Add fluent builders for more flexibly adding data to Shuffleboard (#1022)

wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardValue.h

@@ -0,0 +1,71 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2018 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 <networktables/NetworkTable.h>
+#include <wpi/SmallVector.h>
+#include <wpi/StringRef.h>
+
+namespace frc {
+
+class ShuffleboardValue {
+ public:
+  explicit ShuffleboardValue(const wpi::Twine& title) {
+    wpi::SmallVector<char, 16> storage;
+    m_title = title.toStringRef(storage);
+  }
+
+  virtual ~ShuffleboardValue() = default;
+
+  /**
+   * Gets the title of this Shuffleboard value.
+   */
+  wpi::StringRef GetTitle() const { return m_title; }
+
+  /**
+   * Builds the entries for this value.
+   *
+   * @param parentTable The table containing all the data for the parent. Values
+   *                    that require a complex entry or table structure should
+   *                    call {@code parentTable.getSubtable(getTitle())} to get
+   *                    the table to put data into. Values that only use a
+   *                    single entry should call
+   *                    {@code parentTable.getEntry(getTitle())} to get that
+   *                    entry.
+   * @param metaTable   The table containing all the metadata for this value and
+   *                    its sub-values
+   */
+  virtual void BuildInto(std::shared_ptr<nt::NetworkTable> parentTable,
+                         std::shared_ptr<nt::NetworkTable> metaTable) = 0;
+
+  /**
+   * Enables user control of this widget in the Shuffleboard application.
+   *
+   * This method is package-private to prevent users from enabling control
+   * themselves. Has no effect if the sendable is not marked as an actuator with
+   * {@link SendableBuilder#setActuator}.
+   */
+  virtual void EnableIfActuator() {}
+
+  /**
+   * Disables user control of this widget in the Shuffleboard application.
+   *
+   * This method is package-private to prevent users from enabling control
+   * themselves. Has no effect if the sendable is not marked as an actuator with
+   * {@link SendableBuilder#setActuator}.
+   */
+  virtual void DisableIfActuator() {}
+
+ private:
+  std::string m_title;
+};
+
+}  // namespace frc