lib: Use XDG_DATA_DIRS to query themes (#58)

* lib: use XDG_DATA_DIRS to search themes

* lib: fix some stylistic errors

* lib: more stylistic errors fixed

libhyprcursor/hyprcursor.cpp

@@ -2,6 +2,7 @@
 #include "internalSharedTypes.hpp"
 #include "internalDefines.hpp"
 #include <array>
+#include <cstdio>
 #include <filesystem>
 #include <zip.h>
 #include <cstring>
@@ -15,11 +16,25 @@
 
 using namespace Hyprcursor;
 
-// directories for lookup
-constexpr const std::array<const char*, 1> systemThemeDirs = {"/usr/share/icons"};
+static std::vector<std::string> getSystemThemeDirs() {
+    const auto               envXdgData = std::getenv("XDG_DATA_DIRS");
+    std::vector<std::string> result;
+    if (envXdgData) {
+        std::stringstream envXdgStream(envXdgData);
+        std::string       tmpStr;
+        while (getline(envXdgStream, tmpStr, ':'))
+            result.push_back((tmpStr + "/icons"));
+    } else
+        result = {"/usr/share/icons"};
+
+    return result;
+}
+
+const std::vector<std::string>             systemThemeDirs = getSystemThemeDirs();
 constexpr const std::array<const char*, 2> userThemeDirs   = {"/.local/share/icons", "/.icons"};
 
 //
+
 static std::string themeNameFromEnv(PHYPRCURSORLOGFUNC logfn) {
     const auto ENV = getenv("HYPRCURSOR_THEME");
     if (!ENV) {
@@ -728,7 +743,7 @@ std::optional<std::string> CHyprcursorImplementation::loadTheme() {
                 IMAGE->cairoSurface = cairo_image_surface_create_from_png_stream(::readPNG, IMAGE);
 
                 if (const auto STATUS = cairo_surface_status(IMAGE->cairoSurface); STATUS != CAIRO_STATUS_SUCCESS) {
-                    delete[](char*) IMAGE->data;
+                    delete[] (char*)IMAGE->data;
                     IMAGE->data = nullptr;
                     return "Failed reading cairoSurface, status " + std::to_string((int)STATUS);
                 }

nix/default.nix

@@ -15,11 +15,6 @@ stdenv.mkDerivation {
   inherit version;
   src = ../.;
 
-  patches = [
-    # adds /run/current-system/sw/share/icons to the icon lookup directories
-    ./dirs.patch
-  ];
-
   nativeBuildInputs = [
     cmake
     pkg-config