Resolves issue with the multi-frequency tuner source and P25/MPT1327 (#603)

Resolves issue with the multi-frequency tuner source and P25/MPT1327 (#603) rotating channel frequency configurations failing to maintain lock
on the channel.

Converted the ChannelRotationMonitor from using identifier updates to
now using DecoderStateEvents so that the ChannelState can supply a
steady stream of channel state events to the monitor.

src/main/java/io/github/dsheirer/channel/state/DecoderStateEvent.java

@@ -24,6 +24,14 @@ package io.github.dsheirer.channel.state;
 
 public class DecoderStateEvent
 {
+    private static final DecoderStateEvent ACTIVE_STATE_TIMESLOT_0 =
+        new DecoderStateEvent(null, Event.NOTIFICATION_CHANNEL_ACTIVE_STATE, State.ACTIVE, 0);
+    private static final DecoderStateEvent ACTIVE_STATE_TIMESLOT_1 =
+        new DecoderStateEvent(null, Event.NOTIFICATION_CHANNEL_ACTIVE_STATE, State.ACTIVE, 1);
+    private static final DecoderStateEvent INACTIVE_STATE_TIMESLOT_0 =
+        new DecoderStateEvent(null, Event.NOTIFICATION_CHANNEL_INACTIVE_STATE, State.ACTIVE, 0);
+    private static final DecoderStateEvent INACTIVE_STATE_TIMESLOT_1 =
+        new DecoderStateEvent(null, Event.NOTIFICATION_CHANNEL_INACTIVE_STATE, State.ACTIVE, 1);
     private Object mSource;
     private Event mEvent;
     private State mState;
@@ -54,6 +62,68 @@ public class DecoderStateEvent
         this(source, event, state, 0, frequency);
     }
 
+    /**
+     * Creates a channel state active event for the specified timeslot
+     * @param timeslot that the state applies to
+     * @return new event
+     */
+    public static DecoderStateEvent activeState(int timeslot)
+    {
+        if(timeslot == 0)
+        {
+            return ACTIVE_STATE_TIMESLOT_0;
+        }
+        else if(timeslot == 1)
+        {
+            return ACTIVE_STATE_TIMESLOT_1;
+        }
+        else
+        {
+            throw new IllegalArgumentException("Only timeslots 0 and 1 are currently supported");
+        }
+    }
+
+    /**
+     * Creates a channel state active event for the specified timeslot.
+     * @param state currently
+     * @return new event
+     */
+    public static DecoderStateEvent activeState()
+    {
+        return activeState(0);
+    }
+
+    /**
+     * Creates a channel state inactive event for the specified timeslot
+     * @param timeslot that the state applies to
+     * @return new event
+     */
+    public static DecoderStateEvent inactiveState(int timeslot)
+    {
+        if(timeslot == 0)
+        {
+            return INACTIVE_STATE_TIMESLOT_0;
+        }
+        else if(timeslot == 1)
+        {
+            return INACTIVE_STATE_TIMESLOT_1;
+        }
+        else
+        {
+            throw new IllegalArgumentException("Only timeslots 0 and 1 are currently supported");
+        }
+    }
+
+    /**
+     * Creates a channel state active event for the specified timeslot.
+     * @param state currently
+     * @return new event
+     */
+    public static DecoderStateEvent inactiveState()
+    {
+        return inactiveState(0);
+    }
+
     public String toString()
     {
         StringBuilder sb = new StringBuilder();
@@ -99,6 +169,8 @@ public class DecoderStateEvent
         CONTINUATION,
         DECODE,
         END,
+        NOTIFICATION_CHANNEL_ACTIVE_STATE,
+        NOTIFICATION_CHANNEL_INACTIVE_STATE,
         RESET,
         SOURCE_FREQUENCY,
         START;

src/main/java/io/github/dsheirer/channel/state/MultiChannelState.java

@@ -132,6 +132,16 @@ public class MultiChannelState extends AbstractChannelState implements IDecoderS
     @Override
     public void stateChanged(State state, int timeslot)
     {
+        //Broadcast current channel state so that channel rotation monitor can track
+        if(state.isActiveState())
+        {
+            broadcast(DecoderStateEvent.activeState(timeslot));
+        }
+        else
+        {
+            broadcast(DecoderStateEvent.inactiveState(timeslot));
+        }
+
         ChannelStateIdentifier stateIdentifier = ChannelStateIdentifier.create(state);
         mIdentifierCollectionMap.get(timeslot).update(stateIdentifier);
         mChannelMetadataMap.get(timeslot).receive(new IdentifierUpdateNotification(stateIdentifier, IdentifierUpdateNotification.Operation.ADD, timeslot));

src/main/java/io/github/dsheirer/channel/state/SingleChannelState.java

@@ -122,6 +122,16 @@ public class SingleChannelState extends AbstractChannelState implements IDecoder
     @Override
     public void stateChanged(State state, int timeslot)
     {
+        //Broadcast current channel state so that channel rotation monitor can track
+        if(state.isActiveState())
+        {
+            broadcast(DecoderStateEvent.activeState(timeslot));
+        }
+        else
+        {
+            broadcast(DecoderStateEvent.inactiveState(timeslot));
+        }
+
         ChannelStateIdentifier stateIdentifier = ChannelStateIdentifier.create(state);
         mIdentifierCollection.update(stateIdentifier);
         mChannelMetadata.receive(new IdentifierUpdateNotification(stateIdentifier, IdentifierUpdateNotification.Operation.ADD, timeslot));

src/main/java/io/github/dsheirer/source/tuner/channel/ChannelRotationMonitor.java

@@ -1,32 +1,32 @@
 /*
- * ******************************************************************************
- * sdrtrunk
- * Copyright (C) 2014-2019 Dennis Sheirer
  *
- * This program is free software: you can redistribute it and/or modify
+ *  * ******************************************************************************
- * it under the terms of the GNU General Public License as published by
+ *  * Copyright (C) 2014-2019 Dennis Sheirer
- * the Free Software Foundation, either version 3 of the License, or
+ *  *
- * (at your option) any later version.
+ *  * This program is free software: you can redistribute it and/or modify
+ *  * it under the terms of the GNU General Public License as published by
+ *  * the Free Software Foundation, either version 3 of the License, or
+ *  * (at your option) any later version.
+ *  *
+ *  * This program 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 General Public License for more details.
+ *  *
+ *  * You should have received a copy of the GNU General Public License
+ *  * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *  * *****************************************************************************
  *
- * This program 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 General Public License for more details.
  *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>
- * *****************************************************************************
  */
 
 package io.github.dsheirer.source.tuner.channel;
 
 import com.google.common.eventbus.Subscribe;
+import io.github.dsheirer.channel.state.DecoderStateEvent;
+import io.github.dsheirer.channel.state.IDecoderStateEventListener;
 import io.github.dsheirer.channel.state.State;
 import io.github.dsheirer.eventbus.MyEventBus;
-import io.github.dsheirer.identifier.Identifier;
-import io.github.dsheirer.identifier.IdentifierUpdateListener;
-import io.github.dsheirer.identifier.IdentifierUpdateNotification;
-import io.github.dsheirer.identifier.decoder.ChannelStateIdentifier;
 import io.github.dsheirer.module.Module;
 import io.github.dsheirer.preference.PreferenceType;
 import io.github.dsheirer.preference.UserPreferences;
@@ -43,10 +43,11 @@ import java.util.concurrent.TimeUnit;
 
 /**
  * Monitors channel state to detect when a channel is not in an identified active state and issues a request to rotate
- * the next channel frequency in the list.
+ * the next channel frequency in the list.  This class depends on the ChannelState to provide a continuous
+ * stream of channel active/inactive messaging in the form of DecoderStateEvents.
  */
-public class ChannelRotationMonitor extends Module implements ISourceEventProvider, IdentifierUpdateListener,
+public class ChannelRotationMonitor extends Module implements ISourceEventProvider, IDecoderStateEventListener,
-    Listener<IdentifierUpdateNotification>
+        Listener<DecoderStateEvent>
 {
     private final static Logger mLog = LoggerFactory.getLogger(ChannelRotationMonitor.class);
 
@@ -93,33 +94,27 @@ public class ChannelRotationMonitor extends Module implements ISourceEventProvid
     }
 
     @Override
-    public Listener<IdentifierUpdateNotification> getIdentifierUpdateListener()
+    public Listener<DecoderStateEvent> getDecoderStateListener()
     {
         return this;
     }
 
-    /**
-     * Primary method for receiving channel state identifier notifications, enabling this module to track the
-     * current channel state being provided by the Channel State module.
-     */
     @Override
-    public void receive(IdentifierUpdateNotification identifierUpdateNotification)
+    public void receive(DecoderStateEvent decoderStateEvent)
     {
-        Identifier identifier = identifierUpdateNotification.getIdentifier();
+        if(decoderStateEvent.getEvent() == DecoderStateEvent.Event.NOTIFICATION_CHANNEL_ACTIVE_STATE)
-
-        if(identifier instanceof ChannelStateIdentifier)
         {
-            State currentState = ((ChannelStateIdentifier)identifier).getValue();
+            mActive = true;
-
+        }
-            if(mActiveStates.contains(currentState))
+        else if(decoderStateEvent.getEvent() == DecoderStateEvent.Event.NOTIFICATION_CHANNEL_INACTIVE_STATE)
+        {
+            if(mActive)
             {
-                mActive = true;
+                //If we're toggling from active to inactive, update the timestamp,
-            }
-            else if(mActive)
-            {
-                mActive = false;
                 mInactiveTimestamp = System.currentTimeMillis();
             }
+
+            mActive = false;
         }
     }