feat(client): add support for 8-bit hex color codes in CSS

This allows users to use #RRGGBBAA format in their style.css.
The client now detects 8-bit hex codes, transforms them into
GTK-compatible rgba() syntax, and loads the modified data
into the CSS provider.

- Added utility to detect 8-bit hex patterns.
- Added transformation logic to convert hex alpha to decimal.
- Intercepted CSS loading in Client::setupCss to handle the conversion.

src/client.cpp

@@ -10,6 +10,7 @@
 #include "idle-inhibit-unstable-v1-client-protocol.h"
 #include "util/clara.hpp"
 #include "util/format.hpp"
+#include "util/hex_checker.hpp"
 
 waybar::Client* waybar::Client::inst() {
   static auto* c = new Client();
@@ -22,21 +23,18 @@ void waybar::Client::handleGlobal(void* data, struct wl_registry* registry, uint
 
   if (strcmp(interface, zxdg_output_manager_v1_interface.name) == 0 &&
       version >= ZXDG_OUTPUT_V1_NAME_SINCE_VERSION) {
-
     if (client->xdg_output_manager != nullptr) {
       zxdg_output_manager_v1_destroy(client->xdg_output_manager);
       client->xdg_output_manager = nullptr;
     }
 
-    client->xdg_output_manager = static_cast<struct zxdg_output_manager_v1*>(
-        wl_registry_bind(registry, name, &zxdg_output_manager_v1_interface,
-                         ZXDG_OUTPUT_V1_NAME_SINCE_VERSION));
+    client->xdg_output_manager = static_cast<struct zxdg_output_manager_v1*>(wl_registry_bind(
+        registry, name, &zxdg_output_manager_v1_interface, ZXDG_OUTPUT_V1_NAME_SINCE_VERSION));
 
   } else if (strcmp(interface, zwp_idle_inhibit_manager_v1_interface.name) == 0) {
-
     if (client->idle_inhibit_manager != nullptr) {
       zwp_idle_inhibit_manager_v1_destroy(client->idle_inhibit_manager);
-      client->idle_inhibit_manager = nullptr;   
+      client->idle_inhibit_manager = nullptr;
     }
 
     client->idle_inhibit_manager = static_cast<struct zwp_idle_inhibit_manager_v1*>(
@@ -209,11 +207,15 @@ auto waybar::Client::setupCss(const std::string& css_file) -> void {
   }
 
   css_provider_ = Gtk::CssProvider::create();
-  if (!css_provider_->load_from_path(css_file)) {
-    css_provider_.reset();
-    throw std::runtime_error("Can't open style file");
+  if (has_8bit_hex(css_file)) {
+    std::string modified_css = transform_8bit_to_hex(css_file);
+    css_provider_->load_from_data(modified_css);
+  } else {
+    if (!css_provider_->load_from_path(css_file)) {
+      css_provider_.reset();
+      throw std::runtime_error("Can't open style file");
+    }
   }
-
   Gtk::StyleContext::add_provider_for_screen(screen, css_provider_,
                                              GTK_STYLE_PROVIDER_PRIORITY_USER);
 }

src/util/has_8bit_hex.cpp

@@ -0,0 +1,15 @@
+#include <filesystem>
+#include <fstream>
+#include <regex>
+
+namespace fs = std::filesystem;
+
+bool has_8bit_hex(std::string file_path) {
+  std::ifstream f(file_path, std::ios::in | std::ios::binary);
+  const auto size = fs::file_size(file_path);
+  std::string result(size, '\0');
+  f.read(result.data(), size);
+  std::regex pattern(
+      R"((?:\#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})))");
+  return std::regex_search(result, pattern);
+}

src/util/transform_8bit_to_rgba.cpp

@@ -0,0 +1,41 @@
+#include <filesystem>
+#include <fstream>
+#include <iomanip>
+#include <regex>
+#include <sstream>
+namespace fs = std::filesystem;
+std::string transform_8bit_to_hex(std::string file_path) {
+  std::ifstream f(file_path, std::ios::in | std::ios::binary);
+  const auto size = fs::file_size(file_path);
+  std::string result(size, '\0');
+  f.read(result.data(), size);
+
+  std::regex pattern(
+      R"((?:\#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})))");
+  std::string final_output;
+
+  auto it = std::sregex_iterator(result.begin(), result.end(), pattern);
+  auto eof = std::sregex_iterator();
+  std::smatch match = *it;
+
+  while (it != eof) {
+
+    final_output += match.prefix().str();
+
+    int r = stoi(match[1].str(), nullptr, 16);
+    int g = stoi(match[2].str(), nullptr, 16);
+    int b = stoi(match[3].str(), nullptr, 16);
+    double a = (stoi(match[4].str(), nullptr, 16) / 255.0);
+
+    std::stringstream ss;
+    ss << "rgba(" << r << "," << g << "," << b << "," << std::fixed
+       << std::setprecision(2) << a << ")";
+    final_output += ss.str();
+
+    ++it;
+  }
+
+  final_output += match.suffix().str();
+
+  return final_output;
+}