Add initial support for the XDG Base Directory spec

Spec version 0.7 from https://standards.freedesktop.org/basedir-spec/basedir-spec-0.7.html
(latest as of this commit).

Three virtual methods are added to OS for the various XDG paths we will use:
- OS::get_data_path gives XDG_DATA_HOME, or if missing:
  ~/.local/share on X11, ~/Library/Application Support/ on macOS and %APPDATA% on Windows
- OS::get_config_path gives XDG_CONFIG_HOME, or if missing:
  ~/.config on X11, ~/Library/Application Support/ on macOS and %APPDATA% on Windows
- OS::get_cache_path gives XDG_CACHE_HOME, or if missing:
  ~/.cache on X11, ~/Library/Caches on macOS and %APPDATA% on Windows

So for Windows there are no changes, for Linux we follow the full split spec
and for macOS stuff will move from ~/.godot to ~/Library/Application Support/Godot.

Support for system-wide installation of templates on Unix was removed for now,
as it's a bit hackish and I don't think anyone uses it.

user:// will still be OS::get_data_path() + "/godot/app_userdata/$name" by
default, but when using the application/config/use_shared_user_dir option
it will now use XDG_DATA_HOME/$name, e.g. ~/.local/share/MyGame.

For now everything still goes in EditorSettings::get_settings_dir(), but
this will be changed in a later commit to make use of the new splitting
where relevant.

Part of #3513.

3 files changed, 7 insertions, 33 deletions

diff --git a/drivers/unix/SCsub b/drivers/unix/SCsub
index c560e1289f..ada8255580 100644
--- a/drivers/unix/SCsub
+++ b/drivers/unix/SCsub
@@ -2,16 +2,6 @@
 
 Import('env')
 
-g_set_p = '#ifdef UNIX_ENABLED\n'
-g_set_p += '#include "os_unix.h"\n'
-g_set_p += 'String OS_Unix::get_global_settings_path() const {\n'
-g_set_p += '\treturn "' + env["unix_global_settings_path"] + '";\n'
-g_set_p += '}\n'
-g_set_p += '#endif'
-f = open("os_unix_global_settings_path.gen.cpp", "w")
-f.write(g_set_p)
-f.close()
-
 env.add_source_files(env.drivers_sources, "*.cpp")
 
 env["check_c_headers"] = [ [ "mntent.h", "HAVE_MNTENT" ] ]
diff --git a/drivers/unix/os_unix.cpp b/drivers/unix/os_unix.cpp
index e67de16ae5..ce0967af2c 100644
--- a/drivers/unix/os_unix.cpp
+++ b/drivers/unix/os_unix.cpp
@@ -456,30 +456,19 @@ int OS_Unix::get_processor_count() const {
 
 String OS_Unix::get_user_data_dir() const {
 
-	String an = get_safe_application_name();
-	if (an != "") {
-
-		if (has_environment("HOME")) {
-
-			bool use_godot = ProjectSettings::get_singleton()->get("application/config/use_shared_user_dir");
-			if (use_godot)
-				return get_environment("HOME") + "/.godot/app_userdata/" + an;
-			else
-				return get_environment("HOME") + "/." + an;
+	String appname = get_safe_application_name();
+	if (appname != "") {
+		bool use_godot_dir = ProjectSettings::get_singleton()->get("application/config/use_shared_user_dir");
+		if (use_godot_dir) {
+			return get_data_path().plus_file(get_godot_dir_name()).plus_file("app_userdata").plus_file(appname);
+		} else {
+			return get_data_path().plus_file(appname);
 		}
 	}
 
 	return ProjectSettings::get_singleton()->get_resource_path();
 }
 
-String OS_Unix::get_installed_templates_path() const {
-	String p = get_global_settings_path();
-	if (p != "")
-		return p + "/templates/";
-	else
-		return "";
-}
-
 String OS_Unix::get_executable_path() const {
 
 #ifdef __linux__
diff --git a/drivers/unix/os_unix.h b/drivers/unix/os_unix.h
index ad3c62d737..432f48408f 100644
--- a/drivers/unix/os_unix.h
+++ b/drivers/unix/os_unix.h
@@ -62,8 +62,6 @@ protected:
 
 	String stdin_buf;
 
-	String get_global_settings_path() const;
-
 public:
 	virtual void alert(const String &p_alert, const String &p_title = "ALERT!");
 	virtual String get_stdin_string(bool p_block);
@@ -108,11 +106,8 @@ public:
 
 	virtual void debug_break();
 
-	virtual String get_installed_templates_path() const;
 	virtual String get_executable_path() const;
 	virtual String get_user_data_dir() const;
-
-	//virtual void run( MainLoop * p_main_loop );
 };
 
 class UnixTerminalLogger : public StdLogger {