merge

android/Common/src/com/googlecode/android_scripting/trigger/TriggerRepository.java

@@ -58,26 +58,32 @@ public class TriggerRepository {
    * An interface for objects that are notified when a trigger is added to the repository.
    */
   public interface TriggerRepositoryObserver {
+    /**
+     * Invoked just before the trigger is added to the repository.
+     * 
+     * @param trigger
+     *          The trigger about to be added to the repository.
+     */
     void onPut(Trigger trigger);
 
+    /**
+     * Invoked just after the trigger has been removed from the repository.
+     * 
+     * @param trigger
+     *          The trigger that has just been removed from the repository.
+     */
     void onRemove(Trigger trigger);
   }
 
-  private final Multimap<String, Trigger> mTriggers =
-      Multimaps.synchronizedListMultimap(ArrayListMultimap.<String, Trigger> create());
+  private final Multimap<String, Trigger> mTriggers;
   private final CopyOnWriteArrayList<TriggerRepositoryObserver> mTriggerObservers =
       new CopyOnWriteArrayList<TriggerRepositoryObserver>();
 
   public TriggerRepository(Context context) {
     mContext = context;
     mPreferences = PreferenceManager.getDefaultSharedPreferences(context);
     String triggers = mPreferences.getString(TRIGGERS_PREF_KEY, null);
-    // Iterate and add one at a time instead of using putAll() so that observers are notified.
-    Multimap<String, Trigger> deserializeTriggersFromString =
-        deserializeTriggersFromString(triggers);
-    for (Entry<String, Trigger> entry : deserializeTriggersFromString.entries()) {
-      put(entry.getValue());
-    }
+    mTriggers = deserializeTriggersFromString(triggers);
   }
 
   /** Returns a list of all triggers. The list is unmodifiable. */
@@ -92,17 +98,15 @@ public synchronized Multimap<String, Trigger> getAllTriggers() {
    *          the {@link Trigger} to add
    */
   public synchronized void put(Trigger trigger) {
+    notifyOnAdd(trigger);
     mTriggers.put(trigger.getEventName(), trigger);
     storeTriggers();
-    notifyOnAdd(trigger);
     ensureTriggerServiceRunning();
   }
 
   /** Removes a specific {@link Trigger}. */
   public synchronized void remove(final Trigger trigger) {
-    synchronized (mTriggers) {
-      mTriggers.get(trigger.getEventName()).remove(trigger);
-    }
+    mTriggers.get(trigger.getEventName()).remove(trigger);
     storeTriggers();
     notifyOnRemove(trigger);
   }
@@ -128,7 +132,7 @@ private void notifyOnRemove(Trigger trigger) {
   }
 
   /** Writes the list of triggers to the shared preferences. */
-  private void storeTriggers() {
+  private synchronized void storeTriggers() {
     SharedPreferences.Editor editor = mPreferences.edit();
     final String triggerValue = serializeTriggersToString(mTriggers);
     if (triggerValue != null) {
@@ -168,7 +172,7 @@ private String serializeTriggersToString(Multimap<String, Trigger> triggers) {
   }
 
   /** Returns {@code true} iff the list of triggers is empty. */
-  public boolean isEmpty() {
+  public synchronized boolean isEmpty() {
     return mTriggers.isEmpty();
   }
 
@@ -177,6 +181,20 @@ public void addObserver(TriggerRepositoryObserver observer) {
     mTriggerObservers.add(observer);
   }
 
+  /**
+   * Adds the given {@link TriggerRepositoryObserver} and invokes
+   * {@link TriggerRepositoryObserver#onPut} for all existing triggers.
+   * 
+   * @param observer
+   *          The observer to add.
+   */
+  public synchronized void bootstrapObserver(TriggerRepositoryObserver observer) {
+    addObserver(observer);
+    for (Entry<String, Trigger> trigger : mTriggers.entries()) {
+      observer.onPut(trigger.getValue());
+    }
+  }
+
   /**
    * Removes a {@link TriggerRepositoryObserver}.
    */

android/ScriptingLayer/src/com/googlecode/android_scripting/trigger/EventGenerationControllingObserver.java

@@ -0,0 +1,89 @@
+package com.googlecode.android_scripting.trigger;
+
+import com.google.common.collect.Maps;
+import com.googlecode.android_scripting.facade.FacadeConfiguration;
+import com.googlecode.android_scripting.facade.FacadeManager;
+import com.googlecode.android_scripting.rpc.MethodDescriptor;
+import com.googlecode.android_scripting.trigger.TriggerRepository.TriggerRepositoryObserver;
+
+import java.util.Map;
+
+import org.json.JSONArray;
+
+/**
+ * A {@link TriggerRepositoryObserver} that starts and stops the monitoring of events depending on
+ * whether or not triggers for the event exist.
+ * 
+ * @author Felix Arends ([email protected])
+ */
+public class EventGenerationControllingObserver implements TriggerRepositoryObserver {
+  private final FacadeManager mFacadeManager;
+  private final Map<String, MethodDescriptor> mStartEventGeneratingMethodDescriptors;
+  private final Map<String, MethodDescriptor> mStopEventGeneratingMethodDescriptors;
+  private final Map<String, Integer> mEventTriggerRefCounts = Maps.newHashMap();
+
+  /**
+   * Creates a new StartEventMonitoringObserver for the given trigger repository.
+   * 
+   * @param facadeManager
+   * @param triggerRepository
+   */
+  public EventGenerationControllingObserver(FacadeManager facadeManager) {
+    mFacadeManager = facadeManager;
+    mStartEventGeneratingMethodDescriptors =
+        FacadeConfiguration.collectStartEventMethodDescriptors();
+    mStopEventGeneratingMethodDescriptors = FacadeConfiguration.collectStopEventMethodDescriptors();
+  }
+
+  private synchronized int incrementAndGetRefCount(String eventName) {
+    int refCount =
+        (mEventTriggerRefCounts.containsKey(eventName)) ? mEventTriggerRefCounts.get(eventName) : 0;
+    refCount++;
+    mEventTriggerRefCounts.put(eventName, refCount);
+    return refCount;
+  }
+
+  private synchronized int decrementAndGetRefCount(String eventName) {
+    int refCount =
+        (mEventTriggerRefCounts.containsKey(eventName)) ? mEventTriggerRefCounts.get(eventName) : 0;
+    refCount--;
+    mEventTriggerRefCounts.put(eventName, refCount);
+    return refCount;
+  }
+
+  @Override
+  public synchronized void onPut(Trigger trigger) {
+    // If we're not already monitoring the events corresponding to this trigger, do so.
+    if (incrementAndGetRefCount(trigger.getEventName()) == 1) {
+      startMonitoring(trigger.getEventName());
+    }
+  }
+
+  @Override
+  public synchronized void onRemove(Trigger trigger) {
+    // If there are no more triggers listening to this event, then we need to stop monitoring.
+    if (decrementAndGetRefCount(trigger.getEventName()) == 1) {
+      stopMonitoring(trigger.getEventName());
+    }
+  }
+
+  private void startMonitoring(String eventName) {
+    MethodDescriptor startEventGeneratingMethod =
+        mStartEventGeneratingMethodDescriptors.get(eventName);
+    try {
+      startEventGeneratingMethod.invoke(mFacadeManager, new JSONArray());
+    } catch (Throwable t) {
+      throw new RuntimeException(t);
+    }
+  }
+
+  private void stopMonitoring(String eventName) {
+    MethodDescriptor stopEventGeneratingMethod =
+        mStopEventGeneratingMethodDescriptors.get(eventName);
+    try {
+      stopEventGeneratingMethod.invoke(mFacadeManager, new JSONArray());
+    } catch (Throwable t) {
+      throw new RuntimeException(t);
+    }
+  }
+}

android/ScriptingLayerForAndroid/src/com/googlecode/android_scripting/activity/TriggerService.java

@@ -25,6 +25,7 @@
 import android.os.IBinder;
 import android.widget.RemoteViews;
 
+import com.google.common.base.Preconditions;
 import com.googlecode.android_scripting.BaseApplication;
 import com.googlecode.android_scripting.ForegroundService;
 import com.googlecode.android_scripting.IntentBuilders;
@@ -35,6 +36,7 @@
 import com.googlecode.android_scripting.facade.FacadeConfiguration;
 import com.googlecode.android_scripting.facade.FacadeManager;
 import com.googlecode.android_scripting.facade.EventFacade.EventObserver;
+import com.googlecode.android_scripting.trigger.EventGenerationControllingObserver;
 import com.googlecode.android_scripting.trigger.Trigger;
 import com.googlecode.android_scripting.trigger.TriggerRepository;
 import com.googlecode.android_scripting.trigger.TriggerRepository.TriggerRepositoryObserver;
@@ -82,12 +84,14 @@ public IBinder onBind(Intent intent) {
   public void onCreate() {
     super.onCreate();
 
-    mTriggerRepository = ((BaseApplication) getApplication()).getTriggerRepository();
-    mTriggerRepository.addObserver(new RepositoryObserver());
     mFacadeManager =
         new FacadeManager(FacadeConfiguration.getSdkLevel(), this, null, FacadeConfiguration
             .getFacadeClasses());
     mEventFacade = mFacadeManager.getReceiver(EventFacade.class);
+
+    mTriggerRepository = ((BaseApplication) getApplication()).getTriggerRepository();
+    mTriggerRepository.bootstrapObserver(new RepositoryObserver());
+    mTriggerRepository.bootstrapObserver(new EventGenerationControllingObserver(mFacadeManager));
     installAlarm();
   }
 
@@ -128,15 +132,19 @@ public void onEventReceived(Event event) {
   }
 
   private class RepositoryObserver implements TriggerRepositoryObserver {
+    int mTriggerCount = 0;
+
     @Override
     public void onPut(Trigger trigger) {
+      mTriggerCount++;
       mEventFacade.addNamedEventObserver(trigger.getEventName(), new TriggerEventObserver(trigger));
     }
 
     @Override
     public void onRemove(Trigger trigger) {
+      Preconditions.checkArgument(mTriggerCount > 0);
       // TODO(damonkohler): Tear down EventObserver associated with trigger.
-      if (mTriggerRepository.isEmpty()) {
+      if (--mTriggerCount == 0) {
         // TODO(damonkohler): Use stopSelfResult() which would require tracking startId.
         stopSelf();
       }