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package tim.prune;
/**
* Class responsible for distributing update information
* to all registered listeners
*/
public abstract class UpdateMessageBroker
{
private static final int MAXIMUM_NUMBER_SUBSCRIBERS = 8;
/** Array of all subscribers */
private static DataSubscriber[] _subscribers = new DataSubscriber[MAXIMUM_NUMBER_SUBSCRIBERS];
/** Index from which to start looking for an empty slot*/
private static int _searchStartIndex = 0;
/** Enable/disabled flag */
private static boolean _enabled = true;
/**
* Add a data subscriber to the list
* @param inSub DataSubscriber to add
*/
public static void addSubscriber(DataSubscriber inSub)
{
// Loop looking for first null entry
for (int i=_searchStartIndex; i<MAXIMUM_NUMBER_SUBSCRIBERS; i++)
{
if (_subscribers[i] == null)
{
_subscribers[i] = inSub;
_searchStartIndex = i+1;
break;
}
}
}
/**
* Remove the given subscriber from the list
* @param inSub subscriber to remove
*/
public static void removeSubscriber(DataSubscriber inSub)
{
for (int i=0; i<MAXIMUM_NUMBER_SUBSCRIBERS; i++)
{
if (_subscribers[i] == inSub)
{
_subscribers[i] = null;
// Could break out of the loop here but we want to make sure we remove all of them
}
}
_searchStartIndex = 0; // for the next add, start from beginning to ensure all gaps are filled
}
/**
* Enable or disable the messaging (to allow temporary disabling for multiple operations)
* @param inEnabled false to disable, true to enable again
*/
public static void enableMessaging(boolean inEnabled)
{
_enabled = inEnabled;
}
/**
* Send a message to all subscribers that
* the data has been updated
*/
public static void informSubscribers()
{
informSubscribers(DataSubscriber.ALL);
}
/**
* Send message to all subscribers
* @param inChange Change that occurred
*/
public static void informSubscribers(byte inChange)
{
// TODO: Launch separate thread so that whatever caused the inform can finish
if (!_enabled) return;
for (int i=0; i<_subscribers.length; i++)
{
if (_subscribers[i] != null)
{
_subscribers[i].dataUpdated(inChange);
}
}
}
/**
* Send message to all subscribers
* @param inMessage message to display informing of action completed
*/
public static void informSubscribers(String inMessage)
{
if (!_enabled) return;
for (int i=0; i<_subscribers.length; i++)
{
if (_subscribers[i] != null)
{
_subscribers[i].actionCompleted(inMessage);
}
}
}
}
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