/*
* org.openmicroscopy.shoola.util.ui.component.ObservableComponent
*
*------------------------------------------------------------------------------
* Copyright (C) 2006 University of Dundee. All rights reserved.
*
*
* This program 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 2 of the License, or
* (at your option) any later version.
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*------------------------------------------------------------------------------
*/
package org.openmicroscopy.shoola.util.ui.component;
//Java imports
import java.beans.PropertyChangeListener;
import javax.swing.event.ChangeListener;
//Third-party libraries
//Application-internal dependencies
/**
* Defines the interface that a component usually implements
* to let other components observe state changes of its properties.
* <p>This interface requires implementing classes to support both a <i>push</i>
* and <i>pull</i> model, based on the <i>JavaBeans</i> and <i>Swing</i> APIs.
* In the <i>push</i> model, the publisher (that is the object implementing
* this interface) sends all changed data when it notifies the subscribers
* — or observers, that is <i>listeners</i> in <i>JavaBeans</i> terms.
* Implementing classes are required to support this model through <i>Java
* Beans bound properties</i>. In the <i>pull</i> model, just a change
* notification is sent off and subscribers subsequently query the publisher
* about the state change. Implementing classes are required to support this
* model with <i>Swing</i> light-weight event notifications.</p>
* <p>Implementing classes are required to avoid dispatching the same event to
* the same observer more than once. That is, even if an observer registers
* twice for a given event type, it only gets notified once per each occurrence
* of said event type. This also implies that if an observer registers for
* all <i>bound</i> properties and for a specific one <code>P</code> at the
* same time, then every time <code>P</code> changes the observer has to get
* only <i>one</i> notification.</p>
*
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author <br>Andrea Falconi
* <a href="mailto:a.falconi@dundee.ac.uk">
* a.falconi@dundee.ac.uk</a>
* @version 2.2
* <small>
* (<b>Internal version:</b> $Revision$ $Date$)
* </small>
* @since OME2.2
*/
public interface ObservableComponent
{
/**
* Registers an observer with this component.
* The observer will be notified of <i>every</i> state change.
*
* @param observer The observer to register.
* @throws NullPointerException If <code>observer</code> is
* <code>null</code>.
* @see #removeChangeListener(ChangeListener)
*/
public void addChangeListener(ChangeListener observer);
/**
* Removes an observer from the change notification list.
*
* @param observer The observer to remove.
* @throws NullPointerException If <code>observer</code> is
* <code>null</code>.
* @see #addChangeListener(ChangeListener)
*/
public void removeChangeListener(ChangeListener observer);
/**
* Registers an observer with this component.
* The observer will be notified of every <i>bound property</i> change.
*
* @param observer The observer to register.
* @throws NullPointerException If <code>observer</code> is
* <code>null</code>.
* @see #removePropertyChangeListener(PropertyChangeListener)
*/
public void addPropertyChangeListener(PropertyChangeListener observer);
/**
* Removes an observer from the change notification list.
*
* @param observer The observer to remove.
* @throws NullPointerException If <code>observer</code> is
* <code>null</code>.
* @see #addPropertyChangeListener(PropertyChangeListener)
*/
public void removePropertyChangeListener(PropertyChangeListener observer);
/**
* Registers an observer with this component.
* The observer will be notified of every change to the specified
* <i>bound property</i>.
*
* @param propertyName The name of the property. This is usually defined
* in a <code>public static</code> field by the
* implementing component.
* @param observer The observer to register.
* @throws NullPointerException If <code>propertyName</code> or
* <code>observer</code> is
* <code>null</code>.
* @see #removePropertyChangeListener(String, PropertyChangeListener)
*/
public void addPropertyChangeListener(String propertyName,
PropertyChangeListener observer);
/**
* Removes an observer from the change notification list for the specified
* <i>bound property</i>.
* Note that the observer will still receive notification of other property
* changes if it has registered for other properties.
*
* @param propertyName The name of the property. This is usually defined
* in a <code>public static</code> field by the
* implementing component.
* @param observer The observer to remove.
* @throws NullPointerException If <code>propertyName</code> or
* <code>observer</code> is
* <code>null</code>.
* @see #addPropertyChangeListener(String, PropertyChangeListener)
*/
public void removePropertyChangeListener(String propertyName,
PropertyChangeListener observer);
}