QAbstractFileEngine¶

Inheritance diagram of QAbstractFileEngine

Inherited by: QFSFileEngine

Synopsis¶

Functions¶

def atEnd ()
def error ()
def errorString ()
def map (offset, size, flags)
def setError (error, str)
def unmap (ptr)

Virtual functions¶

def beginEntryList (filters, filterNames)
def caseSensitive ()
def close ()
def copy (newName)
def entryList (filters, filterNames)
def fileFlags ([type=QAbstractFileEngine.FileInfoAll])
def fileName ([file=DefaultName])
def fileTime (time)
def flush ()
def handle ()
def isRelativePath ()
def isSequential ()
def link (newName)
def mkdir (dirName, createParentDirectories)
def open (openMode)
def owner (arg__1)
def ownerId (arg__1)
def pos ()
def read (, maxlen)
def readLine (, maxlen)
def remove ()
def rename (newName)
def rmdir (dirName, recurseParentDirectories)
def seek (pos)
def setFileName (file)
def setPermissions (perms)
def setSize (size)
def size ()
def supportsExtension (extension)
def write (data, len)

Static functions¶

def create (fileName)

Detailed Description¶

The PySide.QtCore.QAbstractFileEngine class provides an abstraction for accessing the filesystem.

The PySide.QtCore.QDir , PySide.QtCore.QFile , and PySide.QtCore.QFileInfo classes all make use of a PySide.QtCore.QAbstractFileEngine internally. If you create your own PySide.QtCore.QAbstractFileEngine subclass (and register it with Qt by creating a PySide.QtCore.QAbstractFileEngineHandler subclass), your file engine will be used when the path is one that your file engine handles.

A PySide.QtCore.QAbstractFileEngine refers to one file or one directory. If the referent is a file, the PySide.QtCore.QAbstractFileEngine.setFileName() , PySide.QtCore.QAbstractFileEngine.rename() , and PySide.QtCore.QAbstractFileEngine.remove() functions are applicable. If the referent is a directory the PySide.QtCore.QAbstractFileEngine.mkdir() , PySide.QtCore.QAbstractFileEngine.rmdir() , and PySide.QtCore.QAbstractFileEngine.entryList() functions are applicable. In all cases the PySide.QtCore.QAbstractFileEngine.caseSensitive() , PySide.QtCore.QAbstractFileEngine.isRelativePath() , PySide.QtCore.QAbstractFileEngine.fileFlags() , PySide.QtCore.QAbstractFileEngine.ownerId() , PySide.QtCore.QAbstractFileEngine.owner() , and PySide.QtCore.QAbstractFileEngine.fileTime() functions are applicable.

A PySide.QtCore.QAbstractFileEngine subclass can be created to do synchronous 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

PySide.QtCore.QAbstractFileEngineHandler

class PySide.QtCore.QAbstractFileEngine¶: Constructs a new PySide.QtCore.QAbstractFileEngine that does not refer to any file or directory.

See also

PySide.QtCore.QAbstractFileEngine.setFileName()

PySide.QtCore.QAbstractFileEngine.FileName¶

These values are used to request a file name in a particular format.

Constant	Description
QAbstractFileEngine.DefaultName	The same filename that was passed to the `PySide.QtCore.QAbstractFileEngine` .
QAbstractFileEngine.BaseName	The name of the file excluding the path.
QAbstractFileEngine.PathName	The path to the file excluding the base name.
QAbstractFileEngine.AbsoluteName	The absolute path to the file (including the base name).
QAbstractFileEngine.AbsolutePathName	The absolute path to the file (excluding the base name).
QAbstractFileEngine.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.)
QAbstractFileEngine.CanonicalName	Often very similar to `LinkName` . Will return the true path to the file.
QAbstractFileEngine.CanonicalPathName	Same as `CanonicalName` , excluding the base name.
QAbstractFileEngine.BundleName	Returns the name of the bundle implies `BundleType` is set.

PySide.QtCore.QAbstractFileEngine.FileTime¶

These are used by the PySide.QtCore.QAbstractFileEngine.fileTime() function.

Constant	Description
QAbstractFileEngine.CreationTime	When the file was created.
QAbstractFileEngine.ModificationTime	When the file was most recently modified.
QAbstractFileEngine.AccessTime	When the file was most recently accessed (e.g. read or written to).

PySide.QtCore.QAbstractFileEngine.FileOwner¶

Constant	Description
QAbstractFileEngine.OwnerUser	The user who owns the file.
QAbstractFileEngine.OwnerGroup	The group who owns the file.

PySide.QtCore.QAbstractFileEngine.Extension¶

This enum describes the types of extensions that the file engine can support. Before using these extensions, you must verify that the extension is supported (i.e., call PySide.QtCore.QAbstractFileEngine.supportsExtension() ).

Constant	Description
QAbstractFileEngine.AtEndExtension	Whether the current file position is at the end of the file or not. This extension allows file engines that implement local buffering to report end-of-file status without having to check the size of the file. It is also useful for sequential files, where the size of the file cannot be used to determine whether or not you have reached the end. This extension returns true if the file is at the end; otherwise it returns false. The input and output arguments to `extension()` are ignored.
QAbstractFileEngine.FastReadLineExtension	Whether the file engine provides a fast implementation for `PySide.QtCore.QAbstractFileEngine.readLine()` or not. If `PySide.QtCore.QAbstractFileEngine.readLine()` remains unimplemented in the file engine, `PySide.QtCore.QAbstractFileEngine` will provide an implementation based on calling `PySide.QtCore.QAbstractFileEngine.read()` repeatedly. If `PySide.QtCore.QAbstractFileEngine.supportsExtension()` returns false for this extension, however, `PySide.QtCore.QIODevice` can provide a faster implementation by making use of its internal buffer. For engines that already provide a fast `PySide.QtCore.QAbstractFileEngine.readLine()` implementation, returning false for this extension can avoid unnnecessary double-buffering in `PySide.QtCore.QIODevice` .
QAbstractFileEngine.MapExtension	Whether the file engine provides the ability to map a file to memory.
QAbstractFileEngine.UnMapExtension	Whether the file engine provides the ability to unmap memory that was previously mapped.

PySide.QtCore.QAbstractFileEngine.FileFlag¶

The permissions and types of a file, suitable for OR’ing together.

Constant	Description
QAbstractFileEngine.ReadOwnerPerm	The owner of the file has permission to read it.
QAbstractFileEngine.WriteOwnerPerm	The owner of the file has permission to write to it.
QAbstractFileEngine.ExeOwnerPerm	The owner of the file has permission to execute it.
QAbstractFileEngine.ReadUserPerm	The current user has permission to read the file.
QAbstractFileEngine.WriteUserPerm	The current user has permission to write to the file.
QAbstractFileEngine.ExeUserPerm	The current user has permission to execute the file.
QAbstractFileEngine.ReadGroupPerm	Members of the current user’s group have permission to read the file.
QAbstractFileEngine.WriteGroupPerm	Members of the current user’s group have permission to write to the file.
QAbstractFileEngine.ExeGroupPerm	Members of the current user’s group have permission to execute the file.
QAbstractFileEngine.ReadOtherPerm	All users have permission to read the file.
QAbstractFileEngine.WriteOtherPerm	All users have permission to write to the file.
QAbstractFileEngine.ExeOtherPerm	All users have permission to execute the file.
QAbstractFileEngine.LinkType	The file is a link to another file (or link) in the file system (i.e. not a file or directory).
QAbstractFileEngine.FileType	The file is a regular file to the file system (i.e. not a link or directory)
QAbstractFileEngine.BundleType	The file is a Mac OS X bundle implies `DirectoryType`
QAbstractFileEngine.DirectoryType	The file is a directory in the file system (i.e. not a link or file).
QAbstractFileEngine.HiddenFlag	The file is hidden.
QAbstractFileEngine.ExistsFlag	The file actually exists in the file system.
QAbstractFileEngine.RootFlag	The file or the file pointed to is the root of the filesystem.
QAbstractFileEngine.LocalDiskFlag	The file resides on the local disk and can be passed to standard file functions.
QAbstractFileEngine.Refresh	Passing this flag will force the file engine to refresh all flags.

PySide.QtCore.QAbstractFileEngine.atEnd()¶

Return type:	`PySide.QtCore.bool`

Returns true if the current position is at the end of the file; otherwise, returns false.

This function bases its behavior on calling extension() with AtEndExtension . If the engine does not support this extension, false is returned.

See also

extension() PySide.QtCore.QAbstractFileEngine.supportsExtension() QFile.atEnd()

PySide.QtCore.QAbstractFileEngine.beginEntryList(filters, filterNames)¶

Parameters:	filters – `PySide.QtCore.QDir.Filters` filterNames – list of strings
Return type:	`PySide.QtCore.QAbstractFileEngineIterator`

PySide.QtCore.QAbstractFileEngine.caseSensitive()¶

Return type:	`PySide.QtCore.bool`

Should return true if the underlying file system is case-sensitive; otherwise return false.

This virtual function must be reimplemented by all subclasses.

PySide.QtCore.QAbstractFileEngine.close()¶

Return type:	`PySide.QtCore.bool`

Closes the file, returning true if successful; otherwise returns false.

The default implementation always returns false.

PySide.QtCore.QAbstractFileEngine.copy(newName)¶

Parameters:	newName – unicode
Return type:	`PySide.QtCore.bool`

Copies the contents of this file to a file with the name newName . Returns true on success; otherwise, false is returned.

static PySide.QtCore.QAbstractFileEngine.create(fileName)¶

Parameters:	fileName – unicode
Return type:	`PySide.QtCore.QAbstractFileEngine`

Creates and returns a PySide.QtCore.QAbstractFileEngine suitable for processing fileName .

You should not need to call this function; use PySide.QtCore.QFile , PySide.QtCore.QFileInfo or PySide.QtCore.QDir directly instead.

If you reimplemnt this function, it should only return file engines that knows how to handle fileName ; otherwise, it should return 0.

PySide.QtCore.QAbstractFileEngine.entryList(filters, filterNames)¶

Parameters:	filters – `PySide.QtCore.QDir.Filters` filterNames – list of strings
Return type:	list of strings

PySide.QtCore.QAbstractFileEngine.error()¶

Return type:	`PySide.QtCore.QFile.FileError`

Returns the QFile.FileError that resulted from the last failed operation. If QFile.UnspecifiedError is returned, PySide.QtCore.QFile will use its own idea of the error status.

PySide.QtCore.QAbstractFileEngine.errorString()¶

Return type:	unicode

Returns the human-readable message appropriate to the current error reported by PySide.QtCore.QAbstractFileEngine.error() . If no suitable string is available, an empty string is returned.

PySide.QtCore.QAbstractFileEngine.fileFlags([type=QAbstractFileEngine.FileInfoAll])¶

Parameters:	type – `PySide.QtCore.QAbstractFileEngine.FileFlags`
Return type:	`PySide.QtCore.QAbstractFileEngine.FileFlags`

PySide.QtCore.QAbstractFileEngine.fileName([file=DefaultName])¶

Parameters:	file – `PySide.QtCore.QAbstractFileEngine.FileName`
Return type:	unicode

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 PySide.QtCore.QAbstractFileEngine.setFileName() when an unhandled format is requested.

This virtual function must be reimplemented by all subclasses.

See also

PySide.QtCore.QAbstractFileEngine.setFileName() QAbstractFileEngine.FileName

PySide.QtCore.QAbstractFileEngine.fileTime(time)¶

Parameters:	time – `PySide.QtCore.QAbstractFileEngine.FileTime`
Return type:	`PySide.QtCore.QDateTime`

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.

PySide.QtCore.QAbstractFileEngine.flush()¶

Return type:	`PySide.QtCore.bool`

Flushes the open file, returning true if successful; otherwise returns false.

The default implementation always returns false.

PySide.QtCore.QAbstractFileEngine.handle()¶

Return type:	`PySide.QtCore.int`

Returns the native file handle for this file engine. This handle must be used with care; its value and type are platform specific, and using it will most likely lead to non-portable code.

PySide.QtCore.QAbstractFileEngine.isRelativePath()¶

Return type:	`PySide.QtCore.bool`

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.

PySide.QtCore.QAbstractFileEngine.isSequential()¶

Return type:	`PySide.QtCore.bool`

Returns true if the file is a sequential access device; returns false if the file is a direct access device.

Operations involving PySide.QtCore.QAbstractFileEngine.size() and seek(int) are not valid on sequential devices.

PySide.QtCore.QAbstractFileEngine.link(newName)¶

Parameters:	newName – unicode
Return type:	`PySide.QtCore.bool`

Creates a link from the file currently specified by PySide.QtCore.QAbstractFileEngine.fileName() to newName . What a link is depends on the underlying filesystem (be it a shortcut on Windows or a symbolic link on Unix). Returns true if successful; otherwise returns false.

PySide.QtCore.QAbstractFileEngine.map(offset, size, flags)¶

Parameters:	offset – `PySide.QtCore.qint64` size – `PySide.QtCore.qint64` flags – `PySide.QtCore.QFile.MemoryMapFlags`
Return type:	`PySide.QtCore.uchar`

PySide.QtCore.QAbstractFileEngine.mkdir(dirName, createParentDirectories)¶

Parameters:	dirName – unicode createParentDirectories – `PySide.QtCore.bool`
Return type:	`PySide.QtCore.bool`

Requests that the directory dirName be created. If createParentDirectories is true, then any sub-directories in dirName that don’t exist must be created. If createParentDirectories is false 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.

PySide.QtCore.QAbstractFileEngine.open(openMode)¶

Parameters:	openMode – `PySide.QtCore.QIODevice.OpenMode`
Return type:	`PySide.QtCore.bool`

PySide.QtCore.QAbstractFileEngine.owner(arg__1)¶

Parameters:	arg__1 – `PySide.QtCore.QAbstractFileEngine.FileOwner`
Return type:	unicode

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.

PySide.QtCore.QAbstractFileEngine.ownerId(arg__1)¶

Parameters:	arg__1 – `PySide.QtCore.QAbstractFileEngine.FileOwner`
Return type:	`PySide.QtCore.uint`

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.

PySide.QtCore.QAbstractFileEngine.pos()¶

Return type:	`PySide.QtCore.qint64`

Returns the current file position.

This is the position of the data read/write head of the file.

PySide.QtCore.QAbstractFileEngine.read(maxlen)¶

Parameters:	maxlen – `PySide.QtCore.qint64`
Return type:	PyObject

Reads a number of characters from the file into data . At most maxlen characters will be read.

Returns -1 if a fatal error occurs, or 0 if there are no bytes to read.

PySide.QtCore.QAbstractFileEngine.readLine(maxlen)¶

Parameters:	maxlen – `PySide.QtCore.qint64`
Return type:	PyObject

This function reads one line, terminated by a ‘n’ character, from the file info data . At most maxlen characters will be read. The end-of-line character is included.

PySide.QtCore.QAbstractFileEngine.remove()¶

Return type:	`PySide.QtCore.bool`

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.

PySide.QtCore.QAbstractFileEngine.rename(newName)¶

Parameters:	newName – unicode
Return type:	`PySide.QtCore.bool`

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.

PySide.QtCore.QAbstractFileEngine.rmdir(dirName, recurseParentDirectories)¶

Parameters:	dirName – unicode recurseParentDirectories – `PySide.QtCore.bool`
Return type:	`PySide.QtCore.bool`

Requests that the directory dirName is deleted from the file system. When recurseParentDirectories is true, then any empty parent-directories in dirName must also be deleted. If recurseParentDirectories is false, only the dirName leaf-node 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.

PySide.QtCore.QAbstractFileEngine.seek(pos)¶

Parameters:	pos – `PySide.QtCore.qint64`
Return type:	`PySide.QtCore.bool`

Sets the file position to the given offset . Returns true if the position was successfully set; otherwise returns false.

The offset is from the beginning of the file, unless the file is sequential.

PySide.QtCore.QAbstractFileEngine.setError(error, str)¶

Parameters:	error – `PySide.QtCore.QFile.FileError` str – unicode

PySide.QtCore.QAbstractFileEngine.setFileName(file)¶

Parameters:	file – unicode

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.

PySide.QtCore.QAbstractFileEngine.setPermissions(perms)¶

Parameters:	perms – `PySide.QtCore.uint`
Return type:	`PySide.QtCore.bool`

Requests that the file’s permissions be set to perms . The argument perms will be set to the OR-ed together combination of QAbstractFileEngine::FileInfo, with only the QAbstractFileEngine.PermsMask being honored. If the operations succceeds return true; otherwise return false;

This virtual function must be reimplemented by all subclasses.

PySide.QtCore.QAbstractFileEngine.setSize(size)¶

Parameters:	size – `PySide.QtCore.qint64`
Return type:	`PySide.QtCore.bool`

Requests that the file be set to size size . If size is larger than the current file then it is filled with 0’s, if smaller it is simply truncated. If the operations succceeds return true; otherwise return false;

This virtual function must be reimplemented by all subclasses.

PySide.QtCore.QAbstractFileEngine.size()¶

Return type:	`PySide.QtCore.qint64`

Returns the size of the file.

PySide.QtCore.QAbstractFileEngine.supportsExtension(extension)¶

Parameters:	extension – `PySide.QtCore.QAbstractFileEngine.Extension`
Return type:	`PySide.QtCore.bool`

This virtual function returns true if the file engine supports extension ; otherwise, false is returned. By default, no extensions are supported.

See also

extension()

PySide.QtCore.QAbstractFileEngine.unmap(ptr)¶

Parameters:	ptr – `PySide.QtCore.uchar`
Return type:	`PySide.QtCore.bool`

Unmaps the memory address . Returns true if the unmap succeeds; otherwise returns false.

This function bases its behavior on calling extension() with UnMapExtensionOption . If the engine does not support this extension, false is returned.

PySide.QtCore.QAbstractFileEngine.write(data, len)¶

Parameters:	data – str len – `PySide.QtCore.qint64`
Return type:	`PySide.QtCore.qint64`

Writes len bytes from data to the file. Returns the number of characters written on success; otherwise returns -1.

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QAbstractFileEngine¶

Synopsis¶

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Static functions¶

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