There's now a bezos_ctl and bezos_cli that can control the presentation window. The bezos_ctl is compile as a windows app so that it won't flash a cmd.exe window when run from launchers like Stream Deck. The bezos_cli is compiled as a console app so you can use it from the command line.

Makefile

@@ -27,16 +27,16 @@ debug_build:
 run: build
 ifeq '$(OS)' 'Windows_NT'
 	powershell "cp ./builddir/bezos.exe ."
-	./bezos ${SAMPLE}
+	./bezos -d ${SAMPLE}
 else
-	./builddir/bezos ${SAMPLE}
+	./builddir/bezos -d ${SAMPLE}
 endif
 
 debug: build
 	gdb --nx -x .gdbinit --ex run --args builddir/bezos
 
 debug_run: build
-	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args builddir/bezos ${SAMPLE}
+	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args builddir/bezos -d ${SAMPLE}
 
 clean:
 	meson compile --clean -C builddir

meson.build

@@ -3,7 +3,7 @@
 project('bezos-loves-slides', 'cpp',
   version: '0.2.0',
   default_options: [
-    'cpp_std=c++20',
+    'cpp_std=c++23',
     'cpp_args=-D_GLIBCXX_DEBUG=1 -D_GLIBCXX_DEBUG_PEDANTIC=1',
   ])
 
@@ -87,6 +87,8 @@ dependencies += [
 ]
 
 
+inc_dirs = include_directories('src')
+
 sources = [
   'src/dbc.cpp',
   'src/control_ui.cpp',
@@ -99,16 +101,51 @@ tests = [
   'tests/parsing.cpp'
 ]
 
-executable('bezos', sources + ['src/main.cpp'],
+
+bezos_lib = static_library('bezos',
+  sources,
+  cpp_args: cpp_args,
+  include_directories: inc_dirs,
+  override_options: exe_defaults,
+  dependencies: dependencies)
+
+bezos_dep = declare_dependency(
+  link_with: bezos_lib,
+  include_directories: inc_dirs)
+
+dependencies += [ bezos_dep ]
+
+executable('bezos', ['src/main.cpp'],
   cpp_args: cpp_args,
   link_args: link_args,
-  include_directories: include_directories('src'),
+  include_directories: inc_dirs,
+  win_subsystem: 'console',
   override_options: exe_defaults,
   dependencies: dependencies)
 
-executable('runtests', sources + tests,
+# bezos_ctrl is a version of bezos_cli compiled to be a windows
+# app instead of console. Ironically you have to do this so that
+# stream deck and other launchers don't open a cmd.exe to run it.
+executable('bezos_ctrl', ['src/bezos_ctl.cpp'],
+  cpp_args: cpp_args,
+  link_args: link_args,
+  include_directories: inc_dirs,
+  override_options: exe_defaults,
+  win_subsystem: 'windows',
+  dependencies: dependencies)
+
+executable('bezos_cli', ['src/bezos_ctl.cpp'],
   cpp_args: cpp_args,
   link_args: link_args,
   include_directories: include_directories('src'),
+  win_subsystem: 'console',
+  override_options: exe_defaults,
+  dependencies: dependencies)
+
+executable('runtests', tests,
+  cpp_args: cpp_args,
+  link_args: link_args,
+  include_directories: inc_dirs,
   override_options: exe_defaults,
+  win_subsystem: 'console',
   dependencies: dependencies + [catch2])

sample/about-bezos.md

@@ -79,8 +79,8 @@ Bare content like this
 {
  "bg_color": [10, 10, 25, 255],
  "font_color": [255, 146, 0, 255],
- "title_color": [255, 255, 0, 255],
- "font_size": 80,
+ "title_color": [255, 200, 0, 255],
+ "font_size": 120,
  "title_size": 120,
  "font_padding": 20
 }

src/bezos_ctl.cpp

@@ -0,0 +1,71 @@
+#include <fmt/xchar.h>
+#include "dbc.hpp"
+#include <SFML/Network/UdpSocket.hpp>
+#include <memory>
+#include <unistd.h>
+
+using namespace std::chrono_literals;
+
+const int DEFAULT_PORT=9898;
+
+struct Options {
+  bool help{false};
+  bool focus{false};
+  bool error{false};
+  unsigned short port=DEFAULT_PORT;
+};
+
+void request_focus(Options& options) {
+  fmt::println("Moving control window front: port={}", options.port);
+  sf::UdpSocket sock;
+  uint32_t cmd = 2;
+  auto localhost = sf::IpAddress::getLocalAddress();
+  auto result = sock.send(&cmd, sizeof cmd, *localhost, options.port);
+}
+
+void print_usage() {
+  fmt::println("USAGE: bezos [-p {}] [-hf] -d deck.md", DEFAULT_PORT);
+}
+
+Options parse_options(int argc, char* argv[]) {
+  int opt = 0;
+  Options result;
+
+  while((opt = getopt(argc, argv, "fhp:")) != -1) {
+    switch(opt) {
+      case 'f':
+        result.focus=true;
+        break;
+      case 'h':
+        print_usage();
+        return {.help=true};
+        break;
+      case 'p':
+        result.port = std::stoi(optarg);
+        break;
+      default:
+        print_usage();
+        return {.error=true};
+    }
+  }
+
+  if(!result.focus) {
+    print_usage();
+  }
+
+  return result;
+}
+
+
+int main(int argc, char *argv[]) {
+  auto options = parse_options(argc, argv);
+
+  if(options.focus) {
+    request_focus(options);
+    return 0;
+  } else if(options.help) {
+    return 0;
+  } else if(options.error) {
+    return 1;
+  }
+}

src/main.cpp

@@ -9,10 +9,20 @@
 #include <filesystem>
 #include <chrono>
 #include <SFML/System/Clock.hpp>
+#include <SFML/Network/UdpSocket.hpp>
 #include <memory>
+#include <unistd.h>
 
 using namespace std::chrono_literals;
 
+struct Options {
+  std::string deck_file{};
+  bool deck_given{false};
+  bool help{false};
+  bool error{false};
+  unsigned short port=9898;
+};
+
 std::shared_ptr<SlidesUI> load_slides(const std::string& input_md, std::shared_ptr<gui::Backend> backend) {
   try {
     auto deck = parse_slides(input_md, [&](nlohmann::json& config) {
@@ -59,8 +69,72 @@ struct ChangeDetector {
   }
 };
 
+void print_usage() {
+  fmt::println("USAGE: bezos [-p PORT] [-hf] -d deck.md");
+}
+
+std::optional<sf::UdpSocket> listen_control(Options& opts) {
+  sf::UdpSocket socket;
+  auto status = socket.bind(opts.port);
+
+  if(status == sf::Socket::Status::Error) {
+    fmt::println("Failed to bind port");
+    return std::nullopt;
+  }
+
+  socket.setBlocking(false);
+
+  fmt::println("Focus listener on port {}", opts.port);
+
+  return socket;
+}
+
+Options parse_options(int argc, char* argv[]) {
+  int opt = 0;
+  Options result;
+
+  while((opt = getopt(argc, argv, "hp:d:")) != -1) {
+    switch(opt) {
+      case 'h':
+        print_usage();
+        return {.help=true};
+        break;
+      case 'p':
+        result.port = std::stoi(optarg);
+        break;
+      case 'd':
+        result.deck_given=true;
+        result.deck_file = optarg;
+        break;
+      default:
+        print_usage();
+        return {.error=true};
+    }
+  }
+
+  if(!result.deck_given) {
+    print_usage();
+    result.error = true;
+  }
+
+  return result;
+}
+
+
 int main(int argc, char *argv[]) {
-  dbc::check(argc >= 2, "USAGE: bezos my_fucking_slides.md");
+  auto options = parse_options(argc, argv);
+
+  if(options.help) {
+    return 0;
+  } else if(options.error) {
+    return 1;
+  }
+
+  auto control = listen_control(options);
+
+  if(control == std::nullopt) {
+    fmt::println("Error binding UDP port {}", options.port);
+  }
 
   auto& modes = sf::VideoMode::getFullscreenModes();
   auto screen_mode = std::find_if(modes.begin(), modes.end(), [=](const auto& a) -> bool {
@@ -77,7 +151,7 @@ int main(int argc, char *argv[]) {
 
   auto backend = std::make_shared<gui::Backend>();
 
-  auto slides = load_slides(argv[1], backend);
+  auto slides = load_slides(options.deck_file, backend);
 
   if(!slides) {
     fmt::println("ERROR in your .md file");
@@ -90,10 +164,19 @@ int main(int argc, char *argv[]) {
 
   dbc::check(control_ui.$status != nullptr, "bad ptr");
 
-  ChangeDetector slides_reloader{argv[1]};
+  ChangeDetector slides_reloader{options.deck_file};
   ChangeDetector layout_reloader{slides->$deck->config["layouts"]};
 
   while(controller.isOpen()) {
+    uint32_t cmd = 0;
+    std::size_t received = 0;
+    std::optional<sf::IpAddress> sender;
+
+    if(control->receive(&cmd, sizeof cmd, received, sender, options.port) == sf::Socket::Status::Done) {
+      fmt::println("sender {} sent {}", sender->toString(), cmd);
+      sf::Mouse::setPosition({WINDOW_WIDTH - 100, WINDOW_HEIGHT - 100}, presenter);
+    }
+
     while(const auto event = presenter.pollEvent()) {
       if(event) slides->handle_events(presenter, *event);
     }
@@ -112,7 +195,7 @@ int main(int argc, char *argv[]) {
       // save the current slide
       auto current_slide = slides->$deck->current;
       // load the new one
-      auto new_slides = load_slides(argv[1], backend);
+      auto new_slides = load_slides(options.deck_file, backend);
 
       if(new_slides) {
         new_slides->set_slide(current_slide);