Remove hasTargets member variable and fix docs warnings (#283)

hasTargets is redundant because the same information can be obtained by
checking the size of the targets array.

photon-lib/.styleguide

@@ -15,6 +15,7 @@ includeProject {
 
 includeOtherLibs {
   ^frc/
+  ^networktables/
   ^units/
   ^wpi/
 }

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

@@ -195,6 +195,7 @@ public class PhotonCamera {
     * @deprecated This method should be replaced with {@link PhotonPipelineResult#hasTargets()}
     * @return Whether the latest target result has targets.
     */
+    @Deprecated
     public boolean hasTargets() {
         return getLatestResult().hasTargets();
     }

photon-lib/src/main/native/cpp/photonlib/PhotonPipelineResult.cpp

@@ -21,13 +21,10 @@ namespace photonlib {
 PhotonPipelineResult::PhotonPipelineResult(
     units::second_t latency, wpi::ArrayRef<PhotonTrackedTarget> targets)
     : latency(latency),
-      targets(targets.data(), targets.data() + targets.size()) {
-  hasTargets = targets.size() != 0;
-}
+      targets(targets.data(), targets.data() + targets.size()) {}
 
 bool PhotonPipelineResult::operator==(const PhotonPipelineResult& other) const {
-  return latency == other.latency && hasTargets == other.hasTargets &&
-         targets == other.targets;
+  return latency == other.latency && targets == other.targets;
 }
 
 bool PhotonPipelineResult::operator!=(const PhotonPipelineResult& other) const {
@@ -35,8 +32,8 @@ bool PhotonPipelineResult::operator!=(const PhotonPipelineResult& other) const {
 }
 
 Packet& operator<<(Packet& packet, const PhotonPipelineResult& result) {
-  // Encode latency, existence of targets, and number of targets.
-  packet << result.latency.to<double>() * 1000 << result.hasTargets
+  // Encode latency and number of targets.
+  packet << result.latency.to<double>() * 1000
          << static_cast<int8_t>(result.targets.size());
 
   // Encode the information of each target.
@@ -50,7 +47,7 @@ Packet& operator>>(Packet& packet, PhotonPipelineResult& result) {
   // Decode latency, existence of targets, and number of targets.
   int8_t targetCount = 0;
   double latencyMillis = 0;
-  packet >> latencyMillis >> result.hasTargets >> targetCount;
+  packet >> latencyMillis >> targetCount;
   result.latency = units::second_t(latencyMillis / 1000.0);
 
   result.targets.clear();

photon-lib/src/main/native/include/photonlib/PhotonCamera.h

@@ -17,12 +17,13 @@
 
 #pragma once
 
+#include <memory>
+#include <string>
+
 #include <networktables/NetworkTable.h>
 #include <networktables/NetworkTableEntry.h>
 #include <networktables/NetworkTableInstance.h>
-
-#include <memory>
-#include <string>
+#include <wpi/deprecated.h>
 
 #include "photonlib/PhotonPipelineResult.h"
 
@@ -118,9 +119,11 @@ class PhotonCamera {
    * This method is deprecated; {@link PhotonPipelineResult#hasTargets()} should
    * be used instead.
    * @deprecated This method should be replaced with {@link
-   * PhotonPipelineResult#hasTargets()}
+   * PhotonPipelineResult#HasTargets()}
    * @return Whether the latest target result has targets.
    */
+  WPI_DEPRECATED(
+      "This method should be replaced with PhotonPipelineResult::HasTargets()")
   bool HasTargets() const { return GetLatestResult().HasTargets(); }
 
  private:

photon-lib/src/main/native/include/photonlib/PhotonPipelineResult.h

@@ -57,12 +57,12 @@ class PhotonPipelineResult {
     if (!HasTargets() && !HAS_WARNED) {
       ::frc::DriverStation::ReportError(
           "This PhotonPipelineResult object has no targets associated with it! "
-          "Please check hasTargets() before calling this method. For more "
+          "Please check HasTargets() before calling this method. For more "
           "information, please review the PhotonLib documentation at "
           "http://docs.photonvision.org");
       HAS_WARNED = true;
     }
-    return hasTargets ? targets[0] : PhotonTrackedTarget();
+    return HasTargets() ? targets[0] : PhotonTrackedTarget();
   }
 
   /**
@@ -75,7 +75,7 @@ class PhotonPipelineResult {
    * Returns whether the pipeline has targets.
    * @return Whether the pipeline has targets.
    */
-  bool HasTargets() const { return hasTargets; }
+  bool HasTargets() const { return targets.size() > 0; }
 
   /**
    * Returns a reference to the vector of targets.
@@ -93,7 +93,6 @@ class PhotonPipelineResult {
 
  private:
   units::second_t latency = 0_s;
-  bool hasTargets = false;
   wpi::SmallVector<PhotonTrackedTarget, 10> targets;
   inline static bool HAS_WARNED = false;
 };

photon-lib/src/test/native/cpp/SimVisionSystemTest.cpp

@@ -18,7 +18,6 @@
 #include <networktables/NetworkTable.h>
 #include <networktables/NetworkTableEntry.h>
 #include <networktables/NetworkTableInstance.h>
-
 #include <units/angle.h>
 #include <units/length.h>
 

photon-targeting/src/main/java/org/photonvision/common/dataflow/structures/Packet.java

@@ -26,7 +26,11 @@ public class Packet {
     // Read and write positions.
     int readPos, writePos;
 
-    /** Constructs an empty packet. */
+    /**
+    * Constructs an empty packet.
+    *
+    * @param size The size of the packet buffer.
+    */
     public Packet(int size) {
         this.size = size;
         packetData = new byte[size];

photon-targeting/src/main/java/org/photonvision/targeting/PhotonPipelineResult.java

@@ -33,9 +33,6 @@ public class PhotonPipelineResult {
     // Latency in milliseconds.
     private double latencyMillis;
 
-    // Whether targets exist.
-    private boolean hasTargets;
-
     /** Constructs an empty pipeline result. */
     public PhotonPipelineResult() {}
 
@@ -47,7 +44,6 @@ public class PhotonPipelineResult {
     */
     public PhotonPipelineResult(double latencyMillis, List<PhotonTrackedTarget> targets) {
         this.latencyMillis = latencyMillis;
-        this.hasTargets = targets.size() != 0;
         this.targets.addAll(targets);
     }
 
@@ -67,7 +63,7 @@ public class PhotonPipelineResult {
     * @return The best target of the pipeline result.
     */
     public PhotonTrackedTarget getBestTarget() {
-        if (!hasTargets && !HAS_WARNED) {
+        if (!hasTargets() && !HAS_WARNED) {
             String errStr =
                     "This PhotonPipelineResult object has no targets associated with it! Please check hasTargets() "
                             + "before calling this method. For more information, please review the PhotonLib "
@@ -76,7 +72,7 @@ public class PhotonPipelineResult {
             new Exception().printStackTrace();
             HAS_WARNED = true;
         }
-        return hasTargets ? targets.get(0) : null;
+        return hasTargets() ? targets.get(0) : null;
     }
 
     /**
@@ -94,7 +90,7 @@ public class PhotonPipelineResult {
     * @return Whether the pipeline has targets.
     */
     public boolean hasTargets() {
-        return hasTargets;
+        return targets.size() > 0;
     }
 
     /**
@@ -112,14 +108,13 @@ public class PhotonPipelineResult {
         if (o == null || getClass() != o.getClass()) return false;
         PhotonPipelineResult that = (PhotonPipelineResult) o;
         boolean latencyMatch = Double.compare(that.latencyMillis, latencyMillis) == 0;
-        boolean hasTargetsMatch = that.hasTargets == hasTargets;
         boolean targetsMatch = that.targets.equals(targets);
-        return latencyMatch && hasTargetsMatch && targetsMatch;
+        return latencyMatch && targetsMatch;
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(latencyMillis, hasTargets, targets);
+        return Objects.hash(latencyMillis, targets);
     }
 
     /**
@@ -131,7 +126,6 @@ public class PhotonPipelineResult {
     public Packet createFromPacket(Packet packet) {
         // Decode latency, existence of targets, and number of targets.
         latencyMillis = packet.decodeDouble();
-        hasTargets = packet.decodeBoolean();
         byte targetCount = packet.decodeByte();
 
         targets.clear();
@@ -155,7 +149,6 @@ public class PhotonPipelineResult {
     public Packet populatePacket(Packet packet) {
         // Encode latency, existence of targets, and number of targets.
         packet.encode(latencyMillis);
-        packet.encode(hasTargets);
         packet.encode((byte) targets.size());
 
         // Encode the information of each target.