refactor(xresources): Use xcb-util-xrm

Drop the Xlib version and handle X resource
lookups using xcb-util-xrm

Refs #356

cmake/build/options.cmake

@@ -72,6 +72,12 @@ option(WITH_XDAMAGE       "XDAMAGE support"            OFF)
 option(WITH_XSYNC         "XSYNC support"              OFF)
 option(WITH_XCOMPOSITE    "XCOMPOSITE support"         OFF)
 option(WITH_XKB           "XKB support"                ON)
+option(WITH_XRM           "xcb-xrm support"            ON)
+
+if(NOT DEFINED WITH_XRM)
+  pkg_check_modules(XRM QUIET xcb-xrm)
+  set(WITH_XRM ${XRM_FOUND} CACHE BOOL "Enable xcb-xrm support")
+endif()
 
 if(NOT DEFINED ENABLE_XRANDR_MONITORS)
   pkg_check_modules(XRANDR QUIET xrandr>=1.5.0)

cmake/build/summary.cmake

@@ -75,3 +75,5 @@ colored_option(STATUS " XSYNC support        ${WITH_XSYNC}" WITH_XSYNC "32;1" "3
 colored_option(STATUS " XCOMPOSITE support   ${WITH_XCOMPOSITE}" WITH_XCOMPOSITE "32;1" "37;2")
 colored_option(STATUS " XKB support          ${WITH_XKB}" WITH_XKB "32;1" "37;2")
 message(STATUS "--------------------------")
+colored_option(STATUS " xcb-util-xrm         ${WITH_XCB_UTIL_XRM}" WITH_XCB_UTIL_XRM "32;1" "37;2")
+message(STATUS "--------------------------")

contrib/polybar-git.aur/.SRCINFO

@@ -12,7 +12,7 @@ pkgbase = polybar-git
 	makedepends = pkg-config
 	depends = libxft
 	depends = xcb-util-wm
-	depends = xcb-util-image
+	depends = xcb-util-xrm
 	optdepends = alsa-lib: volume module support
 	optdepends = libmpdclient: mpd module support
 	optdepends = wireless_tools: network module support

contrib/polybar-git.aur/PKGBUILD

@@ -8,7 +8,7 @@ pkgdesc="A fast and easy-to-use status bar"
 arch=("i686" "x86_64")
 url="https://github.com/jaagr/polybar"
 license=("MIT")
-depends=("libxft" "xcb-util-wm" "xcb-util-image")
+depends=("libxft" "xcb-util-wm" "xcb-util-xrm")
 optdepends=("alsa-lib: volume module support"
             "libmpdclient: mpd module support"
             "wireless_tools: network module support"

contrib/polybar.aur/.SRCINFO

@@ -12,7 +12,7 @@ pkgbase = polybar
 	makedepends = pkg-config
 	depends = libxft
 	depends = xcb-util-wm
-	depends = xcb-util-image
+	depends = xcb-util-xrm
 	optdepends = alsa-lib: volume module support
 	optdepends = libmpdclient: mpd module support
 	optdepends = wireless_tools: network module support

contrib/polybar.aur/PKGBUILD

@@ -7,7 +7,7 @@ pkgdesc="A fast and easy-to-use status bar"
 arch=("i686" "x86_64")
 url="https://github.com/jaagr/polybar"
 license=("MIT")
-depends=("libxft" "xcb-util-wm" "xcb-util-image")
+depends=("libxft" "xcb-util-wm" "xcb-util-xrm")
 optdepends=("alsa-lib: volume module support"
             "libmpdclient: mpd module support"
             "wireless_tools: network module support"

include/components/config.hpp

@@ -5,10 +5,13 @@
 #include "common.hpp"
 #include "components/logger.hpp"
 #include "errors.hpp"
+#include "settings.hpp"
 #include "utils/env.hpp"
 #include "utils/file.hpp"
 #include "utils/string.hpp"
+#ifdef WITH_XRM
 #include "x11/xresources.hpp"
+#endif
 
 POLYBAR_NS
 
@@ -23,7 +26,7 @@ class config {
   using make_type = const config&;
   static make_type make(string path = "", string bar = "");
 
-  explicit config(const logger& logger, const xresource_manager& xrm, string&& path = "", string&& bar = "");
+  explicit config(const logger& logger, string&& path = "", string&& bar = "");
 
   string filepath() const;
   string section() const;
@@ -209,11 +212,11 @@ class config {
     size_t pos;
 
     if (path.compare(0, 4, "env:") == 0) {
-      return dereference_env<T>(path.substr(4), fallback);
+      return dereference_env<T>(path.substr(4));
     } else if (path.compare(0, 5, "xrdb:") == 0) {
-      return dereference_xrdb<T>(path.substr(5), fallback);
+      return dereference_xrdb<T>(path.substr(5));
     } else if (path.compare(0, 5, "file:") == 0) {
-      return dereference_file<T>(path.substr(5), fallback);
+      return dereference_file<T>(path.substr(5));
     } else if ((pos = path.find(".")) != string::npos) {
       return dereference_local<T>(path.substr(0, pos), path.substr(pos + 1), section);
     } else {
@@ -252,9 +255,9 @@ class config {
    *  ${env:key:fallback value}
    */
   template <typename T>
-  T dereference_env(string var, const T&) const {
+  T dereference_env(string var) const {
     size_t pos;
-    string env_default{""};
+    string env_default;
 
     if ((pos = var.find(":")) != string::npos) {
       env_default = var.substr(pos + 1);
@@ -281,15 +284,37 @@ class config {
    *  ${xrdb:key:fallback value}
    */
   template <typename T>
-  T dereference_xrdb(string var, const T& fallback) const {
+  T dereference_xrdb(string var) const {
     size_t pos;
-
+#ifndef WITH_XRM
+    m_log.warn("No built-in support for xrdb (requires xcb-util-xrm). Using default value for `%s`", var);
     if ((pos = var.find(":")) != string::npos) {
-      return convert<T>(m_xrm.get_string(var.substr(0, pos), var.substr(pos + 1)));
+      return var.substr(pos + 1);
+    }
+    return fallback;
+#else
+    if (!m_xrm) {
+      throw application_error("xrm is not initialized");
     }
 
-    string str{m_xrm.get_string(var, "")};
+    string fallback;
-    return str.empty() ? fallback : convert<T>(move(str));
+    if ((pos = var.find(":")) != string::npos) {
+      fallback = var.substr(pos + 1);
+      var.erase(pos);
+    }
+
+    try {
+      auto value = m_xrm->require<string>(var.c_str());
+      m_log.info("Found matching X resource \"%s\" (value=%s)", var, value);
+      return convert<T>(move(value));
+    } catch (const xresource_error& err) {
+      if (!fallback.empty()) {
+        m_log.warn("%s, using defined fallback value \"%s\"", err.what(), fallback);
+        return convert<T>(move(fallback));
+      }
+      throw value_error(sstream() << err.what() << " (no fallback set)");
+    }
+#endif
   }
 
   /**
@@ -297,11 +322,12 @@ class config {
    *  ${file:/absolute/file/path}
    */
   template <typename T>
-  T dereference_file(string var, const T& fallback) const {
+  T dereference_file(string var) const {
-    string filename{move(var)};
+    size_t pos;
-
+    string fallback;
-    if (file_util::exists(filename)) {
+    if ((pos = var.find(":")) != string::npos) {
-      return convert<T>(string_util::trim(file_util::contents(filename), '\n'));
+      fallback = var.substr(pos + 1);
+      var.erase(pos);
     }
 
     return fallback;
@@ -310,10 +336,12 @@ class config {
  private:
   static constexpr const char* KEY_INHERIT{"inherit"};
   const logger& m_log;
-  const xresource_manager& m_xrm;
   string m_file;
   string m_barname;
   sectionmap_t m_sections{};
+#ifdef WITH_XRM
+  unique_ptr<xresource_manager> m_xrm;
+#endif
 };
 
 POLYBAR_NS_END

include/components/logger.hpp

@@ -6,6 +6,7 @@
 #include <thread>
 
 #include "common.hpp"
+#include "settings.hpp"
 
 #ifndef STDOUT_FILENO
 #define STDOUT_FILENO 1

include/settings.hpp.cmake

@@ -25,6 +25,7 @@
 #cmakedefine01 WITH_XSYNC
 #cmakedefine01 WITH_XCOMPOSITE
 #cmakedefine01 WITH_XKB
+#cmakedefine01 WITH_XRM
 
 #if WITH_XRANDR
 #cmakedefine01 ENABLE_XRANDR_MONITORS
@@ -97,14 +98,15 @@ const auto print_build_info = [](bool extended = false) {
     (ENABLE_NETWORK ? '+' : '-'));
   if (extended) {
     printf("\n");
-    printf("X extensions: %cxrandr (%cmonitors) %cxrender %cxdamage %cxsync %cxcomposite %cxkb\n",
+    printf("X extensions: %cxrandr (%cmonitors) %cxrender %cxdamage %cxsync %cxcomposite %cxkb %cxcb-util-xrm\n",
       (WITH_XRANDR            ? '+' : '-'),
       (ENABLE_XRANDR_MONITORS ? '+' : '-'),
       (WITH_XRENDER           ? '+' : '-'),
       (WITH_XDAMAGE           ? '+' : '-'),
       (WITH_XSYNC             ? '+' : '-'),
       (WITH_XCOMPOSITE        ? '+' : '-'),
-      (WITH_XKB               ? '+' : '-'));
+      (WITH_XKB               ? '+' : '-'),
+      (WITH_XRM      ? '+' : '-'));
     printf("\n");
     printf("Build type: @CMAKE_BUILD_TYPE@\n");
     printf("Compiler: @CMAKE_CXX_COMPILER@\n");

include/x11/xresources.hpp

@@ -1,33 +1,64 @@
 #pragma once
 
-#include <X11/X.h>
+#include "settings.hpp"
-#include <X11/Xresource.h>
+
+#if not WITH_XRM
+#error "Not built with support for xcb-xrm..."
+#endif
+
+#include <xcb/xcb_xrm.h>
 
 #include "common.hpp"
+#include "errors.hpp"
+#include "utils/string.hpp"
+#include "x11/connection.hpp"
 
 POLYBAR_NS
 
+DEFINE_ERROR(xresource_error);
+
 class xresource_manager {
  public:
-  using make_type = const xresource_manager&;
+  explicit xresource_manager(xcb_connection_t* conn) : m_xrm(xcb_xrm_database_from_default(conn)) {
-  static make_type make();
+    if (m_xrm == nullptr) {
+      throw application_error("xcb_xrm_database_from_default()");
+    }
+  }
 
-  explicit xresource_manager(Display*);
+  ~xresource_manager() {
-  ~xresource_manager();
+    xcb_xrm_database_free(m_xrm);
+  }
 
-  xresource_manager(const xresource_manager& o) = delete;
+  operator bool() const {
-  xresource_manager& operator=(const xresource_manager& o) = delete;
+    return m_xrm != nullptr;
+  }
 
-  string get_string(string name, string fallback = "") const;
+  template <typename T>
-  float get_float(string name, float fallback = 0.0f) const;
+  T require(const char* name) const {
-  int get_int(string name, int fallback = 0) const;
+    char* result{nullptr};
+    if (xcb_xrm_resource_get_string(m_xrm, string_util::replace(name, "*", ".").c_str(), "String", &result) == -1) {
+      throw xresource_error(sstream() << "X resource \"" << name << "\" not found");
+    } else if (result == nullptr) {
+      throw xresource_error(sstream() << "X resource \"" << name << "\" not found");
+    }
+    return convert<T>(string(result));
+  }
+
+  template <typename T>
+  T get(const char* name, const T& fallback) const {
+    try {
+      return convert<T>(require<T>(name));
+    } catch (const xresource_error) {
+      return fallback;
+    }
+  }
 
  protected:
-  string load_value(const string& key, const string& res_type, size_t n) const;
+  template <typename T>
+  T convert(string&& value) const;
 
  private:
-  XrmDatabase m_db;
+  xcb_xrm_database_t* m_xrm;
-  char* m_manager{nullptr};
 };
 
 POLYBAR_NS_END

src/CMakeLists.txt

@@ -64,6 +64,11 @@ if(WITH_XKB)
 else()
   list(REMOVE_ITEM SOURCES x11/extensions/xkb.cpp modules/xkeyboard.cpp)
 endif()
+if(WITH_XRM)
+  pkg_check_modules(XCB_UTIL_XRM REQUIRED xcb-xrm)
+  set(APP_LIBRARIES ${APP_LIBRARIES} ${XCB_UTIL_XRM_LIBRARIES})
+  set(APP_INCLUDE_DIRS ${APP_INCLUDE_DIRS} ${XCB_UTIL_XRM_INCLUDE_DIRS})
+endif()
 
 string(REPLACE ";" ", " XPP_EXTENSION_LIST "${XPP_EXTENSION_LIST}")
 

src/components/config.cpp

@@ -8,6 +8,7 @@
 #include "utils/math.hpp"
 #include "utils/string.hpp"
 #include "x11/color.hpp"
+#include "x11/xresources.hpp"
 
 POLYBAR_NS
 
@@ -15,18 +16,14 @@ POLYBAR_NS
  * Create instance
  */
 config::make_type config::make(string path, string bar) {
-  return static_cast<config::make_type>(*factory_util::singleton<std::remove_reference_t<config::make_type>>(
+  return *factory_util::singleton<std::remove_reference_t<config::make_type>>(logger::make(), move(path), move(bar));
-      logger::make(), xresource_manager::make(), move(path), move(bar)));
 }
 
 /**
  * Construct config object
  */
-config::config(const logger& logger, const xresource_manager& xrm, string&& path, string&& bar)
+config::config(const logger& logger, string&& path, string&& bar)
-    : m_log(logger)
+    : m_log(logger), m_file(forward<string>(path)), m_barname(forward<string>(bar)) {
-    , m_xrm(forward<decltype(xrm)>(xrm))
-    , m_file(forward<string>(path))
-    , m_barname(forward<string>(bar)) {
   if (!file_util::exists(m_file)) {
     throw application_error("Could not find config file: " + m_file);
   }
@@ -126,6 +123,14 @@ void config::parse_file() {
       }
     }
 
+#ifdef WITH_XRM
+    // Initialize the xresource manage if there are any xrdb refs
+    // present in the configuration
+    if (!m_xrm && value.find("${xrdb") != string::npos) {
+      m_xrm.reset(new xresource_manager{connection::make()});
+    }
+#endif
+
     m_sections[section].emplace_hint(it, move(key), move(value));
   }
 }

src/x11/xresources.cpp

@@ -1,88 +1,15 @@
-#include <X11/Xlib.h>
-#include <cstring>
-#include <utility>
-
-#include "utils/factory.hpp"
-#include "x11/connection.hpp"
 #include "x11/xresources.hpp"
 
 POLYBAR_NS
 
-/**
+template <>
- * Create instance
+string xresource_manager::convert(string&& value) const {
- */
+  return forward<string>(value);
-xresource_manager::make_type xresource_manager::make() {
-  return *factory_util::singleton<xresource_manager>(static_cast<Display*>(connection::make()));
 }
 
-/**
+template <>
- * Construct manager instance
+double xresource_manager::convert(string&& value) const {
- */
+  return std::strtod(value.c_str(), nullptr);
-xresource_manager::xresource_manager(Display* dsp) {
-  XrmInitialize();
-
-  if ((m_manager = XResourceManagerString(dsp)) != nullptr) {
-    m_db = XrmGetStringDatabase(m_manager);
-  }
-}
-
-/**
- * Deconstruct instance
- */
-xresource_manager::~xresource_manager() {
-  if (m_manager != nullptr) {
-    XrmDestroyDatabase(m_db);
-  }
-}
-
-/**
- * Get string value from the X resource db
- */
-string xresource_manager::get_string(string name, string fallback) const {
-  auto result = load_value(move(name), "String", 64);
-  if (result.empty()) {
-    return fallback;
-  }
-  return result;
-}
-
-/**
- * Get float value from the X resource db
- */
-float xresource_manager::get_float(string name, float fallback) const {
-  auto result = load_value(move(name), "String", 64);
-  if (result.empty()) {
-    return fallback;
-  }
-  return strtof(result.c_str(), nullptr);
-}
-
-/**
- * Get integer value from the X resource db
- */
-int xresource_manager::get_int(string name, int fallback) const {
-  auto result = load_value(move(name), "String", 64);
-  if (result.empty()) {
-    return fallback;
-  }
-  return atoi(result.c_str());
-}
-
-/**
- * Query the database for given key
- */
-string xresource_manager::load_value(const string& key, const string& res_type, size_t n) const {
-  if (m_manager != nullptr) {
-    char* type = nullptr;
-    XrmValue ret{};
-
-    if (XrmGetResource(m_db, key.c_str(), res_type.c_str(), &type, &ret)) {
-      if (ret.addr != nullptr && !std::strncmp(res_type.c_str(), type, n)) {
-        return {ret.addr};
-      }
-    }
-  }
-  return "";
 }
 
 POLYBAR_NS_END