/*
 * Copyright (c) 2003,2007 Declarative Engineering LLC.
 * All rights reserved.  This program and the accompanying materials
 * are made available under the terms of the Declarative Engineering LLC
 * verson 1 which accompanies this distribution, and is available at
 * http://declarativeengineering.com/legal/DE_Developer_License_v1.txt
 */
package com.foundation.view;

import com.common.debug.*;
import com.foundation.attribute.AttributeSupport;
import com.foundation.event.EventSupport;
import com.foundation.metadata.Attribute;

/*
 * Models a view association with an entity attribute.
 */
public class AttributeAssociation extends ValueHolderAssociation implements IAttributeAssociation {
	/** The view unique number for this association. */
	private int associationNumber = 0;
	/** The handler which is invoked to get and set the attribute value. */
	private IAssociationHandler handler = null;
	/** The attribute's unique (within the context of the value holder's held type hierarchy) number. */
	private int attributeNumber = 0;
	/** The unique (within the context of the value holder's held type hierarchy) name of the attribute. */
	private String attributeName = null;
	/** The type of value returned when retreiving the attribute value.  Also the type required by the attribute setter method. */
	private Class attributeType = null;
	/** The listener for attribute change events.  This will either be an instance of IAttributeAssociationChangeListener or IEventAssociationChangeListener. */
	private Object listener = null;
/**
 * AttributeAssociation constructor.
 * @param handler The object that handles the method invokations to get and set the attribute value.
 * @param associationNumber The association number which will be passed to the handler when the assocation is invoked.  This number allows fast indexing of the methods that the handler handles.
 * @param component The component the association is connected to.
 * @param rowType The class which defines the attribute.
 * @param attribute The associated attribute's unique (within the class) identifier.
 * @param attributeType The class assignable by values held by the attribute.
 */
public AttributeAssociation(IAssociationHandler handler, int associationNumber, IAbstractComponent component, Class rowType, Attribute attribute, Class attributeType) {
	super(component, null, null, rowType);
	
	this.handler = handler;
	this.associationNumber = associationNumber;
	this.attributeNumber = attribute.getNumber();
	this.attributeName = AttributeSupport.getAttributeName(rowType, attributeNumber);
	this.attributeType = attributeType;
}//AttributeAssociation()//
/**
 * AttributeAssociation constructor.
 * @param handler The object that handles the method invokations to get and set the attribute value.
 * @param associationNumber The association number which will be passed to the handler when the assocation is invoked.  This number allows fast indexing of the methods that the handler handles.
 * @param component The component the association is connected to.
 * @param rowType The class which defines the attribute.
 * @param attributeName The associated attribute's unique (within the class) name.
 * @param attributeType The class assignable by values held by the attribute.
 */
public AttributeAssociation(IAssociationHandler handler, int associationNumber, IAbstractComponent component, Class rowType, String attributeName, Class attributeType) {
	super(component, null, null, rowType);
	
	this.listener = component;
	this.handler = handler;
	this.associationNumber = associationNumber;
	this.attributeName = attributeName;
	this.attributeNumber = AttributeSupport.getAttributeNumber(rowType, attributeName);
	this.attributeType = attributeType;
}//AttributeAssociation()//
/**
 * AttributeAssociation constructor.
 * @param handler The object that handles the method invokations to get and set the attribute value.
 * @param associationNumber The association number which will be passed to the handler when the assocation is invoked.  This number allows fast indexing of the methods that the handler handles.
 * @param component The component the association is connected to.
 * @param valueHolderName The name of the value holder for the attribute.  The value holder's held type defines the association if the value type is null.
 * @param valueHolderType The type that the held value must match in order to be valid.  This is optional and only used if the value holder is non-null.
 * @param attribute The associated attribute's unique (within the class) identifier.
 * @param attributeType The class assignable by values held by the attribute.
 */
public AttributeAssociation(IAssociationHandler handler, int associationNumber, IAbstractComponent component, String valueHolderName, Class valueHolderType, Class rowType, Attribute attribute, Class attributeType) {
	super(component, valueHolderName, valueHolderType, rowType);
	
	this.handler = handler;
	this.associationNumber = associationNumber;
	this.attributeNumber = attribute.getNumber();
	this.attributeName = AttributeSupport.getAttributeName(rowType == null ? getValueHolder().getHeldType() : rowType, attributeNumber);
	this.attributeType = attributeType;
}//AttributeAssociation()//
/**
 * AttributeAssociation constructor.
 * @param handler The object that handles the method invokations to get and set the attribute value.
 * @param associationNumber The association number which will be passed to the handler when the assocation is invoked.  This number allows fast indexing of the methods that the handler handles.
 * @param component The component the association is connected to.
 * @param valueHolderName The name of the value holder for the attribute.  The value holder's held type defines the association if the value type is null.
 * @param valueHolderType The type that the held value must match in order to be valid.  This is optional and only used if the value holder is non-null.
 * @param attributeName The associated attribute's unique (within the class) name.
 * @param attributeType The class assignable by values held by the attribute.
 */
public AttributeAssociation(IAssociationHandler handler, int associationNumber, IAbstractComponent component, String valueHolderName, Class valueHolderType, String attributeName, Class attributeType) {
	super(component, valueHolderName, valueHolderType, null);
	
	this.listener = component;
	this.handler = handler;
	this.associationNumber = associationNumber;
	this.attributeName = attributeName;
	this.attributeNumber = AttributeSupport.getAttributeNumber(valueHolderType == null ? getValueHolder().getHeldType() : valueHolderType, attributeName);
	this.attributeType = attributeType;
}//AttributeAssociation()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#getAttributeValue()
 */
public Object getAttributeValue() {
	try {
		if(getValueHolder().getValue() != null) {
			return handler.invokeGetMethod(associationNumber, getValueHolder().getValue());
		}//if//
		else {
			return null;
		}//else//
	}//try//
	catch(Throwable e) {
		Debug.log(e);
		return null;
	}//catch//
}//getAttributeValue()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#setAttributeValue(Object)
 */
public void setAttributeValue(Object value) {
	try {
		handler.invokeSetMethod(associationNumber, getValueHolder().getValue(), value);
	}//try//
	catch(Throwable e) {
		Debug.log(e);
	}//catch//
}//setAttributeValue()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#getAttributeValue(java.lang.Object)
 */
public Object getAttributeValue(Object object) {
	Object retVal = null;
	
	try {
		if(object != null) {
			retVal = handler.invokeGetMethod(associationNumber, object);
		}//if//
	}//try//
	catch(Throwable e) {
		Debug.log(e);
	}//catch//
	
	return retVal;
}//getAttributeValue()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#setAttributeValue(java.lang.Object, java.lang.Object)
 */
public void setAttributeValue(Object object, Object value) {
	if(object != null) {
		try {
			handler.invokeSetMethod(associationNumber, object, value);
		}//try//
		catch(Throwable e) {
			Debug.log(e);
		}//catch//
	}//if//
}//setAttributeValue()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#getAttributeType()
 */
public Class getAttributeType() {
	return attributeType;
}//getAttributeType()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#register()
 */
public void register() {
	getValueHolder().registerListener(this);
}//register()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#unregister()
 */
public void unregister() {
	getValueHolder().unregisterListener(this);
}//unregister()//
/* (non-Javadoc)
 * @see com.foundation.view.IAttributeAssociation#setChangeListener(com.foundation.view.IAttributeAssociationChangeListener)
 */
public void setChangeListener(IAttributeAssociationChangeListener listener) {
	if(listener == null) {
		listener = getComponent();
	}//if//
	
	this.listener = listener;
}//setChangeListener()//
/* (non-Javadoc)
 * @see com.foundation.view.IEventAssociation#setChangeListener(com.foundation.view.IEventAssociationChangeListener)
 */
public void setChangeListener(IEventAssociationChangeListener listener) {
	if(listener == null) {
		listener = getComponent();
	}//if//
	
	this.listener = listener;
}//setChangeListener()//
/* (non-Javadoc)
 * @see com.common.event.IHandler#evaluate(int, java.lang.Object[], int)
 */
public void evaluate(int eventNumber, Object[] parameters, int flags) {
	//Note: I commented out the isTrustedChangeEvent because we don't want to listen to lazy load and reflection load events which are marked as trusted.//
	//If we did listen to them we would be performing updates before we have finished initializing during an initialization where more than one association is connected to a lazy or reflection loaded attribute.//
	//We do care about reflection updates which are now marked as trusted when setting the attribute, but are not marked as trusted when firing the events.//
	//I don't think there is anything else marked as trusted that we care about here - thus the code is commented out.//
	if(EventSupport.isStandardEvent(flags)/* || EventSupport.isTrustedChangeEvent(flags)*/) {
		//Notify the listener.//
		if(listener instanceof IAttributeAssociationChangeListener) {
			((IAttributeAssociationChangeListener) listener).onValueChanged(this);
		}//if//
		else if(listener instanceof IEventAssociationChangeListener) {
			((IEventAssociationChangeListener) listener).onEventFired(this, EMPTY_ARGS);
		}//else if//
	}//if//
}//evaluate()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IAttributeAssociation#getAttributeName()
 */
public String getAttributeName() {
	return attributeName;
}//getAttributeName()//
/* (non-Javadoc)
 * @see com.foundation.tcv.swt.IEventAssociation#getEventName()
 */
public int getEventNumber() {
	return attributeNumber;
}//getEventNumber()//
}//AttributeAssociation//