Simplify Sendable interface (#1864)

This removes the name and subsystem from individual objects, and instead
puts this data into a new singleton class, SendableRegistry.  Much of
LiveWindow has been refactored into SendableRegistry.

In C++, a new CRTP helper class, SendableHelper, has been added to provide
move and destruction functionality.

Shims for GetName, SetName, GetSubsystem, and SetSubsystem have been added
to Command and Subsystem (both old and new), and also to SendableHelper to
prevent code breakage.

This deprecates SendableBase in preparation for future removal.

wpilibc/src/main/native/include/frc/smartdashboard/SendableHelper.h

@@ -0,0 +1,161 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include <wpi/Twine.h>
+#include <wpi/deprecated.h>
+
+#include "frc/smartdashboard/SendableRegistry.h"
+
+namespace frc {
+
+/**
+ * A helper class for use with objects that add themselves to SendableRegistry.
+ * It takes care of properly calling Move() and Remove() on move and
+ * destruction.  No action is taken if the object is copied.
+ * Use public inheritance with CRTP when using this class.
+ * @tparam CRTP derived class
+ */
+template <typename Derived>
+class SendableHelper {
+ public:
+  SendableHelper(const SendableHelper& rhs) = default;
+  SendableHelper& operator=(const SendableHelper& rhs) = default;
+
+  SendableHelper(SendableHelper&& rhs) {
+    // it is safe to call Move() multiple times with the same rhs
+    SendableRegistry::GetInstance().Move(static_cast<Derived*>(this),
+                                         static_cast<Derived*>(&rhs));
+  }
+
+  SendableHelper& operator=(SendableHelper&& rhs) {
+    // it is safe to call Move() multiple times with the same rhs
+    SendableRegistry::GetInstance().Move(static_cast<Derived*>(this),
+                                         static_cast<Derived*>(&rhs));
+    return *this;
+  }
+
+  /**
+   * Gets the name of this Sendable object.
+   *
+   * @return Name
+   */
+  WPI_DEPRECATED("use SendableRegistry::GetName()")
+  std::string GetName() const {
+    return SendableRegistry::GetInstance().GetName(
+        static_cast<const Derived*>(this));
+  }
+
+  /**
+   * Sets the name of this Sendable object.
+   *
+   * @param name name
+   */
+  WPI_DEPRECATED("use SendableRegistry::SetName()")
+  void SetName(const wpi::Twine& name) {
+    SendableRegistry::GetInstance().SetName(static_cast<Derived*>(this), name);
+  }
+
+  /**
+   * Sets both the subsystem name and device name of this Sendable object.
+   *
+   * @param subsystem subsystem name
+   * @param name device name
+   */
+  WPI_DEPRECATED("use SendableRegistry::SetName()")
+  void SetName(const wpi::Twine& subsystem, const wpi::Twine& name) {
+    SendableRegistry::GetInstance().SetName(static_cast<Derived*>(this),
+                                            subsystem, name);
+  }
+
+  /**
+   * Gets the subsystem name of this Sendable object.
+   *
+   * @return Subsystem name
+   */
+  WPI_DEPRECATED("use SendableRegistry::GetSubsystem()")
+  std::string GetSubsystem() const {
+    return SendableRegistry::GetInstance().GetSubsystem(
+        static_cast<const Derived*>(this));
+  }
+
+  /**
+   * Sets the subsystem name of this Sendable object.
+   *
+   * @param subsystem subsystem name
+   */
+  WPI_DEPRECATED("use SendableRegistry::SetSubsystem()")
+  void SetSubsystem(const wpi::Twine& subsystem) {
+    SendableRegistry::GetInstance().SetSubsystem(static_cast<Derived*>(this),
+                                                 subsystem);
+  }
+
+ protected:
+  /**
+   * Add a child component.
+   *
+   * @param child child component
+   */
+  WPI_DEPRECATED("use SendableRegistry::AddChild()")
+  void AddChild(std::shared_ptr<Sendable> child) {
+    SendableRegistry::GetInstance().AddChild(static_cast<Derived*>(this),
+                                             child.get());
+  }
+
+  /**
+   * Add a child component.
+   *
+   * @param child child component
+   */
+  WPI_DEPRECATED("use SendableRegistry::AddChild()")
+  void AddChild(void* child) {
+    SendableRegistry::GetInstance().AddChild(static_cast<Derived*>(this),
+                                             child);
+  }
+
+  /**
+   * Sets the name of the sensor with a channel number.
+   *
+   * @param moduleType A string that defines the module name in the label for
+   *                   the value
+   * @param channel    The channel number the device is plugged into
+   */
+  WPI_DEPRECATED("use SendableRegistry::SetName()")
+  void SetName(const wpi::Twine& moduleType, int channel) {
+    SendableRegistry::GetInstance().SetName(static_cast<Derived*>(this),
+                                            moduleType, channel);
+  }
+
+  /**
+   * Sets the name of the sensor with a module and channel number.
+   *
+   * @param moduleType   A string that defines the module name in the label for
+   *                     the value
+   * @param moduleNumber The number of the particular module type
+   * @param channel      The channel number the device is plugged into (usually
+   * PWM)
+   */
+  WPI_DEPRECATED("use SendableRegistry::SetName()")
+  void SetName(const wpi::Twine& moduleType, int moduleNumber, int channel) {
+    SendableRegistry::GetInstance().SetName(static_cast<Derived*>(this),
+                                            moduleType, moduleNumber, channel);
+  }
+
+ protected:
+  SendableHelper() = default;
+
+  ~SendableHelper() {
+    // it is safe to call Remove() multiple times with the same object
+    SendableRegistry::GetInstance().Remove(static_cast<Derived*>(this));
+  }
+};
+
+}  // namespace frc