/*
* Copyright (c) 2016, 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
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*/
package org.jowidgets.spi.impl.controller;
import org.jowidgets.common.widgets.controller.IVisibilityStateListener;
import org.jowidgets.common.widgets.controller.IVisibilityStateObservable;
import org.jowidgets.util.collection.IObserverSet;
import org.jowidgets.util.collection.IObserverSetFactory.Strategy;
import org.jowidgets.util.collection.ObserverSetFactory;
public class VisibilityStateObservable implements IVisibilityStateObservable {
private final IObserverSet<IVisibilityStateListener> listeners;
private Boolean lastVisible;
public VisibilityStateObservable(final boolean visible) {
this(Boolean.valueOf(visible));
}
public VisibilityStateObservable() {
this(null);
}
private VisibilityStateObservable(final Boolean visible) {
this.listeners = ObserverSetFactory.create(Strategy.HIGH_PERFORMANCE);
}
@Override
public final void addVisibilityStateListener(final IVisibilityStateListener listener) {
listeners.add(listener);
}
@Override
public final void removeVisibilityStateListener(final IVisibilityStateListener listener) {
listeners.remove(listener);
}
public final void fireVisibilityStateChanged(final boolean visible) {
if (lastVisible == null || lastVisible.booleanValue() != visible) {
lastVisible = Boolean.valueOf(visible);
for (final IVisibilityStateListener listener : listeners) {
listener.visibilityStateChanged(visible);
}
}
}
}