stack.cpp

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// $Id: stack.cpp 1282 2006-06-09 09:46:49Z alex $
/* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE
================================XARAHEADERSTART===========================
 
               Xara LX, a vector drawing and manipulation program.
                    Copyright (C) 1993-2006 Xara Group Ltd.
       Copyright on certain contributions may be held in joint with their
              respective authors. See AUTHORS file for details.

LICENSE TO USE AND MODIFY SOFTWARE
----------------------------------

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=================================XARAHEADEREND============================
 */
/*
//*/

// Implementation of the Stack and MarkedStack classes 

#include "camtypes.h" 
#include "stack.h"
//#include "errors.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "ensure.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "listitem.h" - in camtypes.h [AUTOMATICALLY REMOVED]

DECLARE_SOURCE("$Revision: 1282 $");

// Declare smart memory handling in Debug builds
#define new CAM_DEBUG_NEW

/********************************************************************************************

>   Stack::Stack()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Stack constructor
    Errors:     -
    SeeAlso:    -

********************************************************************************************/


Stack::Stack()
{
}

/********************************************************************************************

>   Stack::~Stack()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Stack destructor. The items on the stack are not deleted
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

Stack::~Stack()
{
    
}

/********************************************************************************************

>   void Stack::Push(ListItem* Item)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Pushes Item onto the stack 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

void Stack::Push(ListItem* Item)
{
    stack.AddTail(Item); // Add the item to the top of the stack 
}

/********************************************************************************************

>   ListItem* Stack::Pop(void)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    The top item on the stack, or NULL if the stack is empty 
    Purpose:    Removes the item from the top of the stack, and returns it 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

ListItem* Stack::Pop(void)
{   
    return (stack.RemoveTail()); 
}

/********************************************************************************************

>   ListItem* Stack::GetTop(void)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    14/2/94
    Inputs:     -
    Outputs:    -
    Returns:    The item at the top of the stack
    Purpose:    Allows you to find out what item is on the top of the stack (the item is not
                removed). 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

ListItem* Stack::GetTop(void)
{
    return (stack.GetTail()); 
}


/********************************************************************************************

>   void Stack::DeleteAll()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Removes and deletes all items on the stack 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

void Stack::DeleteAll()
{
    stack.DeleteAll(); // Call the list's DeleteAll method 
}

/********************************************************************************************

>   INT32 Stack::Size()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    The number of items on the stack 
    Purpose:    For finding the size of the stack 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

INT32 Stack::Size()
{
    return stack.GetCount(); 
}

// ------------------------------------------------------------------------------------------
// MarkedStack methods 

/********************************************************************************************

>   MarkedStack::MarkedStack()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    MarkedStack constructor 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

MarkedStack::MarkedStack()
{
}

/********************************************************************************************

>   MarkedStack::~MarkedStack()

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    MarkedStack destructor. The items on the stack are not deleted
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

MarkedStack::~MarkedStack()
{
}

/********************************************************************************************

>   MarkedStack::Push(ListItem* Item)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Pushes Item onto the stack 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/


void MarkedStack::Push(ListItem* Item)
{
    AddTail(Item); // Add the item to the top of the stack 
}

/********************************************************************************************

>   ListItem* MarkedStack::Pop(void)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    The top item on the stack, or NULL if the stack is empty 
    Purpose:    Removes the item from the top of the stack, and returns it 
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

ListItem* MarkedStack::Pop(void)
{   
    return (RemoveTail()); 
}


/********************************************************************************************

>   BOOL MarkedStack::Mark(void)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    TRUE if we could create Mark, FALSE if we are out of memory 

    Purpose:    Marks the current Top of the stack so that we can easily return to the 
                same state by calling Release(). 

    Errors:     ERRORIF is called if we are out of memory 
    SeeAlso:    MarkedStack::Release()

********************************************************************************************/

BOOL MarkedStack::Mark(void)
{           
    // Firstly create a mark                                                    
    ListItemPtrItem* pMark = new ListItemPtrItem(); 
    // Return with an error if we could not create the mark
    if (pMark == NULL)
        return FALSE; 
    pMark->pListItem = GetTail();   // This will be NULL if the list is empty 

    // Push the mark onto the MarkStack
    MarkStack.Push(pMark); 
    return TRUE; // Success
}   

/********************************************************************************************

>   void MarkedStack::Release(void)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Pops and then deletes items from the stack until we find the first mark. 
                If there are no marks then all items on the stack are removed and deleted
    Errors:     -
    SeeAlso:    MarkedStack::Mark

********************************************************************************************/

         
void MarkedStack::Release(void)
{
    // Find the mark to stop at 
    ListItemPtrItem* MarkRec = (ListItemPtrItem*)MarkStack.Pop();
    ListItem* Mark; 
    if (MarkRec == NULL)                        // There are no marks to find 
    {
        Mark = NULL; 
    } else 
    {
        Mark = MarkRec->pListItem; 
    }  
    ListItem* TopOfStack = GetTail(); 
    ListItem* AsGoodAsDead; 

    while (TopOfStack != Mark)          // Loop until we find Mark
    {
        ENSURE(TopOfStack != NULL, "A Mark could not be found in the Marked stack"); 
        TopOfStack = GetPrev(TopOfStack);
        AsGoodAsDead = RemoveTail();
        delete AsGoodAsDead; 
    }
    if (MarkRec != NULL)
    {
        delete (MarkRec); // Restored State to that pointed to by Mark, so delete it 
    }
} 

/********************************************************************************************

>   void MarkedStack::DeleteAll()   

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    8/2/94
    Inputs:     -
    Outputs:    -
    Returns:    -
    Purpose:    Deletes all marks and elements in the MarkedStack
    Errors:     -
    SeeAlso:    -

********************************************************************************************/

void MarkedStack::DeleteAll()
{
    ListItem* TopOfStack;
    TopOfStack = GetTail(); 
    while (TopOfStack != NULL)   // loop while the stack is not empty 
    {
        Release(); // Deletes mark and all items before the mark        
        TopOfStack = GetTail(); 
    }   
    // Make sure there are no marks left
    ENSURE(MarkStack.Pop() == NULL, "All marks have not been deleted from the MarkedStack"); 
}   

---