connectivity/source/commontools/conncleanup.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <connectivity/conncleanup.hxx>
  21 #include <com/sun/star/beans/XPropertySet.hpp>
  22 #include <com/sun/star/lang/XComponent.hpp>
  23 #include <com/sun/star/sdbc/XRowSet.hpp>
  24 #include <com/sun/star/sdbc/XConnection.hpp>
  25 #include <osl/diagnose.h>
  26
  27
  28 namespace dbtools
  29 {
  30
  31
  32     using namespace css::uno;
  33     using namespace css::beans;
  34     using namespace css::sdbc;
  35     using namespace css::lang;
  36
  37     static const char ACTIVE_CONNECTION_PROPERTY_NAME[] = "ActiveConnection";
  38
  39     OAutoConnectionDisposer::OAutoConnectionDisposer(const Reference< XRowSet >& _rxRowSet, const Reference< XConnection >& _rxConnection)
  40         :m_xRowSet( _rxRowSet )
  41         ,m_bRSListening( false )
  42         ,m_bPropertyListening( false )
  43     {
  44         Reference< XPropertySet > xProps(_rxRowSet, UNO_QUERY);
  45         OSL_ENSURE(xProps.is(), "OAutoConnectionDisposer::OAutoConnectionDisposer: invalid rowset (no XPropertySet)!");
  46
  47         if (!xProps.is())
  48             return;
  49
  50         try
  51         {
  52             xProps->setPropertyValue( ACTIVE_CONNECTION_PROPERTY_NAME, makeAny( _rxConnection ) );
  53             m_xOriginalConnection = _rxConnection;
  54             startPropertyListening( xProps );
  55         }
  56         catch( const Exception& )
  57         {
  58             OSL_FAIL( "OAutoConnectionDisposer::OAutoConnectionDisposer: caught an exception!" );
  59         }
  60     }
  61
  62
  63     void OAutoConnectionDisposer::startPropertyListening( const Reference< XPropertySet >& _rxRowSet )
  64     {
  65         try
  66         {
  67             _rxRowSet->addPropertyChangeListener( ACTIVE_CONNECTION_PROPERTY_NAME, this );
  68             m_bPropertyListening = true;
  69         }
  70         catch( const Exception& )
  71         {
  72             OSL_FAIL( "OAutoConnectionDisposer::startPropertyListening: caught an exception!" );
  73         }
  74     }
  75
  76
  77     void OAutoConnectionDisposer::stopPropertyListening( const Reference< XPropertySet >& _rxEventSource )
  78     {
  79         // prevent deletion of ourself while we're herein
  80         Reference< XInterface > xKeepAlive(static_cast< XWeak* >(this));
  81
  82         try
  83         {   // remove ourself as property change listener
  84             OSL_ENSURE( _rxEventSource.is(), "OAutoConnectionDisposer::stopPropertyListening: invalid event source (no XPropertySet)!" );
  85             if ( _rxEventSource.is() )
  86             {
  87                 _rxEventSource->removePropertyChangeListener( ACTIVE_CONNECTION_PROPERTY_NAME, this );
  88                 m_bPropertyListening = false;
  89             }
  90         }
  91         catch( const Exception& )
  92         {
  93             OSL_FAIL( "OAutoConnectionDisposer::stopPropertyListening: caught an exception!" );
  94         }
  95     }
  96
  97
  98     void OAutoConnectionDisposer::startRowSetListening()
  99     {
 100         OSL_ENSURE( !m_bRSListening, "OAutoConnectionDisposer::startRowSetListening: already listening!" );
 101         try
 102         {
 103             if ( !m_bRSListening )
 104                 m_xRowSet->addRowSetListener( this );
 105         }
 106         catch( const Exception& )
 107         {
 108             OSL_FAIL( "OAutoConnectionDisposer::startRowSetListening: caught an exception!" );
 109         }
 110         m_bRSListening = true;
 111     }
 112
 113
 114     void OAutoConnectionDisposer::stopRowSetListening()
 115     {
 116         OSL_ENSURE( m_bRSListening, "OAutoConnectionDisposer::stopRowSetListening: not listening!" );
 117         try
 118         {
 119             m_xRowSet->removeRowSetListener( this );
 120         }
 121         catch( const Exception& )
 122         {
 123             OSL_FAIL( "OAutoConnectionDisposer::stopRowSetListening: caught an exception!" );
 124         }
 125         m_bRSListening = false;
 126     }
 127
 128
 129     void SAL_CALL OAutoConnectionDisposer::propertyChange( const PropertyChangeEvent& _rEvent )
 130     {
 131         if ( _rEvent.PropertyName == ACTIVE_CONNECTION_PROPERTY_NAME )
 132         {   // somebody set a new ActiveConnection
 133
 134             Reference< XConnection > xNewConnection;
 135             _rEvent.NewValue >>= xNewConnection;
 136
 137             if ( isRowSetListening() )
 138             {
 139                 // we're listening at the row set, this means that the row set does not have our
 140                 // m_xOriginalConnection as active connection anymore
 141                 // So there are two possibilities
 142                 // a. somebody sets a new connection which is not our original one
 143                 // b. somebody sets a new connection, which is exactly the original one
 144                 // a. we're not interested in a, but in b: In this case, we simply need to move to the state
 145                 // we had originally: listen for property changes, do not listen for row set changes, and
 146                 // do not dispose the connection until the row set does not need it anymore
 147                 if ( xNewConnection.get() == m_xOriginalConnection.get() )
 148                 {
 149                     stopRowSetListening();
 150                 }
 151             }
 152             else
 153             {
 154                 // start listening at the row set. We're allowed to dispose the old connection as soon
 155                 // as the RowSet changed
 156
 157                 // Unfortunately, the our database form implementations sometimes fire the change of their
 158                 // ActiveConnection twice. This is an error in forms/source/component/DatabaseForm.cxx, but
 159                 // changing this would require incompatible changes we can't do for a while.
 160                 // So for the moment, we have to live with it here.
 161                 //
 162                 // The only scenario where this doubled notification causes problems is when the connection
 163                 // of the form is reset to the one we're responsible for (m_xOriginalConnection), so we
 164                 // check this here.
 165                 //
 166                 // Yes, this is a HACK :(
 167                 if ( xNewConnection.get() != m_xOriginalConnection.get() )
 168                 {
 169 #if OSL_DEBUG_LEVEL > 0
 170                     Reference< XConnection > xOldConnection;
 171                     _rEvent.OldValue >>= xOldConnection;
 172                     OSL_ENSURE( xOldConnection.get() == m_xOriginalConnection.get(), "OAutoConnectionDisposer::propertyChange: unexpected (original) property value!" );
 173 #endif
 174                     startRowSetListening();
 175                 }
 176             }
 177         }
 178     }
 179
 180
 181     void SAL_CALL OAutoConnectionDisposer::disposing( const EventObject& _rSource )
 182     {
 183         // the rowset is being disposed, and nobody has set a new ActiveConnection in the meantime
 184         if ( isRowSetListening() )
 185             stopRowSetListening();
 186
 187         clearConnection();
 188
 189         if ( m_bPropertyListening )
 190             stopPropertyListening( Reference< XPropertySet >( _rSource.Source, UNO_QUERY ) );
 191     }
 192
 193     void OAutoConnectionDisposer::clearConnection()
 194     {
 195         try
 196         {
 197             // dispose the old connection
 198             Reference< XComponent > xComp(m_xOriginalConnection, UNO_QUERY);
 199             if (xComp.is())
 200                 xComp->dispose();
 201             m_xOriginalConnection.clear();
 202         }
 203         catch(Exception&)
 204         {
 205             OSL_FAIL("OAutoConnectionDisposer::clearConnection: caught an exception!");
 206         }
 207     }
 208
 209     void SAL_CALL OAutoConnectionDisposer::cursorMoved( const css::lang::EventObject& /*event*/ )
 210     {
 211     }
 212
 213     void SAL_CALL OAutoConnectionDisposer::rowChanged( const css::lang::EventObject& /*event*/ )
 214     {
 215     }
 216
 217     void SAL_CALL OAutoConnectionDisposer::rowSetChanged( const css::lang::EventObject& /*event*/ )
 218     {
 219         stopRowSetListening();
 220         clearConnection();
 221
 222     }
 223
 224
 225 }   // namespace dbtools
 226
 227
 228 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */