/*
* Copyright (c) 2014, grossmann
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the jo-widgets.org nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.jowidgets.impl.dnd;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.Set;
import org.jowidgets.api.clipboard.TransferType;
import org.jowidgets.api.dnd.IDragDataResponse;
import org.jowidgets.api.dnd.IDragEvent;
import org.jowidgets.api.dnd.IDragSourceListener;
import org.jowidgets.api.dnd.IDragSourceObservable;
import org.jowidgets.common.dnd.DropAction;
import org.jowidgets.common.types.IVetoable;
import org.jowidgets.util.Assert;
abstract class AbstractDragSourceObservable implements IDragSourceObservable {
private final Set<IDragSourceListener> listeners;
AbstractDragSourceObservable() {
this.listeners = new LinkedHashSet<IDragSourceListener>();
}
@Override
public final void addDragSourceListener(final IDragSourceListener listener) {
Assert.paramNotNull(listener, "listener");
final int lastSize = listeners.size();
listeners.add(listener);
if (lastSize == 0) {
setActive(true);
}
}
@Override
public final void removeDragSourceListener(final IDragSourceListener listener) {
Assert.paramNotNull(listener, "listener");
final int lastSize = listeners.size();
listeners.remove(listener);
if (lastSize == 1 && listeners.size() == 0) {
setActive(false);
}
}
final void fireDragStart(final IDragEvent event, final IVetoable veto) {
for (final IDragSourceListener listener : new LinkedList<IDragSourceListener>(listeners)) {
listener.dragStart(event, veto);
}
}
final void fireDragSetData(
final IDragEvent event,
final IVetoable veto,
final TransferType<?> transferType,
final IDragDataResponse dragData) {
for (final IDragSourceListener listener : new LinkedList<IDragSourceListener>(listeners)) {
listener.dragSetData(event, veto, transferType, dragData);
}
}
final void fireDragFinished(final IDragEvent event, final DropAction dropAction) {
for (final IDragSourceListener listener : new LinkedList<IDragSourceListener>(listeners)) {
listener.dragFinished(event, dropAction);
}
}
protected abstract void setActive(boolean active);
}