add scheduled and done trigger factories to Commands java

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Command.java

@@ -12,6 +12,9 @@
 import edu.wpi.first.util.sendable.Sendable;
 import edu.wpi.first.util.sendable.SendableBuilder;
 import edu.wpi.first.util.sendable.SendableRegistry;
+import edu.wpi.first.wpilibj.event.EventLoop;
+import edu.wpi.first.wpilibj2.command.button.Trigger;
+
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
@@ -497,6 +500,65 @@ public WrapperCommand finallyDo(Runnable end) {
     return finallyDo(interrupted -> end.run());
   }
 
+  /**
+   * Returns a {@link Trigger} that follows if this command is scheduled.
+   * 
+   * @param eventLoop the event loop to use
+   * @return the trigger
+   */
+  public Trigger scheduled(EventLoop eventLoop) {
+    return new Trigger(eventLoop, this::isScheduled);
+  }
+
+  /**
+   * Returns a {@link Trigger} that follows if this command is scheduled.
+   * 
+   * @return the trigger
+   */
+  public Trigger scheduled() {
+    return new Trigger(this::isScheduled);
+  }
+
+  /**
+   * Returns a {@link Trigger} that follows if this command is done.
+   * 
+   * <p>This trigger emits 1 rising edge and 1 falling edge when the command
+   * finishes or is interupted/canceled.
+   * 
+   * @param eventLoop the event loop to use
+   * @return the trigger
+   */
+  public Trigger done(EventLoop eventLoop) {
+    BooleanSupplier isDone =
+        new BooleanSupplier() {
+          boolean wasJustScheduled = false;
+
+          @Override
+          public boolean getAsBoolean() {
+            if (isScheduled()) {
+              wasJustScheduled = true;
+            } else if (wasJustScheduled) {
+              wasJustScheduled = false;
+              return true;
+            }
+            return false;
+          }
+        };
+    return new Trigger(eventLoop, isDone);
+  }
+
+  /**
+   * Returns a {@link Trigger} that follows if this command is done.
+   * 
+   * <p>This trigger emits 1 rising edge and 1 falling edge when the command
+   * finishes or is interupted/canceled.
+   * 
+   * @return the trigger
+   */
+  public Trigger done() {
+    return done(CommandScheduler.getInstance().getActiveButtonLoop());
+  }
+
   /**
    * Decorates this command with a lambda to call on interrupt, following the command's inherent
    * {@link #end(boolean)} method.