4 files changed, 31 insertions, 3 deletions

diff --git a/libkcal/incidence.cpp b/libkcal/incidence.cpp
index 11f7ecc..e4bcc5e 100644
--- a/libkcal/incidence.cpp
+++ b/libkcal/incidence.cpp
@@ -280,9 +280,29 @@ void Incidence::setReadOnly( bool readOnly )
 {
   IncidenceBase::setReadOnly( readOnly );
   recurrence()->setRecurReadOnly( readOnly);
 }
-
+void Incidence::setLastModifiedSubInvalid()
+{
+    mLastModifiedSub = QDateTime();
+    if ( mRelatedTo )
+        mRelatedTo->setLastModifiedSubInvalid();
+}
+QDateTime Incidence::lastModifiedSub()
+{
+    if ( !mRelations.count() )
+        return lastModified();
+    if ( mLastModifiedSub.isValid() )
+        return mLastModifiedSub;
+    mLastModifiedSub = lastModified();
+    Incidence * inc;
+    QPtrList<Incidence> Relations = relations();
+    for (inc=Relations.first();inc;inc=Relations.next()) {
+        if ( inc->lastModifiedSub() > mLastModifiedSub )
+            mLastModifiedSub = inc->lastModifiedSub();
+    }
+    return mLastModifiedSub;
+}
 void Incidence::setCreated(QDateTime created)
 {
   if (mReadOnly) return;
   mCreated = getEvenTime(created);
@@ -467,19 +487,19 @@ void Incidence::addRelationsToList(QPtrList<Incidence> *rel)
 }
 
 void Incidence::addRelation(Incidence *event)
 {
+    setLastModifiedSubInvalid();
   if( mRelations.findRef( event ) == -1 ) {
     mRelations.append(event);
     //updated();
   }
 }
 
 void Incidence::removeRelation(Incidence *event)
 {
-  
+    setLastModifiedSubInvalid();
   mRelations.removeRef(event); 
- 
 //  if (event->getRelatedTo() == this) event->setRelatedTo(0);
 }
 
 bool Incidence::recursOn(const QDate &qd) const
diff --git a/libkcal/incidence.h b/libkcal/incidence.h
index c88ba2f..d4af9f0 100644
--- a/libkcal/incidence.h
+++ b/libkcal/incidence.h
@@ -276,8 +276,10 @@ class Incidence : public IncidenceBase
     QDateTime dtStart() const;
     bool isHoliday() const;
     bool isBirthday() const;
     bool isAnniversary() const;
+    QDateTime lastModifiedSub();
+    void setLastModifiedSubInvalid();
     
 
 protected:
     QPtrList<Alarm> mAlarms;
@@ -291,8 +293,9 @@ protected:
     bool mCancelled;
 
     // base components of jounal, event and todo
     QDateTime mCreated;
+    QDateTime mLastModifiedSub;
     QString mDescription;
     QString mSummary;
     QStringList mCategories;
     Incidence *mRelatedTo;
diff --git a/libkcal/incidencebase.cpp b/libkcal/incidencebase.cpp
index 1a19f3e..022dead 100644
--- a/libkcal/incidencebase.cpp
+++ b/libkcal/incidencebase.cpp
@@ -190,15 +190,19 @@ void IncidenceBase::setUid(const QString &uid)
 QString IncidenceBase::uid() const
 {
   return mUid;
 }
+void IncidenceBase::setLastModifiedSubInvalid()
+{
 
+}
 void IncidenceBase::setLastModified(const QDateTime &lm)
 {
     if ( blockLastModified ) return;
   // DON'T! updated() because we call this from
   // Calendar::updateEvent().
   mLastModified = getEvenTime(lm);
+  setLastModifiedSubInvalid();
   //qDebug("IncidenceBase::setLastModified %s ",lm.toString().latin1());
 }
 
 QDateTime IncidenceBase::lastModified() const
diff --git a/libkcal/incidencebase.h b/libkcal/incidencebase.h
index bed73db..665c1f6 100644
--- a/libkcal/incidencebase.h
+++ b/libkcal/incidencebase.h
@@ -148,8 +148,9 @@ class IncidenceBase : public CustomProperties
     void setAlarmEnabled( bool );
     bool alarmEnabled() const;
     bool isTagged() const;
     void setTagged( bool );
+    virtual void setLastModifiedSubInvalid();
   protected:
     bool blockLastModified;
     bool mIsTagged;
     QDateTime mDtStart;