PoC

src/modules/cabi.cpp

@@ -0,0 +1,50 @@
+#include "modules/cabi.hpp"
+
+#include <dlfcn.h>
+
+namespace waybar::modules {
+
+CABI::CABI(const std::string& name, const std::string& id, const Json::Value& config)
+    : AModule(config, name, id, true, true) {
+  const auto dynlib_path = config_["path"].asString();
+
+  void* handle = dlopen(dynlib_path.c_str(), RTLD_LAZY);
+  if (handle == nullptr) {
+    throw std::runtime_error{dlerror()};
+  }
+
+  // Fetch ABI version
+  auto wbcabi_version = reinterpret_cast<size_t*>(dlsym(handle, "wbcabi_version"));
+  if (wbcabi_version == nullptr) {
+    throw std::runtime_error{"Missing wbcabi_version"};
+  }
+
+  // Fetch functions
+  if (*wbcabi_version == 1) {
+    wbcabi_init_ = reinterpret_cast<void* (*)(GtkContainer*)>(dlsym(handle, "wbcabi_init"));
+    if (wbcabi_init_ == nullptr) {
+      throw std::runtime_error{"Missing wbcabi_init function"};
+    }
+    if (auto fn = reinterpret_cast<void (*)(void*)>(dlsym(handle, "wbcabi_deinit")))
+      wbcabi_deinit_ = fn;
+    if (auto fn = reinterpret_cast<const char* (*)(void*)>(dlsym(handle, "wbcabi_last_error_str")))
+      wbcabi_last_error_str_ = fn;
+  } else {
+    throw std::runtime_error{"Unknown wbcabi_version " + std::to_string(*wbcabi_version)};
+  }
+
+  cabi_instance_ = wbcabi_init_(dynamic_cast<Gtk::Container*>(&event_box_)->gobj());
+  if (cabi_instance_ == nullptr) {
+    const auto err_str = wbcabi_last_error_str_(cabi_instance_);
+    throw std::runtime_error{std::string{"Failed to initialize C ABI plugin: "} +
+                             (err_str != nullptr ? err_str : "unknown error")};
+  }
+}
+
+CABI::~CABI() {
+  if (cabi_instance_ != nullptr) {
+    wbcabi_deinit_(cabi_instance_);
+  }
+}
+
+}  // namespace waybar::modules