Squashed 'third_party/allwpilib_2017/' content from commit 35ac87d

Change-Id: I7bb6f5556c30d3f5a092e68de0be9c710c60c9f4
git-subtree-dir: third_party/allwpilib_2017
git-subtree-split: 35ac87d6ff8b7f061c4f18c9ea316e5dccd4888a
diff --git a/wpilibc/shared/src/Commands/Command.cpp b/wpilibc/shared/src/Commands/Command.cpp
new file mode 100644
index 0000000..3d7d2ac
--- /dev/null
+++ b/wpilibc/shared/src/Commands/Command.cpp
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+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2011-2017. 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "Commands/Command.h"
+
+#include <typeinfo>
+
+#include "Commands/CommandGroup.h"
+#include "Commands/Scheduler.h"
+#include "RobotState.h"
+#include "Timer.h"
+#include "WPIErrors.h"
+
+using namespace frc;
+
+static const std::string kName = "name";
+static const std::string kRunning = "running";
+static const std::string kIsParented = "isParented";
+
+int Command::m_commandCounter = 0;
+
+/**
+ * Creates a new command.
+ * The name of this command will be default.
+ */
+Command::Command() : Command("", -1.0) {}
+
+/**
+ * Creates a new command with the given name and no timeout.
+ *
+ * @param name the name for this command
+ */
+Command::Command(const std::string& name) : Command(name, -1.0) {}
+
+/**
+ * Creates a new command with the given timeout and a default name.
+ *
+ * @param timeout the time (in seconds) before this command "times out"
+ * @see Command#isTimedOut() isTimedOut()
+ */
+Command::Command(double timeout) : Command("", timeout) {}
+
+/**
+ * Creates a new command with the given name and timeout.
+ *
+ * @param name    the name of the command
+ * @param timeout the time (in seconds) before this command "times out"
+ * @see Command#isTimedOut() isTimedOut()
+ */
+Command::Command(const std::string& name, double timeout) {
+  // We use -1.0 to indicate no timeout.
+  if (timeout < 0.0 && timeout != -1.0)
+    wpi_setWPIErrorWithContext(ParameterOutOfRange, "timeout < 0.0");
+
+  m_timeout = timeout;
+
+  // If name contains an empty string
+  if (name.length() == 0) {
+    m_name = std::string("Command_") + std::string(typeid(*this).name());
+  } else {
+    m_name = name;
+  }
+}
+
+Command::~Command() {
+  if (m_table != nullptr) m_table->RemoveTableListener(this);
+}
+
+/**
+ * Get the ID (sequence number) for this command.
+ *
+ * The ID is a unique sequence number that is incremented for each command.
+ *
+ * @return the ID of this command
+ */
+int Command::GetID() const { return m_commandID; }
+
+/**
+ * Sets the timeout of this command.
+ *
+ * @param timeout the timeout (in seconds)
+ * @see Command#isTimedOut() isTimedOut()
+ */
+void Command::SetTimeout(double timeout) {
+  if (timeout < 0.0)
+    wpi_setWPIErrorWithContext(ParameterOutOfRange, "timeout < 0.0");
+  else
+    m_timeout = timeout;
+}
+
+/**
+ * Returns the time since this command was initialized (in seconds).
+ *
+ * This function will work even if there is no specified timeout.
+ *
+ * @return the time since this command was initialized (in seconds).
+ */
+double Command::TimeSinceInitialized() const {
+  if (m_startTime < 0.0)
+    return 0.0;
+  else
+    return Timer::GetFPGATimestamp() - m_startTime;
+}
+
+/**
+ * This method specifies that the given {@link Subsystem} is used by this
+ * command.
+ *
+ * This method is crucial to the functioning of the Command System in general.
+ *
+ * <p>Note that the recommended way to call this method is in the
+ * constructor.</p>
+ *
+ * @param subsystem the {@link Subsystem} required
+ * @see Subsystem
+ */
+void Command::Requires(Subsystem* subsystem) {
+  if (!AssertUnlocked("Can not add new requirement to command")) return;
+
+  if (subsystem != nullptr)
+    m_requirements.insert(subsystem);
+  else
+    wpi_setWPIErrorWithContext(NullParameter, "subsystem");
+}
+
+/**
+ * Called when the command has been removed.
+ *
+ * This will call {@link Command#interrupted() interrupted()} or
+ * {@link Command#end() end()}.
+ */
+void Command::Removed() {
+  if (m_initialized) {
+    if (IsCanceled()) {
+      Interrupted();
+      _Interrupted();
+    } else {
+      End();
+      _End();
+    }
+  }
+  m_initialized = false;
+  m_canceled = false;
+  m_running = false;
+  if (m_table != nullptr) m_table->PutBoolean(kRunning, false);
+}
+
+/**
+ * Starts up the command.  Gets the command ready to start.
+ *
+ * <p>Note that the command will eventually start, however it will not
+ * necessarily do so immediately, and may in fact be canceled before initialize
+ * is even called.</p>
+ */
+void Command::Start() {
+  LockChanges();
+  if (m_parent != nullptr)
+    wpi_setWPIErrorWithContext(
+        CommandIllegalUse,
+        "Can not start a command that is part of a command group");
+
+  Scheduler::GetInstance()->AddCommand(this);
+}
+
+/**
+ * The run method is used internally to actually run the commands.
+ *
+ * @return whether or not the command should stay within the {@link Scheduler}.
+ */
+bool Command::Run() {
+  if (!m_runWhenDisabled && m_parent == nullptr && RobotState::IsDisabled())
+    Cancel();
+
+  if (IsCanceled()) return false;
+
+  if (!m_initialized) {
+    m_initialized = true;
+    StartTiming();
+    _Initialize();
+    Initialize();
+  }
+  _Execute();
+  Execute();
+  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() {}
+
+/**
+ * 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() {}
+
+void Command::_Execute() {}
+
+void Command::_End() {}
+
+/**
+ * Called to indicate that the timer should start.
+ *
+ * This is called right before {@link Command#initialize() initialize()} is,
+ * inside the {@link Command#run() run()} method.
+ */
+void Command::StartTiming() { m_startTime = Timer::GetFPGATimestamp(); }
+
+/**
+ * Returns whether or not the
+ * {@link Command#timeSinceInitialized() timeSinceInitialized()} method returns
+ * a number which is greater than or equal to the timeout for the command.
+ *
+ * If there is no timeout, this will always return false.
+ *
+ * @return whether the time has expired
+ */
+bool Command::IsTimedOut() const {
+  return m_timeout != -1 && TimeSinceInitialized() >= m_timeout;
+}
+
+/**
+ * Returns the requirements (as an std::set of {@link Subsystem Subsystems}
+ * pointers) of this command.
+ *
+ * @return the requirements (as an std::set of {@link Subsystem Subsystems}
+ *         pointers) of this command
+ */
+Command::SubsystemSet Command::GetRequirements() const {
+  return m_requirements;
+}
+
+/**
+ * Prevents further changes from being made.
+ */
+void Command::LockChanges() { m_locked = true; }
+
+/**
+ * If changes are locked, then this will generate a CommandIllegalUse error.
+ *
+ * @param message the message to report on error (it is appended by a default
+ *                message)
+ * @return true if assert passed, false if assert failed
+ */
+bool Command::AssertUnlocked(const std::string& message) {
+  if (m_locked) {
+    std::string buf =
+        message + " after being started or being added to a command group";
+    wpi_setWPIErrorWithContext(CommandIllegalUse, buf);
+    return false;
+  }
+  return true;
+}
+
+/**
+ * Sets the parent of this command.  No actual change is made to the group.
+ *
+ * @param parent the parent
+ */
+void Command::SetParent(CommandGroup* parent) {
+  if (parent == nullptr) {
+    wpi_setWPIErrorWithContext(NullParameter, "parent");
+  } else if (m_parent != nullptr) {
+    wpi_setWPIErrorWithContext(CommandIllegalUse,
+                               "Can not give command to a command group after "
+                               "already being put in a command group");
+  } else {
+    LockChanges();
+    m_parent = parent;
+    if (m_table != nullptr) {
+      m_table->PutBoolean(kIsParented, true);
+    }
+  }
+}
+
+/**
+ * Clears list of subsystem requirements. This is only used by
+ * {@link ConditionalCommand} so cancelling the chosen command works properly in
+ * {@link CommandGroup}.
+ */
+void Command::ClearRequirements() { m_requirements.clear(); }
+
+/**
+ * This is used internally to mark that the command has been started.
+ *
+ * The lifecycle of a command is:
+ *
+ * startRunning() is called.
+ * run() is called (multiple times potentially)
+ * removed() is called
+ *
+ * It is very important that startRunning and removed be called in order or some
+ * assumptions of the code will be broken.
+ */
+void Command::StartRunning() {
+  m_running = true;
+  m_startTime = -1;
+  if (m_table != nullptr) m_table->PutBoolean(kRunning, true);
+}
+
+/**
+ * Returns whether or not the command is running.
+ *
+ * This may return true even if the command has just been canceled, as it may
+ * not have yet called {@link Command#interrupted()}.
+ *
+ * @return whether or not the command is running
+ */
+bool Command::IsRunning() const { return m_running; }
+
+/**
+ * This will cancel the current command.
+ *
+ * <p>This will cancel the current command eventually.  It can be called
+ * multiple times. And it can be called when the command is not running.  If
+ * the command is running though, then the command will be marked as canceled
+ * and eventually removed.</p>
+ *
+ * <p>A command can not be canceled if it is a part of a command group, you
+ * must cancel the command group instead.</p>
+ */
+void Command::Cancel() {
+  if (m_parent != nullptr)
+    wpi_setWPIErrorWithContext(
+        CommandIllegalUse,
+        "Can not cancel a command that is part of a command group");
+
+  _Cancel();
+}
+
+/**
+ * This works like cancel(), except that it doesn't throw an exception if it is
+ * a part of a command group.
+ *
+ * Should only be called by the parent command group.
+ */
+void Command::_Cancel() {
+  if (IsRunning()) m_canceled = true;
+}
+
+/**
+ * Returns whether or not this has been canceled.
+ *
+ * @return whether or not this has been canceled
+ */
+bool Command::IsCanceled() const { return m_canceled; }
+
+/**
+ * Returns whether or not this command can be interrupted.
+ *
+ * @return whether or not this command can be interrupted
+ */
+bool Command::IsInterruptible() const { return m_interruptible; }
+
+/**
+ * Sets whether or not this command can be interrupted.
+ *
+ * @param interruptible whether or not this command can be interrupted
+ */
+void Command::SetInterruptible(bool interruptible) {
+  m_interruptible = interruptible;
+}
+
+/**
+ * Checks if the command requires the given {@link Subsystem}.
+ *
+ * @param system the system
+ * @return whether or not the subsystem is required (false if given nullptr)
+ */
+bool Command::DoesRequire(Subsystem* system) const {
+  return m_requirements.count(system) > 0;
+}
+
+/**
+ * Returns the {@link CommandGroup} that this command is a part of.
+ *
+ * Will return null if this {@link Command} is not in a group.
+ *
+ * @return the {@link CommandGroup} that this command is a part of (or null if
+ *         not in group)
+ */
+CommandGroup* Command::GetGroup() const { return m_parent; }
+
+/**
+ * Sets whether or not this {@link Command} should run when the robot is
+ * disabled.
+ *
+ * <p>By default a command will not run when the robot is disabled, and will in
+ * fact be canceled.</p>
+ *
+ * @param run whether or not this command should run when the robot is disabled
+ */
+void Command::SetRunWhenDisabled(bool run) { m_runWhenDisabled = run; }
+
+/**
+ * Returns whether or not this {@link Command} will run when the robot is
+ * disabled, or if it will cancel itself.
+ *
+ * @return whether or not this {@link Command} will run when the robot is
+ *         disabled, or if it will cancel itself
+ */
+bool Command::WillRunWhenDisabled() const { return m_runWhenDisabled; }
+
+std::string Command::GetName() const { return m_name; }
+
+std::string Command::GetSmartDashboardType() const { return "Command"; }
+
+void Command::InitTable(std::shared_ptr<ITable> subtable) {
+  if (m_table != nullptr) m_table->RemoveTableListener(this);
+  m_table = subtable;
+  if (m_table != nullptr) {
+    m_table->PutString(kName, GetName());
+    m_table->PutBoolean(kRunning, IsRunning());
+    m_table->PutBoolean(kIsParented, m_parent != nullptr);
+    m_table->AddTableListener(kRunning, this, false);
+  }
+}
+
+std::shared_ptr<ITable> Command::GetTable() const { return m_table; }
+
+void Command::ValueChanged(ITable* source, llvm::StringRef key,
+                           std::shared_ptr<nt::Value> value, bool isNew) {
+  if (!value->IsBoolean()) return;
+  if (value->GetBoolean()) {
+    if (!IsRunning()) Start();
+  } else {
+    if (IsRunning()) Cancel();
+  }
+}