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Diffstat (limited to 'projects/net.wotonomy.ui/src/main/java/net/wotonomy/ui/MasterDetailAssociation.java')
| -rw-r--r-- | projects/net.wotonomy.ui/src/main/java/net/wotonomy/ui/MasterDetailAssociation.java | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/projects/net.wotonomy.ui/src/main/java/net/wotonomy/ui/MasterDetailAssociation.java b/projects/net.wotonomy.ui/src/main/java/net/wotonomy/ui/MasterDetailAssociation.java new file mode 100644 index 0000000..2aea8d3 --- /dev/null +++ b/projects/net.wotonomy.ui/src/main/java/net/wotonomy/ui/MasterDetailAssociation.java @@ -0,0 +1,406 @@ +/* +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.ui; + +import net.wotonomy.control.EOClassDescription; +import net.wotonomy.control.EODataSource; +import net.wotonomy.control.EOEditingContext; +import net.wotonomy.control.EOObserverCenter; +import net.wotonomy.control.PropertyDataSource; +import net.wotonomy.foundation.NSArray; +import net.wotonomy.foundation.NSMutableArray; + +/** +* MasterDetailAssociation binds a display group to a property +* on the selected object of another display group. +* Bindings are: +* <ul> +* <li>parent: The property on the selected object of the +* bound display group that is expected to be an indexed property.</li> +* </ul> +* +* @author michael@mpowers.net +* @author $Author: cgruber $ +* @version $Revision: 904 $ +*/ +public class MasterDetailAssociation extends EOAssociation +{ + static final NSArray aspects = + new NSArray( new Object[] { + ParentAspect + } ); + static final NSArray aspectSignatures = + new NSArray( new Object[] { + AttributeToOneAspectSignature + } ); + static final NSArray objectKeysTaken = + new NSArray( new Object[] { + "allObjects" + } ); + + /** + * Used to be notified of changes to objects in the + * controlled display group. requalify() should place + * all objects fetched into the controlled group into + * this array. + * Otherwise, the parent object is only marked as + * changed for inserts and deletes. + */ + protected NSMutableArray observableArray; + + /** + * Constructor expecting an EODisplayGroup. + * If the controlled display group does not have a data source, + * a new PropertyDataSource will be used. + */ + public MasterDetailAssociation ( Object anObject ) + { + super( anObject ); + observableArray = new ObservableArray( this ); + } + + /** + * 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 ( anObject instanceof EODisplayGroup ); + } + + /** + * 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 ParentAspect; + } + + /** + * 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 ( aspects.containsObject( anAspect ) ); + } + + /** + * Establishes a connection between this association + * and the controlled object. Subclasses should begin + * listening for events from their controlled object here. + */ + public void establishConnection () + { + //NOTE: if nothing refers to this assocation, it gets gc'd. + // otherwise, this is not needed. + component().addObserver( this ); + + EODisplayGroup displayGroup = + displayGroupForAspect( ParentAspect ); + String key = + displayGroupKeyForAspect( ParentAspect ); + + // obtain and qualify new data source from existing source if necessary + if ( component().dataSource() == null ) + { + if ( ( displayGroup != null ) && ( displayGroup.dataSource() != null ) ) + { + component().setDataSource( + displayGroup.dataSource(). + dataSourceQualifiedByKey( key ) ); + } + } + + // set up proxy data source if necessary + if ( component().dataSource() == null ) + { + // get context and class desc from master group + EOEditingContext editingContext = null; + EOClassDescription classDesc = null; + if ( displayGroup != null ) + { + EODataSource dataSource = displayGroup.dataSource(); + if ( dataSource != null ) + { + editingContext = dataSource.editingContext(); + EOClassDescription parentDesc = dataSource.classDescriptionForObjects(); + if ( parentDesc != null ) + { + classDesc = parentDesc.classDescriptionForDestinationKey( key ); + } + } + } + + //FIXME: should this be called DetailDataSource? + component().setDataSource( + new PropertyDataSource( editingContext, classDesc ) ); + } + + super.establishConnection(); + requalify(); + } + + /** + * Breaks the connection between this association and + * its object. Override to stop listening for events + * from the object. + */ + public void breakConnection () + { + //NOTE: if nothing refers to this assocation, it gets gc'd. + // otherwise, this is not needed. + component().deleteObserver( this ); + + super.breakConnection(); + } + + /** + * Called when either the selection or the contents + * of an associated display group have changed. + */ + public void subjectChanged () + { + EODisplayGroup displayGroup; + + // parent aspect + displayGroup = displayGroupForAspect( ParentAspect ); + if ( displayGroup != null ) + { + if ( displayGroup.selectionChanged() ) + { + requalify(); + } + else + if ( displayGroup.contentsChanged() ) + { + requalify(); + } + } + } + + /** + * Overridden to intercept notifications of changes to objects + * in the controlled display group and broadcast a change on the + * parent group's selected object. All other notifications are + * passed to the super implementation. + */ + public void objectWillChange ( Object anObject ) + { + // if child display group is notifying + if ( ! ( anObject instanceof EODisplayGroup ) ) + { + // mark parent group's object as changed + EODisplayGroup displayGroup = displayGroupForAspect( ParentAspect ); + if ( displayGroup != null ) + { + Object selected = displayGroup.selectedObject(); + if ( selected != null ) + { + // only notify if childrenKey is an attribute of parentDesc + // (and therefore not a toOne or toMany relationship) + EOClassDescription parentDesc = + EOClassDescription.classDescriptionForClass( + selected.getClass() ); + String key = displayGroupKeyForAspect( ParentAspect ); + if ( key != null ) + { + int idx = key.indexOf( '.' ); + if ( idx != -1 ) key = key.substring( 0, idx ); + if ( parentDesc.attributeKeys().contains( key ) ) + { + // only notify if we are an attribute key + EOObserverCenter.notifyObserversObjectWillChange( selected ); + } + } + } + } + } + else // display group is notifying + { + // call super so subjectChanged will be called + super.objectWillChange( anObject ); + } + } + + /** + * Called by subjectChanged() to requalify the controlled + * display group with the selected object and the bound key. + */ + protected void requalify() + { + EODisplayGroup component = component(); + EODisplayGroup displayGroup = displayGroupForAspect( ParentAspect ); + String key = displayGroupKeyForAspect( ParentAspect ); + + if ( ( displayGroup.selectedObject() != null ) + && ( component.dataSource() != null ) ) + { + component.dataSource().qualifyWithRelationshipKey( + key, displayGroup.selectedObject() ); + component.fetch(); + observableArray.setArray( component.allObjects() ); + } + else // no selection or no data source, clear + { + component.setObjectArray( null ); + observableArray.removeAllObjects(); + } + component.updateDisplayedObjects(); + } + + /** + * This implementation returns ObserverPrioritySecond + * so that master detail assocations are notified before + * other associations. + */ + public int priority () + { + return ObserverPrioritySecond; + } + + // convenience + + private EODisplayGroup component() + { + return (EODisplayGroup) object(); + } + +} + +/* + * $Log$ + * 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 1.14 2004/02/04 20:00:49 mpowers + * Improved change notification for dotted key paths. + * + * Revision 1.13 2003/08/06 23:07:52 chochos + * general code cleanup (mostly, removing unused imports) + * + * Revision 1.12 2001/10/26 18:39:05 mpowers + * Now a delayed observer with a higher priority, so that it is processed + * before other associations. + * + * Revision 1.11 2001/06/26 21:39:33 mpowers + * Added check for null component data source before requalifying. + * + * Revision 1.10 2001/05/21 14:04:15 mpowers + * No longer changing a detail group's data source if it's already specified. + * + * Revision 1.9 2001/05/18 21:08:46 mpowers + * Now calling updateDisplayedObjects on detail after master changes. + * + * Revision 1.8 2001/05/14 15:26:42 mpowers + * Modified logic for controlled groups that have no data source already set. + * + * Revision 1.7 2001/05/04 14:42:58 mpowers + * Now getting stored values in KeyValueCoding. + * MasterDetail now marks dirty based on whether it's an attribute + * or relation. + * Implemented editing context marker. + * + * Revision 1.6 2001/04/29 02:29:31 mpowers + * Debugging relationship faulting. + * + * Revision 1.4 2001/02/20 16:38:55 mpowers + * MasterDetailAssociations now observe their controlled display group's + * objects for changes to that the parent object will be marked as updated. + * Before, only inserts and deletes to an object's items are registered. + * Also, moved ObservableArray to package access. + * + * Revision 1.3 2001/01/18 16:57:18 mpowers + * Fixed problem with losing connection: the association was getting + * garbage collected because nothing referred to it. All other associations + * make themselves listeners of their controlled object, and that has been + * the only thing keeping them from getting gc'd. This will need to be fixed. + * + * Revision 1.2 2001/01/17 23:06:09 mpowers + * TreeAssociation now modifies the contents of the children display + * group rather than adding items to the titles display group. + * + * Revision 1.1.1.1 2000/12/21 15:48:23 mpowers + * Contributing wotonomy. + * + * Revision 1.5 2000/12/20 16:25:40 michael + * Added log to all files. + * + * + */ + |