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// history.cpp
//
// (C) 2001 Stefan Kebekus
// Distributed under the GPL
#include <config.h>
#include <kdebug.h>
#include "history.h"
HistoryItem::HistoryItem(Q_UINT32 p, Q_UINT32 y)
: page(p), ypos(y)
{
}
bool HistoryItem::operator== (const HistoryItem& item) const
{
return page == item.page && ypos == item.ypos;
}
History::History()
{
}
void History::add(Q_UINT32 page, Q_UINT32 ypos)
{
HistoryItem item(page, ypos);
if (historyList.empty())
{
currentItem = historyList.append(item);
}
else
{
// Don't add the same item several times in a row
if (item == *currentItem)
return;
currentItem++;
if (currentItem == historyList.end())
{
currentItem = historyList.append(item);
}
else
{
currentItem = historyList.insert(currentItem, item);
}
// Delete items starting after currentItem to the end of the list.
QValueList<HistoryItem>::iterator deleteItemsStart = currentItem;
deleteItemsStart++;
historyList.erase(deleteItemsStart, historyList.end());
if (historyList.size() > HISTORYLENGTH)
historyList.pop_front();
}
emit backItem(currentItem != historyList.begin());
emit forwardItem(false);
}
HistoryItem* History::forward()
{
if (historyList.empty() || currentItem == historyList.fromLast())
return 0;
currentItem++;
emit backItem(true);
emit forwardItem(currentItem != historyList.fromLast());
return &(*currentItem);
}
HistoryItem* History::back()
{
if (historyList.empty() || currentItem == historyList.begin())
return 0;
currentItem--;
emit backItem(currentItem != historyList.begin());
emit forwardItem(true);
return &(*currentItem);
}
void History::clear()
{
historyList.clear();
currentItem = historyList.begin();
emit backItem(false);
emit forwardItem(false);
}
#include "history.moc"
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