desktop: Add functionality to enumerate paths of interest

This allows querying things such as the user's home dir, drive letters
(Windows-only), and game paths such as the data dir, preferences, user
data, and binaries. The results are presented in a format that's
suitable for UI use, with translatable labels used wherever applicable.

At some point there'll be support for listing user-defined bookmarks as
well.

projectfiles/CodeBlocks/wesnoth.cbp

@@ -243,6 +243,8 @@
 		<Unit filename="../../src/desktop/notifications.hpp" />
 		<Unit filename="../../src/desktop/open.cpp" />
 		<Unit filename="../../src/desktop/open.hpp" />
+		<Unit filename="../../src/desktop/paths.cpp" />
+		<Unit filename="../../src/desktop/paths.hpp" />
 		<Unit filename="../../src/desktop/version.cpp" />
 		<Unit filename="../../src/desktop/version.hpp" />
 		<Unit filename="../../src/desktop/windows_tray_notification.cpp" />

src/CMakeLists.txt

@@ -693,6 +693,7 @@ set(wesnoth-main_SRC
 	game_initialization/depcheck.cpp
 	desktop/notifications.cpp
 	desktop/open.cpp
+	desktop/paths.cpp
 	desktop/version.cpp
 	display_chat_manager.cpp
 	editor/action/action.cpp

src/SConscript

@@ -250,6 +250,7 @@ wesnoth_sources = Split("""
     countdown_clock.cpp
     desktop/notifications.cpp
     desktop/open.cpp
+    desktop/paths.cpp
     desktop/version.cpp
     display_chat_manager.cpp
     editor/action/action_item.cpp

src/desktop/paths.cpp

@@ -0,0 +1,226 @@
+/*
+   Copyright (C) 2016 by Ignacio R. Morelle <shadowm2006@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#include "desktop/paths.hpp"
+
+#include "game_config.hpp"
+#include "filesystem.hpp"
+#include "gettext.hpp"
+#include "log.hpp"
+#include "serialization/string_utils.hpp"
+#include "serialization/unicode.hpp"
+
+#if !defined(_WIN32) && !defined(__APPLE__)
+#include <boost/filesystem.hpp>
+#endif
+
+#ifndef _WIN32
+
+// For username stuff on Unix:
+#include <pwd.h>
+#include <sys/types.h>
+
+#else // _WIN32
+
+#ifndef UNICODE
+#define UNICODE
+#endif
+
+#define WIN32_LEAN_AND_MEAN
+
+#include <windows.h>
+#include <shlobj.h>
+
+#endif
+
+static lg::log_domain log_desktop("desktop");
+#define ERR_DU LOG_STREAM(err,   log_desktop)
+#define LOG_DU LOG_STREAM(info,  log_desktop)
+#define DBG_DU LOG_STREAM(debug, log_desktop)
+
+namespace desktop
+{
+
+namespace
+{
+
+void enumerate_storage_devices(std::vector<path_info>& res)
+{
+#ifdef _WIN32
+
+	const DWORD drive_table = GetLogicalDrives();
+
+	for(unsigned n = 0; n < 26; ++n) {
+		if((drive_table >> n) & 1) {
+			std::string u8drive = "A:";
+			u8drive[0] += n;
+
+			LOG_DU << "enumerate_win32_drives(): " << u8drive << " is reported to be present\n";
+
+			wchar_t drive[] = L"A:\\";
+			drive[0] += n;
+
+			constexpr DWORD label_bufsize = MAX_PATH + 1;
+			wchar_t label[label_bufsize] = { 0 };
+
+			if(GetVolumeInformation(drive, label, label_bufsize, NULL, NULL, NULL, NULL, 0) == 0) {
+				const DWORD err = GetLastError();
+				ERR_DU << "enumerate_win32_drives(): GetVolumeInformation() failed (" << err << ")\n";
+				continue;
+			}
+
+			// Trailing slash so that we don't get compatibility per-drive working dirs
+			// involved in path resolution.
+			res.push_back({u8drive, unicode_cast<std::string>(std::wstring{label}), u8drive + '\\'});
+		}
+	}
+
+#elif defined(__APPLE__)
+
+	// Probably as unreliable as /media|/mnt on other platforms, not worth
+	// examining in detail.
+	res.push_back({{ N_("filesystem_path_system^Volumes"), GETTEXT_DOMAIN }, "", "/Volumes"});
+
+#else
+
+	namespace bsys = boost::system;
+	namespace bfs = boost::filesystem;
+
+	// These are either used as mount points themselves, or host mount points. The
+	// reasoning here is that if any or all of them are non-empty, they are
+	// probably used for _something_ that might be of interest to the user (if not
+	// directly and actively controlled by the user themselves).
+	static const std::vector<std::string> candidates = { "/media", "/mnt" };
+
+	for(const auto& mnt : candidates) {
+		bsys::error_code e;
+		if(bfs::is_directory(mnt, e) && !bfs::is_empty(mnt, e) && !e) {
+			DBG_DU << "enumerate_mount_parents(): " << mnt << " appears to be a non-empty dir\n";
+			res.push_back({mnt, "", mnt});
+		}
+	}
+
+#endif
+}
+
+bool have_path(const std::vector<path_info>& pathset, const std::string& path)
+{
+	for(const auto& pinfo : pathset) {
+		if(pinfo.path == path) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+inline std::string pretty_path(const std::string& path)
+{
+	return filesystem::normalize_path(path, true, true);
+}
+
+} // unnamed namespace
+
+std::string user_profile_dir()
+{
+#ifndef _WIN32
+
+	// TODO: The filesystem API uses $HOME for this purpose, which may be
+	//       overridden or missing. Not sure which one really makes more sense
+	//       for us here.
+	const passwd* const pwd = getpwuid(geteuid());
+
+	if(!pwd || !pwd->pw_dir || !*pwd->pw_dir) {
+		return "";
+	}
+
+	return pwd->pw_dir;
+
+#else // _WIN32
+
+	wchar_t profile_path[MAX_PATH];
+	HRESULT res = SHGetFolderPath(nullptr, CSIDL_PROFILE, nullptr, SHGFP_TYPE_CURRENT, profile_path);
+	return res != S_OK ? "" : unicode_cast<std::string>(std::wstring{profile_path});
+
+#endif // _WIN32
+}
+
+std::string path_info::display_name() const
+{
+	return label.empty() ? name : label + " (" + name + ")";
+}
+
+std::ostream& operator<<(std::ostream& os, const path_info& pinf)
+{
+	return os << pinf.name << " [" << pinf.label << "] - " << pinf.path;
+}
+
+std::vector<path_info> game_paths(unsigned path_types)
+{
+	static const std::string& game_bin_dir = pretty_path(filesystem::get_exe_dir());
+	static const std::string& game_data_dir = pretty_path(game_config::path);
+	static const std::string& game_user_data_dir = pretty_path(filesystem::get_user_data_dir());
+	static const std::string& game_user_pref_dir = pretty_path(filesystem::get_user_config_dir());
+
+	std::vector<path_info> res;
+
+	if(path_types & GAME_BIN_DIR && !have_path(res, game_bin_dir)) {
+		res.push_back({{ N_("filesystem_path_game^Game executables"), GETTEXT_DOMAIN }, "", game_bin_dir});
+	}
+
+	if(path_types & GAME_CORE_DATA_DIR && !have_path(res, game_data_dir)) {
+		res.push_back({{ N_("filesystem_path_game^Game data"), GETTEXT_DOMAIN }, "", game_data_dir});
+	}
+
+	if(path_types & GAME_USER_DATA_DIR && !have_path(res, game_user_data_dir)) {
+		res.push_back({{ N_("filesystem_path_game^User data"), GETTEXT_DOMAIN }, "", game_user_data_dir});
+	}
+
+	if(path_types & GAME_USER_PREFS_DIR && !have_path(res, game_user_pref_dir)) {
+		res.push_back({{ N_("filesystem_path_game^User preferences"), GETTEXT_DOMAIN }, "", game_user_pref_dir});
+	}
+
+	if(path_types & GAME_USER_BOOKMARKS) {
+		// TODO
+	}
+
+	return res;
+}
+
+std::vector<path_info> system_paths(unsigned path_types)
+{
+	static const std::string& home_dir = user_profile_dir();
+
+	std::vector<path_info> res;
+
+	if(path_types & SYSTEM_USER_PROFILE && !home_dir.empty()) {
+		res.push_back({{ N_("filesystem_path_system^Home"), GETTEXT_DOMAIN }, "", home_dir});
+	}
+
+	if(path_types & SYSTEM_ALL_DRIVES) {
+		enumerate_storage_devices(res);
+	}
+
+#ifndef _WIN32
+	if(path_types & SYSTEM_ROOTFS) {
+		res.push_back({{ N_("filesystem_path_system^Root"), GETTEXT_DOMAIN }, "", "/"});
+	}
+#endif
+
+	return res;
+}
+
+} // namespace desktop

src/desktop/paths.hpp

@@ -0,0 +1,94 @@
+/*
+   Copyright (C) 2016 by Ignacio R. Morelle <shadowm2006@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+/**
+ * @file
+ * Desktop paths, storage media and bookmark functions.
+ */
+
+#ifndef DESKTOP_PATHS_HPP_INCLUDED
+#define DESKTOP_PATHS_HPP_INCLUDED
+
+#include "tstring.hpp"
+
+#include <iosfwd>
+#include <vector>
+
+namespace desktop
+{
+
+/**
+ * Returns the path to the user profile dir (e.g. /home/username).
+ *
+ * An empty string is returned if the path cannot be determined somehow.
+ */
+std::string user_profile_dir();
+
+struct path_info
+{
+	/** Path name or drive letter/mount point path; may be a translatable string if it's a game resources path. */
+	t_string    name;
+	/** System-defined label, if the path is a drive or mount point. */
+	std::string label;
+	/** Real path. */
+	std::string path;
+
+	/**
+	 * Formats this path for UI display.
+	 */
+	std::string display_name() const;
+};
+
+std::ostream& operator<<(std::ostream& os, const path_info& pinf);
+
+enum GAME_PATH_TYPES
+{
+	GAME_BIN_DIR = 0x1,				/**< Game executable dir. */
+	GAME_CORE_DATA_DIR = 0x2,		/**< Game data dir. */
+	GAME_USER_PREFS_DIR = 0x4,		/**< User preferences dir. */
+	GAME_USER_DATA_DIR = 0x8,		/**< User data dir. */
+	GAME_USER_BOOKMARKS = 0x10		/**< User-defined bookmarked paths. */
+};
+
+enum SYSTEM_PATH_TYPES
+{
+	SYSTEM_ALL_DRIVES = 0x1,		/**< Paths for each storage media found (Windows), /media and/or /mnt (X11, if non-empty). */
+	SYSTEM_USER_PROFILE = 0x2,		/**< Path to the user's profile dir (e.g. /home/username or X:\\Users\\Username). */
+	SYSTEM_ROOTFS = 0x4				/**< Path to the root of the filesystem hierarchy (ignored on Windows). */
+};
+
+/**
+ * Returns a list of game-related paths.
+ *
+ * These paths are guaranteed to be their canonical forms (with links and dot
+ * entries resolved) and using the platform's preferred path delimiter.
+ */
+std::vector<path_info> game_paths(unsigned path_types = GAME_CORE_DATA_DIR | GAME_USER_DATA_DIR | GAME_USER_BOOKMARKS);
+
+/**
+ * Returns a list of system-defined paths.
+ *
+ * This includes removable media on platforms where we can reasonably
+ * accurately enumerate those (FIXME: only Windows right now), the path to the
+ * user's profile directory (/home/username, X:\\Users\\Username, etc.), and
+ * the system drive root.
+ *
+ * These paths are guaranteed to be their canonical forms (with links and dot
+ * entries resolved) and using the platform's preferred path delimiter.
+ */
+std::vector<path_info> system_paths(unsigned path_types = SYSTEM_ALL_DRIVES | SYSTEM_USER_PROFILE | SYSTEM_ROOTFS);
+
+} // namespace desktop
+
+#endif