Add AutoLogOutput annotation

docs/CODE-STRUCTURE.md

@@ -177,9 +177,33 @@ Logger.recordOutput("MySwerveModuleStates", stateA, stateB, stateC, stateD);
 Logger.recordOutput("MySwerveModuleStates", new SwerveModuleState[] { stateA, stateB, stateC, stateD });
 ```
 
-AdvantageKit can also log [`Mechanism2d`](https://docs.wpilib.org/en/stable/docs/software/dashboards/glass/mech2d-widget.html) objects as outputs, which can be viewed using AdvantageScope. Note that the call below only records the current state of the `Mechanism2d`, so it must be called every loop cycle after the object is updated.
+The `@AutoLogOutput` annotation can also be used to automatically log the value of a field or getter method as an output periodically (including private fields and methods). The key will be selected automatically, or it can be overriden using the `key` parameter. All data types are supported, including arrays and structured data types.
 
 ```java
-Mechanism2d mechanism = new Mechanism2d(3, 3);
-Logger.recordOutput("MyMechanism", mechanism);
+public class Example {
+    @AutoLogOutput // Logged as "Example/MyPose"
+    private Pose2d myPose = new Pose2d();
+
+    @AutoLogOutput(key = "Custom/Speeds")
+    public double[] getSpeeds() {
+        ...
+    }
+}
+```
+
+> Note: The parent class where `@AutoLogOutput` is used must be instantiated within the first loop cycle, be accessible by a recursive search of the fields of `Robot`, and be within the same package as `Robot` (or a subpackage). This feature is primarily intended to log outputs from subsystems and other similar classes. For classes that do not fit the criteria above, call `Logger.recordOutput` periodically to record outputs.
+
+AdvantageKit can also log [`Mechanism2d`](https://docs.wpilib.org/en/stable/docs/software/dashboards/glass/mech2d-widget.html) objects as outputs, which can be viewed using AdvantageScope. If not using `@AutoLogOutput`, note that the logging call only records the current state of the `Mechanism2d` and so it must be called periodically.
+
+```java
+public class Example {
+    @AutoLogOutput // Auto logged as "Example/Mechanism"
+    private Mechanism2d mechanism = new Mechanism2d(3, 3);
+
+    public void periodic() {
+        // Alternative approach if not using @AutoLogOutput
+        // (Must be called periodically)
+        Logger.recordOutput("Example/Mechanism", mechanism);
+    }
+}
 ```

example_projects/diff_drive/src/main/java/frc/robot/subsystems/drive/Drive.java

@@ -19,6 +19,7 @@
 import edu.wpi.first.math.util.Units;
 import edu.wpi.first.wpilibj.drive.DifferentialDrive;
 import edu.wpi.first.wpilibj2.command.SubsystemBase;
+import org.littletonrobotics.junction.AutoLogOutput;
 import org.littletonrobotics.junction.Logger;
 
 public class Drive extends SubsystemBase {
@@ -39,9 +40,8 @@ public void periodic() {
     io.updateInputs(inputs);
     Logger.processInputs("Drive", inputs);
 
-    // Update odometry and log the new pose
+    // Update odometry
     odometry.update(inputs.gyroYaw, getLeftPositionMeters(), getRightPositionMeters());
-    Logger.recordOutput("Odometry", getPose());
   }
 
   /** Run open loop at the specified percentage. */
@@ -61,6 +61,7 @@ public void stop() {
   }
 
   /** Returns the current odometry pose in meters. */
+  @AutoLogOutput
   public Pose2d getPose() {
     return odometry.getPoseMeters();
   }
@@ -71,21 +72,25 @@ public void setPose(Pose2d pose) {
   }
 
   /** Returns the position of the left wheels in meters. */
+  @AutoLogOutput
   public double getLeftPositionMeters() {
     return inputs.leftPositionRad * WHEEL_RADIUS;
   }
 
   /** Returns the position of the right wheels in meters. */
+  @AutoLogOutput
   public double getRightPositionMeters() {
     return inputs.rightPositionRad * WHEEL_RADIUS;
   }
 
   /** Returns the velocity of the left wheels in meters/second. */
+  @AutoLogOutput
   public double getLeftVelocityMeters() {
     return inputs.leftVelocityRadPerSec * WHEEL_RADIUS;
   }
 
   /** Returns the velocity of the right wheels in meters/second. */
+  @AutoLogOutput
   public double getRightVelocityMeters() {
     return inputs.rightVelocityRadPerSec * WHEEL_RADIUS;
   }

example_projects/diff_drive/src/main/java/frc/robot/subsystems/flywheel/Flywheel.java

@@ -17,6 +17,7 @@
 import edu.wpi.first.math.util.Units;
 import edu.wpi.first.wpilibj2.command.SubsystemBase;
 import frc.robot.Constants;
+import org.littletonrobotics.junction.AutoLogOutput;
 import org.littletonrobotics.junction.Logger;
 
 public class Flywheel extends SubsystemBase {
@@ -50,9 +51,6 @@ public Flywheel(FlywheelIO io) {
   public void periodic() {
     io.updateInputs(inputs);
     Logger.processInputs("Flywheel", inputs);
-
-    // Log flywheel speed in RPM
-    Logger.recordOutput("FlywheelSpeedRPM", getVelocityRPM());
   }
 
   /** Run closed loop at the specified velocity. */
@@ -61,7 +59,7 @@ public void runVelocity(double velocityRPM) {
     io.setVelocity(velocityRadPerSec, ffModel.calculate(velocityRadPerSec));
 
     // Log flywheel setpoint
-    Logger.recordOutput("FlywheelSetpointRPM", velocityRPM);
+    Logger.recordOutput("Flywheel/SetpointRPM", velocityRPM);
   }
 
   /** Stops the flywheel. */
@@ -70,6 +68,7 @@ public void stop() {
   }
 
   /** Returns the current velocity in RPM. */
+  @AutoLogOutput
   public double getVelocityRPM() {
     return Units.radiansPerSecondToRotationsPerMinute(inputs.velocityRadPerSec);
   }

example_projects/swerve_drive/src/main/java/frc/robot/subsystems/drive/Drive.java

@@ -30,6 +30,7 @@
 import edu.wpi.first.wpilibj.DriverStation;
 import edu.wpi.first.wpilibj2.command.SubsystemBase;
 import frc.robot.util.LocalADStarAK;
+import org.littletonrobotics.junction.AutoLogOutput;
 import org.littletonrobotics.junction.Logger;
 
 public class Drive extends SubsystemBase {
@@ -94,10 +95,6 @@ public void periodic() {
         module.stop();
       }
     }
-
-    // Log measured states
-    Logger.recordOutput("SwerveStates/Measured", getModuleStates());
-
     // Log empty setpoint states when disabled
     if (DriverStation.isDisabled()) {
       Logger.recordOutput("SwerveStates/Setpoints", new SwerveModuleState[] {});
@@ -123,7 +120,6 @@ public void periodic() {
     }
     // Apply the twist (change since last loop cycle) to the current pose
     pose = pose.exp(twist);
-    Logger.recordOutput("Odometry/Robot", getPose());
   }
 
   /**
@@ -184,6 +180,7 @@ public double getCharacterizationVelocity() {
   }
 
   /** Returns the module states (turn angles and drive velocitoes) for all of the modules. */
+  @AutoLogOutput(key = "SwerveStates/Measured")
   private SwerveModuleState[] getModuleStates() {
     SwerveModuleState[] states = new SwerveModuleState[4];
     for (int i = 0; i < 4; i++) {
@@ -193,6 +190,7 @@ private SwerveModuleState[] getModuleStates() {
   }
 
   /** Returns the current odometry pose. */
+  @AutoLogOutput(key = "Odometry/Robot")
   public Pose2d getPose() {
     return pose;
   }

example_projects/swerve_drive/src/main/java/frc/robot/subsystems/flywheel/Flywheel.java

@@ -17,6 +17,7 @@
 import edu.wpi.first.math.util.Units;
 import edu.wpi.first.wpilibj2.command.SubsystemBase;
 import frc.robot.Constants;
+import org.littletonrobotics.junction.AutoLogOutput;
 import org.littletonrobotics.junction.Logger;
 
 public class Flywheel extends SubsystemBase {
@@ -50,9 +51,6 @@ public Flywheel(FlywheelIO io) {
   public void periodic() {
     io.updateInputs(inputs);
     Logger.processInputs("Flywheel", inputs);
-
-    // Log flywheel speed in RPM
-    Logger.recordOutput("FlywheelSpeedRPM", getVelocityRPM());
   }
 
   /** Run closed loop at the specified velocity. */
@@ -61,7 +59,7 @@ public void runVelocity(double velocityRPM) {
     io.setVelocity(velocityRadPerSec, ffModel.calculate(velocityRadPerSec));
 
     // Log flywheel setpoint
-    Logger.recordOutput("FlywheelSetpointRPM", velocityRPM);
+    Logger.recordOutput("Flywheel/SetpointRPM", velocityRPM);
   }
 
   /** Stops the flywheel. */
@@ -70,6 +68,7 @@ public void stop() {
   }
 
   /** Returns the current velocity in RPM. */
+  @AutoLogOutput
   public double getVelocityRPM() {
     return Units.radiansPerSecondToRotationsPerMinute(inputs.velocityRadPerSec);
   }

junction/core/src/org/littletonrobotics/junction/AutoLogOutput.java

@@ -0,0 +1,25 @@
+// Copyright 2021-2023 FRC 6328
+// http://github.com/Mechanical-Advantage
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// version 3 as published by the Free Software Foundation or
+// available in the root directory of this project.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+package org.littletonrobotics.junction;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.FIELD, ElementType.METHOD })
+public @interface AutoLogOutput {
+    public String key() default "";
+}