Motivation
Feedback from 2022 showed that the Trigger API is rather confusing, mostly due to the following:
- duplicate Trigger and Button APIs were available; users were confused searching for a nonexistent difference between them.
- the when terminology was ambiguous and unclear whether it refers to the high state or specifically the rising edge.
- the Active terminology didn't unambiguously refer to the high state; it wasn't unintuitive to understand it as "when the binding is active/polled".
- whileHeld vs whenHeld was very confusing, and the difference between them wasn't obvious. The parallel Trigger verbs, whileActiveContinuously and whileActiveOnce are much less confusing.
Solution
Deprecating Button and its binding methods. The rationale for deprecating Button (and not Trigger) is because Button uses terminology that is needlessly more specific and restricting to the button use case, making the use case of arbitrary trigger conditions unintuitive.
After consideration, deprecation of Button's subclasses was decided against:
- NetworkButton (a trigger condition based on a boolean NT entry/topic) is a use case that is not necessarily intuitive for teams to implement themselves, so it is an abstraction that should be provided in the library. A parallel class for the BooleanEvent level, NetworkBooleanEvent, was also added as part of NT4. NT listeners were considered as a alternative solution, but they require attention to thread safety, and aren't interoperable with the EventLoop API.
- JoystickButton/POVButton provide abstractions around HID buttons. The new Trigger-returning factories on the HID classes are an equal (if not more concise) alternative, but there is no reason not to keep them for those who find their use preferable.
At a later date in the deprecation cycle (perhaps for 2024), when Button is removed, these subclasses should be changed to inherit directly from Trigger.
Trigger's bindings are changed to use True/False terminology, as it should be unambiguous. Each binding type has both True and False variants; for brevity, only the True variants are listed here:
- onTrue (replaces whenActive): schedule on rising edge.
- whileTrue (replaces whileActiveOnce): schedule on rising edge, cancel on falling edge.
- toggleOnTrue (replaces toggleWhenActive): on rising edge, schedule if unscheduled and cancel if scheduled.
Two binding types are completely deprecated:
- cancelWhenActive: this is a fairly niche use case which is better described as having the trigger's rising edge (Trigger.rising()) as an end condition for the command (using Command.until()).
- whileActiveContinuously: however common, this relied on the no-op behavior of scheduling an already-scheduled command. The more correct way to repeat the command if it ends before the falling edge is using Command.repeatedly/RepeatCommand or a RunCommand -- the only difference is if the command is interrupted, but that is more likely to result in two commands perpetually canceling each other than achieve the desired behavior. Manually implementing a blindly-scheduling binding like whileActiveContinuously is still possible, though might not be intuitive.
Notes
It was considered to share BooleanEvent's digital signal terminology; however, once it was decided that Trigger should not inherit from BooleanEvent (due to overload incompatibility) the common terminology was not worth the unintuitiveness stemming from users' unfamiliarity with the signal processing terms.
Checkstyle naming conventions were changed to allow most of what's in
wpimath. Naming rules were disabled completely in wpimath since almost
all suppressions are for math notation.
until() was recently added as a more intuitive alias for this. At this point, keeping this decorator will just cause confusion, given the functionally-equivalent until() alias and the similarly-named getInterruptionBehavior/withInterruptBehavior
Fixes several cases where calling scheduler operations from a command callback could result in NPEs or other issues.
Co-authored-by: Tyler Veness <calcmogul@gmail.com>
This allows us to error out on deprecation warnings for thirdparty
libraries and standard library features.
Co-authored-by: Starlight220 <53231611+Starlight220@users.noreply.github.com>
This previously always returned false; the get method it inherited was not used in the getAsBoolean defined in the Trigger class. The fix is to swap get() and getAsBoolean() implementations in the Trigger class.
This also makes the Gradle build work with JDK 17.
The extra JVM args in gradle.properties works around a bug with spotless
and JDK 17: https://github.com/diffplug/spotless/issues/834
PMD.CloseResource was ignored because it's almost always a false
positive, and there are many of them.
Supersedes #2358 with updates and cleanups.
Closes#2482 and closes#2487 because we shouldn't support both
time-based and count-based debouncing approaches.
Co-authored-by: oblarg <emichaelbarnett@gmail.com>
The non-NT portion has been moved to wpiutil.
The NT portion has been moved to ntcore (as NTSendable).
SendableBuilder similarly split and moved.
SendableRegistry moved to wpiutil.
In C++, SendableHelper also moved to wpiutil.
This enables use of Sendable from wpimath and also enables
moving several classes from wpilib to wpimath.
Some valid warnings like throwing NullPointerException or using a for
loop instead of System.arraycopy() were fixed.
Abstract classes marked with PMD.AbstractClassWithoutAbstractMethod were
made concrete because they already had protected constructors.
Fixes#1697.
