[ntcore] Add sub option for local vs remote changes (#4731)

This is the subscriber readQueue version of the local value listener flag.

ntcore/src/main/native/cpp/LocalStorage.cpp

@@ -492,9 +492,12 @@ bool LSImpl::SetValue(TopicData* topic, const Value& value,
 
 void LSImpl::NotifyValue(TopicData* topic, unsigned int eventFlags,
                          bool isDuplicate) {
+  bool isNetwork = (eventFlags & NT_EVENT_VALUE_REMOTE) != 0;
   for (auto&& subscriber : topic->localSubscribers) {
     if (subscriber->active &&
-        (subscriber->config.keepDuplicates || !isDuplicate)) {
+        (subscriber->config.keepDuplicates || !isDuplicate) &&
+        ((isNetwork && subscriber->config.fromRemote) ||
+         (!isNetwork && subscriber->config.fromLocal))) {
       subscriber->pollStorage.emplace_back(topic->lastValue);
       subscriber->handle.Set();
       if (!subscriber->valueListeners.empty()) {

ntcore/src/main/native/cpp/PubSubOptions.cpp

@@ -29,6 +29,25 @@ nt::PubSubOptions::PubSubOptions(std::span<const PubSubOption> options) {
       case NT_PUBSUB_POLLSTORAGE:
         pollStorageSize = static_cast<size_t>(option.value);
         break;
+      case NT_PUBSUB_LOCALREMOTE:
+        switch (static_cast<int>(option.value)) {
+          case 0:
+          case 3:
+            fromLocal = true;
+            fromRemote = true;
+            break;
+          case 1:
+            fromLocal = true;
+            fromRemote = false;
+            break;
+          case 2:
+            fromLocal = false;
+            fromRemote = true;
+            break;
+          default:
+            break;
+        }
+        break;
       default:
         break;
     }

ntcore/src/main/native/cpp/PubSubOptions.h

@@ -22,6 +22,8 @@ class PubSubOptions {
   bool topicsOnly = false;
   bool prefixMatch = false;
   bool keepDuplicates = false;
+  bool fromRemote = true;
+  bool fromLocal = true;
 };
 
 }  // namespace nt

ntcore/src/main/native/include/ntcore_c.h

@@ -95,6 +95,7 @@ enum NT_PubSubOptionType {
   NT_PUBSUB_TOPICSONLY,     /* only send topic changes, no value changes */
   NT_PUBSUB_POLLSTORAGE,    /* polling storage for subscription */
   NT_PUBSUB_KEEPDUPLICATES, /* preserve duplicate values */
+  NT_PUBSUB_LOCALREMOTE,    /* local, remote, or any value changes */
 };
 
 /** Event notification flags. */
@@ -287,7 +288,8 @@ struct NT_PubSubOption {
 
   /**
    * Option value.  1 (true) or 0 (false) for immediate and logging options,
-   * time between updates, in seconds, for periodic option.
+   * time between updates, in seconds, for periodic option.  For local/remote
+   * option, 1=local only, 2=remote only, 0 or 3=both local and remote.
    */
   double value;
 };

ntcore/src/main/native/include/ntcore_cpp.h

@@ -314,7 +314,7 @@ class PubSubOption {
 
   /**
    * Polling storage for subscription. Specifies the maximum number of updates
-   * NetworkTables should store between calls to the subscriber's poll()
+   * NetworkTables should store between calls to the subscriber's ReadQueue()
    * function. Defaults to 1 if SendAll is false, 20 if SendAll is true.
    *
    * @param depth number of entries to save for polling.
@@ -324,6 +324,39 @@ class PubSubOption {
     return PubSubOption{NT_PUBSUB_POLLSTORAGE, static_cast<double>(depth)};
   }
 
+  /**
+   * If only local value updates should be queued for ReadQueue(). See also
+   * RemoteOnly() and AllUpdates(). Default is AllUpdates. Only has an effect on
+   * subscriptions.
+   *
+   * @return option
+   */
+  static constexpr PubSubOption LocalOnly() {
+    return PubSubOption{NT_PUBSUB_LOCALREMOTE, 1.0};
+  }
+
+  /**
+   * If only remote value updates should be queued for ReadQueue(). See also
+   * LocalOnly() and AllUpdates(). Default is AllUpdates. Only has an effect on
+   * subscriptions.
+   *
+   * @return option
+   */
+  static constexpr PubSubOption RemoteOnly() {
+    return PubSubOption{NT_PUBSUB_LOCALREMOTE, 2.0};
+  }
+
+  /**
+   * If both local and remote value updates should be queued for ReadQueue().
+   * See also LocalOnly() and RemoteOnly(). Default is AllUpdates. Only has an
+   * effect on subscriptions.
+   *
+   * @return option
+   */
+  static constexpr PubSubOption AllUpdates() {
+    return PubSubOption{NT_PUBSUB_LOCALREMOTE, 0.0};
+  }
+
   NT_PubSubOptionType type;
   double value;
 };