Package edu.wpi.first.wpilibj.buttons

Class Trigger

java.lang.Object
edu.wpi.first.wpilibj.buttons.Trigger
All Implemented Interfaces:
Sendable
Direct Known Subclasses:
Button
public abstract class Trigger
extends Object
implements Sendable
This class provides an easy way to link commands to inputs.

It is very easy to link a button to a command. For instance, you could link the trigger button of a joystick to a "score" command.

It is encouraged that teams write a subclass of Trigger if they want to have something unusual (for instance, if they want to react to the user holding a button while the robot is reading a certain sensor input). For this, they only have to write the get() method to get the full functionality of the Trigger class.

  • Constructor Details

  • Method Details

    • get

      public abstract boolean get()
      Returns whether or not the trigger is active.

      This method will be called repeatedly a command is linked to the Trigger.

      Returns:
      whether or not the trigger condition is active.

    • whenActive

      public void whenActive​(Command command)
      Starts the given command whenever the trigger just becomes active.
      Parameters:
      command - the command to start

    • whileActive

      public void whileActive​(Command command)
      Constantly starts the given command while the button is held.

      Command.start() will be called repeatedly while the trigger is active, and will be canceled when the trigger becomes inactive.

      Parameters:
      command - the command to start

    • whenInactive

      public void whenInactive​(Command command)
      Starts the command when the trigger becomes inactive.
      Parameters:
      command - the command to start

    • toggleWhenActive

      public void toggleWhenActive​(Command command)
      Toggles a command when the trigger becomes active.
      Parameters:
      command - the command to toggle

    • cancelWhenActive

      public void cancelWhenActive​(Command command)
      Cancels a command when the trigger becomes active.
      Parameters:
      command - the command to cancel

    • initSendable

      public void initSendable​(SendableBuilder builder)
      Description copied from interface: Sendable
      Initializes this Sendable object.
      Specified by:
      initSendable in interface Sendable
      Parameters:
      builder - sendable builder