Add NetworkTableSource

.gitignore

@@ -88,3 +88,7 @@ bower_components
 **/generated
 */generated_tests
 /bin/
+
+### NetworkTables
+networktables.ini
+networktables.ini.bak

core/src/main/java/edu/wpi/grip/core/GripCoreModule.java

@@ -11,6 +11,7 @@
 import edu.wpi.grip.core.sources.HttpSource;
 import edu.wpi.grip.core.sources.ImageFileSource;
 import edu.wpi.grip.core.sources.MultiImageFileSource;
+import edu.wpi.grip.core.sources.NetworkTableEntrySource;
 import edu.wpi.grip.core.util.ExceptionWitness;
 import edu.wpi.grip.core.util.GripMode;
 
@@ -144,6 +145,9 @@ public <I> void hear(TypeLiteral<I> type, TypeEncounter<I> encounter) {
     install(new FactoryModuleBuilder()
         .implement(HttpSource.class, HttpSource.class)
         .build(HttpSource.Factory.class));
+    install(new FactoryModuleBuilder()
+        .implement(NetworkTableEntrySource.class, NetworkTableEntrySource.class)
+        .build(NetworkTableEntrySource.Factory.class));
 
     install(new FactoryModuleBuilder().build(ExceptionWitness.Factory.class));
   }

core/src/main/java/edu/wpi/grip/core/Source.java

@@ -5,6 +5,7 @@
 import edu.wpi.grip.core.sources.HttpSource;
 import edu.wpi.grip.core.sources.ImageFileSource;
 import edu.wpi.grip.core.sources.MultiImageFileSource;
+import edu.wpi.grip.core.sources.NetworkTableEntrySource;
 import edu.wpi.grip.core.util.ExceptionWitness;
 
 import com.google.common.collect.ImmutableList;
@@ -111,6 +112,8 @@ public static class SourceFactoryImpl implements SourceFactory {
     MultiImageFileSource.Factory multiImageFactory;
     @Inject
     HttpSource.Factory httpFactory;
+    @Inject
+    NetworkTableEntrySource.Factory networkTableEntryFactory;
 
     @Override
     public Source create(Class<?> type, Properties properties) throws IOException {
@@ -122,6 +125,8 @@ public Source create(Class<?> type, Properties properties) throws IOException {
         return multiImageFactory.create(properties);
       } else if (type.isAssignableFrom(HttpSource.class)) {
         return httpFactory.create(properties);
+      } else if (type.isAssignableFrom(NetworkTableEntrySource.class)) {
+        return networkTableEntryFactory.create(properties);
       } else {
         throw new IllegalArgumentException(type + " was not a valid type");
       }

core/src/main/java/edu/wpi/grip/core/operations/network/GripNetworkModule.java

@@ -34,5 +34,10 @@ protected void configure() {
     bind(ROSNetworkPublisherFactory.class)
         .annotatedWith(Names.named("rosManager"))
         .to(ROSManager.class);
+
+    // Network receiver bindings
+    bind(MapNetworkReceiverFactory.class)
+        .annotatedWith(Names.named("ntManager"))
+        .to(NTManager.class);
   }
 }

core/src/main/java/edu/wpi/grip/core/operations/network/MapNetworkReceiverFactory.java

@@ -0,0 +1,10 @@
+package edu.wpi.grip.core.operations.network;
+
+
+/**
+ * A factory to create {@link NetworkReceiver NetworkRecievers}.
+ */
+@FunctionalInterface
+public interface MapNetworkReceiverFactory {
+  NetworkReceiver create(String path);
+}

core/src/main/java/edu/wpi/grip/core/operations/network/NetworkReceiver.java

@@ -0,0 +1,45 @@
+package edu.wpi.grip.core.operations.network;
+
+import java.util.function.Consumer;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Manages the interface between the {@link PublishAnnotatedOperation} and the actual network
+ * protocol implemented by a specific {@link Manager}.
+ */
+public abstract class NetworkReceiver implements AutoCloseable {
+
+  protected final String path;
+
+  /**
+   * Create a new NetworkReceiver with the specified path.
+   *
+   * @param path The path of the object to get
+   */
+  public NetworkReceiver(String path) {
+    checkNotNull(path, "Path cannot be null");
+    checkArgument(!path.isEmpty(), "Path cannot be an empty string");
+    this.path = path;
+  }
+
+  /**
+   * Get the value of the object.
+   *
+   * @return The value of this NetworkReceiver
+   */
+  public abstract Object getValue();
+
+  /**
+   * Add a listener to the NetworkReceiver item.
+   *
+   * @param consumer The consumer to call when this item has a update
+   */
+  public abstract void addListener(Consumer<Object> consumer);
+
+  /**
+   * Close the network reciever. This should not throw an exception.
+   */
+  public abstract void close();
+}

core/src/main/java/edu/wpi/grip/core/operations/network/networktables/NTManager.java

@@ -5,6 +5,8 @@
 import edu.wpi.grip.core.operations.network.Manager;
 import edu.wpi.grip.core.operations.network.MapNetworkPublisher;
 import edu.wpi.grip.core.operations.network.MapNetworkPublisherFactory;
+import edu.wpi.grip.core.operations.network.MapNetworkReceiverFactory;
+import edu.wpi.grip.core.operations.network.NetworkReceiver;
 import edu.wpi.grip.core.settings.ProjectSettings;
 import edu.wpi.grip.core.util.GripMode;
 
@@ -19,13 +21,15 @@
 import edu.wpi.first.wpilibj.tables.ITable;
 
 import java.io.File;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-
 import javax.inject.Inject;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -34,18 +38,18 @@
  * This class encapsulates the way we map various settings to the global NetworkTables state.
  */
 @Singleton
-public class NTManager implements Manager, MapNetworkPublisherFactory {
+public class NTManager implements Manager, MapNetworkPublisherFactory, MapNetworkReceiverFactory {
   /*
    * Nasty hack that is unavoidable because of how NetworkTables works.
    */
-  private static final AtomicInteger publisherCount = new AtomicInteger(0);
+  private static final AtomicInteger count = new AtomicInteger(0);
 
   /**
    * Information from: https://github.com/PeterJohnson/ntcore/blob/master/src/Log.h and
    * https://github.com/PeterJohnson/ntcore/blob/e6054f543a6ab10aa27af6cace855da66d67ee44
    * /include/ntcore_c.h#L39
    */
-  private static final Map<Integer, Level> ntLogLevels = ImmutableMap.<Integer, Level>builder()
+  protected static final Map<Integer, Level> ntLogLevels = ImmutableMap.<Integer, Level>builder()
       .put(40, Level.SEVERE)
       .put(30, Level.WARNING)
       .put(20, Level.INFO)
@@ -120,11 +124,69 @@ public void updateSettings(ProjectSettingsChangedEvent event) {
 
   @Override
   public <P> MapNetworkPublisher<P> create(Set<String> keys) {
-    // Keep track of ever publisher created.
-    publisherCount.getAndAdd(1);
+    // Keep track of every publisher created.
+    count.getAndAdd(1);
     return new NTPublisher<>(keys);
   }
 
+  @Override
+  public NetworkReceiver create(String path) {
+    count.getAndAdd(1);
+    return new NTReceiver(path);
+  }
+
+  private static final class NTReceiver extends NetworkReceiver {
+
+    private int entryListenerFunctionUid;
+    private Object object = false;
+    private final List<Consumer<Object>> listeners = new LinkedList<>();
+
+    protected NTReceiver(String path) {
+      super(path);
+      addListener();
+
+      synchronized (NetworkTable.class) {
+        NetworkTable.initialize();
+      }
+    }
+
+    private void addListener() {
+      entryListenerFunctionUid = NetworkTablesJNI.addEntryListener(path,
+          (uid, key, value, flags) -> {
+            object = value;
+            listeners.forEach(c -> c.accept(object));
+          },
+          ITable.NOTIFY_IMMEDIATE
+              | ITable.NOTIFY_NEW
+              | ITable.NOTIFY_UPDATE
+              | ITable.NOTIFY_DELETE
+              | ITable.NOTIFY_LOCAL);
+    }
+
+    @Override
+    public void addListener(Consumer<Object> consumer) {
+      listeners.add(consumer);
+    }
+
+    @Override
+    public Object getValue() {
+      return object;
+    }
+
+    @Override
+    public void close() {
+      NetworkTablesJNI.removeEntryListener(entryListenerFunctionUid);
+
+      synchronized (NetworkTable.class) {
+        // This receiver is no longer used.
+        if (NTManager.count.addAndGet(-1) == 0) {
+          // We are the last resource using NetworkTables so shut it down
+          NetworkTable.shutdown();
+        }
+      }
+    }
+  }
+
   private static final class NTPublisher<P> extends MapNetworkPublisher<P> {
     private final ImmutableSet<String> keys;
     private Optional<String> name = Optional.empty();
@@ -184,8 +246,8 @@ public void close() {
       }
       synchronized (NetworkTable.class) {
         // This publisher is no longer used.
-        if (NTManager.publisherCount.addAndGet(-1) == 0) {
-          // We are the last publisher so shut it down
+        if (NTManager.count.addAndGet(-1) == 0) {
+          // We are the last resource using NetworkTables so shut it down
           NetworkTable.shutdown();
         }
       }

core/src/main/java/edu/wpi/grip/core/sockets/SocketHints.java

@@ -193,5 +193,13 @@ public static SocketHint<Number> createNumberSocketHint(final String identifier,
         defaultValue) {
       return createNumberSocketHintBuilder(identifier, defaultValue).build();
     }
+
+    public static SocketHint<String> createStringSocketHint(final String identifier,
+                                                            String defaultValue) {
+      return new SocketHint.Builder<String>(String.class)
+          .identifier(identifier)
+          .initialValue(defaultValue)
+          .build();
+    }
   }
 }