This class turns an analog axis on a Joystick device, into a button which can be used to trigger commands.It is intended to be used with the WPILib Command Based robot project on FRC robots.

JoystickAnalogButton.java

import edu.wpi.first.wpilibj.GenericHID;
import edu.wpi.first.wpilibj.buttons.Button;

/**
 * This class allows you to trigger commands from an analog input on
 * a joystick (sich as the triggers - Axis 3). 
 * 
 * 
 * The following example code placed in OI class turns axis 3 into two buttons:
 * ----------------------------------------------------------------------------
 * //Create an AnalogButton for each trigger
 * int joystickChannel = 1;
 * public JoystickAnalogButton TriggerR = new JoystickAnalogButton(joystickChannel, 3, -0.5),
 *                             TriggerL = new JoystickAnalogButton(joystickChannel, 3, 0.5)
 * 
 * //Link the buttons to commands
 * TriggerR.whenPressed(new ExampleCommand1());
 * TriggerL.whenPressed(new ExampleCommand2())
 * 
 * Note that since both buttons are on the same Axis channel, they cannot be
 * pressed simultaneously. One trigger will negate the other and neither will
 * look pressed. So plan your controls accordingly.
 * 
 * @author James@team2168.org
 *
 */
public class JoystickAnalogButton extends Button {

  GenericHID m_joystick;
  int m_axisNumber;
  private double THRESHOLD = 0.5;

  /**
   * Create a button for triggering commands off a joystick's analog axis
   * 
   * @param joystick The GenericHID object that has the button (e.g. Joystick, KinectStick, etc)
   * @param axisNumber The axis number
   */
  public JoystickAnalogButton(GenericHID joystick, int axisNumber) {
      m_joystick = joystick;
      m_axisNumber = axisNumber;
  }

  /**
   * Create a button for triggering commands off a joystick's analog axis
   * 
   * @param joystick The GenericHID object that has the button (e.g. Joystick, KinectStick, etc)
   * @param axisNumber The axis number
   * @param threshold The threshold to trigger above (positive) or below (negative)
   */
  public JoystickAnalogButton(GenericHID joystick, int axisNumber, double threshold) {
  	m_joystick = joystick;
      m_axisNumber = axisNumber;
      THRESHOLD = threshold;
  }

  /**
   * Set the value above which triggers should occur (for positive thresholds)
   *  or below which triggers should occur (for negative thresholds)
   * The default threshold value is 0.5
   *  
   * @param threshold the threshold value (1 to -1)
   */
  public void setThreshold(double threshold){
  	THRESHOLD = threshold;
  }
 
  /**
   * Get the defined threshold value.
   * @return the threshold value
   */
  public double getThreshold(){
  	return THRESHOLD;
  }
  

  public boolean get() {
    if(THRESHOLD < 0){
      return m_joystick.getRawAxis(m_axisNumber) < THRESHOLD;    //Return true if axis value is less than negative threshold
    } else {
      return m_joystick.getRawAxis(m_axisNumber) > THRESHOLD;    //Return true if axis value is greater than positive threshold
    }
  }

}

Awesome, thanks! I'd love to use this myself in an FRC library our team is writing—do you mind if we do that?

Awesome, thanks! I'd love to use this myself in an FRC library our team is writing—do you mind if we do that?

@battery-staple please do.
There may be something similar you could use in newer versions of WPILib.

If you do end up using, please attribute to james@team2168.org

this is great, exactly what I was about to do for FTClib in ftc