WPILib Reorganization

This is a major restructuring of the WPILib repository to simply build
procedures and remove the remnants of Maven from everything except the
eclipse plugins. Gradle files have been largely simplified or rewritten,
taking advantage of splitting up parts of the build into separate build
files for ease of reading.

The eclipse plugins are now in a separate project, as is ntcore. All
dependencies are resolved via Maven dependencies, with the
Jenkins-maintained WPILib repo. Project structures have also been
simplified: we no longer have separate subprojects inside wpilibc and
wpilibj. Where possible, these changes hav been done with git renames,
to make sure we still have full history for all repositories. Other
unrelated subprojects have also been broken out: OutlineViewer is now a
separate project.

Change-Id: Ib4e2a6e1a2f66427a14f16612b0e0d69ed661878

wpilibc/shared/src/Commands/Subsystem.cpp

@@ -0,0 +1,147 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2011. 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 $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+
+#include "Commands/Subsystem.h"
+
+#include "Commands/Command.h"
+#include "Commands/Scheduler.h"
+#include "WPIErrors.h"
+
+/**
+ * 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();
+    auto iter = requirements.begin();
+    for (; 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; }
+
+/**
+ * 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> table) {
+  m_table = table;
+  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; }