Adds default methods for Commands (#238) (#238)

Closes #235

wpilibc/shared/src/Commands/Command.cpp

@@ -188,6 +188,56 @@ bool Command::Run() {
   return !IsFinished();
 }
 
+/**
+ * The initialize method is called the first time this Command is run after
+ * being started.
+ */
+void Command::Initialize() {}
+
+/**
+ * The execute method is called repeatedly until this Command either finishes
+ * or is canceled.
+ */
+void Command::Execute() {}
+
+/**
+ * Called when the command ended peacefully.  This is where you may want
+ * to wrap up loose ends, like shutting off a motor that was being used
+ * in the command.
+ */
+void Command::End() {}
+
+/**
+ * Returns whether this command is finished.
+ * If it is, then the command will be removed and {@link Command#end() end()}
+ * will be called.
+ *
+ * <p>It may be useful for a team to reference the {@link Command#isTimedOut()
+ * isTimedOut()} method for time-sensitive commands.</p>
+ *
+ * <p>By default this will always return false, which means it will never end
+ * automatically. It may still be cancelled manually or interrupted by another
+ * command. For most real-world scenarios you will override this method with
+ * additional logic.</p>
+ *
+ * @return whether this command is finished.
+ * @see Command#isTimedOut() isTimedOut()
+ */
+bool Command::IsFinished() { return false; }
+
+/**
+ * Called when the command ends because somebody called
+ * {@link Command#cancel() cancel()} or another command shared the same
+ * requirements as this one, and booted it out.
+ *
+ * <p>This is where you may want to wrap up loose ends, like shutting off a
+ * motor that was being used in the command.</p>
+ *
+ * <p>Generally, it is useful to simply call the {@link Command#end() end()}
+ * method within this method, as done here.</p>
+ */
+void Command::Interrupted() { End(); }
+
 void Command::_Initialize() {}
 
 void Command::_Interrupted() {}