nall: Account for macOS app bundles in program path. (#1373)

Contains three main changes:
* In `Path::program()`, account for the macOS app bundle, so that
portable config support works with the app bundle.
* Create a new function `Path::resources()` for the resources path,
since `Path::program()` can no longer trivially be used to construct the
bundle resources path (no guarantee what the .app is named). On macOS
this returns the path to "ares.app/Contents/Resources", on other
platforms (in case they use it in the future) it just returns the same
as `Path::program()`.
* Fix an issue where, if Ares is stored in a sub-directory of the
desktop, the path settings UI will display paths next to the program as
relative to the desktop instead of relative to the program directory.

desktop-ui/desktop-ui.cpp

@@ -14,7 +14,7 @@ auto locate(const string& name) -> string {
 
   // On macOS, also check the AppBundle Resource path
   #if defined(PLATFORM_MACOS)
-    location = {Path::program(), "../Resources/", name};
+    location = {Path::resources(), name};
     if(inode::exists(location)) return location;
   #endif
 

desktop-ui/settings/paths.cpp

@@ -118,14 +118,14 @@ auto PathSettings::construct() -> void {
 auto PathSettings::refresh() -> void {
   //simplifies pathnames by abbreviating the home folder and trailing slash
   auto pathname = [](string name) -> string {
-    if(name.beginsWith(Path::user())) {
-      name.trimLeft(Path::user(), 1L);
-      name.prepend("~/");
-    }
     if(name.beginsWith(Path::program())) {
       name.trimLeft(Path::program(), 1L);
       name.prepend("./");
     }
+    if(name.beginsWith(Path::user())) {
+      name.trimLeft(Path::user(), 1L);
+      name.prepend("~/");
+    }
     if(name != "/") name.trimRight("/", 1L);
     return name;
   };

mia/mia.cpp

@@ -16,7 +16,7 @@ auto locate(const string& name) -> string {
 
   // On macOS, also check the AppBundle Resource path
 #if defined(PLATFORM_MACOS)
-  location = {Path::program(), "../Resources/", name};
+  location = {Path::resources(), name};
   if(inode::exists(location)) return location;
 #endif
 

nall/path.cpp

@@ -2,6 +2,8 @@
 
 #if defined(PLATFORM_WINDOWS)
   #include <shlobj.h>
+#elif defined(PLATFORM_MACOS)
+  #include <CoreFoundation/CFBundle.h>
 #endif
 
 namespace nall::Path {
@@ -14,12 +16,34 @@ NALL_HEADER_INLINE auto program() -> string {
   result.transform("\\", "/");
   return Path::real(result);
   #else
+  #if defined(PLATFORM_MACOS)
+  if (CFBundleRef bundle = CFBundleGetMainBundle()) {
+    char path[PATH_MAX] = "";
+    CFURLRef url = CFBundleCopyBundleURL(bundle);
+    CFURLGetFileSystemRepresentation(url, true, reinterpret_cast<UInt8*>(path), sizeof(path));
+    CFRelease(url);
+    return Path::real(path);
+  }
+  #endif
   Dl_info info;
   dladdr((void*)&program, &info);
   return Path::real(info.dli_fname);
   #endif
 }
 
+NALL_HEADER_INLINE auto resources() -> string {
+  #if defined(PLATFORM_MACOS)
+  if (CFBundleRef bundle = CFBundleGetMainBundle()) {
+    char path[PATH_MAX] = "";
+    CFURLRef url = CFBundleCopyBundleURL(bundle);
+    CFURLGetFileSystemRepresentation(url, true, reinterpret_cast<UInt8*>(path), sizeof(path));
+    CFRelease(url);
+    return string(path).append("/Contents/Resources/");
+  }
+  #endif
+  return program();
+}
+
 NALL_HEADER_INLINE auto root() -> string {
   #if defined(PLATFORM_WINDOWS)
   wchar_t path[PATH_MAX] = L"";

nall/path.hpp

@@ -26,6 +26,10 @@ inline auto real(string_view name) -> string {
 
 auto program() -> string;
 
+// program()
+// ./ares.app/Contents/Resources/
+auto resources() -> string;
+
 // /
 // c:/
 auto root() -> string;