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The QFileEngine class provides an abstraction for accessing the filesystem. More...
#include <QFileEngine>
Inherits QIOEngine.
Note: All the functions in this class are reentrant.
The QFileEngine class provides an abstraction for accessing the filesystem.
The QDir, QFile, and QFileInfo classes all make use of a QFileEngine internally. If you create your own QFileEngine subclass (and register it with Qt by creating a QFileEngineHandler subclass), your file engine will be used when the path is one that your file engine handles.
A QFileEngine refers to one file or one directory. If the referent is a file the setFileName(), rename(), and remove() functions are applicable. If the referent is a directory the mkdir(), rmdir(), entryList(), and isRoot() functions are applicable. In all cases the caseSensitive(), isRelativePath(), fileFlags(), ownerId(), owner(), and fileTime() functions are applicable.
A QFileEngine subclass can be created to do syncronous network I/O based file system operations, local file system operations, or to operate as a resource system to access file based resources.
See also QFileEngineHandler and setFileName().
The permissions and types of a file, suitable for OR'ing together.
QFileEngine::ReadOwnerPerm | The owner of the file has permission to read it. |
QFileEngine::WriteOwnerPerm | The owner of the file has permission to write to it. |
QFileEngine::ExeOwnerPerm | The owner of the file has permission to execute it. |
QFileEngine::ReadUserPerm | The current user has permission to read the file. |
QFileEngine::WriteUserPerm | The current user has permission to write to the file. |
QFileEngine::ExeUserPerm | The current user has permission to execute the file. |
QFileEngine::ReadGroupPerm | Members of the current user's group have permission to read the file. |
QFileEngine::WriteGroupPerm | Members of the current user's group have permission to write to the file. |
QFileEngine::ExeGroupPerm | Members of the current user's group have permission to execute the file. |
QFileEngine::ReadOtherPerm | All users have permission to read the file. |
QFileEngine::WriteOtherPerm | All users have permission to write to the file. |
QFileEngine::ExeOtherPerm | All users have permission to execute the file. |
QFileEngine::LinkType | The file is a link to another file (or link) in the file system (i.e. not a file or directory). |
QFileEngine::FileType | The file is a regular file to the file system (i.e. not a link or directory) |
QFileEngine::DirectoryType | The file is a directory in the file system (i.e. not a link or file). |
QFileEngine::HiddenFlag | The file is hidden. |
QFileEngine::ExistsFlag | The file actually exists in the file system. |
See also fileFlags() and setFileName().
These values are used to request a file name in a particular format.
QFileEngine::DefaultName | The same filename that was passed to the QFileEngine. |
QFileEngine::BaseName | The name of the file excluding the path. |
QFileEngine::PathName | The path to the file excluding the BaseName. |
QFileEngine::AbsoluteName | The absolute path to the file (including the BaseName). |
QFileEngine::AbsolutePathName | The absolute path to the file (excluding the BaseName). |
QFileEngine::LinkName | The full file name of the file that this file is a link to. (This will be empty if this file is not a link.) |
QFileEngine::CanonicalName | Often very similar to LinkName will return the true path to the file |
See also fileName() and setFileName().
QFileEngine::OwnerUser | The user who owns the file. |
QFileEngine::OwnerGroup | The group who owns the file. |
See also owner(), ownerId(), and setFileName().
These are used by the fileTime() function.
QFileEngine::CreationTime | When the file was created. |
QFileEngine::ModificationTime | When the file was most recently modified. |
QFileEngine::AccessTime | When the file was most recently accessed (e.g. read or written to). |
See also setFileName().
Constructs a new QFileEngine that does not refer to any file or directory.
See also setFileName().
Destroys the QFileEngine.
Should return true if the underlying file system is case-sensitive; otherwise return false.
This virtual function must be reimplemented by all subclasses.
Creates a new QFileEngine instance for the given file. This function will always return a valid QFileEngine. The default file engine that is created if no custom file engine handles files of file's path is one that operates on the local file system.
Requests that a list of all the files matching the filters list based on the filterSpec in the file engine's directory are returned.
Should return an empty list if the file engine refers to a file rather than a directory, or if the directory is unreadable or does not exist or if nothing matches the specifications.
This virtual function must be reimplemented by all subclasses.
See also setFileName().
This function should return the set of OR'd QFileEngine::FileInfo members that are true for the file engine's file, and that are in the type's OR'd members.
In your reimplementation you can use the type argument as an optimization hint and only return the OR'd set of members that are true and that match those in type; in other words you can ignore any members not mentioned in type, thus avoiding some potentially expensive lookups or system calls.
This virtual function must be reimplemented by all subclasses.
See also setFileName() and FileInfo.
Return the file engine's current file name in the format specified by file.
If you don't handle some FileName possibilities, return the file name set in setFileName() when an unhandled format is requested.
This virtual function must be reimplemented by all subclasses.
See also setFileName() and FileName.
If time is CreationTime, return when the file was created. If time is ModificationTime, return when the file was most recently modified. If time is AccessTime, return when the file was most recently accessed (e.g. read or written). If the time cannot be determined return QDateTime() (an invalid date time).
This virtual function must be reimplemented by all subclasses.
See also setFileName(), QDateTime, QDateTime::isValid(), and FileTime.
Return true if the file referred to by this file engine has a relative path; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName().
Return true if the file referred to by this file engine is the root of the file system; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName().
Requests that the directory dirName be created. If recurse is QDir::Recursive then any sub-directories in dirName that don't exist must be created. If recurse is QDir::NonRecursive then any sub-directories in dirName must already exist for the function to succeed. If the operation succeeds return true; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName(), rmdir(), and isRelativePath().
If owner is OwnerUser return the name of the user who owns the file. If owner is OwnerGroup return the name of the group that own the file. If you can't determine the owner return QString().
This virtual function must be reimplemented by all subclasses.
See also ownerId(), setFileName(), and FileOwner.
If owner is OwnerUser return the ID of the user who owns the file. If owner is OwnerGroup return the ID of the group that own the file. If you can't determine the owner return -2.
This virtual function must be reimplemented by all subclasses.
See also owner(), setFileName(), and FileOwner.
Requests that the file is deleted from the file system. If the operation succeeds return true; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName() and rmdir().
Requests that the file be renamed to newName in the file system. If the operation succeeds return true; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName().
Requests that the directory dirName is deleted from the file system. When recurse is QDir::Recursive then any empty sub-directories in dirName must also be deleted. If recurse is QDir::NonRecursive then only dirName should be deleted. In most file systems a directory cannot be deleted using this function if it is non-empty. If the operation succeeds return true; otherwise return false.
This virtual function must be reimplemented by all subclasses.
See also setFileName(), remove(), mkdir(), and isRelativePath().
Sets the file engine's file name to file. This file name is the file that the rest of the virtual functions will operate on.
This virtual function must be reimplemented by all subclasses.
See also rename().
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