Add wrapper for Commands

ppl.pro

@@ -80,7 +80,8 @@ HEADERS += \
     src/action.h \
     src/smoothed.h \
     src/processor.h \
-    src/vertexbuffer.hpp
+    src/vertexbuffer.hpp \
+    src/command.h
 
 SOURCES += \
     src/pluginpath.cpp \
@@ -96,7 +97,8 @@ SOURCES += \
     src/logwriter.cpp \
     src/menuitem.cpp \
     src/processor.cpp \
-    src/vertexbuffer.cpp
+    src/vertexbuffer.cpp \
+    src/command.cpp
 
 withsound {
     win32 {

src/command.cpp

@@ -0,0 +1,78 @@
+#include "command.h"
+
+/* Copyright (c) 2018, Jack Deeth github@jackdeeth.org.uk
+// All rights reserved
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The views and conclusions contained in the software and documentation are
+those
+// of the authors and should not be interpreted as representing official
+policies,
+// either expressed or implied, of the FreeBSD Project.
+*/
+
+PPL::Command::Command(XPLMCommandRef ref,
+                      std::function<Outcome(XPLMCommandRef, Phase)> cb,
+                      bool run_before_sim)
+    : callback(cb), ref_(ref), before_(run_before_sim ? 1 : 0) {
+  XPLMRegisterCommandHandler(ref_, scb, before_, this);
+}
+
+PPL::Command::Command(std::string cmd_to_replace,
+                      std::function<Outcome(XPLMCommandRef, Phase)> callback,
+                      bool run_before)
+    : Command(XPLMFindCommand(cmd_to_replace.c_str()), callback, run_before) {}
+
+PPL::Command::Command(std::string new_cmd,
+                      std::string description,
+                      std::function<Outcome(XPLMCommandRef, Phase)> callback,
+                      bool run_before)
+    : Command(XPLMCreateCommand(new_cmd.c_str(), description.c_str()),
+              callback,
+              run_before) {}
+
+PPL::Command::~Command() {
+  XPLMUnregisterCommandHandler(ref_, scb, before_, this);
+}
+
+PPL::Command::Phase PPL::Command::phase() const { return phase_; }
+
+void PPL::Command::begin() { XPLMCommandBegin(ref_); }
+
+void PPL::Command::end() { XPLMCommandEnd(ref_); }
+
+void PPL::Command::once() { XPLMCommandOnce(ref_); }
+
+int PPL::Command::scb(XPLMCommandRef ref, XPLMCommandPhase phase, void *vp) {
+  // scb = shared/static call-back
+  // converts C conventions with (post?)modern C++
+  auto cmd = reinterpret_cast<Command *>(vp);
+  if (phase == xplm_CommandBegin) cmd->phase_ = Phase::Begin;
+  if (phase == xplm_CommandContinue) cmd->phase_ = Phase::Continue;
+  if (phase == xplm_CommandEnd) cmd->phase_ = Phase::End;
+  auto outcome = cmd->callback(ref, cmd->phase_);
+  return outcome == Outcome::Halt ? 0 : 1;
+}

src/command.h

@@ -0,0 +1,132 @@
+#pragma once
+
+/* Copyright (c) 2018, Jack Deeth github@jackdeeth.org.uk
+// All rights reserved
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The views and conclusions contained in the software and documentation are
+those
+// of the authors and should not be interpreted as representing official
+policies,
+// either expressed or implied, of the FreeBSD Project.
+*/
+
+/* Example usage:
+
+// disable an existing command
+PPL::Command left_brake_cmd_{"sim/flight_controls/left_brake"};
+
+// hijack an existing command
+const auto End{PPL::Command::Phase::End};
+const auto Halt{PPL::Command::Outcome::Halt};
+PPL::Command brake_toggle_cmd_{
+    "sim/flight_controls/brakes_toggle_regular",
+    [&](XPLMCommandRef, PPL::Command::Phase phase) {
+      if (phase == End) {
+        if (handbrake_lever_ratio_ < 0.5f)
+          handbrake_lever_ratio_ = 0.5f;
+        else
+          handbrake_lever_ratio_ = 0.f;
+      }
+      return Halt;
+    }};
+
+// create a new command
+class CompileMessage {
+public:
+  CompileMessage(std::string command_name =
+"YourName/YourProject/show_compile_msg",
+                 std::string desc = "Announces compilation date/time of plugin"
+      : cmd_{command_name, desc, [](XPLMCommandRef, PPL::Command::Phase phase) {
+               if (phase == PPL::Command::Phase::Begin)
+                 XPLMSpeakString(compile_message().c_str());
+               return PPL::Command::Outcome::Halt;
+             }} {}
+
+  static std::string compile_message() {
+    std::stringstream msg;
+    msg << "Compiled " << __DATE__ << " at " << __TIME__;
+    return msg.str();
+  }
+private:
+  PPL::Command cmd_;
+};
+
+*/
+
+#include <XPLMUtilities.h>
+
+#include <functional>
+#include <string>
+
+// RAII wrapper for X-Plane Commands API
+
+namespace PPL {
+
+class Command {
+public:
+  enum class Outcome { Continue, Halt };
+  enum class Phase { Begin, Continue, End };
+
+  // Finds a command by reference and attaches a new callback to it
+  Command(XPLMCommandRef ref,
+          std::function<Outcome(XPLMCommandRef, Phase)> callback =
+              [](...) { return Outcome::Halt; },
+          bool run_before = true);
+
+  // Finds a command by name and attaches a new callback to it
+  // (useful for hijacking and/or blocking existing commands)
+  Command(std::string cmd_to_replace,
+          std::function<Outcome(XPLMCommandRef, Phase)> callback =
+              [](...) { return Outcome::Halt; },
+          bool run_before = true);
+
+  // Creates a new command and attaches a callback to it
+  Command(std::string new_cmd,
+          std::string description,
+          std::function<Outcome(XPLMCommandRef, Phase)> callback =
+              [](...) { return Outcome::Halt; },
+          bool run_before = true);
+
+  ~Command();
+
+  Phase phase() const;
+
+  void begin();
+  void end();
+  void once();
+
+  std::function<Outcome(XPLMCommandRef, Phase)> callback;
+
+  static int scb(XPLMCommandRef ref, XPLMCommandPhase phase, void *vp);
+
+private:
+  XPLMCommandRef ref_;
+  int before_;
+  Phase phase_{Phase::End};
+};
+
+}  // namespace