mirror of
https://github.com/wpilibsuite/allwpilib
synced 2026-06-19 00:41:43 +00:00
02c6030251
Commands are no longer able to outlive their schedule-site's scope,
regardless of how they were scheduled (set as a default command, bound
to a trigger, or manually scheduled)
As a consequence, default commands need better tracking so the default
command setting can be released when their scope exits and the next-most
appropriate default command can be rescheduled (eg, an opmode sets a
default command, then the globally-scoped default is restored when the
opmode exits). Some complexity is required here to make it work well for
edge cases.
Like `schedule()`, `setDefaultCommand()` will immediately start the new
default command if called inside of another command to avoid 1-loop
delays. However, this does not apply when called by the _current_
default command, as it would result in attempting to cancel the default
command while it's mounted (which is impossible and would throw an
exception)
```java
class Robot extends OpModeRobot {
final Drive drive = new Drive();
final CommandXboxController controller = new CommandXboxController(1);
public Robot() {
// global default command, active unless overridden in an opmode or command
drive.setDefaultCommand(drive.stop());
// global trigger binding, always active
controller.rightBumper().onTrue(drive.setX());
}
}
@Teleop
class ExampleOpMode extends PeriodicOpMode {
public ExampleOpMode(Robot robot) {
// opmode-specific default command
robot.drive.setDefaultCommand(robot.drive.operatorControl(robot.controller));
// opmode-specific binding
robot.controller.leftBumper().whileTrue(robot.drive.stop());
// opmode-specific binding that takes precedence over the global binding
// because it happens last; it "wins out" over the `setX()` binding
robot.controller.rightBumper().onTrue(robot.drive.selfTest());
}
@Override
public void periodic() {
Scheduler.getDefault().run();
}
}
```