/*
* Ext GWT - Ext for GWT
* Copyright(c) 2007-2009, Ext JS, LLC.
* licensing@extjs.com
*
* http://extjs.com/license
*/
package com.extjs.gxt.ui.client.binding;
import java.util.Collection;
import java.util.Map;
import com.extjs.gxt.ui.client.core.FastMap;
import com.extjs.gxt.ui.client.data.ModelData;
import com.extjs.gxt.ui.client.event.BaseObservable;
import com.extjs.gxt.ui.client.event.BindingEvent;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.widget.form.Field;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.DeferredCommand;
/**
* Aggregates one to many field bindings.
*
* <dl>
* <dt>Events:</dt>
*
* <dd><b>BeforeBind</b> : BindingEvent(source, model)<br>
* <div>Fires before binding.</div>
* <ul>
* <li>source : this</li>
* <li>model : the model to bind</li>
* </ul>
* </dd>
*
* <dd><b>Bind</b> : BindingEvent(source, model)<br>
* <div>Fires after successful binding.</div>
* <ul>
* <li>source : this</li>
* <li>model : the binded model</li>
* </ul>
* </dd>
*
* <dd><b>UnBind</b> : BindingEvent(source, model)<br>
* <div>Fires after successful unbinding.</div>
* <ul>
* <li>source : this</li>
* <li>model : the unbound model</li>
* </ul>
* </dd>
* </dl>
*
* @see FieldBinding
*/
public class Bindings extends BaseObservable {
protected ModelData model;
protected Map<String, FieldBinding> bindings;
/**
* Creates a new bindings instance.
*/
public Bindings() {
bindings = new FastMap<FieldBinding>();
}
/**
* Adds a field binding.
*
* @param binding the binding instance to add
*/
public void addFieldBinding(FieldBinding binding) {
bindings.put(binding.getField().getId(), binding);
}
/**
* Binds the model instance.
*
* @param model the model
*/
public void bind(final ModelData model) {
DeferredCommand.addCommand(new Command() {
public void execute() {
BindingEvent e = new BindingEvent(Bindings.this, model);
if (fireEvent(Events.BeforeBind, e)) {
if (Bindings.this.model != null) {
unbind();
}
Bindings.this.model = model;
for (FieldBinding binding : bindings.values()) {
binding.bind(model);
}
fireEvent(Events.Bind, e);
}
}
});
}
/**
* Clears all fields by setting the value for each field to <code>null</code>.
*/
public void clear() {
for (FieldBinding fieldBinding : getBindings()) {
fieldBinding.getField().clear();
}
}
/**
* Returns the field binding for the given field.
*
* @param field the field
* @return the field binding or null of no match
*/
public FieldBinding getBinding(Field<?> field) {
return bindings.get(field.getId());
}
/**
* Returns all bindings.
*
* @return the collection of bindings
*/
public Collection<FieldBinding> getBindings() {
return bindings.values();
}
/**
* Returns the currently bound model;
*
* @return the currently bound model;
*/
public ModelData getModel() {
return model;
}
/**
* Removes a field binding.
*
* @param binding the binding instance to remove
*/
public void removeFieldBinding(FieldBinding binding) {
bindings.remove(binding.getField().getId());
}
/**
* Unbinds the current model.
*/
public void unbind() {
if (model != null) {
for (FieldBinding binding : bindings.values()) {
binding.unbind();
}
fireEvent(Events.UnBind, new BindingEvent(this, model));
model = null;
}
}
}