1*b1cdbd2cSJim Jagielski /************************************************************** 2*b1cdbd2cSJim Jagielski * 3*b1cdbd2cSJim Jagielski * Licensed to the Apache Software Foundation (ASF) under one 4*b1cdbd2cSJim Jagielski * or more contributor license agreements. See the NOTICE file 5*b1cdbd2cSJim Jagielski * distributed with this work for additional information 6*b1cdbd2cSJim Jagielski * regarding copyright ownership. The ASF licenses this file 7*b1cdbd2cSJim Jagielski * to you under the Apache License, Version 2.0 (the 8*b1cdbd2cSJim Jagielski * "License"); you may not use this file except in compliance 9*b1cdbd2cSJim Jagielski * with the License. You may obtain a copy of the License at 10*b1cdbd2cSJim Jagielski * 11*b1cdbd2cSJim Jagielski * http://www.apache.org/licenses/LICENSE-2.0 12*b1cdbd2cSJim Jagielski * 13*b1cdbd2cSJim Jagielski * Unless required by applicable law or agreed to in writing, 14*b1cdbd2cSJim Jagielski * software distributed under the License is distributed on an 15*b1cdbd2cSJim Jagielski * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*b1cdbd2cSJim Jagielski * KIND, either express or implied. See the License for the 17*b1cdbd2cSJim Jagielski * specific language governing permissions and limitations 18*b1cdbd2cSJim Jagielski * under the License. 19*b1cdbd2cSJim Jagielski * 20*b1cdbd2cSJim Jagielski *************************************************************/ 21*b1cdbd2cSJim Jagielski 22*b1cdbd2cSJim Jagielski 23*b1cdbd2cSJim Jagielski 24*b1cdbd2cSJim Jagielski using System; 25*b1cdbd2cSJim Jagielski using unoidl.com.sun.star.lang; 26*b1cdbd2cSJim Jagielski 27*b1cdbd2cSJim Jagielski namespace uno.util 28*b1cdbd2cSJim Jagielski { 29*b1cdbd2cSJim Jagielski 30*b1cdbd2cSJim Jagielski /** This class can be used as a base class for UNO objects. 31*b1cdbd2cSJim Jagielski It implements the capability to be kept weakly 32*b1cdbd2cSJim Jagielski (unoidl.com.sun.star.uno.XWeak) and it implements 33*b1cdbd2cSJim Jagielski unoidl.com.sun.star.lang.XTypeProvider which is necessary for 34*b1cdbd2cSJim Jagielski using the object from StarBasic. 35*b1cdbd2cSJim Jagielski In addition, it implements the interface 36*b1cdbd2cSJim Jagielski unoidl.com.sun.star.lang.XComponent to be disposed explicitly. 37*b1cdbd2cSJim Jagielski */ 38*b1cdbd2cSJim Jagielski public class WeakComponentBase : WeakBase, XComponent 39*b1cdbd2cSJim Jagielski { t_disposing( EventObject evt )40*b1cdbd2cSJim Jagielski private delegate void t_disposing( EventObject evt ); 41*b1cdbd2cSJim Jagielski private t_disposing m_disposing = null; 42*b1cdbd2cSJim Jagielski private bool m_inDispose = false; 43*b1cdbd2cSJim Jagielski private bool m_disposed = false; 44*b1cdbd2cSJim Jagielski 45*b1cdbd2cSJim Jagielski /** Indicates whether object is alrady disposed. 46*b1cdbd2cSJim Jagielski 47*b1cdbd2cSJim Jagielski @return 48*b1cdbd2cSJim Jagielski true, if object has been disposed 49*b1cdbd2cSJim Jagielski */ isDisposed()50*b1cdbd2cSJim Jagielski protected bool isDisposed() 51*b1cdbd2cSJim Jagielski { 52*b1cdbd2cSJim Jagielski lock (this) 53*b1cdbd2cSJim Jagielski { 54*b1cdbd2cSJim Jagielski return m_disposed; 55*b1cdbd2cSJim Jagielski } 56*b1cdbd2cSJim Jagielski } 57*b1cdbd2cSJim Jagielski 58*b1cdbd2cSJim Jagielski /** Checks whether this object is disposed and throws a DisposedException 59*b1cdbd2cSJim Jagielski if it is already disposed. 60*b1cdbd2cSJim Jagielski */ checkUnDisposed()61*b1cdbd2cSJim Jagielski protected void checkUnDisposed() 62*b1cdbd2cSJim Jagielski { 63*b1cdbd2cSJim Jagielski if (! isDisposed()) 64*b1cdbd2cSJim Jagielski { 65*b1cdbd2cSJim Jagielski throw new unoidl.com.sun.star.lang.DisposedException( 66*b1cdbd2cSJim Jagielski "object already disposed!", this ); 67*b1cdbd2cSJim Jagielski } 68*b1cdbd2cSJim Jagielski } 69*b1cdbd2cSJim Jagielski ~WeakComponentBase()70*b1cdbd2cSJim Jagielski ~WeakComponentBase() 71*b1cdbd2cSJim Jagielski { 72*b1cdbd2cSJim Jagielski bool doDispose; 73*b1cdbd2cSJim Jagielski lock (this) 74*b1cdbd2cSJim Jagielski { 75*b1cdbd2cSJim Jagielski doDispose = (!m_inDispose && !m_disposed); 76*b1cdbd2cSJim Jagielski } 77*b1cdbd2cSJim Jagielski if (doDispose) 78*b1cdbd2cSJim Jagielski { 79*b1cdbd2cSJim Jagielski dispose(); 80*b1cdbd2cSJim Jagielski } 81*b1cdbd2cSJim Jagielski } 82*b1cdbd2cSJim Jagielski 83*b1cdbd2cSJim Jagielski /** Override to perform extra clean-up work. Provided for subclasses. 84*b1cdbd2cSJim Jagielski It is called during dispose() 85*b1cdbd2cSJim Jagielski */ preDisposing()86*b1cdbd2cSJim Jagielski protected void preDisposing() 87*b1cdbd2cSJim Jagielski { 88*b1cdbd2cSJim Jagielski } 89*b1cdbd2cSJim Jagielski 90*b1cdbd2cSJim Jagielski /** Override to become notified right before the disposing action is 91*b1cdbd2cSJim Jagielski performed. 92*b1cdbd2cSJim Jagielski */ postDisposing()93*b1cdbd2cSJim Jagielski protected void postDisposing() 94*b1cdbd2cSJim Jagielski { 95*b1cdbd2cSJim Jagielski } 96*b1cdbd2cSJim Jagielski 97*b1cdbd2cSJim Jagielski // XComponent impl 98*b1cdbd2cSJim Jagielski /** This method is called by the owner of this object to explicitly 99*b1cdbd2cSJim Jagielski dispose it. This implementation of dispose() first notifies this object 100*b1cdbd2cSJim Jagielski via preDisposing(), then all registered event listeners and 101*b1cdbd2cSJim Jagielski finally this object again calling postDisposing(). 102*b1cdbd2cSJim Jagielski */ dispose()103*b1cdbd2cSJim Jagielski public void dispose() 104*b1cdbd2cSJim Jagielski { 105*b1cdbd2cSJim Jagielski // Determine in a thread-safe way if this is the first call to this 106*b1cdbd2cSJim Jagielski // method. Only then we proceed with the notification of event 107*b1cdbd2cSJim Jagielski // listeners. It is an error to call this method more then once. 108*b1cdbd2cSJim Jagielski bool doDispose = false; 109*b1cdbd2cSJim Jagielski t_disposing call = null; 110*b1cdbd2cSJim Jagielski lock (this) 111*b1cdbd2cSJim Jagielski { 112*b1cdbd2cSJim Jagielski if (! m_inDispose && !m_disposed) 113*b1cdbd2cSJim Jagielski { 114*b1cdbd2cSJim Jagielski call = m_disposing; 115*b1cdbd2cSJim Jagielski m_disposing = null; 116*b1cdbd2cSJim Jagielski m_inDispose = true; 117*b1cdbd2cSJim Jagielski doDispose = true; 118*b1cdbd2cSJim Jagielski } 119*b1cdbd2cSJim Jagielski } 120*b1cdbd2cSJim Jagielski // The notification occures in an unsynchronized block in order to avoid 121*b1cdbd2cSJim Jagielski // deadlocks if one of the listeners calls back in a different thread on 122*b1cdbd2cSJim Jagielski // a synchronized method which uses the same object. 123*b1cdbd2cSJim Jagielski if (doDispose) 124*b1cdbd2cSJim Jagielski { 125*b1cdbd2cSJim Jagielski try 126*b1cdbd2cSJim Jagielski { 127*b1cdbd2cSJim Jagielski // call sub class 128*b1cdbd2cSJim Jagielski preDisposing(); 129*b1cdbd2cSJim Jagielski // send disposing notifications to listeners 130*b1cdbd2cSJim Jagielski if (null != call) 131*b1cdbd2cSJim Jagielski { 132*b1cdbd2cSJim Jagielski EventObject evt = new EventObject( this ); 133*b1cdbd2cSJim Jagielski call( evt ); 134*b1cdbd2cSJim Jagielski } 135*b1cdbd2cSJim Jagielski // call sub class 136*b1cdbd2cSJim Jagielski postDisposing(); 137*b1cdbd2cSJim Jagielski } 138*b1cdbd2cSJim Jagielski finally 139*b1cdbd2cSJim Jagielski { 140*b1cdbd2cSJim Jagielski // finally makes sure that the flags are set ensuring 141*b1cdbd2cSJim Jagielski // that this function is only called once. 142*b1cdbd2cSJim Jagielski m_disposed = true; 143*b1cdbd2cSJim Jagielski m_inDispose = false; 144*b1cdbd2cSJim Jagielski } 145*b1cdbd2cSJim Jagielski } 146*b1cdbd2cSJim Jagielski else 147*b1cdbd2cSJim Jagielski { 148*b1cdbd2cSJim Jagielski // in a multithreaded environment, it can't be avoided, 149*b1cdbd2cSJim Jagielski // that dispose is called twice. 150*b1cdbd2cSJim Jagielski // However this condition is traced, because it MAY indicate an 151*b1cdbd2cSJim Jagielski // error. 152*b1cdbd2cSJim Jagielski #if DEBUG 153*b1cdbd2cSJim Jagielski Console.WriteLine( 154*b1cdbd2cSJim Jagielski "WeakComponentBase.dispose() - dispose called twice" ); 155*b1cdbd2cSJim Jagielski #endif 156*b1cdbd2cSJim Jagielski // Debug.Fail( "WeakComponentBase.dispose() - dispose called twice" ); 157*b1cdbd2cSJim Jagielski } 158*b1cdbd2cSJim Jagielski } 159*b1cdbd2cSJim Jagielski /** Registers an event listener being notified when this object is disposed. 160*b1cdbd2cSJim Jagielski 161*b1cdbd2cSJim Jagielski @param xListener event listener 162*b1cdbd2cSJim Jagielski */ addEventListener( XEventListener xListener )163*b1cdbd2cSJim Jagielski public void addEventListener( XEventListener xListener ) 164*b1cdbd2cSJim Jagielski { 165*b1cdbd2cSJim Jagielski bool add; 166*b1cdbd2cSJim Jagielski lock (this) 167*b1cdbd2cSJim Jagielski { 168*b1cdbd2cSJim Jagielski add = (! m_inDispose && !m_disposed); 169*b1cdbd2cSJim Jagielski if (add) 170*b1cdbd2cSJim Jagielski m_disposing += new t_disposing( xListener.disposing ); 171*b1cdbd2cSJim Jagielski } 172*b1cdbd2cSJim Jagielski if (! add) 173*b1cdbd2cSJim Jagielski xListener.disposing( new EventObject( this ) ); 174*b1cdbd2cSJim Jagielski } 175*b1cdbd2cSJim Jagielski /** Revokes an event listener from being notified when this object 176*b1cdbd2cSJim Jagielski is disposed. 177*b1cdbd2cSJim Jagielski 178*b1cdbd2cSJim Jagielski @param xListener event listener 179*b1cdbd2cSJim Jagielski */ removeEventListener( XEventListener xListener )180*b1cdbd2cSJim Jagielski public void removeEventListener( XEventListener xListener ) 181*b1cdbd2cSJim Jagielski { 182*b1cdbd2cSJim Jagielski lock (this) 183*b1cdbd2cSJim Jagielski { 184*b1cdbd2cSJim Jagielski if (! m_inDispose && !m_disposed) 185*b1cdbd2cSJim Jagielski m_disposing -= new t_disposing( xListener.disposing ); 186*b1cdbd2cSJim Jagielski } 187*b1cdbd2cSJim Jagielski } 188*b1cdbd2cSJim Jagielski } 189*b1cdbd2cSJim Jagielski 190*b1cdbd2cSJim Jagielski } 191