scummvm/backends/fs/fs.h

210 lines
6.3 KiB
C++

/* ScummVM - Scumm Interpreter
* Copyright (C) 2002-2005 The ScummVM project
*
* 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; 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*/
#ifndef FS_H
#define FS_H
/*
* The API described in this header is meant to allow for file system browsing in a
* portable fashions. To this ends, multiple or single roots have to be supported
* (compare Unix with a single root, Windows with multiple roots C:, D:, ...).
*
* To this end, we abstract away from paths; implementations can be based on
* paths (and it's left to them whether / or \ or : is the path separator :-);
* but it is also possible to use inodes or vrefs (MacOS 9) or anything else.
*
* NOTE: Backends still have to provide a way to extract a path from a FSIntern
*
* You may ask now: "isn't this cheating? Why do we go through all this when we use
* a path in the end anyway?!?".
* Well, for once as long as we don't provide our own file open/read/write API, we
* still have to use fopen(). Since all our targets already support fopen(), it should
* be possible to get a fopen() compatible string for any file system node.
*
* Secondly, with this abstraction layer, we still avoid a lot of complications based on
* differences in FS roots, different path separators, or even systems with no real
* paths (MacOS 9 doesn't even have the notion of a "current directory").
* And if we ever want to support devices with no FS in the classical sense (Palm...),
* we can build upon this.
*/
/*
* TODO - Instead of starting with getRoot(), we should rather add a getDefaultDir()
* call that on Unix might return the current dir or the users home dir...
* i.e. the root dir is usually not the best starting point for browsing.
*/
#include "common/array.h"
#include "common/str.h"
class FilesystemNode;
/**
* List of multiple file system nodes. E.g. the contents of a given directory.
*/
class FSList : public Common::Array<FilesystemNode> {
public:
void sort();
};
/**
* File system node.
*/
class AbstractFilesystemNode {
protected:
friend class FilesystemNode;
typedef Common::String String;
/**
* The parent node of this directory.
* The parent of the root is the root itself.
*/
virtual AbstractFilesystemNode *parent() const = 0;
/**
* This method is a rather ugly hack which is used internally by the
* actual node implementions to wrap up raw nodes inside FilesystemNode
* objects. We probably want to get rid of this eventually and replace it
* with a cleaner / more elegant solution, but for now it works.
* @note This takes over ownership of node. Do not delete it yourself,
* else you'll get ugly crashes. You've been warned!
*/
static FilesystemNode wrap(AbstractFilesystemNode *node);
public:
/**
* Flag to tell listDir() which kind of files to list.
*/
typedef enum {
kListFilesOnly = 1,
kListDirectoriesOnly = 2,
kListAll = 3
} ListMode;
virtual ~AbstractFilesystemNode() {}
/**
* Return display name, used by e.g. the GUI to present the file in the file browser.
* @return the display name
*/
virtual String displayName() const = 0;
/**
* Is this node valid (i.e. referring to an actual FS object)?
*/
virtual bool isValid() const = 0;
/**
* Is this node a directory or not?
*/
virtual bool isDirectory() const = 0;
/**
* A path representation suitable for use with fopen()
*/
virtual String path() const = 0;
/**
* List the content of this directory node.
* If this node is not a directory, throw an exception or call error().
*/
virtual FSList listDir(ListMode mode = kListDirectoriesOnly) const = 0;
/**
* Compare the name of this node to the name of another.
*/
virtual bool operator< (const AbstractFilesystemNode& node) const
{
return scumm_stricmp(displayName().c_str(), node.displayName().c_str()) < 0;
}
/* TODO:
bool exists();
bool isDirectory();
bool isFile();
bool isReadable();
bool isWriteable();
*/
};
class FilesystemNode : public AbstractFilesystemNode {
friend class AbstractFilesystemNode;
typedef Common::String String;
private:
AbstractFilesystemNode *_realNode;
int *_refCount;
/**
* Returns a special node representing the FS root. The starting point for
* any file system browsing.
* On Unix, this will be simply the node for / (the root directory).
* On Windows, it will be a special node which "contains" all drives (C:, D:, E:).
*/
static AbstractFilesystemNode *getRoot();
/*
* Construct a node based on a path; the path is in the same format as it
* would be for calls to fopen().
*
* I.e. getNodeForPath(oldNode.path()) should create a new node identical to oldNode.
*
* @TODO: This is of course a place where non-portable code easily will sneak
* in, because the format of the path used here is not well-defined.
* So we really should reconsider this API and try to come up with
* something which is more portable but still flexible enough for our
* purposes.
*/
static AbstractFilesystemNode *getNodeForPath(const String &path);
public:
FilesystemNode();
FilesystemNode(const FilesystemNode &node);
FilesystemNode(const String &path);
~FilesystemNode();
FilesystemNode &operator =(const FilesystemNode &node);
FilesystemNode getParent() const;
virtual String displayName() const { return _realNode->displayName(); }
virtual bool isValid() const { return _realNode->isValid(); }
virtual bool isDirectory() const { return _realNode->isDirectory(); }
virtual String path() const { return _realNode->path(); }
virtual FSList listDir(ListMode mode = kListDirectoriesOnly) const { return _realNode->listDir(mode); }
protected:
void decRefCount();
virtual AbstractFilesystemNode *parent() const { return 0; }
};
#endif