[commands] Refactor ProxyScheduleCommand, SelectCommand into ProxyCommand (#4534)

wpilibNewCommands/src/main/native/cpp/frc2/command/Command.cpp

@@ -12,7 +12,6 @@
 #include "frc2/command/ParallelDeadlineGroup.h"
 #include "frc2/command/ParallelRaceGroup.h"
 #include "frc2/command/PerpetualCommand.h"
-#include "frc2/command/ProxyScheduleCommand.h"
 #include "frc2/command/RepeatCommand.h"
 #include "frc2/command/SequentialCommandGroup.h"
 #include "frc2/command/WaitCommand.h"

wpilibNewCommands/src/main/native/cpp/frc2/command/CommandPtr.cpp

@@ -13,7 +13,7 @@
 #include "frc2/command/ParallelDeadlineGroup.h"
 #include "frc2/command/ParallelRaceGroup.h"
 #include "frc2/command/PrintCommand.h"
-#include "frc2/command/ProxyScheduleCommand.h"
+#include "frc2/command/ProxyCommand.h"
 #include "frc2/command/RepeatCommand.h"
 #include "frc2/command/SequentialCommandGroup.h"
 #include "frc2/command/WaitCommand.h"
@@ -37,7 +37,7 @@ CommandPtr CommandPtr::Repeatedly() && {
 
 CommandPtr CommandPtr::AsProxy() && {
   AssertValid();
-  m_ptr = std::make_unique<ProxyScheduleCommand>(std::move(m_ptr));
+  m_ptr = std::make_unique<ProxyCommand>(std::move(m_ptr));
   return std::move(*this);
 }
 

wpilibNewCommands/src/main/native/cpp/frc2/command/Commands.cpp

@@ -10,9 +10,7 @@
 #include "frc2/command/ParallelCommandGroup.h"
 #include "frc2/command/ParallelDeadlineGroup.h"
 #include "frc2/command/ParallelRaceGroup.h"
-#include "frc2/command/PerpetualCommand.h"
 #include "frc2/command/PrintCommand.h"
-#include "frc2/command/ProxyScheduleCommand.h"
 #include "frc2/command/RunCommand.h"
 #include "frc2/command/SequentialCommandGroup.h"
 #include "frc2/command/WaitCommand.h"

wpilibNewCommands/src/main/native/cpp/frc2/command/ProxyCommand.cpp

@@ -0,0 +1,37 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "frc2/command/ProxyCommand.h"
+
+using namespace frc2;
+
+ProxyCommand::ProxyCommand(wpi::unique_function<Command*()> supplier)
+    : m_supplier(std::move(supplier)) {}
+
+ProxyCommand::ProxyCommand(Command* command)
+    : m_supplier([command] { return command; }) {}
+
+ProxyCommand::ProxyCommand(std::unique_ptr<Command> command)
+    : m_supplier([command = std::move(command)] { return command.get(); }) {}
+
+void ProxyCommand::Initialize() {
+  m_command = m_supplier();
+  m_command->Schedule();
+}
+
+void ProxyCommand::End(bool interrupted) {
+  if (interrupted) {
+    m_command->Cancel();
+  }
+  m_command = nullptr;
+}
+
+void ProxyCommand::Execute() {}
+
+bool ProxyCommand::IsFinished() {
+  // because we're between `initialize` and `end`, `m_command` is necessarily
+  // not null but if called otherwise and m_command is null, it's UB, so we can
+  // do whatever we want -- like return true.
+  return m_command == nullptr || !m_command->IsScheduled();
+}

wpilibNewCommands/src/main/native/cpp/frc2/command/ProxyScheduleCommand.cpp

@@ -15,13 +15,6 @@ ProxyScheduleCommand::ProxyScheduleCommand(Command* toSchedule) {
   SetInsert(m_toSchedule, {&toSchedule, 1});
 }
 
-ProxyScheduleCommand::ProxyScheduleCommand(
-    std::unique_ptr<Command>&& toSchedule)
-    : m_owning(std::move(toSchedule)) {
-  Command* ptr = m_owning.get();
-  SetInsert(m_toSchedule, {&ptr, 1});
-}
-
 void ProxyScheduleCommand::Initialize() {
   for (auto* command : m_toSchedule) {
     command->Schedule();

wpilibNewCommands/src/main/native/include/frc2/command/Command.h

@@ -25,7 +25,6 @@ std::string GetTypeName(const T& type) {
 }
 
 class PerpetualCommand;
-class ProxyScheduleCommand;
 
 /**
  * A state machine representing a complete action to be performed by the robot.
@@ -225,7 +224,7 @@ safe) semantics.
 
   /**
    * Decorates this command to run "by proxy" by wrapping it in a
-   * ProxyScheduleCommand. This is useful for "forking off" from command groups
+   * ProxyCommand. This is useful for "forking off" from command groups
    * when the user does not wish to extend the command's requirements to the
    * entire command group.
    *

wpilibNewCommands/src/main/native/include/frc2/command/CommandPtr.h

@@ -49,7 +49,7 @@ class CommandPtr final {
 
   /**
    * Decorates this command to run "by proxy" by wrapping it in a
-   * ProxyScheduleCommand. This is useful for "forking off" from command groups
+   * ProxyCommand. This is useful for "forking off" from command groups
    * when the user does not wish to extend the command's requirements to the
    * entire command group.
    *

wpilibNewCommands/src/main/native/include/frc2/command/ProxyCommand.h

@@ -0,0 +1,68 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <memory>
+#include <span>
+
+#include <wpi/FunctionExtras.h>
+
+#include "frc2/command/CommandBase.h"
+#include "frc2/command/CommandHelper.h"
+#include "frc2/command/SetUtilities.h"
+
+namespace frc2 {
+/**
+ * Schedules the given command when this command is initialized, and ends when
+ * it ends. Useful for forking off from CommandGroups. If this command is
+ * interrupted, it will cancel the command.
+ *
+ * <p>This class is provided by the NewCommands VendorDep
+ */
+class ProxyCommand : public CommandHelper<CommandBase, ProxyCommand> {
+ public:
+  /**
+   * Creates a new ProxyCommand that schedules the supplied command when
+   * initialized, and ends when it is no longer scheduled. Useful for lazily
+   * creating commands at runtime.
+   *
+   * @param supplier the command supplier
+   */
+  explicit ProxyCommand(wpi::unique_function<Command*()> supplier);
+
+  /**
+   * Creates a new ProxyCommand that schedules the given command when
+   * initialized, and ends when it is no longer scheduled.
+   *
+   * @param command the command to run by proxy
+   */
+  explicit ProxyCommand(Command* command);
+
+  /**
+   * Creates a new ProxyCommand that schedules the given command when
+   * initialized, and ends when it is no longer scheduled.
+   *
+   * <p>Note that this constructor passes ownership of the given command to the
+   * returned ProxyCommand.
+   *
+   * @param command the command to schedule
+   */
+  explicit ProxyCommand(std::unique_ptr<Command> command);
+
+  ProxyCommand(ProxyCommand&& other) = default;
+
+  void Initialize() override;
+
+  void End(bool interrupted) override;
+
+  void Execute() override;
+
+  bool IsFinished() override;
+
+ private:
+  wpi::unique_function<Command*()> m_supplier;
+  Command* m_command = nullptr;
+};
+}  // namespace frc2

wpilibNewCommands/src/main/native/include/frc2/command/ProxyScheduleCommand.h

@@ -8,6 +8,7 @@
 #include <span>
 
 #include <wpi/SmallVector.h>
+#include <wpi/deprecated.h>
 
 #include "frc2/command/CommandBase.h"
 #include "frc2/command/CommandHelper.h"
@@ -30,22 +31,14 @@ class ProxyScheduleCommand
    * initialized, and ends when they are all no longer scheduled.
    *
    * @param toSchedule the commands to schedule
+   * @deprecated Replace with {@link ProxyCommand},
+   * composing multiple of them in a {@link ParallelRaceGroup} if needed.
    */
+  WPI_DEPRECATED("Replace with ProxyCommand")
   explicit ProxyScheduleCommand(std::span<Command* const> toSchedule);
 
   explicit ProxyScheduleCommand(Command* toSchedule);
 
-  /**
-   * Creates a new ProxyScheduleCommand that schedules the given command when
-   * initialized, and ends when it is no longer scheduled.
-   *
-   * <p>Note that this constructor passes ownership of the given command to the
-   * returned ProxyScheduleCommand.
-   *
-   * @param toSchedule the command to schedule
-   */
-  explicit ProxyScheduleCommand(std::unique_ptr<Command>&& toSchedule);
-
   ProxyScheduleCommand(ProxyScheduleCommand&& other) = default;
 
   void Initialize() override;

wpilibNewCommands/src/main/native/include/frc2/command/SelectCommand.h

@@ -108,7 +108,10 @@ class SelectCommand : public CommandHelper<CommandBase, SelectCommand<Key>> {
    * Creates a new selectcommand.
    *
    * @param toRun a supplier providing the command to run
+   * @deprecated Replace with {@link ProxyCommand},
+   * composing multiple of them in a {@link ParallelRaceGroup} if needed.
    */
+  WPI_DEPRECATED("Replace with ProxyCommand")
   explicit SelectCommand(std::function<Command*()> toRun)
       : m_toRun{std::move(toRun)} {}