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/ConditionalCommand.cpp b/wpilibc/shared/src/Commands/ConditionalCommand.cpp
new file mode 100644
index 0000000..6d36086
--- /dev/null
+++ b/wpilibc/shared/src/Commands/ConditionalCommand.cpp
@@ -0,0 +1,84 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 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/ConditionalCommand.h"
+
+#include "Commands/Scheduler.h"
+
+using namespace frc;
+
+/**
+ * Creates a new ConditionalCommand with given onTrue and onFalse Commands.
+ *
+ * @param onTrue The Command to execute if {@link
+ * ConditionalCommand#Condition()} returns true
+ * @param onFalse The Command to execute if {@link
+ * ConditionalCommand#Condition()} returns false
+ */
+ConditionalCommand::ConditionalCommand(Command* onTrue, Command* onFalse) {
+  m_onTrue = onTrue;
+  m_onFalse = onFalse;
+
+  for (auto requirement : m_onTrue->GetRequirements()) Requires(requirement);
+  for (auto requirement : m_onFalse->GetRequirements()) Requires(requirement);
+}
+
+/**
+ * Creates a new ConditionalCommand with given onTrue and onFalse Commands.
+ *
+ * @param name the name for this command group
+ * @param onTrue The Command to execute if {@link
+ * ConditionalCommand#Condition()} returns true
+ * @param onFalse The Command to execute if {@link
+ * ConditionalCommand#Condition()} returns false
+ */
+ConditionalCommand::ConditionalCommand(const std::string& name, Command* onTrue,
+                                       Command* onFalse)
+    : Command(name) {
+  m_onTrue = onTrue;
+  m_onFalse = onFalse;
+
+  for (auto requirement : m_onTrue->GetRequirements()) Requires(requirement);
+  for (auto requirement : m_onFalse->GetRequirements()) Requires(requirement);
+}
+
+void ConditionalCommand::_Initialize() {
+  if (Condition()) {
+    m_chosenCommand = m_onTrue;
+  } else {
+    m_chosenCommand = m_onFalse;
+  }
+
+  /*
+   * This is a hack to make cancelling the chosen command inside a CommandGroup
+   * work properly
+   */
+  m_chosenCommand->ClearRequirements();
+
+  m_chosenCommand->Start();
+}
+
+void ConditionalCommand::_Cancel() {
+  if (m_chosenCommand != nullptr && m_chosenCommand->IsRunning()) {
+    m_chosenCommand->Cancel();
+  }
+
+  Command::_Cancel();
+}
+
+bool ConditionalCommand::IsFinished() {
+  return m_chosenCommand != nullptr && m_chosenCommand->IsRunning() &&
+         m_chosenCommand->IsFinished();
+}
+
+void ConditionalCommand::Interrupted() {
+  if (m_chosenCommand != nullptr && m_chosenCommand->IsRunning()) {
+    m_chosenCommand->Cancel();
+  }
+
+  Command::Interrupted();
+}