Only report active cameras in error print

Author: mcm001

photon-lib/src/main/java/org/photonvision/PhotonCamera.java

@@ -45,8 +45,9 @@
 import edu.wpi.first.networktables.StringSubscriber;
 import edu.wpi.first.wpilibj.DriverStation;
 import edu.wpi.first.wpilibj.Timer;
+import java.util.List;
 import java.util.Optional;
-import java.util.Set;
+import java.util.stream.Collectors;
 import org.photonvision.common.hardware.VisionLEDMode;
 import org.photonvision.common.networktables.PacketSubscriber;
 import org.photonvision.targeting.PhotonPipelineResult;
@@ -74,6 +75,8 @@ public class PhotonCamera implements AutoCloseable {
     IntegerSubscriber heartbeatEntry;
     DoubleArraySubscriber cameraIntrinsicsSubscriber;
     DoubleArraySubscriber cameraDistortionSubscriber;
+    MultiSubscriber m_topicNameSubscriber;
+    NetworkTable rootPhotonTable;
 
     @Override
     public void close() {
@@ -97,6 +100,7 @@ public void close() {
         pipelineIndexRequest.close();
         cameraIntrinsicsSubscriber.close();
         cameraDistortionSubscriber.close();
+        m_topicNameSubscriber.close();
     }
 
     private final String path;
@@ -124,8 +128,8 @@ public static void setVersionCheckEnabled(boolean enabled) {
      */
     public PhotonCamera(NetworkTableInstance instance, String cameraName) {
         name = cameraName;
-        var photonvision_root_table = instance.getTable(kTableName);
-        this.cameraTable = photonvision_root_table.getSubTable(cameraName);
+        rootPhotonTable = instance.getTable(kTableName);
+        this.cameraTable = rootPhotonTable.getSubTable(cameraName);
         path = cameraTable.getPath();
         var rawBytesEntry =
                 cameraTable
@@ -147,14 +151,17 @@ public PhotonCamera(NetworkTableInstance instance, String cameraName) {
         cameraDistortionSubscriber =
                 cameraTable.getDoubleArrayTopic("cameraDistortion").subscribe(null);
 
-        ledModeRequest = photonvision_root_table.getIntegerTopic("ledModeRequest").publish();
-        ledModeState = photonvision_root_table.getIntegerTopic("ledModeState").subscribe(-1);
-        versionEntry = photonvision_root_table.getStringTopic("version").subscribe("");
+        ledModeRequest = rootPhotonTable.getIntegerTopic("ledModeRequest").publish();
+        ledModeState = rootPhotonTable.getIntegerTopic("ledModeState").subscribe(-1);
+        versionEntry = rootPhotonTable.getStringTopic("version").subscribe("");
 
         // Existing is enough to make this multisubscriber do its thing
-        MultiSubscriber m_topicNameSubscriber =
+        m_topicNameSubscriber =
                 new MultiSubscriber(
-                        instance, new String[] {"/photonvision/"}, PubSubOption.topicsOnly(true));
+                        instance,
+                        new String[] {"/photonvision/"},
+                        PubSubOption.topicsOnly(true),
+                        PubSubOption.disableLocal(true));
 
         HAL.report(tResourceType.kResourceType_PhotonCamera, InstanceCount);
         InstanceCount++;
@@ -346,20 +353,28 @@ private void verifyVersion() {
         // Heartbeat entry is assumed to always be present. If it's not present, we
         // assume that a camera with that name was never connected in the first place.
         if (!heartbeatEntry.exists()) {
-            Set<String> cameraNames = cameraTable.getInstance().getTable(kTableName).getSubTables();
+            var cameraNames = getTablesThatLookLikePhotonCameras();
             if (cameraNames.isEmpty()) {
                 DriverStation.reportError(
-                        "Could not find any PhotonVision coprocessors on NetworkTables. Double check that PhotonVision is running, and that your camera is connected!",
+                        "Could not find **any** PhotonVision coprocessors on NetworkTables. Double check that PhotonVision is running, and that your camera is connected!",
                         false);
             } else {
                 DriverStation.reportError(
                         "PhotonVision coprocessor at path "
                                 + path
                                 + " not found on NetworkTables. Double check that your camera names match!",
                         true);
+
+                var cameraNameStr = new StringBuilder();
+                for (var c : cameraNames) {
+                    cameraNameStr.append(" ==> ");
+                    cameraNameStr.append(c);
+                    cameraNameStr.append("\n");
+                }
+
                 DriverStation.reportError(
-                        "Found the following PhotonVision cameras on NetworkTables:\n"
-                                + String.join("\n", cameraNames),
+                        "Found the following PhotonVision cameras active on NetworkTables:\n"
+                                + String.join("\n", cameraNameStr),
                         false);
             }
         }
@@ -404,4 +419,13 @@ else if (!isConnected()) {
             throw new UnsupportedOperationException(versionMismatchMessage);
         }
     }
+
+    private List<String> getTablesThatLookLikePhotonCameras() {
+        return rootPhotonTable.getSubTables().stream()
+                .filter(
+                        it -> {
+                            return rootPhotonTable.getSubTable(it).getEntry("rawBytes").exists();
+                        })
+                .collect(Collectors.toList());
+    }
 }