Initial import from SVN

1 files changed, 259 insertions, 0 deletions

diff --git a/projects/net.wotonomy.persistence/src/main/java/net/wotonomy/control/internal/Surrogate.java b/projects/net.wotonomy.persistence/src/main/java/net/wotonomy/control/internal/Surrogate.java
new file mode 100644
index 0000000..e12fda0
--- /dev/null
+++ b/projects/net.wotonomy.persistence/src/main/java/net/wotonomy/control/internal/Surrogate.java
@@ -0,0 +1,259 @@
+/*
+Wotonomy: OpenStep design patterns for pure Java applications.
+Copyright (C) 2000 Intersect Software Corporation
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 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
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, see http://www.gnu.org
+*/
+
+package net.wotonomy.control.internal;
+
+import net.wotonomy.control.EOObserverCenter;
+import net.wotonomy.foundation.NSMutableDictionary;
+import net.wotonomy.foundation.internal.Introspector;
+
+/**
+* A Surrogate is a special object that can be used in a display
+* group when you wish to emulate other objects or modify their
+* behaviors.  Because it is a Map, it makes use of Introspector's
+* ability to treat keys in a map as if they were properties to
+* implement the following features.
+* <ul>
+* <li>By default, Surrogate works like a Map, and reading and 
+* writing properties to a Surrogate gets and puts values in the 
+* Map.</li>
+* <li>If one or more delegate objects are specified, property keys 
+* that do not exist in the map are read from and written to the 
+* delegate object.</li>
+* <li>If a default value is specified, that value will be returned
+* for all property reads that do not exist in the map or in the
+* delegate object.  (Subsequent writes to those properties will
+* create a key in the map and then subsequent reads will read not
+* read the default object.)</li>
+* <li>Subclasses can override the get(Object) method to further
+* customize the behavior of a Surrogate.
+* </ul>
+*
+* @author michael@mpowers.net
+* @date $Date: 2006-02-18 17:46:44 -0500 (Sat, 18 Feb 2006) $
+* @revision $Revision: 900 $
+*/
+public class Surrogate extends NSMutableDictionary
+{
+	protected Object[] delegates;
+	protected Object defaultValue;
+	
+	/**
+	* Default constructor with no delegate object and no default value.
+	*/
+	public Surrogate()
+	{
+		delegates = null;
+		defaultValue = null;
+	}
+	
+	/**
+	* Constructor specifying a delegate object.
+	*/
+	public Surrogate( Object[] aDelegateArray )
+	{
+		setDelegates( aDelegateArray );
+	}
+
+	/**
+	* Constructor specifying a default value.
+	*/
+	public Surrogate( Object aDefault )
+	{
+		setDefaultValue( aDefault );
+	}
+
+	/**
+	* Constructor specifying a delegate object and a default value.
+	*/
+	public Surrogate( Object[] aDelegateArray, Object aDefault )
+	{
+		setDelegates( aDelegateArray );
+		setDefaultValue( aDefault );
+	}
+
+	/**
+	* Returns the first delegate object, or null if no delegates exist.
+	*/
+	public Object getDelegate()
+	{
+		if ( delegates == null ) return null;
+		if ( delegates.length == 0 ) return null;
+		return delegates[0];
+	}
+	
+	/**
+	* Sets the delegate object list to contain only the
+	* specified object.
+	*/
+	public void setDelegate( Object aDelegate )
+	{
+		setDelegates( new Object[] { aDelegate } );
+	}
+	
+	/**
+	* Returns the list of delegates in the order in which
+	* they are consulted.
+	*/
+	public Object[] getDelegates()
+	{
+		if ( delegates == null ) delegates = new Object[0];
+		return delegates;	
+	}
+	
+	/**
+	* Sets the list of delegates in the order in which they
+	* will be consulted.
+	*/
+	public void setDelegates( Object[] aDelegateArray )
+	{
+		delegates = aDelegateArray;
+	}
+
+	/**
+	* Returns the current default value, or null if no default exists.
+	*/
+	public Object getDefaultValue()
+	{
+		return defaultValue;
+	}
+	
+	/**
+	* Sets the default value.
+	*/
+	public void setDefaultValue( Object aDefault )
+	{
+		defaultValue = aDefault;
+	}
+	
+	/**
+	* Called by get to retrieve a value from the internal map.
+	* This implementation simply calls super.get().
+	*/
+	public Object directGet( Object aKey )
+	{
+		return super.get( aKey );	
+	}
+	
+	/**
+	* Called by put to retrieve a value from the internal map.
+	* This implementation simply calls super.put().
+	*/
+	public Object directPut( Object aKey, Object aValue )
+	{
+		return super.put( aKey, aValue );	
+	}
+	
+	/**
+	* Overridden to consult each delegate before 
+	* checking the internal list of keys.  No matching
+	* key is found, returns the default object, or 
+	* null if no default object exists.
+	*/
+	public Object get( Object aKey )
+	{
+		// check all delegates in order
+		int i, j;
+		Object[] list = getDelegates();
+		String[] properties;
+		for ( i = 0; i < list.length; i++ )
+		{
+			// for each delegate
+			properties = 
+				Introspector.getReadPropertiesForObject( list[i] );
+			for ( j = 0; j < properties.length; j++ )
+			{
+				// if delegate has property
+				if ( properties[j].equals( aKey ) )
+				{
+					// use this delegate
+					return Introspector.get( list[i], aKey.toString() );	
+				}
+			}
+		}
+		
+		// return from internal map
+		Object result = directGet( aKey );
+		if ( result == null )
+		{
+			// if not in map, return default object
+			result = getDefaultValue();
+		}
+		return result;		
+	}
+	
+	/** 
+	* Overridden to attempt to write each delegate, writing to
+	* only the first successful delegate, before storing the 
+	* value in the internal map.
+	*/
+	public Object put( Object aKey, Object aValue )
+	{
+		// check all delegates in order
+		int i, j;
+		Object[] list = getDelegates();
+		String[] properties;
+		for ( i = 0; i < list.length; i++ )
+		{
+			// for each delegate
+			properties = 
+				Introspector.getWritePropertiesForObject( list[i] );
+			for ( j = 0; j < properties.length; j++ )
+			{
+				// if delegate has property
+				if ( properties[j].equals( aKey ) )
+				{
+					// use this delegate
+					EOObserverCenter.notifyObserversObjectWillChange( list[i] );
+					return Introspector.set( list[i], aKey.toString(), aValue );	
+				}
+			}
+		}
+		
+		// set on internal map
+		EOObserverCenter.notifyObserversObjectWillChange( this );
+		return directPut( aKey, aValue );
+	}
+
+	/**
+	* Overridden to compare by reference.
+	*/
+	public boolean equals( Object anObject )
+	{
+		return ( this == anObject );
+	}
+
+}
+
+/*
+ * $Log$
+ * Revision 1.1  2006/02/18 22:46:44  cgruber
+ * Add Surrogate map from .util into control's internal package, and fix imports.
+ *
+ * Revision 1.1  2006/02/16 13:22:22  cgruber
+ * Check in all sources in eclipse-friendly maven-enabled packages.
+ *
+ * Revision 1.1.1.1  2000/12/21 15:52:21  mpowers
+ * Contributing wotonomy.
+ *
+ * Revision 1.2  2000/12/20 16:25:48  michael
+ * Added log to all files.
+ *
+ *
+ */
+