Implemented a basic translation system

include/Translation.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <string>
+#include <unordered_map>
+
+namespace gsr {
+    class Translation {
+    public:
+        static Translation& instance();
+        void init(const char* translations_directory, const char* initial_language = nullptr);
+        bool load_language(const char* lang);
+        const char* translate(const char* key);
+
+        template<typename... Args>
+        std::string format(const char* key, Args&&... args) {
+            const char* fmt = translate(key);
+
+            // result buffer
+            char buffer[4096];
+            snprintf(buffer, sizeof(buffer), fmt, std::forward<Args>(args)...);
+            return std::string(buffer);
+        }
+
+    private:
+        std::string get_system_language();
+        std::string trim(const std::string& str);
+
+    private:
+        std::string translations_directory;
+        std::string current_language = "en";
+        std::unordered_map<std::string, std::string> translations;
+    };
+}
+
+#define TR(s) gsr::Translation::instance().translate(s)
+#define TRF(s, ...) gsr::Translation::instance().format(s, __VA_ARGS__)

meson.build

@@ -55,6 +55,7 @@ src = [
     'src/ClipboardFile.cpp',
     'src/LedIndicator.cpp',
     'src/Rpc.cpp',
+    'src/Translation.cpp',
     'src/main.cpp',
 ]
 
@@ -142,6 +143,7 @@ executable(
 
 install_subdir('images', install_dir : gsr_ui_resources_path)
 install_subdir('fonts', install_dir : gsr_ui_resources_path)
+install_subdir('translations', install_dir : gsr_ui_resources_path)
 
 if get_option('desktop-files') == true
     install_data(files('gpu-screen-recorder.desktop'), install_dir : join_paths(prefix, datadir, 'applications'))

src/Translation.cpp

@@ -0,0 +1,101 @@
+#include "../include/Translation.hpp"
+#include <cstring>
+#include <unordered_map>
+#include <fstream>
+
+namespace gsr {
+    std::string Translation::get_system_language() {
+        const char* lang = getenv("LANGUAGE");
+        if (!lang || !lang[0]) lang = getenv("LC_ALL");
+        if (!lang || !lang[0]) lang = getenv("LC_MESSAGES");
+        if (!lang || !lang[0]) lang = getenv("LANG");
+
+        if (lang && lang[0]) {
+            std::string lang_str(lang);
+
+            // we usually need only two symbols
+            size_t underscore = lang_str.find('_');
+            if (underscore != std::string::npos) {
+                return lang_str.substr(0, underscore);
+            }
+            size_t dot = lang_str.find('.');
+            if (dot != std::string::npos) {
+                return lang_str.substr(0, dot);
+            }
+            return lang_str;
+        }
+
+        return "en";
+    }
+
+    std::string Translation::trim(const std::string& str) {
+        size_t start = str.find_first_not_of(" \t\r\n");
+        if (start == std::string::npos) return "";
+        size_t end = str.find_last_not_of(" \t\r\n");
+        return str.substr(start, end - start + 1);
+    }
+
+    bool Translation::load_language(const char* lang) {
+        translations.clear();
+        current_language = lang;
+
+        if (strcmp(lang, "en") == 0) {
+            return true; // english is the base
+        }
+
+        std::string paths[] = {
+            std::string("translations/") + lang + ".txt",
+            std::string(this->translations_directory) + lang + ".txt"
+        };
+
+        for (const auto& path : paths) {
+            std::ifstream file(path);
+            if (!file.is_open()) continue;
+
+            std::string line;
+            while (std::getline(file, line)) {
+                line = trim(line);
+
+                if (line.empty() || line[0] == '#') continue;
+
+                size_t eq_pos = line.find('=');
+                if (eq_pos == std::string::npos) continue;
+
+                std::string key = trim(line.substr(0, eq_pos));
+                std::string value = trim(line.substr(eq_pos + 1));
+
+                size_t pos = 0;
+                while ((pos = value.find("\\n", pos)) != std::string::npos) {
+                    value.replace(pos, 2, "\n");
+                    pos += 1;
+                }
+
+                translations[key] = value;
+            }
+
+            return true;
+        }
+
+        fprintf(stderr, "Warning: translation file for '%s' not found\n", lang);
+        return false;
+    }
+
+    Translation& Translation::instance() {
+        static Translation tr;
+        return tr;
+    }
+
+    void Translation::init(const char* translations_directory, const char* initial_language) {
+        this->translations_directory = translations_directory;
+
+        load_language(initial_language == nullptr ? get_system_language().c_str() : initial_language);
+    }
+
+    const char* Translation::translate(const char* key) {
+        auto it = translations.find(key);
+        if (it != translations.end()) {
+            return it->second.c_str();
+        }
+        return key; // falling back if nothing found
+    }
+}

src/main.cpp

@@ -4,6 +4,7 @@
 #include "../include/Process.hpp"
 #include "../include/Rpc.hpp"
 #include "../include/Theme.hpp"
+#include "../include/Translation.hpp"
 
 #include <signal.h>
 #include <string.h>

translations/ru.txt

@@ -0,0 +1,5 @@
+# Testing formatted translations
+Test of %s and %s=Тест %1$s и %2$s
+
+# General
+Record=Запись