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org.scopemvc.model.basic
Class BasicModel  

java.lang.Object
  org.scopemvc.model.basic.BasicModel

All Implemented Interfaces:

org.scopemvc.core.ModelChangeEventSource, org.scopemvc.core.ModelChangeListener, org.scopemvc.core.ModelChangeTypes

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public abstract class BasicModel

extends java.lang.Object

implements org.scopemvc.core.ModelChangeEventSource, org.scopemvc.core.ModelChangeTypes

A simple implementation of ModelChangeEventSource for use as a base class. An alternative (JavaBeans style) is to use ModelChangeEventSupport as a delegate in all models.

To implement a BasicModel:

1. extend BasicModel,
2. Notify interested listeners of changes in Model state at the end of set methods by: fireModelChange(...)
3. Register as a ModelChangeListener with submodels in the appropriate set methods to ensure event propogation up the tree of models. For example:

    public final static Selector NAME = Selector.fromString("name");
    public final static Selector ADDRESS = Selector.fromString("address");
    
    public void setAddress(AddressModel inAddress) throws ModelException {
        if (inAddress == address) {
    			return;
    		}
        unlistenOldSubmodel(ADDRESS);
        address = inAddress;
        listenNewSubmodel(ADDRESS);
        fireModelChange(VALUE_CHANGE, ADDRESS);
    }
    

   This ensures that any change in the Address's state is received by this parent which will then fire its own ModelChangeEvent to its listeners. See ModelChangeEventSource for more discussion. Note the use of the Selector constants: this is for convenience (and performance).
4. Use Scope's collection models instead of the regular Java collections: Scope collections propogate changes to submodels as above and are compliant ModelChangeEventSources. These collections must be listened to in the same way as other submodel properties. Note that Scope collections are just thin wrappers on native Java collections.

Version:

$Revision: 1.6 $ $Date: 2002/01/26 09:46:20 $

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Field Summary
private static org.apache.commons.logging.Log	LOG
private  org.scopemvc.core.PropertyManager	manager
private  ModelChangeEventSupport	mceSupport

 

Fields inherited from interface org.scopemvc.core.ModelChangeTypes

ACCESS_CHANGED, VALUE_ADDED, VALUE_CHANGED, VALUE_REMOVED

 

Constructor Summary

BasicModel()

 

Method Summary
void	addModelChangeListener(org.scopemvc.core.ModelChangeListener inListener)
void	fireModelChange(int inChangeType, org.scopemvc.core.Selector inSelector)
protected  void	listenNewSubmodel(org.scopemvc.core.Selector inSelector)           Convenience for BasicModel implementors: call this at the end of setters for submodel properties (ie properties of type ModelChangeEventSource) to register this as a ModelChangeListener to the current submodel for event propogation.
void	makeActive(boolean inActive)            Control whether this BasicModel broadcasts ModelChangeEvents.
void	modelChanged(org.scopemvc.core.ModelChangeEvent inEvent)            Handle changes to children ModelChangeEventSources by firing a change event from this (and propogating the original Selector).
void	removeModelChangeListener(org.scopemvc.core.ModelChangeListener inListener)
protected  void	unlistenOldSubmodel(org.scopemvc.core.Selector inSelector)           Convenience for BasicModel implementors: call this at the start of setters for submodel properties (ie properties of type ModelChangeEventSource) to deregister this as a ModelChangeListener to the current submodel (about to be set to another Model).

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Field Detail

LOG

private static final org.apache.commons.logging.Log LOG

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mceSupport

private ModelChangeEventSupport mceSupport

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manager

private org.scopemvc.core.PropertyManager manager

Constructor Detail

BasicModel

public BasicModel()

Method Detail

addModelChangeListener

public final void addModelChangeListener(org.scopemvc.core.ModelChangeListener inListener)

Specified by:

addModelChangeListener in interface org.scopemvc.core.ModelChangeEventSource

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removeModelChangeListener

public final void removeModelChangeListener(org.scopemvc.core.ModelChangeListener inListener)

Specified by:

removeModelChangeListener in interface org.scopemvc.core.ModelChangeEventSource

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fireModelChange

public final void fireModelChange(int inChangeType,
                                  org.scopemvc.core.Selector inSelector)

Specified by:

fireModelChange in interface org.scopemvc.core.ModelChangeEventSource

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modelChanged

public void modelChanged(org.scopemvc.core.ModelChangeEvent inEvent)

Handle changes to children ModelChangeEventSources by firing a change event from this (and propogating the original Selector). If the event's source is no longer a child property of this parent then there is no need to continue propogating the event.

Specified by:

modelChanged in interface org.scopemvc.core.ModelChangeEventSource

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unlistenOldSubmodel

protected final void unlistenOldSubmodel(org.scopemvc.core.Selector inSelector)

Convenience for BasicModel implementors: call this at the start of setters for submodel properties (ie properties of type ModelChangeEventSource) to deregister this as a ModelChangeListener to the current submodel (about to be set to another Model).

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listenNewSubmodel

protected final void listenNewSubmodel(org.scopemvc.core.Selector inSelector)

Convenience for BasicModel implementors: call this at the end of setters for submodel properties (ie properties of type ModelChangeEventSource) to register this as a ModelChangeListener to the current submodel for event propogation.

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makeActive

public void makeActive(boolean inActive)

Control whether this BasicModel broadcasts ModelChangeEvents. Make sure nested calls are properly matched to fully re-activate a BasicModel that was deactivated.

Subclasses may override this to propogate the activation state to child BasicModel properties if necessary.

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> scopemvc >> model >> [ basic overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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