/**********************************************
    * Copyright (C) 2011 Lukas Laag
    * This file is part of svgreal.
    * 
    * svgreal is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * svgreal 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 General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with svgreal.  If not, see http://www.gnu.org/licenses/
   **********************************************/package org.vectomatic.svg.edit.client.model;
  
  import java.util.Collection;
  import java.util.Map;
  
  import com.extjs.gxt.ui.client.data.ChangeEvent;
  import com.extjs.gxt.ui.client.data.ChangeEventSupport;
  import com.extjs.gxt.ui.client.data.ChangeListener;
  import com.extjs.gxt.ui.client.data.Model;
  import com.extjs.gxt.ui.client.data.PropertyChangeEvent;
  import com.extjs.gxt.ui.client.store.Store;
  import com.extjs.gxt.ui.client.util.Util;
  import com.google.gwt.core.client.GWT;
  
  /**
   * Base class for GXT {@link com.extjs.gxt.ui.client.data.Model}
   * implementations which rely on a {@link MetaModel} to supply
   * the model properties.
   * @author laaglu
   */
  public abstract class AbstractModel<U> implements Model {
  	/**
  	 * To implement ChangeEventSource
  	 */
  	protected transient ChangeEventSupport changeEventSupport;
  	/**
  	 * The native object backing this model
  	 */
  	protected U element;
  
  	public AbstractModel(U element) {
  	    this.element = element;
  	    changeEventSupport = new ChangeEventSupport();
  	}
  	
  	public abstract MetaModel<U> getMetaModel();
  	
  	public U getElement() {
  		return element;
  	}
  	
  	/**
  	 * Returns the store which contains this model
  	 * @return
  	 */
  	public abstract Store getStore();
  
  	///////////////////////////////////////////////////
  	// Implementation of the ModelData interface
  	///////////////////////////////////////////////////
  	
  	@Override
  	public <X> X get(String property) {
  		IMetadata propertyDefinition = getMetaModel().getMetadata(property);
  		assert propertyDefinition != null : "Undefined property " + property;
  		return (X)propertyDefinition.get(element);
  	}
  
  	@Override
  	public Map<String, Object> getProperties() {
  		return getMetaModel().getProperties(element);
  	}
  
  	@Override
  	public Collection<String> getPropertyNames() {
  		return getMetaModel().getPropertyNames();
  	}
  
  	@Override
  	public <X> X remove(String property) {
  		IMetadata propertyDefinition = getMetaModel().getMetadata(property);
  		assert propertyDefinition != null : "Undefined property " + property;
  		X oldValue = (X)propertyDefinition.remove(element);
  		notifyPropertyChanged(propertyDefinition.getName(), null, oldValue);
  		return oldValue;
  	}
  
  	@Override
  	public <X> X set(String property, X value) {
  		IMetadata propertyDefinition = getMetaModel().getMetadata(property);
  		assert propertyDefinition != null : "Undefined property " + property;
  		X oldValue = (X)propertyDefinition.set(element, value);
  		GWT.log("AbstractModel.set(" + property + ") = " + oldValue + ", " + value);
 		notifyPropertyChanged(propertyDefinition.getName(), value, oldValue);
 		return oldValue;
 	}
 	
 	///////////////////////////////////////////////////
 	// Implementation of the ChangeEventSource interface
 	///////////////////////////////////////////////////
 	@Override
 	public void addChangeListener(ChangeListener... listener) {
 	    changeEventSupport.addChangeListener(listener);
 	}
 
 	@Override
 	public void removeChangeListener(ChangeListener... listener) {
 	    changeEventSupport.removeChangeListener(listener);
 	}
 
 	@Override
 	public void removeChangeListeners() {
 	    changeEventSupport.removeChangeListeners();
 	}
 
 	@Override
 	public void setSilent(boolean silent) {
 	    changeEventSupport.setSilent(silent);
 	}
 
 	@Override
 	public void notify(ChangeEvent event) {
 	    changeEventSupport.notify(event);
 	}
 	
 	protected void notifyPropertyChanged(String name, Object value, Object oldValue) {
 		if (!Util.equalWithNull(value, oldValue)) {
 			notify(new PropertyChangeEvent(Update, this, name, oldValue, value));
 		}
 	}
 	
 	public boolean isSilent() {
 	    return changeEventSupport.isSilent();
 	}
 
 	protected void fireEvent(int type) {
 		notify(new ChangeEvent(type, this));
 	}
 
 	protected void fireEvent(int type, Model item) {
 		notify(new ChangeEvent(type, this, item));
 	}
 }