Add Drive Filesystem

Is a virtual filesystem that lists drive letters on e.g. Windows.
The filesystem is deactivated on all other platforms right now.

Invented a new filetype "Filesystem" for delegation of the drive FS to the native FS.
This is kinda a hack but I couldn't think of a better way to add this...

CMakeLists.txt

@@ -120,6 +120,8 @@ add_library(${PROJECT_NAME} OBJECT
 	src/fileext_guesser.h
 	src/filesystem.cpp
 	src/filesystem.h
+	src/filesystem_drive.cpp
+	src/filesystem_drive.h	
 	src/filesystem_lzh.cpp
 	src/filesystem_lzh.h
 	src/filesystem_native.cpp

Makefile.am

@@ -103,6 +103,8 @@ libeasyrpg_player_a_SOURCES = \
 	src/fileext_guesser.h \
 	src/filesystem.cpp \
 	src/filesystem.h \
+	src/filesystem_drive.cpp \
+	src/filesystem_drive.h \
 	src/filesystem_lzh.cpp \
 	src/filesystem_lzh.h \
 	src/filesystem_native.cpp \

src/directory_tree.h

@@ -43,6 +43,8 @@ class DirectoryTree {
 		Regular,
 		/** Directory */
 		Directory,
+		/** A virtual directory that will access a different virtual filesystem */
+		Filesystem,
 		/** Anything of no interest such as block devices */
 		Other
 	};
@@ -53,8 +55,15 @@ class DirectoryTree {
 		std::string name;
 		/** File type */
 		FileType type;
+		/** Human readable name shown in the Game Browser (if different to the filename) */
+		std::string human_name;
 
 		Entry(std::string name, FileType type) : name(std::move(name)), type(type) {}
+		Entry(std::string name, FileType type, std::string human_name) : name(std::move(name)), type(type), human_name(std::move(human_name)) {}
+
+		StringView GetReadableName() const {
+			return human_name.empty() ? name : human_name;
+		}
 	};
 
 	/** Argument struct for more complex find operations */

src/filesystem.cpp

@@ -87,9 +87,13 @@ void Filesystem::ClearCache(StringView path) const {
 FilesystemView Filesystem::Create(StringView path) const {
 	// Determine the proper file system to use
 
-	// When the path doesn't exist check if the path contains a file that can
-	// be handled by another filesystem
-	if (!IsDirectory(path, true)) {
+	if (IsFilesystemNode(path)) {
+		// The support for "mounted" virtual filesystems is very limited and the only
+		// use right now is to delegate from DriveFilesystem to NativeFilesystem.
+		return CreateFromNode(path);
+	} else if (!IsDirectory(path, true)) {
+		// When the path doesn't exist check if the path contains a file that can
+		// be handled by another filesystem
 		std::string dir_of_file;
 		std::string path_prefix;
 		std::vector<std::string> components = FileFinder::SplitPath(path);
@@ -175,10 +179,18 @@ FilesystemView Filesystem::Subtree(std::string sub_path) const {
 	return FilesystemView(shared_from_this(), sub_path);
 }
 
+bool Filesystem::IsFilesystemNode(StringView) const {
+	return false;
+}
+
 bool Filesystem::MakeDirectory(StringView, bool) const {
 	return false;
 }
 
+FilesystemView Filesystem::CreateFromNode(StringView) const {
+	return FilesystemView();
+}
+
 bool Filesystem::IsValid() const {
 	// FIXME: better way to do this?
 	return Exists("");
@@ -307,6 +319,11 @@ bool FilesystemView::IsDirectory(StringView path, bool follow_symlinks) const {
 	return fs->IsDirectory(MakePath(path), follow_symlinks);
 }
 
+bool FilesystemView::IsFilesystemNode(StringView path) const {
+	assert(fs);
+	return fs->IsFilesystemNode(MakePath(path));
+}
+
 bool FilesystemView::Exists(StringView path) const {
 	assert(fs);
 	return fs->Exists(MakePath(path));
@@ -372,6 +389,11 @@ bool FilesystemView::MakeDirectory(StringView dir, bool follow_symlinks) const {
 	return fs->MakeDirectory(MakePath(dir), follow_symlinks);
 }
 
+FilesystemView FilesystemView::CreateFromNode(StringView path) const {
+	assert(fs);
+	return fs->CreateFromNode(MakePath(path));
+}
+
 bool FilesystemView::IsFeatureSupported(Filesystem::Feature f) const {
 	assert(fs);
 	return fs->IsFeatureSupported(f);
@@ -393,6 +415,10 @@ FilesystemView FilesystemView::GoUp() const {
 
 	auto [path, file] = FileFinder::GetPathAndFilename(GetSubPath());
 
+	if (path == GetSubPath()) {
+		return fs->GetParent();
+	}
+
 	return FilesystemView(fs, path);
 }
 

src/filesystem.h

@@ -217,9 +217,11 @@ class Filesystem : public std::enable_shared_from_this<Filesystem> {
 	/** @{ */
 	virtual bool IsFile(StringView path) const = 0;
 	virtual bool IsDirectory(StringView path, bool follow_symlinks) const = 0;
+	virtual bool IsFilesystemNode(StringView path) const;
 	virtual bool Exists(StringView path) const = 0;
 	virtual int64_t GetFilesize(StringView path) const = 0;
 	virtual bool MakeDirectory(StringView dir, bool follow_symlinks) const;
+	virtual FilesystemView CreateFromNode(StringView path) const;
 	virtual bool IsFeatureSupported(Feature f) const;
 	virtual std::string Describe() const = 0;
 	/** @} */
@@ -369,6 +371,12 @@ class FilesystemView {
 	 */
 	bool IsDirectory(StringView path, bool follow_symlinks) const;
 
+	/**
+	 * @param path Path to check
+	 * @return True when path is pointing to a virtual filesystem
+	 */
+	bool IsFilesystemNode(StringView path) const;
+
 	/**
 	 * @param path Path to check
 	 * @return True when a file exists at the path
@@ -461,6 +469,14 @@ class FilesystemView {
 	 */
 	bool MakeDirectory(StringView dir, bool follow_symlinks) const;
 
+	/**
+	 * Create a filesystem view from the passed in path.
+	 * The path must point to a virtual filesystem entry (type Filesystem).
+	 * @param path Path to create filesystem from
+	 * @return view pointing at the new fs
+	 */
+	FilesystemView CreateFromNode(StringView path) const;
+
 	/**
 	 * @param f Filesystem feature to check
 	 * @return true when the feature is supported.

src/filesystem_drive.cpp

@@ -0,0 +1,118 @@
+/*
+ * This file is part of EasyRPG Player.
+ *
+ * EasyRPG Player 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EasyRPG Player is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EasyRPG Player. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "filesystem_drive.h"
+#include "filefinder.h"
+#include "output.h"
+
+#include <algorithm>
+
+#ifdef _WIN32
+#  include <windows.h>
+#  include <fileapi.h>
+#endif
+
+namespace {
+#ifdef _WIN32
+	StringView drive_sep = "\\";
+#else
+	StringView drive_sep = "/";
+#endif
+}
+
+DriveFilesystem::DriveFilesystem() : Filesystem("", FilesystemView()) {
+#ifdef _WIN32
+	std::wstring volume = L"A:\\";
+
+	DWORD logical_drives = GetLogicalDrives();
+	for (int i = 0; i < 26; i++) {
+		if ((logical_drives & (1 << i)) > 0) {
+			DirectoryTree::Entry entry = { Utils::FromWideString(volume), DirectoryTree::FileType::Filesystem };
+
+			wchar_t volume_name[MAX_PATH];
+			if (GetVolumeInformation(volume.c_str(), volume_name, MAX_PATH, nullptr, nullptr, nullptr, nullptr, 0) != 0) {
+				entry.human_name = fmt::format("{} ({})", Utils::FromWideString(volume), Utils::FromWideString(volume_name));
+			}
+
+			drives.push_back(entry);
+		}
+		volume[0]++; // Increment drive letter
+	}
+#endif
+}
+
+bool DriveFilesystem::HasDrives() const {
+	return !drives.empty();
+}
+
+bool DriveFilesystem::IsFile(StringView path) const {
+	(void)path;
+	return false;
+}
+
+bool DriveFilesystem::IsDirectory(StringView path, bool) const {
+	return path.empty();
+}
+
+bool DriveFilesystem::IsFilesystemNode(StringView path) const {
+	for (const auto& drive: drives) {
+		if (drive.name == path) {
+			return true;
+		}
+#ifdef _WIN32
+		if (drive.name == Utils::ReplaceAll(ToString(path), "/", "\\")) {
+			return true;
+		}
+#endif
+	}
+
+	return false;
+}
+
+bool DriveFilesystem::Exists(StringView path) const {
+	return IsDirectory(path, false) || IsFilesystemNode(path);
+}
+
+int64_t DriveFilesystem::GetFilesize(StringView path) const {
+	(void)path;
+	return 0;
+}
+
+FilesystemView DriveFilesystem::CreateFromNode(StringView path) const {
+	if (!IsFilesystemNode(path)) {
+		return {};
+	}
+
+	return FileFinder::Root().Create(path);
+}
+
+std::streambuf* DriveFilesystem::CreateInputStreambuffer(StringView path, std::ios_base::openmode mode) const {
+	return nullptr;
+}
+
+bool DriveFilesystem::GetDirectoryContent(StringView path, std::vector<DirectoryTree::Entry>& tree) const {
+	if (!path.empty()) {
+		return false;
+	}
+
+	tree = drives;
+	return true;
+}
+
+std::string DriveFilesystem::Describe() const {
+	return "[Drive]";
+}

src/filesystem_drive.h

@@ -0,0 +1,56 @@
+/*
+ * This file is part of EasyRPG Player.
+ *
+ * EasyRPG Player 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EasyRPG Player is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EasyRPG Player. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef EP_FILESYSTEM_DRIVE_H
+#define EP_FILESYSTEM_DRIVE_H
+
+#include "filesystem.h"
+
+/**
+ * A virtual filesystem that lists e.g. drive letters on Windows
+ */
+class DriveFilesystem : public Filesystem {
+public:
+	/**
+	 * Initializes a OS Filesystem on the given os path
+	 */
+	explicit DriveFilesystem();
+
+	/** @return Whether the current target platform has drive letters to list */
+	bool HasDrives() const;
+
+protected:
+	/**
+ 	 * Implementation of abstract methods
+ 	 */
+	/** @{ */
+	bool IsFile(StringView path) const override;
+	bool IsDirectory(StringView path, bool follow_symlinks) const override;
+	bool IsFilesystemNode(StringView path) const override;
+	bool Exists(StringView path) const override;
+	int64_t GetFilesize(StringView path) const override;
+	FilesystemView CreateFromNode(StringView path) const override;
+	std::streambuf* CreateInputStreambuffer(StringView path, std::ios_base::openmode mode) const override;
+	bool GetDirectoryContent(StringView path, std::vector<DirectoryTree::Entry>& entries) const override;
+	std::string Describe() const override;
+	/** @} */
+
+private:
+	std::vector<DirectoryTree::Entry> drives;
+};
+
+#endif

src/filesystem_root.cpp

@@ -16,6 +16,7 @@
  */
 
 #include "filesystem_root.h"
+#include "filesystem_drive.h"
 #include "output.h"
 
 #if defined(__ANDROID__) && !defined(USE_LIBRETRO)
@@ -28,12 +29,20 @@ constexpr const StringView root_ns = "root://";
 RootFilesystem::RootFilesystem() : Filesystem("", FilesystemView()) {
 	// Add platform specific namespaces here
 #if defined(__ANDROID__) && !defined(USE_LIBRETRO)
-	fs_list.push_back(std::make_pair("apk", std::make_unique<ApkFilesystem>()));
-	fs_list.push_back(std::make_pair("content", std::make_unique<SafFilesystem>("", FilesystemView())));
+	fs_list.push_back(std::make_pair("apk", std::make_shared<ApkFilesystem>()));
+	fs_list.push_back(std::make_pair("content", std::make_shared<SafFilesystem>("", FilesystemView())));
 #endif
 
+	// Support for drive letters on e.g. Windows (and similiar concepts on other platforms)
+	auto drive_fs = std::make_shared<DriveFilesystem>();
+	FilesystemView drive_view;
+	if (drive_fs->HasDrives()) {
+		drive_view = *drive_fs;
+		fs_list.push_back(std::make_pair("drive", drive_fs));
+	}
+
 	// IMPORTANT: This must be the last filesystem in the list, do not push anything to fs_list afterwards!
-	fs_list.push_back(std::make_pair("file", std::make_unique<NativeFilesystem>("", FilesystemView())));
+	fs_list.push_back(std::make_pair("file", std::make_shared<NativeFilesystem>("", drive_view)));
 
 	assert(fs_list.back().first == "file" && "File namespace must be last!");
 }

src/scene_gamebrowser.cpp

@@ -194,9 +194,7 @@ void Scene_GameBrowser::BootGame() {
 		return;
 	}
 
-	FilesystemView fs;
-	std::string entry;
-	std::tie(fs, entry) = gamelist_window->GetGameFilesystem();
+	FilesystemView fs = gamelist_window->GetGameFilesystem();
 
 	if (!fs) {
 		Output::Warning("The selected file or directory cannot be opened");