Class Trigger
java.lang.Object
edu.wpi.first.wpilibj2.command.button.Trigger
- All Implemented Interfaces:
BooleanSupplier
- Direct Known Subclasses:
InternalButton
,JoystickButton
,NetworkButton
,POVButton
public class Trigger extends Object implements BooleanSupplier
This class provides an easy way to link commands to conditions.
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.
Triggers can easily be composed for advanced functionality using the and(BooleanSupplier)
, or(BooleanSupplier)
, negate()
operators.
This class is provided by the NewCommands VendorDep
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Constructor Summary
Constructors Constructor Description Trigger(EventLoop loop, BooleanSupplier condition)
Creates a new trigger based on the given condition.Trigger(BooleanSupplier condition)
Creates a new trigger based on the given condition. -
Method Summary
Modifier and Type Method Description Trigger
and(BooleanSupplier trigger)
Composes two triggers with logical AND.Trigger
debounce(double seconds)
Creates a new debounced trigger from this trigger - it will become active when this trigger has been active for longer than the specified period.Trigger
debounce(double seconds, Debouncer.DebounceType type)
Creates a new debounced trigger from this trigger - it will become active when this trigger has been active for longer than the specified period.boolean
getAsBoolean()
Trigger
negate()
Creates a new trigger that is active when this trigger is inactive, i.e.Trigger
onChange(Command command)
Starts the command when the condition changes.Trigger
onFalse(Command command)
Starts the given command whenever the condition changes from `true` to `false`.Trigger
onTrue(Command command)
Starts the given command whenever the condition changes from `false` to `true`.Trigger
or(BooleanSupplier trigger)
Composes two triggers with logical OR.Trigger
toggleOnFalse(Command command)
Toggles a command when the condition changes from `true` to `false`.Trigger
toggleOnTrue(Command command)
Toggles a command when the condition changes from `false` to `true`.Trigger
whileFalse(Command command)
Starts the given command when the condition changes to `false` and cancels it when the condition changes to `true`.Trigger
whileTrue(Command command)
Starts the given command when the condition changes to `true` and cancels it when the condition changes to `false`.
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Constructor Details
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Trigger
Creates a new trigger based on the given condition.- Parameters:
loop
- The loop instance that polls this trigger.condition
- the condition represented by this trigger
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Trigger
Creates a new trigger based on the given condition.Polled by the default scheduler button loop.
- Parameters:
condition
- the condition represented by this trigger
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Method Details
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onChange
Starts the command when the condition changes.- Parameters:
command
- the command to start- Returns:
- this trigger, so calls can be chained
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onTrue
Starts the given command whenever the condition changes from `false` to `true`.- Parameters:
command
- the command to start- Returns:
- this trigger, so calls can be chained
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onFalse
Starts the given command whenever the condition changes from `true` to `false`.- Parameters:
command
- the command to start- Returns:
- this trigger, so calls can be chained
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whileTrue
Starts the given command when the condition changes to `true` and cancels it when the condition changes to `false`.Doesn't re-start the command if it ends while the condition is still `true`. If the command should restart, see
RepeatCommand
.- Parameters:
command
- the command to start- Returns:
- this trigger, so calls can be chained
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whileFalse
Starts the given command when the condition changes to `false` and cancels it when the condition changes to `true`.Doesn't re-start the command if it ends while the condition is still `false`. If the command should restart, see
RepeatCommand
.- Parameters:
command
- the command to start- Returns:
- this trigger, so calls can be chained
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toggleOnTrue
Toggles a command when the condition changes from `false` to `true`.- Parameters:
command
- the command to toggle- Returns:
- this trigger, so calls can be chained
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toggleOnFalse
Toggles a command when the condition changes from `true` to `false`.- Parameters:
command
- the command to toggle- Returns:
- this trigger, so calls can be chained
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getAsBoolean
- Specified by:
getAsBoolean
in interfaceBooleanSupplier
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and
Composes two triggers with logical AND.- Parameters:
trigger
- the condition to compose with- Returns:
- A trigger which is active when both component triggers are active.
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or
Composes two triggers with logical OR.- Parameters:
trigger
- the condition to compose with- Returns:
- A trigger which is active when either component trigger is active.
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negate
Creates a new trigger that is active when this trigger is inactive, i.e. that acts as the negation of this trigger.- Returns:
- the negated trigger
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debounce
Creates a new debounced trigger from this trigger - it will become active when this trigger has been active for longer than the specified period.- Parameters:
seconds
- The debounce period.- Returns:
- The debounced trigger (rising edges debounced only)
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debounce
Creates a new debounced trigger from this trigger - it will become active when this trigger has been active for longer than the specified period.- Parameters:
seconds
- The debounce period.type
- The debounce type.- Returns:
- The debounced trigger.
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