**
michael@0:      * Removes the Object last returned by the next() or previous() methods;
michael@0:      * @return the removed Object pointer
michael@0:     **/
michael@0:     void* remove();
michael@0: 
michael@0:     /**
michael@0:      * Resets the current location within the txList to the beginning of the txList
michael@0:     **/
michael@0:     void reset();
michael@0: 
michael@0:     /**
michael@0:      * Resets the current location within the txList to the end of the txList
michael@0:     **/
michael@0:     void resetToEnd();
michael@0: 
michael@0: private:
michael@0: 
michael@0:    //-- points to the current list item
michael@0:    txList::ListItem* currentItem;
michael@0: 
michael@0:    //-- points to the list to iterator over
michael@0:    txList* list;
michael@0: 
michael@0:    //-- we've moved off the end of the list
michael@0:    bool atEndOfList;
michael@0: };
michael@0: 
michael@0: typedef txList List;
michael@0: 
michael@0: #endif