[wpilib] Remove PIDController, PIDOutput, PIDSource

Move them to the old commands vendordep so that PIDCommand and PIDSubsystem
continue to work.

This also removes Filter and LinearDigitalFilter.

wpilibOldCommands/src/main/java/edu/wpi/first/wpilibj/PIDController.java

@@ -0,0 +1,172 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj;
+
+import edu.wpi.first.wpilibj.smartdashboard.SendableBuilder;
+
+/**
+ * Class implements a PID Control Loop.
+ *
+ * <p>Creates a separate thread which reads the given PIDSource and takes care of the integral
+ * calculations, as well as writing the given PIDOutput.
+ *
+ * <p>This feedback controller runs in discrete time, so time deltas are not used in the integral
+ * and derivative calculations. Therefore, the sample rate affects the controller's behavior for a
+ * given set of PID constants.
+ *
+ * @deprecated Use {@link edu.wpi.first.wpilibj.controller.PIDController} instead.
+ */
+@Deprecated(since = "2020", forRemoval = true)
+public class PIDController extends PIDBase implements Controller {
+  Notifier m_controlLoop = new Notifier(this::calculate);
+
+  /**
+   * Allocate a PID object with the given constants for P, I, D, and F.
+   *
+   * @param Kp the proportional coefficient
+   * @param Ki the integral coefficient
+   * @param Kd the derivative coefficient
+   * @param Kf the feed forward term
+   * @param source The PIDSource object that is used to get values
+   * @param output The PIDOutput object that is set to the output percentage
+   * @param period the loop time for doing calculations in seconds. This particularly affects
+   *     calculations of the integral and differential terms. The default is 0.05 (50ms).
+   */
+  @SuppressWarnings("ParameterName")
+  public PIDController(
+      double Kp,
+      double Ki,
+      double Kd,
+      double Kf,
+      PIDSource source,
+      PIDOutput output,
+      double period) {
+    super(Kp, Ki, Kd, Kf, source, output);
+    m_controlLoop.startPeriodic(period);
+  }
+
+  /**
+   * Allocate a PID object with the given constants for P, I, D and period.
+   *
+   * @param Kp the proportional coefficient
+   * @param Ki the integral coefficient
+   * @param Kd the derivative coefficient
+   * @param source the PIDSource object that is used to get values
+   * @param output the PIDOutput object that is set to the output percentage
+   * @param period the loop time for doing calculations in seconds. This particularly affects
+   *     calculations of the integral and differential terms. The default is 0.05 (50ms).
+   */
+  @SuppressWarnings("ParameterName")
+  public PIDController(
+      double Kp, double Ki, double Kd, PIDSource source, PIDOutput output, double period) {
+    this(Kp, Ki, Kd, 0.0, source, output, period);
+  }
+
+  /**
+   * Allocate a PID object with the given constants for P, I, D, using a 50ms period.
+   *
+   * @param Kp the proportional coefficient
+   * @param Ki the integral coefficient
+   * @param Kd the derivative coefficient
+   * @param source The PIDSource object that is used to get values
+   * @param output The PIDOutput object that is set to the output percentage
+   */
+  @SuppressWarnings("ParameterName")
+  public PIDController(double Kp, double Ki, double Kd, PIDSource source, PIDOutput output) {
+    this(Kp, Ki, Kd, source, output, kDefaultPeriod);
+  }
+
+  /**
+   * Allocate a PID object with the given constants for P, I, D, using a 50ms period.
+   *
+   * @param Kp the proportional coefficient
+   * @param Ki the integral coefficient
+   * @param Kd the derivative coefficient
+   * @param Kf the feed forward term
+   * @param source The PIDSource object that is used to get values
+   * @param output The PIDOutput object that is set to the output percentage
+   */
+  @SuppressWarnings("ParameterName")
+  public PIDController(
+      double Kp, double Ki, double Kd, double Kf, PIDSource source, PIDOutput output) {
+    this(Kp, Ki, Kd, Kf, source, output, kDefaultPeriod);
+  }
+
+  @Override
+  public void close() {
+    m_controlLoop.close();
+    m_thisMutex.lock();
+    try {
+      m_pidOutput = null;
+      m_pidInput = null;
+      m_controlLoop = null;
+    } finally {
+      m_thisMutex.unlock();
+    }
+  }
+
+  /** Begin running the PIDController. */
+  @Override
+  public void enable() {
+    m_thisMutex.lock();
+    try {
+      m_enabled = true;
+    } finally {
+      m_thisMutex.unlock();
+    }
+  }
+
+  /** Stop running the PIDController, this sets the output to zero before stopping. */
+  @Override
+  public void disable() {
+    // Ensures m_enabled check and pidWrite() call occur atomically
+    m_pidWriteMutex.lock();
+    try {
+      m_thisMutex.lock();
+      try {
+        m_enabled = false;
+      } finally {
+        m_thisMutex.unlock();
+      }
+
+      m_pidOutput.pidWrite(0);
+    } finally {
+      m_pidWriteMutex.unlock();
+    }
+  }
+
+  /** Set the enabled state of the PIDController. */
+  public void setEnabled(boolean enable) {
+    if (enable) {
+      enable();
+    } else {
+      disable();
+    }
+  }
+
+  /** Return true if PIDController is enabled. */
+  public boolean isEnabled() {
+    m_thisMutex.lock();
+    try {
+      return m_enabled;
+    } finally {
+      m_thisMutex.unlock();
+    }
+  }
+
+  /** Reset the previous error, the integral term, and disable the controller. */
+  @Override
+  public void reset() {
+    disable();
+
+    super.reset();
+  }
+
+  @Override
+  public void initSendable(SendableBuilder builder) {
+    super.initSendable(builder);
+    builder.addBooleanProperty("enabled", this::isEnabled, this::setEnabled);
+  }
+}