Update to 2018_v4 image and new build system. (#598)

* Revert "Force OpenCV to 3.1.0 (#602)"

This reverts commit 50ed55e8e2.

* Removes Simulation

* Removes old build system

* Removes old gtest

* Adds new gmock and gtest

* Updates to new ni-libraries

* removes MyRobot (to be replaced)

* moves files to new location

* Adds new sim backend and new test executables

* updates .styleguide and .gitignore

* Changes cpp WPILibVersion to a function

MSVC throws an AV with the old version.

* Disables USBCamera on all systems except for linux

* 2018 NI Libraries

* New build system

wpilibc/src/main/native/cpp/Commands/Subsystem.cpp

@@ -0,0 +1,156 @@
+/*----------------------------------------------------------------------------*/
+/* 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/Subsystem.h"
+
+#include "Commands/Command.h"
+#include "Commands/Scheduler.h"
+#include "WPIErrors.h"
+
+using namespace frc;
+
+/**
+ * Creates a subsystem with the given name.
+ *
+ * @param name the name of the subsystem
+ */
+Subsystem::Subsystem(const std::string& name) {
+  m_name = name;
+  Scheduler::GetInstance()->RegisterSubsystem(this);
+}
+/**
+ * Initialize the default command for this subsystem.
+ *
+ * This is meant to be the place to call SetDefaultCommand in a subsystem and
+ * will be called on all the subsystems by the CommandBase method before the
+ * program starts running by using the list of all registered Subsystems inside
+ * the Scheduler.
+ *
+ * This should be overridden by a Subsystem that has a default Command
+ */
+void Subsystem::InitDefaultCommand() {}
+
+/**
+ * Sets the default command.  If this is not called or is called with null,
+ * then there will be no default command for the subsystem.
+ *
+ * <p><b>WARNING:</b> This should <b>NOT</b> be called in a constructor if the
+ * subsystem is a singleton.</p>
+ *
+ * @param command the default command (or null if there should be none)
+ */
+void Subsystem::SetDefaultCommand(Command* command) {
+  if (command == nullptr) {
+    m_defaultCommand = nullptr;
+  } else {
+    bool found = false;
+    Command::SubsystemSet requirements = command->GetRequirements();
+    for (auto iter = requirements.begin(); iter != requirements.end(); iter++) {
+      if (*iter == this) {
+        found = true;
+        break;
+      }
+    }
+
+    if (!found) {
+      wpi_setWPIErrorWithContext(
+          CommandIllegalUse, "A default command must require the subsystem");
+      return;
+    }
+
+    m_defaultCommand = command;
+  }
+  if (m_table != nullptr) {
+    if (m_defaultCommand != nullptr) {
+      m_table->PutBoolean("hasDefault", true);
+      m_table->PutString("default", m_defaultCommand->GetName());
+    } else {
+      m_table->PutBoolean("hasDefault", false);
+    }
+  }
+}
+
+/**
+ * Returns the default command (or null if there is none).
+ *
+ * @return the default command
+ */
+Command* Subsystem::GetDefaultCommand() {
+  if (!m_initializedDefaultCommand) {
+    m_initializedDefaultCommand = true;
+    InitDefaultCommand();
+  }
+  return m_defaultCommand;
+}
+
+/**
+ * Sets the current command.
+ *
+ * @param command the new current command
+ */
+void Subsystem::SetCurrentCommand(Command* command) {
+  m_currentCommand = command;
+  m_currentCommandChanged = true;
+}
+
+/**
+ * Returns the command which currently claims this subsystem.
+ *
+ * @return the command which currently claims this subsystem
+ */
+Command* Subsystem::GetCurrentCommand() const { return m_currentCommand; }
+
+/**
+ * When the run method of the scheduler is called this method will be called.
+ */
+void Subsystem::Periodic() {}
+
+/**
+ * Call this to alert Subsystem that the current command is actually the
+ * command.
+ *
+ * Sometimes, the {@link Subsystem} is told that it has no command while the
+ * {@link Scheduler} is going through the loop, only to be soon after given a
+ * new one.  This will avoid that situation.
+ */
+void Subsystem::ConfirmCommand() {
+  if (m_currentCommandChanged) {
+    if (m_table != nullptr) {
+      if (m_currentCommand != nullptr) {
+        m_table->PutBoolean("hasCommand", true);
+        m_table->PutString("command", m_currentCommand->GetName());
+      } else {
+        m_table->PutBoolean("hasCommand", false);
+      }
+    }
+    m_currentCommandChanged = false;
+  }
+}
+
+std::string Subsystem::GetName() const { return m_name; }
+
+std::string Subsystem::GetSmartDashboardType() const { return "Subsystem"; }
+
+void Subsystem::InitTable(std::shared_ptr<ITable> subtable) {
+  m_table = subtable;
+  if (m_table != nullptr) {
+    if (m_defaultCommand != nullptr) {
+      m_table->PutBoolean("hasDefault", true);
+      m_table->PutString("default", m_defaultCommand->GetName());
+    } else {
+      m_table->PutBoolean("hasDefault", false);
+    }
+    if (m_currentCommand != nullptr) {
+      m_table->PutBoolean("hasCommand", true);
+      m_table->PutString("command", m_currentCommand->GetName());
+    } else {
+      m_table->PutBoolean("hasCommand", false);
+    }
+  }
+}
+
+std::shared_ptr<ITable> Subsystem::GetTable() const { return m_table; }