/*
* Copyright (C) 2012, Katy Hilgenberg.
* Special acknowledgments to: Knowledge & Data Engineering Group, University of Kassel (http://www.kde.cs.uni-kassel.de).
* Contact: sdcf@cs.uni-kassel.de
*
* This file is part of the SDCFramework (Sensor Data Collection Framework) project.
*
* The SDCFramework is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The SDCFramework 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the SDCFramework. If not, see <http://www.gnu.org/licenses/>.
*/
package de.unikassel.android.sdcframework.util;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Environment;
import de.unikassel.android.sdcframework.util.ExternalStorageStateChangeEventImpl.State;
import de.unikassel.android.sdcframework.util.facade.EventObserver;
import de.unikassel.android.sdcframework.util.facade.ExternalStorageStateChangeEvent;
import de.unikassel.android.sdcframework.util.facade.ObservableEventSource;
/**
* Implementation of an external storage state change listener as broadcast
* receiver and observable source for the related
* {@linkplain ExternalStorageStateChangeEvent event}.
*
* @author Katy Hilgenberg
*
*/
public class ExternalStorageAvailabilityListener
extends BroadcastReceiver
implements ObservableEventSource< ExternalStorageStateChangeEvent >
{
/**
* The observable event source to delegate to
*/
private final ObservableEventSource< ExternalStorageStateChangeEvent > eventSource;
/**
* last known external storage state
*/
private ExternalStorageStateChangeEvent lastEvent;
/**
* Constructor
*/
public ExternalStorageAvailabilityListener()
{
eventSource =
new ObservableEventSourceImpl< ExternalStorageStateChangeEvent >();
onExternalStorageStateChange();
}
/*
* (non-Javadoc)
*
* @see
* de.unikassel.android.sdcframework.util.facade.ObservableEventSource#notify
* (de.unikassel.android.sdcframework.util.facade.ObservableEvent)
*/
@Override
public void notify( ExternalStorageStateChangeEvent data )
{
eventSource.notify( data );
}
/*
* (non-Javadoc)
*
* @seede.unikassel.android.sdcframework.util.facade.ObserverRegistration#
* registerEventObserver
* (de.unikassel.android.sdcframework.util.facade.EventObserver)
*/
@SuppressWarnings( "unchecked" )
@Override
public void registerEventObserver(
EventObserver< ? extends ExternalStorageStateChangeEvent > observer )
{
eventSource.registerEventObserver( observer );
// notify new observers about the initial state
notifyLastEvent( (EventObserver< ExternalStorageStateChangeEvent >) observer );
}
/**
* Does notify the observer about the last event
*
* @param observer
* the observer to notify
*/
private void notifyLastEvent(
EventObserver< ExternalStorageStateChangeEvent > observer )
{
observer.onEvent( this, lastEvent );
}
/*
* (non-Javadoc)
*
* @seede.unikassel.android.sdcframework.util.facade.ObserverRegistration#
* removeAllObservers()
*/
@Override
public void removeAllObservers()
{
eventSource.removeAllObservers();
}
/*
* (non-Javadoc)
*
* @seede.unikassel.android.sdcframework.util.facade.ObserverRegistration#
* unregisterEventObserver
* (de.unikassel.android.sdcframework.util.facade.EventObserver)
*/
@Override
public void unregisterEventObserver(
EventObserver< ? extends ExternalStorageStateChangeEvent > observer )
{
eventSource.unregisterEventObserver( observer );
}
/*
* (non-Javadoc)
*
* @see android.content.BroadcastReceiver#onReceive(android.content.Context,
* android.content.Intent)
*/
@Override
public void onReceive( Context context, Intent intent )
{
onExternalStorageStateChange();
}
/**
* handler for external storage state change events
*/
private void onExternalStorageStateChange()
{
State actualState = State.UNAVAILABLE;
String state = Environment.getExternalStorageState();
if ( Environment.MEDIA_MOUNTED.equals( state ) )
{
actualState = State.AVAILABLE_FOR_WRITE;
}
else if ( Environment.MEDIA_MOUNTED_READ_ONLY.equals( state ) )
{
actualState = State.AVAILABLE_FOR_READ;
}
lastEvent = new ExternalStorageStateChangeEventImpl( actualState );
notify( lastEvent );
}
/* (non-Javadoc)
* @see de.unikassel.android.sdcframework.util.facade.ObservableEventSource#hasObservers()
*/
@Override
public boolean hasObservers()
{
return eventSource.hasObservers();
}
}