Coverage Report

Coverage Report - net.wotonomy.ui.GenericAssociation

Classes in this File

1.824

 /*
 Wotonomy: OpenStep design patterns for pure Java applications.
 Copyright (C) 2001 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.ui;
 
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
 
 import net.wotonomy.control.EOKeyValueCoding;
 import net.wotonomy.control.EOKeyValueCodingSupport;
 import net.wotonomy.control.EOObserverCenter;
 import net.wotonomy.foundation.NSArray;
 
 /**
 * GenericAssociation binds one or more properties on an 
 * observable object to a display group.  The controlled
 * object is expected to use the ObserverCenter and will
 * be observed by this association. <br><br>
 *
 * Bindings for this association are <i>generic</i>: the 
 * name of the aspect will be treated as a property key 
 * on the displayed object(s) and synchronized with the 
 * bound property on the controlled object. <br><br>
 *
 * NOTE: because we cannot assume that the controlled
 * object will retain a reference to this association,
 * you must explicitly retain a reference to prevent
 * the association from getting garbage collected.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $
 */
 public class GenericAssociation extends EOAssociation
 {
     protected boolean objectModified;
     protected Set aspectsModified;
     
     static final NSArray aspects = 
         new NSArray( new Object[] {
         } );
     static final NSArray aspectSignatures = 
         new NSArray( new Object[] {
         } );
     static final NSArray objectKeysTaken = 
         new NSArray( new Object[] {
         } );
                 
     /**
     * Constructor specifying the object to be controlled by this
     * association.  Does not establish connection.
     */
     public GenericAssociation ( Object anObject )
     {
         super( anObject );
         objectModified = false;
         aspectsModified = new HashSet();
     }
     
     /**
     * Returns a List of aspect signatures whose contents
     * correspond with the aspects list.  Each element is 
     * a string whose characters represent a capability of
     * the corresponding aspect. <ul>
     * <li>"A" attribute: the aspect can be bound to
     * an attribute.</li>
     * <li>"1" to-one: the aspect can be bound to a
     * property that returns a single object.</li>
     * <li>"M" to-one: the aspect can be bound to a
     * property that returns multiple objects.</li>
     * </ul> 
     * An empty signature "" means that the aspect can
     * bind without needing a key.
     * This implementation returns "A1M" for each
     * element in the aspects array.
     */
     public static NSArray aspectSignatures ()
     {
         return aspectSignatures;
     }
     
     /**
     * Returns a List that describes the aspects supported
     * by this class.  Each element in the list is the string
     * name of the aspect.  This implementation returns an
     * empty list.
     */
     public static NSArray aspects ()
     {
         return aspects;
     }
     
     /**
     * Returns a List of EOAssociation subclasses that,
     * for the objects that are usable for this association,
     * are less suitable than this association.
     */
     public static NSArray associationClassesSuperseded ()
     {
         return new NSArray();
     }
     
     /**
     * Returns whether this class can control the specified 
     * object. 
     */
     public static boolean isUsableWithObject ( Object anObject )
     {
         return true;
     }
     
     /**
     * Returns a List of properties of the controlled object
     * that are controlled by this class.  For example,
     * "stringValue", or "selected".
     */
     public static NSArray objectKeysTaken ()
     {
         return objectKeysTaken;
     }
     
     /**
     * Returns the aspect that is considered primary
     * or default.  This is typically "value" or somesuch.
     */
     public static String primaryAspect ()
     {
         return "";
     }
         
     /**
     * Returns whether this association can bind to the
     * specified display group on the specified key for
     * the specified aspect.  
     */
     public boolean canBindAspect ( 
         String anAspect, EODisplayGroup aDisplayGroup, String aKey)
     {
         return true;
     }
     
     /**
     * Establishes a connection between this association
     * and the controlled object.  This implementation 
         * registers with ObserverCenter for change notifications
     * from the controlled object.
     */
     public void establishConnection ()
     {
                 EOObserverCenter.addObserver( this, object() );
         super.establishConnection();
                 
                 // forces update from bindings
                 subjectChanged();
     }
         
     /**
     * Breaks the connection between this association and 
     * its object.  Override to stop listening for events
     * from the object.
     */
     public void breakConnection ()
     {
                 EOObserverCenter.removeObserver( this, object() );
         super.breakConnection();
     }
     
     /**
     * Overridden to track which observed object is changing.
     */
     public void objectWillChange( Object anObject )
     {
         if ( object() == anObject ) 
         { 
             objectModified = true;
         }
         else
         {
             aspectsModified.add( aspectToGroup.allKeysForObject( anObject ) );
         }
     }
 
     /**
     * Called when either the selection or the contents 
     * of an associated display group have changed.
     */
     public void subjectChanged ()
     {
         String aspect;
         String key;
         Object value;
         EODisplayGroup displayGroup;
         Iterator iterator;
         
         iterator = aspectsModified.iterator();
         while ( iterator.hasNext() )
         {
             aspect = (String) iterator.next();
             key = displayGroupKeyForAspect( aspect );
             displayGroup = displayGroupForAspect( aspect );
 
             value = readValueFromDisplayGroupForKey( displayGroup, key );    
             writeValueForKey( object(), value, key );
         }
         aspectsModified.clear();
         
         if ( objectModified )
         {
             iterator = aspectToGroup.keySet().iterator();
             while ( iterator.hasNext() )
             {
                 aspect = (String) iterator.next();
                 key = displayGroupKeyForAspect( aspect );
                 value = readValueForKey( object(), key );
                 displayGroup = displayGroupForAspect( aspect );
                 displayGroup.setSelectedObjectValue( value, key );
             }
         }
     }
     
     protected Object readValueForKey( Object object, String key )
     {
         if ( object instanceof EOKeyValueCoding )
         {
             return ((EOKeyValueCoding)object).valueForKey( key );
         }
         return EOKeyValueCodingSupport.valueForKey( object, key );
     }
     
     protected void writeValueForKey( Object object, Object value, String key )
     {
         if ( object instanceof EOKeyValueCoding )
         {
             ((EOKeyValueCoding)object).takeValueForKey( value, key );
         }
         else
         {
             EOKeyValueCodingSupport.takeValueForKey( object, value, key );
         }
     }
     
     protected Object readValueFromDisplayGroupForKey( 
         EODisplayGroup displayGroup, String key )
     {
         Object value;
         
         if ( displayGroup.selectedObjects().size() > 1 )
         {
             // if there're more than one object selected, set
             // the value to blank for all of them.
             Object previousValue;
 
             Iterator indexIterator = displayGroup.selectionIndexes().
                                       iterator();
 
             // get value for the first selected object.
             int initialIndex = ( (Integer)indexIterator.next() ).intValue();
             previousValue = displayGroup.valueForObjectAtIndex(
                                       initialIndex, key );
             value = null;
 
             // go through the rest of the selected objects, compare each
             // value with the previous one. continue comparing if two
             // values are equal, break the while loop if they're different.
             // the final value will be the common value of all selected objects
             // if there is one, or be blank if there is not.
             while ( indexIterator.hasNext() )
             {
                 int index = ( (Integer)indexIterator.next() ).intValue();
                 Object currentValue = displayGroup.valueForObjectAtIndex(
                                       index, key );
                 if ( currentValue != null && !currentValue.equals( previousValue ) )
                 {
                     value = null;
                     break;
                 }
                 else
                 {
                     // currentValue is the same as the previous one
                     value = currentValue;
                 }
 
             } // end while
 
         } else {
 
             value = displayGroup.selectedObjectValueForKey( key );
         } // end checking size of displayGroup
         
         return value;
     }
         
         /**
         * Writes the value currently in the component
         * to the selected object in the display group
         * bound to the value aspect.
     * @return false if there were problems validating,
     * or true to continue.
         */
         protected boolean writeValueForAspect( Object value, String aspect )
         {
                 EODisplayGroup displayGroup = 
                         displayGroupForAspect( aspect );
                 if ( displayGroup != null )
                 {
                         String key = displayGroupKeyForAspect( aspect );
 
             boolean returnValue = true;
             Iterator selectedIterator = displayGroup.selectionIndexes().iterator();
             while ( selectedIterator.hasNext() )
             {
                 int index = ( (Integer)selectedIterator.next() ).intValue();
 
                 if ( !displayGroup.setValueForObjectAtIndex( value, index, key ) )
                 {
                     returnValue = false;
                 }
             }
             return returnValue;
                 }
                 return false;
         }
 
     /**
     * Forces this association to cause the object to 
     * stop editing and validate the user's input.
     * @return false if there were problems validating,
     * or true to continue.
     */
     public boolean endEditing ()
     {        
         return false;
 //!            return writeValueToDisplayGroup();
     }
         
 }
 
 /*
  * $Log$
  * Revision 1.2  2006/02/18 23:14:35  cgruber
  * Update imports and maven dependencies.
  *
  * Revision 1.1  2006/02/16 13:22:22  cgruber
  * Check in all sources in eclipse-friendly maven-enabled packages.
  *
  * Revision 1.3  2003/08/06 23:07:52  chochos
  * general code cleanup (mostly, removing unused imports)
  *
  * Revision 1.2  2001/11/08 19:51:24  mpowers
  * Draft implementation.
  *
  * Revision 1.1  2001/11/02 23:15:04  mpowers
  * Contributing "generic association".
  *
  *
  */
 

1		/*
2		Wotonomy: OpenStep design patterns for pure Java applications.
3		Copyright (C) 2001 Intersect Software Corporation
4
5		This library is free software; you can redistribute it and/or
6		modify it under the terms of the GNU Lesser General Public
7		License as published by the Free Software Foundation; either
8		version 2.1 of the License, or (at your option) any later version.
9
10		This library is distributed in the hope that it will be useful,
11		but WITHOUT ANY WARRANTY; without even the implied warranty of
12		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13		Lesser General Public License for more details.
14
15		You should have received a copy of the GNU Lesser General Public
16		License along with this library; if not, see http://www.gnu.org
17		*/
18
19		package net.wotonomy.ui;
20
21		import java.util.HashSet;
22		import java.util.Iterator;
23		import java.util.Set;
24
25		import net.wotonomy.control.EOKeyValueCoding;
26		import net.wotonomy.control.EOKeyValueCodingSupport;
27		import net.wotonomy.control.EOObserverCenter;
28		import net.wotonomy.foundation.NSArray;
29
30		/**
31		* GenericAssociation binds one or more properties on an
32		* observable object to a display group. The controlled
33		* object is expected to use the ObserverCenter and will
34		* be observed by this association. <br><br>
35		*
36		* Bindings for this association are <i>generic</i>: the
37		* name of the aspect will be treated as a property key
38		* on the displayed object(s) and synchronized with the
39		* bound property on the controlled object. <br><br>
40		*
41		* NOTE: because we cannot assume that the controlled
42		* object will retain a reference to this association,
43		* you must explicitly retain a reference to prevent
44		* the association from getting garbage collected.
45		*
46		* @author michael@mpowers.net
47		* @author $Author: cgruber $
48		* @version $Revision: 904 $
49		*/
50	0	public class GenericAssociation extends EOAssociation
51		{
52		protected boolean objectModified;
53		protected Set aspectsModified;
54
55	0	static final NSArray aspects =
56	0	new NSArray( new Object[] {
57		} );
58	0	static final NSArray aspectSignatures =
59	0	new NSArray( new Object[] {
60		} );
61	0	static final NSArray objectKeysTaken =
62	0	new NSArray( new Object[] {
63		} );
64
65		/**
66		* Constructor specifying the object to be controlled by this
67		* association. Does not establish connection.
68		*/
69		public GenericAssociation ( Object anObject )
70		{
71	0	super( anObject );
72	0	objectModified = false;
73	0	aspectsModified = new HashSet();
74	0	}
75
76		/**
77		* Returns a List of aspect signatures whose contents
78		* correspond with the aspects list. Each element is
79		* a string whose characters represent a capability of
80		* the corresponding aspect. <ul>
81		* <li>"A" attribute: the aspect can be bound to
82		* an attribute.</li>
83		* <li>"1" to-one: the aspect can be bound to a
84		* property that returns a single object.</li>
85		* <li>"M" to-one: the aspect can be bound to a
86		* property that returns multiple objects.</li>
87		* </ul>
88		* An empty signature "" means that the aspect can
89		* bind without needing a key.
90		* This implementation returns "A1M" for each
91		* element in the aspects array.
92		*/
93		public static NSArray aspectSignatures ()
94		{
95	0	return aspectSignatures;
96		}
97
98		/**
99		* Returns a List that describes the aspects supported
100		* by this class. Each element in the list is the string
101		* name of the aspect. This implementation returns an
102		* empty list.
103		*/
104		public static NSArray aspects ()
105		{
106	0	return aspects;
107		}
108
109		/**
110		* Returns a List of EOAssociation subclasses that,
111		* for the objects that are usable for this association,
112		* are less suitable than this association.
113		*/
114		public static NSArray associationClassesSuperseded ()
115		{
116	0	return new NSArray();
117		}
118
119		/**
120		* Returns whether this class can control the specified
121		* object.
122		*/
123		public static boolean isUsableWithObject ( Object anObject )
124		{
125	0	return true;
126		}
127
128		/**
129		* Returns a List of properties of the controlled object
130		* that are controlled by this class. For example,
131		* "stringValue", or "selected".
132		*/
133		public static NSArray objectKeysTaken ()
134		{
135	0	return objectKeysTaken;
136		}
137
138		/**
139		* Returns the aspect that is considered primary
140		* or default. This is typically "value" or somesuch.
141		*/
142		public static String primaryAspect ()
143		{
144	0	return "";
145		}
146
147		/**
148		* Returns whether this association can bind to the
149		* specified display group on the specified key for
150		* the specified aspect.
151		*/
152		public boolean canBindAspect (
153		String anAspect, EODisplayGroup aDisplayGroup, String aKey)
154		{
155	0	return true;
156		}
157
158		/**
159		* Establishes a connection between this association
160		* and the controlled object. This implementation
161		* registers with ObserverCenter for change notifications
162		* from the controlled object.
163		*/
164		public void establishConnection ()
165		{
166	0	EOObserverCenter.addObserver( this, object() );
167	0	super.establishConnection();
168
169		// forces update from bindings
170	0	subjectChanged();
171	0	}
172
173		/**
174		* Breaks the connection between this association and
175		* its object. Override to stop listening for events
176		* from the object.
177		*/
178		public void breakConnection ()
179		{
180	0	EOObserverCenter.removeObserver( this, object() );
181	0	super.breakConnection();
182	0	}
183
184		/**
185		* Overridden to track which observed object is changing.
186		*/
187		public void objectWillChange( Object anObject )
188		{
189	0	if ( object() == anObject )
190		{
191	0	objectModified = true;
192	0	}
193		else
194		{
195	0	aspectsModified.add( aspectToGroup.allKeysForObject( anObject ) );
196		}
197	0	}
198
199		/**
200		* Called when either the selection or the contents
201		* of an associated display group have changed.
202		*/
203		public void subjectChanged ()
204		{
205		String aspect;
206		String key;
207		Object value;
208		EODisplayGroup displayGroup;
209		Iterator iterator;
210
211	0	iterator = aspectsModified.iterator();
212	0	while ( iterator.hasNext() )
213		{
214	0	aspect = (String) iterator.next();
215	0	key = displayGroupKeyForAspect( aspect );
216	0	displayGroup = displayGroupForAspect( aspect );
217
218	0	value = readValueFromDisplayGroupForKey( displayGroup, key );
219	0	writeValueForKey( object(), value, key );
220	0	}
221	0	aspectsModified.clear();
222
223	0	if ( objectModified )
224		{
225	0	iterator = aspectToGroup.keySet().iterator();
226	0	while ( iterator.hasNext() )
227		{
228	0	aspect = (String) iterator.next();
229	0	key = displayGroupKeyForAspect( aspect );
230	0	value = readValueForKey( object(), key );
231	0	displayGroup = displayGroupForAspect( aspect );
232	0	displayGroup.setSelectedObjectValue( value, key );
233	0	}
234		}
235	0	}
236
237		protected Object readValueForKey( Object object, String key )
238		{
239	0	if ( object instanceof EOKeyValueCoding )
240		{
241	0	return ((EOKeyValueCoding)object).valueForKey( key );
242		}
243	0	return EOKeyValueCodingSupport.valueForKey( object, key );
244		}
245
246		protected void writeValueForKey( Object object, Object value, String key )
247		{
248	0	if ( object instanceof EOKeyValueCoding )
249		{
250	0	((EOKeyValueCoding)object).takeValueForKey( value, key );
251	0	}
252		else
253		{
254	0	EOKeyValueCodingSupport.takeValueForKey( object, value, key );
255		}
256	0	}
257
258		protected Object readValueFromDisplayGroupForKey(
259		EODisplayGroup displayGroup, String key )
260		{
261		Object value;
262
263	0	if ( displayGroup.selectedObjects().size() > 1 )
264		{
265		// if there're more than one object selected, set
266		// the value to blank for all of them.
267		Object previousValue;
268
269	0	Iterator indexIterator = displayGroup.selectionIndexes().
270	0	iterator();
271
272		// get value for the first selected object.
273	0	int initialIndex = ( (Integer)indexIterator.next() ).intValue();
274	0	previousValue = displayGroup.valueForObjectAtIndex(
275	0	initialIndex, key );
276	0	value = null;
277
278		// go through the rest of the selected objects, compare each
279		// value with the previous one. continue comparing if two
280		// values are equal, break the while loop if they're different.
281		// the final value will be the common value of all selected objects
282		// if there is one, or be blank if there is not.
283	0	while ( indexIterator.hasNext() )
284		{
285	0	int index = ( (Integer)indexIterator.next() ).intValue();
286	0	Object currentValue = displayGroup.valueForObjectAtIndex(
287	0	index, key );
288	0	if ( currentValue != null && !currentValue.equals( previousValue ) )
289		{
290	0	value = null;
291	0	break;
292		}
293		else
294		{
295		// currentValue is the same as the previous one
296	0	value = currentValue;
297		}
298
299	0	} // end while
300
301	0	} else {
302
303	0	value = displayGroup.selectedObjectValueForKey( key );
304		} // end checking size of displayGroup
305
306	0	return value;
307		}
308
309		/**
310		* Writes the value currently in the component
311		* to the selected object in the display group
312		* bound to the value aspect.
313		* @return false if there were problems validating,
314		* or true to continue.
315		*/
316		protected boolean writeValueForAspect( Object value, String aspect )
317		{
318	0	EODisplayGroup displayGroup =
319	0	displayGroupForAspect( aspect );
320	0	if ( displayGroup != null )
321		{
322	0	String key = displayGroupKeyForAspect( aspect );
323
324	0	boolean returnValue = true;
325	0	Iterator selectedIterator = displayGroup.selectionIndexes().iterator();
326	0	while ( selectedIterator.hasNext() )
327		{
328	0	int index = ( (Integer)selectedIterator.next() ).intValue();
329
330	0	if ( !displayGroup.setValueForObjectAtIndex( value, index, key ) )
331		{
332	0	returnValue = false;
333		}
334	0	}
335	0	return returnValue;
336		}
337	0	return false;
338		}
339
340		/**
341		* Forces this association to cause the object to
342		* stop editing and validate the user's input.
343		* @return false if there were problems validating,
344		* or true to continue.
345		*/
346		public boolean endEditing ()
347		{
348	0	return false;
349		//! return writeValueToDisplayGroup();
350		}
351
352		}
353
354		/*
355		* $Log$
356		* Revision 1.2 2006/02/18 23:14:35 cgruber
357		* Update imports and maven dependencies.
358		*
359		* Revision 1.1 2006/02/16 13:22:22 cgruber
360		* Check in all sources in eclipse-friendly maven-enabled packages.
361		*
362		* Revision 1.3 2003/08/06 23:07:52 chochos
363		* general code cleanup (mostly, removing unused imports)
364		*
365		* Revision 1.2 2001/11/08 19:51:24 mpowers
366		* Draft implementation.
367		*
368		* Revision 1.1 2001/11/02 23:15:04 mpowers
369		* Contributing "generic association".
370		*
371		*
372		*/
373