Add a whenHeld to a custom trigger class

src/main/java/frc/team4909/robot/operator/generic/BionicJoystick.java

@@ -134,7 +134,7 @@ public boolean get() {
         }
     }
 
-    private class BionicJoystickPOVButton extends Trigger {
+    private class BionicJoystickPOVButton extends BionicTrigger {
         private BionicJoystick inputJoystick;
         private int povAngle;
 

src/main/java/frc/team4909/robot/operator/generic/BionicTrigger.java

@@ -0,0 +1,207 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2008-2018 FIRST. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package frc.team4909.robot.operator.generic;
+
+import edu.wpi.first.wpilibj.SendableBase;
+import edu.wpi.first.wpilibj.buttons.Trigger;
+import edu.wpi.first.wpilibj.command.Command;
+import edu.wpi.first.wpilibj.command.Scheduler;
+import edu.wpi.first.wpilibj.smartdashboard.SendableBuilder;
+
+/**
+ * This class provides an easy way to link commands to inputs.
+ *
+ * <p>
+ * 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.
+ *
+ * <p>
+ * 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 {@link Trigger#get()} method to get the full
+ * functionality of the Trigger class.
+ */
+public abstract class BionicTrigger extends SendableBase {
+    private volatile boolean m_sendablePressed;
+
+    /**
+     * Returns whether or not the trigger is active.
+     *
+     * <p>
+     * This method will be called repeatedly a command is linked to the Trigger.
+     *
+     * @return whether or not the trigger condition is active.
+     */
+    public abstract boolean get();
+
+    /**
+     * Returns whether get() return true or the internal table for SmartDashboard
+     * use is pressed.
+     *
+     * @return whether get() return true or the internal table for SmartDashboard
+     *         use is pressed.
+     */
+    @SuppressWarnings("PMD.UselessParentheses")
+    private boolean grab() {
+        return get() || m_sendablePressed;
+    }
+
+    /**
+     * Starts the given command whenever the trigger just becomes active.
+     *
+     * @param command the command to start
+     */
+    public void whenActive(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (!m_pressedLast && pressed) {
+                    command.start();
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    /**
+     * Constantly starts the given command while the button is held.
+     *
+     * {@link Command#start()} will be called repeatedly while the trigger is
+     * active, and will be canceled when the trigger becomes inactive.
+     *
+     * @param command the command to start
+     */
+    public void whileActive(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (pressed) {
+                    command.start();
+                } else if (m_pressedLast && !pressed) {
+                    command.cancel();
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    /**
+     * Starts the given command when the button is pressed, cancels when released.
+     *
+     * {@link Command#start()} will be called once when the trigger is
+     * active, and will be canceled when the trigger becomes inactive.
+     *
+     * @param command the command to start
+     */
+    public void whenHeld(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (!m_pressedLast && pressed) {
+                    command.start();
+                } else if (m_pressedLast && !pressed) {
+                    command.cancel();
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    /**
+     * Starts the command when the trigger becomes inactive.
+     *
+     * @param command the command to start
+     */
+    public void whenInactive(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (m_pressedLast && !pressed) {
+                    command.start();
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    /**
+     * Toggles a command when the trigger becomes active.
+     *
+     * @param command the command to toggle
+     */
+    public void toggleWhenActive(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (!m_pressedLast && pressed) {
+                    if (command.isRunning()) {
+                        command.cancel();
+                    } else {
+                        command.start();
+                    }
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    /**
+     * Cancels a command when the trigger becomes active.
+     *
+     * @param command the command to cancel
+     */
+    public void cancelWhenActive(final Command command) {
+        new Trigger.ButtonScheduler() {
+            private boolean m_pressedLast = grab();
+
+            @Override
+            public void execute() {
+                boolean pressed = grab();
+
+                if (!m_pressedLast && pressed) {
+                    command.cancel();
+                }
+
+                m_pressedLast = pressed;
+            }
+        }.start();
+    }
+
+    @Override
+    public void initSendable(SendableBuilder builder) {
+        builder.setSmartDashboardType("Button");
+        builder.setSafeState(() -> m_sendablePressed = false);
+        builder.addBooleanProperty("pressed", this::grab, value -> m_sendablePressed = value);
+    }
+}