smarter faster conflict search

4 files changed, 71 insertions, 23 deletions

diff --git a/bin/kdepim/WhatsNew.txt b/bin/kdepim/WhatsNew.txt
index 1f06f1e..c0d63e5 100644
--- a/bin/kdepim/WhatsNew.txt
+++ b/bin/kdepim/WhatsNew.txt
@@ -1,71 +1,72 @@
 Info about the changes in new versions of KDE-Pim/Pi
 
 ********** VERSION 2.1.16 ************
 
 Fixed a problem with the menu bar in KO/Pi and using the "Menu" hardware key on the Zaurus.
 Added columns for datetime in todo view: Last modified, created and last modified subtodo
 Fixed a bug in agenda view displaying recurring multiday events which are longer than two days.
+Made conflict detection up to 4 times faster.
 
 ********** VERSION 2.1.15 ************
 
 Fixed two layout problems on the Z:
 Made the with of the newly added buttons on the Quick-Todo smaller.
 Made listweek layout in 2 columns on the Z760 in portait screen and full menubar visible.
 
 
 ********** VERSION 2.1.14 ************
 
 Added some buttons to the KO/Pi Quick-todo line to make it possible to quickly access some todo view layout settings like display all flat/open/close and hide/show running/done.
 Added a button to add a subtodo quickly.
 
 Added a possibility to search for conflicting events. (In the Action menu. Keyboard shortcut "q", shift+q or ctrl +q ).
 Added an option to change the layout of the list week to column mode.
 
 Fixed some usability problems in pi-sync mode by adding some progress information about file transfer.
 
 Fixed pi-sync problems with the new multi calendar feature.
 Now pi-sync behaviour should be:
 1) Local sends file request ( as usual )
 2) Remote sends file which contains data of all enabled ( the calendar where the "eye" column is checked ) calendars.
 3) Local syncs with data, adds new entries to default calendar and sends file back ( as usual ).
    If the data which local receives contains entries which are on disabled calendars on local this entries are updated and not added as duplicates to the default calendar.
 4) Remote updates the data and adds new entries to default calendar. Readonly entries are not changed on remote.
    If the data which remote receives contains entries which are on disabled calendars on remote this entries are updated and not added as duplicates to the default calendar.
 
 Summary: 
 No new item ( new created after the last sync ) in a disabled calendar is propagated to the sync partner. Readonly items are synced and added/changed on the sync partner if it is not readonly on the sync partner.
 If you have different calendars on remote and local and some of them disabled you may get some "strange" bahaviour.
 Well, the syncing has become quite complicated ... you should have no problems if you enable all calendars. 
 
 ********** VERSION 2.1.13 ************
 
 Fixed a problem in KA/Pi search.
 Fixed some minor problems in KO/Pi.
 Added calendar selection possibility to the todo view popup and to the event/todo/journal editor.
 
 Fixed memory usage problems in KA/Pi:
 When loading data KA/Pi did load the file data twice.
 Example:
   A 600k file did consume 1200k memory during loading process.
   This is fixed, it does now consume only  600k during loading process.
 When saving data KA/Pi did consume a lot of memory for the data parsing during the save process.
 This is fixed.
 Example:
   Before saving a 600k file KA/Pi did consume 21.7 Meg of Ram.
   When saving  KA/Pi did consume 28.6 Meg of Ram. That causes a crash on the Zaurus because there was no memeory left in the system.
   Now  KA/Pi is consuming on saving the same data 22.0 Meg of Ram during the save process. 
 Note: The memory usage of KA/Pi after the data is loaded/saved has not changed.
 The saving of data may be a bit slower now.
 
 Fixed memory usage problems in KO/Pi:
 When KO/Pi did save the data to file, it did not release the used buffers after saving.
 The used buffer was released after saving the next time, but there was new buffer space allocated again on that save operation.
 This is fixed.
 Example:
   When saving a 400k file KO/Pi do now use 400k less memory now.
 
 Optimized memory usage in KO/Pi Agenda view:
 KO/Pi is storing some paint information in extra buffers for faster repainting of the agenda view.
 These buffers were not made smaller (i.e. downsized)  because of performance reasons.
 The handling of these buffers are now much smarter:
 Two (of six) buffers are removed completely.
diff --git a/korganizer/calendarview.cpp b/korganizer/calendarview.cpp
index a9e402e..427d71b 100644
--- a/korganizer/calendarview.cpp
+++ b/korganizer/calendarview.cpp
@@ -598,197 +598,214 @@ void CalendarView::init()
   
 
 
 
 
     connect(QApplication::clipboard(),SIGNAL(dataChanged()),
             SLOT(checkClipboard()));
     connect( mTodoList,SIGNAL( incidenceSelected( Incidence * ) ),
              SLOT( processTodoListSelection( Incidence * ) ) );
     connect(mTodoList,SIGNAL(isModified(bool)),SLOT(setModified(bool)));
 
     // kdDebug() << "CalendarView::CalendarView() done" << endl; 
 
     mDateFrame = new QVBox(0,0,WType_Popup);
     //mDateFrame->setFrameStyle(QFrame::PopupPanel | QFrame::Raised);
     mDateFrame->setFrameStyle( QFrame::WinPanel |QFrame::Raised );
     mDateFrame->setLineWidth(3);
     mDateFrame->hide(); 
     mDateFrame->setCaption( i18n( "Pick a date to display"));
     mDatePicker = new KDatePicker ( mDateFrame , QDate::currentDate() );
  
     connect(mDatePicker,SIGNAL(dateSelected(QDate)),SLOT(slotSelectPickerDate(QDate)));
  
     mEventEditor = mDialogManager->getEventEditor();  
     mTodoEditor = mDialogManager->getTodoEditor();  
    
     mFlagEditDescription = false; 
 
     mSuspendTimer = new QTimer( this );
     mAlarmTimer = new QTimer( this );
     mRecheckAlarmTimer = new QTimer( this );
     connect( mRecheckAlarmTimer, SIGNAL(  timeout ()  ), SLOT( recheckTimerAlarm() ) );
     connect( mSuspendTimer, SIGNAL(  timeout ()  ), SLOT( suspendAlarm() ) );
     connect( mAlarmTimer, SIGNAL(  timeout ()  ), SLOT( timerAlarm() ) );
     mAlarmDialog = new AlarmDialog( this );
     connect( mAlarmDialog, SIGNAL( addAlarm(const QDateTime &, const QString &  ) ), SLOT( addSuspendAlarm(const QDateTime &, const QString &  ) ) );
     mAlarmDialog->setServerNotification( false );
     mAlarmDialog->setSuspendTime( KOPrefs::instance()->mAlarmSuspendTime );
 
 
 #ifndef DESKTOP_VERSION
 //US listen for arriving address resultsets
   connect(ExternalAppHandler::instance(), SIGNAL(receivedBirthdayListEvent(const QString&, const QStringList&, const QStringList&, const QStringList&, const QStringList&, const QStringList&, const QStringList&)),
           this, SLOT(insertBirthdays(const QString&, const QStringList&, const QStringList&, const QStringList&, const QStringList&, const QStringList&, const QStringList&)));
 #endif
   mDateNavigator->setCalendar( mCalendar );
 }
 
 
 CalendarView::~CalendarView()
 {
     // kdDebug() << "~CalendarView()" << endl;
     //qDebug("CalendarView::~CalendarView() ");
     delete mDialogManager;
     delete mViewManager;
     delete mStorage;
     delete mDateFrame ;
     delete mEventViewerDialog;
     //kdDebug() << "~CalendarView() done" << endl;
 }
 
 
 void CalendarView::nextConflict( bool all, bool allday )
 {
-    
+    static bool block = false;
+    if ( block ) return;
+    block = true;
     QPtrList<Event> testlist = mCalendar->events();
     Event * test = testlist.first();
     while ( test ) {
         test->setTagged( false );
         test = testlist.next();
     }
     QTime st ( 0,0,0);
     if ( mViewManager->currentView() == mViewManager->agendaView()  )
         st = mViewManager->agendaView()->agenda()->getEndTime();
     //qDebug("time %s ", st.toString().latin1());
     QDateTime startDT = QDateTime (mNavigator->selectedDates().first(),st);
     QDateTime conflict;
     QDateTime retVal;
     bool found = false;
     Event * cE = 0;
     Event * cE2 = 0;
     QPtrList<Event> testlist2 = testlist;
     test = testlist.first();
     bool skip = false;
     topLevelWidget()->setCaption( i18n("Checking conflicts ... please wait") );
+    //QTime tm;
+    //tm.start();
     while ( test ) {
         qApp->processEvents();
         skip = false;
         if ( !all ) skip = ( allday != test->doesFloat() );
         if ( !skip ) {
+            if ( found )
+                skip =  !test->matchTime( &startDT, &conflict );
+            else 
+               skip =  !test->matchTime( &startDT, 0 ); 
+        }
+        if ( !skip ) {
             Event * test2 = testlist2.first();
             while ( test2 ) { 
-                skip = false;
-                if ( !all ) skip = ( allday != test2->doesFloat() );
+                skip = test2->isTagged();
+                if ( !skip  && !all ) skip = ( allday != test2->doesFloat() );
+                if ( !skip ) {
+                    if ( found )
+                        skip =  !test2->matchTime( &startDT, &conflict );
+                    else 
+                        skip =  !test2->matchTime( &startDT, 0 ); 
+                }
                 if ( !skip ) {
-                    if ( !test2->isTagged() ) {
-                        if ( test->isOverlapping ( test2, &retVal, &startDT ) ) {
-                            //qDebug("overlap ");
-                            if ( ! found ) {
-                                if ( retVal >= startDT ) {
-                                    conflict = retVal; 
-                                    cE = test;
-                                    cE2 = test2;
-                                    found = true;
-                                }
-                            } else {
-                                if ( retVal >= startDT && retVal < conflict ) {
-                                    conflict = retVal; 
-                                    cE = test;
-                                    cE2 = test2;
-                                }
+                    if ( test->isOverlapping ( test2, &retVal, &startDT ) ) {
+                        //qDebug("overlap ");
+                        if ( ! found ) {
+                            if ( retVal >= startDT ) {
+                                conflict = retVal; 
+                                cE = test;
+                                cE2 = test2;
+                                found = true;
+                            }
+                        } else {
+                            if ( retVal >= startDT && retVal < conflict ) {
+                                conflict = retVal; 
+                                cE = test;
+                                cE2 = test2;
                             }
                         }
                     }
                 }
                 test2 = testlist2.next();
             }
         }
         test->setTagged( true );
         test = testlist.next();
     }
+    //qDebug("Search time : %d", tm.elapsed());
     if ( found ) {
         if ( mViewManager->currentView() != mViewManager->agendaView() || mNavigator->selectedDates().count() > 1 )
             mViewManager->showDayView();
         mNavigator->slotDaySelect( conflict.date() );
         int hour = conflict.time().hour();
         mViewManager->agendaView()->setStartHour( hour  );
         topLevelWidget()->setCaption( i18n("Conflict %1 <-> %2"). arg( cE->summary().left( 20 ) ).arg( cE2->summary().left( 20 ) ) );
+        block = false;
         return;
     }
 
     topLevelWidget()->setCaption( i18n("No conflict found") );
     qDebug("No conflict found ");
+    block = false;
     return;
 }
 
 void CalendarView::conflictAll()
 {
     nextConflict ( true, true );
 }
 void CalendarView::conflictAllday()
 {
     nextConflict ( false, true );
 }
 void CalendarView::conflictNotAll()
 {
     nextConflict ( false, false );
 }
 
 void CalendarView::setCalReadOnly( int id, bool readO )
 {
     if ( readO ) {
         emit save();
     }
     mCalendar->setReadOnly( id, readO );   
 }
 void CalendarView::setScrollBarStep(int val )
 {
 #ifdef DESKTOP_VERSION
     mDateScrollBar->setLineStep ( val );
 #endif
 }
 void CalendarView::scrollBarValue(int val )
 {
 #ifdef DESKTOP_VERSION
     if ( QApplication::desktop()->width() < 800 ) return;
     static bool block = false;
     if ( block ) return;
     block = true;
     int count = mNavigator->selectedDates().count();
     int day = mNavigator->selectedDates().first().dayOfYear();
     int  stepdays = val;
     if ( mDateScrollBar->lineStep () <= count ) {
         //val = val/mDateScrollBar->lineStep ()*mDateScrollBar->lineStep();
         //qDebug("VAL %d ",val );
         stepdays = (val-day)/mDateScrollBar->lineStep ()*mDateScrollBar->lineStep();
         stepdays = day+stepdays;
         if ( stepdays < 0 ) stepdays = 0;
     }
     if ( stepdays == day ) {
         block = false;
         return;
     }
     int year =  mNavigator->selectedDates().first().year();
     QDate d ( year,1,1 );
     mNavigator->selectDates( d.addDays(  stepdays-1) , count );
     block = false;
 #endif
 
 }
 void CalendarView::updateView(const QDate &start, const QDate &end)
 {
 #ifdef DESKTOP_VERSION
     if ( ! mDateScrollBar->draggingSlider () ) {
         int dof = start.dayOfYear();
         //qDebug("dof %d day %d val %d ", dof, start.dayOfYear(),mDateScrollBar->value() );
         if (  dof != mDateScrollBar->value() ) {
@@ -2711,139 +2728,148 @@ void CalendarView::eventDeleted()
 void CalendarView::changeTodoDisplay(Todo *which, int action)
 {
     changeIncidenceDisplay((Incidence *)which,  action);
     mDateNavigator->updateView(); //LR
     //mDialogManager->updateSearchDialog();
 
     if (which) {
         mViewManager->updateWNview();
         //mTodoList->updateView();
     }
    
 }
 
 void CalendarView::changeIncidenceDisplay(Incidence *which, int action)
 {
     updateUnmanagedViews();
     //qDebug(" CalendarView::changeIncidenceDisplay++++++++++++++++++++++++++  %d  %d ",which, action );
     if ( action == KOGlobals::EVENTDELETED ) { //delete
         mCalendar->checkAlarmForIncidence( 0, true );
         if ( mEventViewerDialog )
             mEventViewerDialog->hide();
     } 
     else
         mCalendar->checkAlarmForIncidence( which , false );
 }
 
 // most of the changeEventDisplays() right now just call the view's
 // total update mode, but they SHOULD be recoded to be more refresh-efficient.
 void CalendarView::changeEventDisplay(Event *which, int action)
 {
     //  kdDebug() << "CalendarView::changeEventDisplay" << endl;
     changeIncidenceDisplay((Incidence *)which,  action);
     static bool clearallviews = false;
     if ( KOPrefs::instance()->mGlobalUpdateDisabled ) {
         if ( clearallviews ) {
             clearAllViews();
             clearallviews = false;
         }
         return;
     }
     clearallviews = true;
     mDateNavigator->updateView();
     //mDialogManager->updateSearchDialog();
     if (which) {
         // If there is an event view visible update the display
         mViewManager->currentView()->changeEventDisplay(which,action);
         // TODO: check, if update needed
         //    if (which->getTodoStatus()) {
         mTodoList->updateView();
         if (  action != KOGlobals::EVENTDELETED ) {
             mConflictingEvent = which ;
             QTimer::singleShot( 1000, this, SLOT ( checkConflictForEvent() ) );
         }
         //    }
     } else {
         mViewManager->currentView()->updateView();
     }
 }
 void CalendarView::checkConflictForEvent()
 {
 
     if (!KOPrefs::instance()->mConfirm)
         return;
     if ( ! mConflictingEvent ) return;
-    topLevelWidget()->setCaption( i18n("Checking conflicts ... please wait") );
+    QDateTime current = QDateTime::currentDateTime();
+    if ( ! mConflictingEvent->matchTime( &current, 0 ) ) {
+        mConflictingEvent = 0;
+        return;
+    }
     QPtrList<Event> testlist = mCalendar->events();
     Event * test = testlist.first();
     QDateTime conflict;
     QDateTime retVal;
     bool found = false;
     Event * cE = 0;
-    QDateTime current = QDateTime::currentDateTime();
+    topLevelWidget()->setCaption( i18n("Checking conflicts ... please wait") );
     while ( test ) {
-        qApp->processEvents();
-        if ( !test->doesFloat() ) {
+        qApp->processEvents(); 
+        bool skip = false;
+        if ( found )
+            skip =  !test->matchTime( &current, &conflict );
+        else 
+            skip =  !test->matchTime( &current, 0 ); 
+        if ( !skip && !test->doesFloat() ) {
             if ( mConflictingEvent->isOverlapping ( test, &retVal, &current ) ) {
                 if ( ! found ) {
                     conflict = retVal; 
                     cE = test;
                 } else {
                     if ( retVal < conflict ) {
                         conflict = retVal; 
                         cE = test;
                     }
                 }
                 found = true;
             }
         }
         test = testlist.next();
     }
     if ( found ) {
         QString mess = i18n("The event\n%1\nconflicts with event\n%2\nat date\n%3.\n").arg(KGlobal::formatMessage ( mConflictingEvent->summary(),0 ) ).arg( KGlobal::formatMessage ( cE->summary(),0 )).arg(KGlobal::locale()->formatDate(conflict.date()) ) ;
         qApp->processEvents();
         int km = KMessageBox::warningContinueCancel(this,mess,
                                                     i18n("KO/Pi Conflict delected"),i18n("Show date"),i18n("No problem!"));
         if ( km != KMessageBox::Continue )
             return;
 
         if ( mViewManager->currentView() != mViewManager->agendaView() || mNavigator->selectedDates().count() > 1 )
             mViewManager->showDayView();
         mNavigator->slotDaySelect( conflict.date() );
         int hour = conflict.time().hour();
         mViewManager->agendaView()->setStartHour( hour  );
         topLevelWidget()->setCaption( i18n("Conflict %1 <-> %2"). arg( mConflictingEvent->summary().left( 20 ) ).arg( cE->summary().left( 20 ) ) );
     } else
         topLevelWidget()->setCaption( i18n("No conflict found") );
     mConflictingEvent = 0;
     return;
    
 }
 
 void CalendarView::updateTodoViews()
 {
     mTodoList->updateView();
     mViewManager->currentView()->updateView();
  
 }
 
 
 
 void CalendarView::clearAllViews()
 {
     mTodoList->clearList();
     mViewManager->clearAllViews();
     SearchDialog * sd = mDialogManager->getSearchDialog();
     if ( sd ) {
         KOListView* kol = sd->listview();
         if ( kol )
             kol->clearList();
     }
 }
 void CalendarView::updateView()
 {
     static bool clearallviews = false;
     if ( KOPrefs::instance()->mGlobalUpdateDisabled ) {
         if ( clearallviews ) {
             clearAllViews();
             clearallviews = false;
         }
diff --git a/libkcal/event.cpp b/libkcal/event.cpp
index 5285559..ad66639 100644
--- a/libkcal/event.cpp
+++ b/libkcal/event.cpp
@@ -110,128 +110,148 @@ void Event::setDtEnd(const QDateTime &dtEnd)
   mDtEnd = getEvenTime( dtEnd );
 
   setHasEndDate(true);
   setHasDuration(false);
 
   updated();
 }
 
 QDateTime Event::dtEnd() const
 {
   if (hasEndDate()) return mDtEnd;
   if (hasDuration()) return dtStart().addSecs(duration());
 
   return dtStart();
 }
 
 QString Event::dtEndTimeStr() const
 {
   return KGlobal::locale()->formatTime(mDtEnd.time());
 }
 
 QString Event::dtEndDateStr(bool shortfmt) const
 {
   return KGlobal::locale()->formatDate(mDtEnd.date(),shortfmt);
 }
 
 QString Event::dtEndStr(bool shortfmt) const
 {
   return KGlobal::locale()->formatDateTime(mDtEnd, shortfmt);
 }
 
 void Event::setHasEndDate(bool b)
 {
   mHasEndDate = b;
 }
 
 bool Event::hasEndDate() const
 {
   return mHasEndDate;
 }
 
 bool Event::isMultiDay() const
 {
   bool multi = !(dtStart().date() == dtEnd().date());
   return multi;
 }
 
 void Event::setTransparency(Event::Transparency transparency)
 {
   if (mReadOnly) return;
   mTransparency = transparency;
   updated();
 }
 
 Event::Transparency Event::transparency() const
 {
   return mTransparency;
 }
 
 void Event::setDuration(int seconds)
 {
   setHasEndDate(false);
   Incidence::setDuration(seconds);
 }
+bool Event::matchTime(QDateTime*startDT, QDateTime* endDT)
+{
+    if ( ! doesRecur() ) {
+        if ( doesFloat() ) {
+            if ( mDtEnd.addDays( 1 ) < *startDT)
+                return false;
+            if ( endDT && mDtStart > * endDT)
+                return false;
+        } else {
+            if ( mDtEnd < *startDT )
+                return false;
+            if ( endDT && mDtStart > * endDT)
+                return false;
+        }
+    } else {
+        if ( endDT && mDtStart > * endDT)
+            return false;
+    }
+    return true;
+}
 bool Event::isOverlapping (  Event* testEvent,  QDateTime* overlapDT, QDateTime* startDT )
 {
     if ( testEvent == this )
         return false;
     if ( ! doesRecur() && !testEvent->doesRecur() ) {
         QDateTime te;
         if ( testEvent->doesFloat() )
             te = testEvent->mDtEnd.addDays( 1 );
         else
             te = testEvent->mDtEnd;
         QDateTime e; 
         if ( doesFloat() )
             e = mDtEnd.addDays( 1 );
         else
             e = mDtEnd;
         if ( mDtStart < te && testEvent->mDtStart < e ) {
             if ( mDtStart < testEvent->mDtStart )
                 *overlapDT =  testEvent->mDtStart;
             else
                 *overlapDT =  mDtStart;
             if ( startDT )
                 return (*overlapDT >= *startDT );
             return true;
         }
         return false;
     }
     if ( !doesFloat() && !testEvent->doesFloat() && !isMultiDay() && !testEvent->isMultiDay() ) {
         if ( mDtStart.time() >=  testEvent->mDtEnd.time() || testEvent->mDtStart.time() >=  mDtEnd.time() ) {
             // no need to test. times mismatch
             //fprintf(stderr,"timi ");
             return false;
         }
     }
     Event *nonRecur = 0;
     Event *recurEvent = 0;
     if ( ! doesRecur() ) {
         nonRecur = this;
         recurEvent = testEvent;
     }
     else if ( !testEvent->doesRecur() ) {
         nonRecur = testEvent;
         recurEvent = this;
     }
     if ( nonRecur ) {
         QDateTime enr; 
         if ( nonRecur->doesFloat() )
             enr = nonRecur->mDtEnd.addDays( 1 );
         else
             enr = nonRecur->mDtEnd;
         if ( enr < recurEvent->mDtStart )
             return false;
         if ( startDT && enr < *startDT )
             return false;
         
         int recDuration = recurEvent->mDtStart.secsTo( recurEvent->mDtEnd );
         if ( recurEvent->doesFloat() )
             recDuration += 86400;
         bool ok = false;
         QDateTime recStart;
         if ( startDT ) {
             recStart = recurEvent->recurrence()->getPreviousDateTime( startDT->addSecs( 61 ), &ok );
         }
         if ( recStart.isValid() ) {
             //qDebug("%s start at %s ", startDT->  toString().latin1(),       recStart.toString().latin1());
diff --git a/libkcal/event.h b/libkcal/event.h
index e6055a5..2da9770 100644
--- a/libkcal/event.h
+++ b/libkcal/event.h
@@ -1,93 +1,94 @@
 /*
     This file is part of libkcal.
     Copyright (c) 2001 Cornelius Schumacher <schumacher@kde.org>
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Library General Public License for more details.
 
     You should have received a copy of the GNU Library General Public License
     along with this library; see the file COPYING.LIB.  If not, write to
     the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
 */
 
 #ifndef EVENT_H
 #define EVENT_H
 //
 // Event component, representing a VEVENT object
 //
 
 #include "incidence.h"
 namespace KCal {
 
 /**
   This class provides an Event in the sense of RFC2445.
 */
 class Event : public Incidence
 {
   public:
     enum Transparency { Opaque, Transparent };
     typedef ListBase<Event> List;
     Event();
     Event(const Event &);
     ~Event();
+    bool matchTime(QDateTime*startDT, QDateTime* endDT);
 
     QCString type() const { return "Event"; }
     IncTypeID typeID() const { return eventID; }
 
     Incidence *clone();
     QDateTime getNextAlarmDateTime( bool * ok, int * offset ,QDateTime start_dt  ) const;
 
     /** for setting an event's ending date/time with a QDateTime. */
     void setDtEnd(const QDateTime &dtEnd);
     /** Return the event's ending date/time as a QDateTime. */
     virtual QDateTime dtEnd() const;
     /** returns an event's end time as a string formatted according to the
      users locale settings */
     QString dtEndTimeStr() const;
     /** returns an event's end date as a string formatted according to the
      users locale settings */
     QString dtEndDateStr(bool shortfmt=true) const;
     /** returns an event's end date and time as a string formatted according
      to the users locale settings */
     QString dtEndStr(bool shortfmt=true) const;
     void setHasEndDate(bool);
     /** Return whether the event has an end date/time. */
     bool hasEndDate() const;
 
     /** Return true if the event spans multiple days, otherwise return false. */
     bool isMultiDay() const;
 
     /** set the event's time transparency level. */
     void setTransparency(Transparency transparency);
     /** get the event's time transparency level. */
     Transparency transparency() const;
 
     void setDuration(int seconds);
 
     bool contains ( Event*);
 
     bool isOverlapping (  Event*,  QDateTime*, QDateTime* );
 
   private:
     bool accept(Visitor &v) { return v.visit(this); }
 
     QDateTime mDtEnd;
     bool mHasEndDate;
     Transparency mTransparency;
 };
 
 bool operator==( const Event&, const Event& );
 
 
 }
 
 
 #endif