1 files changed, 91 insertions, 0 deletions
diff --git a/kviewshell/history.cpp b/kviewshell/history.cpp
new file mode 100644
index 00000000..a8765220
--- /dev/null
+++ b/kviewshell/history.cpp
@@ -0,0 +1,91 @@
+// 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"