DigitalInput.h

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// 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.
 
#pragma once
 
#include <hal/DIO.h>
#include <wpi/sendable/Sendable.h>
#include <wpi/sendable/SendableHelper.h>
 
#include "frc/DigitalSource.h"
 
namespace frc {
 
class DigitalGlitchFilter;
 
/**
 * Class to read a digital input.
 *
 * This class will read digital inputs and return the current value on the
 * channel. Other devices such as encoders, gear tooth sensors, etc. that are
 * implemented elsewhere will automatically allocate digital inputs and outputs
 * as required. This class is only for devices like switches etc. that aren't
 * implemented anywhere else.
 */
class DigitalInput : public DigitalSource,
                     public wpi::Sendable,
                     public wpi::SendableHelper<DigitalInput> {
 public:
  /**
   * Create an instance of a Digital Input class.
   *
   * Creates a digital input given a channel.
   *
   * @param channel The DIO channel 0-9 are on-board, 10-25 are on the MXP port
   */
  explicit DigitalInput(int channel);
 
  DigitalInput(DigitalInput&&) = default;
  DigitalInput& operator=(DigitalInput&&) = default;
 
  ~DigitalInput() override = default;
 
  /**
   * Get the value from a digital input channel.
   *
   * Retrieve the value of a single digital input channel from the FPGA.
   */
  bool Get() const;
 
  // Digital Source Interface
  /**
   * @return The HAL Handle to the specified source.
   */
  HAL_Handle GetPortHandleForRouting() const override;
 
  /**
   * @return The type of analog trigger output to be used. 0 for Digitals
   */
  AnalogTriggerType GetAnalogTriggerTypeForRouting() const override;
 
  /**
   * Is source an AnalogTrigger
   */
  bool IsAnalogTrigger() const override;
 
  /**
   * @return The GPIO channel number that this object represents.
   */
  int GetChannel() const override;
 
  /**
   * Indicates this input is used by a simulated device.
   *
   * @param device simulated device handle
   */
  void SetSimDevice(HAL_SimDeviceHandle device);
 
  void InitSendable(wpi::SendableBuilder& builder) override;
 
 private:
  int m_channel;
  hal::Handle<HAL_DigitalHandle, HAL_FreeDIOPort> m_handle;
 
  friend class DigitalGlitchFilter;
};
 
}  // namespace frc