cli_ure/source/ure/uno/util/WeakBase.cs

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  30
  31 using System;
  32 using System.Collections;
  33 using unoidl.com.sun.star.uno;
  34 using unoidl.com.sun.star.lang;
  35
  36 namespace uno.util
  37 {
  38
  39 /** This class can be used as a base class for UNO objects.
  40     It implements the capability to be kept weakly
  41     (unoidl.com.sun.star.uno.XWeak) and it implements
  42     unoidl.com.sun.star.lang.XTypeProvider which is necessary for
  43     using the object from StarBasic.
  44 */
  45 public class WeakBase : XWeak, XTypeProvider
  46 {
  47     // Contains all WeakAdapter which have been created in this class
  48     // They have to be notified when this object dies
  49     private WeakAdapter m_adapter = null;
  50
  51     protected static Hashtable s_types = new Hashtable();
  52     protected static Hashtable s_impl_ids = new Hashtable();
  53
  54     // XWeak impl
  55     /** The returned XAdapter implementation can be used to keap a
  56         weak reference to this object.
  57
  58         @return a weak adapter
  59     */
  60     public XAdapter queryAdapter()
  61     {
  62         if (null == m_adapter)
  63         {
  64             lock (this)
  65             {
  66                 if (null == m_adapter)
  67                     m_adapter = new WeakAdapter( this );
  68             }
  69         }
  70         return m_adapter;
  71     }
  72
  73     /** Overrides of Object.Finalize method.
  74         When there are no references to this object anymore, then the
  75         garbage collector calls this method, thereby causing the adapter
  76         object to be notified.  The adapter, in turn, notifies all
  77         listeners (unoidl.com.sun.star.uno.XReference).
  78     */
  79     ~WeakBase()
  80     {
  81         if (null != m_adapter)
  82             m_adapter.referentDying();
  83     }
  84
  85     // XTypeProvider impl
  86
  87     /** Returns an array of Type objects which represent all implemented
  88         UNO interfaces of this object.
  89
  90        @return Type objects of all implemented interfaces.
  91     */
  92     public Type [] getTypes()
  93     {
  94         Type [] types;
  95         Type type = GetType();
  96         lock (s_types)
  97         {
  98             types = (Type []) s_types[ type ];
  99             if (null == types)
 100             {
 101                 Type [] interfaces = type.GetInterfaces();
 102                 ArrayList list = new ArrayList( interfaces.Length );
 103                 for ( Int32 pos = 0; pos < interfaces.Length; ++pos )
 104                 {
 105                     Type iface = interfaces[ pos ];
 106                     // xxx todo: as long as the bridge cannot introduce
 107                     // native CTS types into UNO on the fly
 108                     if (iface.FullName.StartsWith( "unoidl." ))
 109                     {
 110                         list.Add( iface );
 111                     }
 112                 }
 113                 Int32 len = list.Count;
 114                 Type [] ar = new Type [ len ];
 115                 for ( Int32 pos = 0; pos < len; ++pos )
 116                     ar[ pos ] = (Type) list[ pos ];
 117                 s_types[ type ] = ar;
 118                 types = ar;
 119             }
 120         }
 121         return types;
 122     }
 123
 124     /** Provides an identifier that represents the set of UNO interfaces
 125         implemented by this class.  All instances of this class which run
 126         in the same CLR return the same array.
 127
 128         @return identifier as array of bytes
 129     */
 130     public byte [] getImplementationId()
 131     {
 132         byte [] id;
 133         Type type = GetType();
 134         lock (s_impl_ids)
 135         {
 136             id = (byte []) s_impl_ids[ type ];
 137             if (null == id)
 138             {
 139                 Int32 hash = GetHashCode();
 140                 String name = type.FullName;
 141                 Int32 len= name.Length;
 142
 143                 id = new byte[ 4 + (2 * len) ];
 144                 id[ 0 ]= (byte) (hash & 0xff);
 145                 id[ 1 ]= (byte) ((hash >> 8) & 0xff);
 146                 id[ 2 ]= (byte) ((hash >> 16) & 0xff);
 147                 id[ 3 ]= (byte) ((hash >> 24) & 0xff);
 148
 149                 for ( Int32 pos = 0; pos < len; ++pos )
 150                 {
 151                     UInt16 c = Convert.ToUInt16( name[ pos ] );
 152                     id[ 4 + (2 * pos) ] = (byte) (c & 0xff);
 153                     id[ 4 + (2 * pos) +1 ] = (byte) ((c >> 8) & 0xff);
 154                 }
 155                 s_impl_ids[ type ] = id;
 156             }
 157         }
 158         return id;
 159     }
 160
 161     // System.Object
 162     public override String ToString()
 163     {
 164         System.Text.StringBuilder buf =
 165             new System.Text.StringBuilder( base.ToString(), 256 );
 166         buf.Append( "\nUNO Object Implementation:\n\tImplementationId: " );
 167         buf.Append( getImplementationId() );
 168         buf.Append( "\n\tInterfaces: " );
 169         Type [] types = getTypes();
 170         for ( Int32 pos = 0; pos < types.Length; ++pos )
 171         {
 172             buf.Append( types[ pos ].FullName );
 173             if (pos < (types.Length -1))
 174                 buf.Append( ", " );
 175         }
 176         return buf.ToString();
 177     }
 178 }
 179
 180 }
 181