package com.cedarsoft.presenter.model;
import com.cedarsoft.commons.struct.StructPart;
import com.cedarsoft.commons.struct.StructureChangedEvent;
import com.cedarsoft.commons.struct.StructureListener;
import com.cedarsoft.lookup.LookupChangeEvent;
import com.cedarsoft.lookup.LookupChangeListener;
import org.jetbrains.annotations.NotNull;
import javax.swing.ListModel;
import javax.swing.event.ListDataEvent;
import javax.swing.event.ListDataListener;
import java.lang.Override;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
/**
*
*/
public class StructBasedListModel implements ListModel {
@NotNull
protected final StructPart node;
private final List<ListDataListener> listeners = new ArrayList<ListDataListener>();
private final Map<StructPart, ChildLookupChangeListener> childListeners = new WeakHashMap<StructPart, ChildLookupChangeListener>();
@SuppressWarnings( {"FieldCanBeLocal"} )
//Keep as field --> is only added weak
private final StructureListener structureListener;
public StructBasedListModel( @NotNull StructPart node ) {
this.node = node;
//Register the lookup change listeners to all children
for ( StructPart child : node.getChildren() ) {
addChildLookupListener( child );
}
structureListener = new StructureListener() {
@Override
public void childAdded( @NotNull StructureChangedEvent event ) {
addChildLookupListener( event.getStructPart() );
//Notify the listeners that an entry has been added
int index = event.getIndex();
for ( ListDataListener listener : listeners ) {
listener.intervalAdded( new ListDataEvent( StructBasedListModel.this, ListDataEvent.INTERVAL_ADDED, index, index ) );
}
}
@Override
public void childDetached( @NotNull StructureChangedEvent event ) {
detachChildLookupListener( event.getStructPart() );
//Notify the listeners that an entry has been removed
int index = event.getIndex();
for ( ListDataListener listener : listeners ) {
listener.intervalRemoved( new ListDataEvent( StructBasedListModel.this, ListDataEvent.INTERVAL_REMOVED, index, index ) );
}
}
};
node.addStructureListenerWeak( structureListener );
}
/**
* Detaches the child lookup listener
*
* @param child the child the listener is detached from
*/
protected void detachChildLookupListener( @NotNull StructPart child ) {
StructBasedListModel.ChildLookupChangeListener listener = childListeners.remove( child );
if ( listener == null ) {
throw new IllegalStateException( "No listener found for " + child );
}
child.getLookup().removeChangeListener( listener );
}
/**
* Registers a lookup listener at the given child
*
* @param child the child the lookup listener is registered at
*/
protected final void addChildLookupListener( @NotNull StructPart child ) {
ChildLookupChangeListener listener = new ChildLookupChangeListener( child );
if ( childListeners.get( child ) != null ) {
throw new IllegalStateException( "Still added a listener for the given child " + child );
}
childListeners.put( child, listener );
child.getLookup().addChangeListenerWeak( listener );
}
@Override
public int getSize() {
return node.getChildren().size();
}
@Override
@NotNull
public StructPart getElementAt( int index ) {
return node.getChildren().get( index );
}
@Override
public void addListDataListener( ListDataListener l ) {
listeners.add( l );
}
@Override
public void removeListDataListener( ListDataListener l ) {
listeners.remove( l );
}
/**
* A listener that notifies all listeners that a lookup has been changed
*/
private class ChildLookupChangeListener implements LookupChangeListener<Object> {
@NotNull
private final StructPart part;
private ChildLookupChangeListener( @NotNull StructPart part ) {
this.part = part;
}
@Override
public void lookupChanged( @NotNull LookupChangeEvent<?> event ) {
int index = node.getChildren().indexOf( part );
for ( ListDataListener listener : listeners ) {
listener.contentsChanged( new ListDataEvent( StructBasedListModel.this, ListDataEvent.CONTENTS_CHANGED, index, index ) );
}
}
}
}