/*******************************************************************************
* Copyright (c) 2008 Matthew Hall and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Matthew Hall - initial API and implementation (bug 194734)
* Matthew Hall - bug 195222, 247997
******************************************************************************/
package org.eclipse.core.databinding.property.list;
import java.util.Collections;
import java.util.List;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.list.ListDiff;
import org.eclipse.core.databinding.property.INativePropertyListener;
import org.eclipse.core.databinding.property.ISimplePropertyListener;
import org.eclipse.core.internal.databinding.property.list.SimplePropertyObservableList;
/**
* Simplified abstract implementation of IListProperty. This class takes care of
* most of the functional requirements for an IListProperty implementation,
* leaving only the property-specific details to subclasses.
* <p>
* Subclasses must implement these methods:
* <ul>
* <li> {@link #getElementType()}
* <li> {@link #doGetList(Object)}
* <li> {@link #doSetList(Object, List, ListDiff)}
* <li> {@link #adaptListener(ISimplePropertyListener)}
* <li> {@link #doAddListener(Object, INativePropertyListener)}
* <li> {@link #doRemoveListener(Object, INativePropertyListener)}
* </ul>
* <p>
* In addition, we recommended overriding {@link #toString()} to return a
* description suitable for debugging purposes.
*
* @since 1.2
*/
public abstract class SimpleListProperty extends ListProperty {
public IObservableList observe(Realm realm, Object source) {
return new SimplePropertyObservableList(realm, source, this);
}
// Accessors
/**
* Returns an unmodifiable List with the current contents of the source's
* list property
*
* @param source
* the property source
* @return an unmodifiable List with the current contents of the source's
* list property
* @noreference This method is not intended to be referenced by clients.
*/
public final List getList(Object source) {
if (source == null)
return Collections.EMPTY_LIST;
return Collections.unmodifiableList(doGetList(source));
}
/**
* Returns a List with the current contents of the source's list property
*
* @param source
* the property source
* @return a List with the current contents of the source's list property
* @noreference This method is not intended to be referenced by clients.
*/
protected abstract List doGetList(Object source);
// Mutators
/**
* Updates the property on the source with the specified change.
*
* @param source
* the property source
* @param list
* the new list
* @param diff
* a diff describing the change
* @noreference This method is not intended to be referenced by clients.
*/
public final void setList(Object source, List list, ListDiff diff) {
if (source != null && !diff.isEmpty())
doSetList(source, list, diff);
}
/**
* Updates the property on the source with the specified change.
*
* @param source
* the property source
* @param list
* the new list
* @param diff
* a diff describing the change
* @noreference This method is not intended to be referenced by clients.
*/
protected abstract void doSetList(Object source, List list, ListDiff diff);
/**
* Returns a listener which implements the correct listener interface for
* the expected source object, and which parlays property change events from
* the source object to the given listener. If there is no listener API for
* this property, this method returns null.
*
* @param listener
* the property listener to receive events
* @return a native listener which parlays property change events to the
* specified listener.
* @noreference This method is not intended to be referenced by clients.
*/
public abstract INativePropertyListener adaptListener(
ISimplePropertyListener listener);
/**
* Adds the specified listener as a listener for this property on the
* specified property source. If the source object has no listener API for
* this property (i.e. {@link #adaptListener(ISimplePropertyListener)}
* returns null), this method does nothing.
*
* @param source
* the property source
* @param listener
* a listener obtained from calling
* {@link #adaptListener(ISimplePropertyListener)}.
* @noreference This method is not intended to be referenced by clients.
*/
public final void addListener(Object source,
INativePropertyListener listener) {
if (source != null)
doAddListener(source, listener);
}
/**
* Adds the specified listener as a listener for this property on the
* specified property source. If the source object has no listener API for
* this property (i.e. {@link #adaptListener(ISimplePropertyListener)}
* returns null), this method does nothing.
*
* @param source
* the property source
* @param listener
* a listener obtained from calling
* {@link #adaptListener(ISimplePropertyListener)}.
* @noreference This method is not intended to be referenced by clients.
*/
protected abstract void doAddListener(Object source,
INativePropertyListener listener);
/**
* Removes the specified listener as a listener for this property on the
* specified property source. If the source object has no listener API for
* this property (i.e. {@link #adaptListener(ISimplePropertyListener)}
* returns null), this method does nothing.
*
* @param source
* the property source
* @param listener
* a listener obtained from calling
* {@link #adaptListener(ISimplePropertyListener)}.
* @noreference This method is not intended to be referenced by clients.
*/
public final void removeListener(Object source,
INativePropertyListener listener) {
if (source != null)
doRemoveListener(source, listener);
}
/**
* Removes the specified listener as a listener for this property on the
* specified property source. If the source object has no listener API for
* this property (i.e. {@link #adaptListener(ISimplePropertyListener)}
* returns null), this method does nothing.
*
* @param source
* the property source
* @param listener
* a listener obtained from calling
* {@link #adaptListener(ISimplePropertyListener)}.
* @noreference This method is not intended to be referenced by clients.
*/
protected abstract void doRemoveListener(Object source,
INativePropertyListener listener);
}