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Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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QAbstractFileEngine Class Reference

\inmodule QtCore \reentrant More...

#include <qabstractfileengine_p.h>

+ Inheritance diagram for QAbstractFileEngine:
+ Collaboration diagram for QAbstractFileEngine:

Classes

class  ExtensionOption
 \inmodule QtCore More...
 
class  ExtensionReturn
 \inmodule QtCore More...
 
class  MapExtensionOption
 
class  MapExtensionReturn
 
class  UnMapExtensionOption
 

Public Types

enum  FileFlag {
  ReadOwnerPerm = 0x4000 , WriteOwnerPerm = 0x2000 , ExeOwnerPerm = 0x1000 , ReadUserPerm = 0x0400 ,
  WriteUserPerm = 0x0200 , ExeUserPerm = 0x0100 , ReadGroupPerm = 0x0040 , WriteGroupPerm = 0x0020 ,
  ExeGroupPerm = 0x0010 , ReadOtherPerm = 0x0004 , WriteOtherPerm = 0x0002 , ExeOtherPerm = 0x0001 ,
  LinkType = 0x10000 , FileType = 0x20000 , DirectoryType = 0x40000 , BundleType = 0x80000 ,
  HiddenFlag = 0x0100000 , LocalDiskFlag = 0x0200000 , ExistsFlag = 0x0400000 , RootFlag = 0x0800000 ,
  Refresh = 0x1000000 , PermsMask = 0x0000FFFF , TypesMask = 0x000F0000 , FlagsMask = 0x0FF00000 ,
  FileInfoAll = FlagsMask | PermsMask | TypesMask
}
 The permissions and types of a file, suitable for OR'ing together. More...
 
enum  FileName {
  DefaultName , BaseName , PathName , AbsoluteName ,
  AbsolutePathName , AbsoluteLinkTarget , CanonicalName , CanonicalPathName ,
  BundleName , JunctionName , RawLinkPath , NFileNames
}
 These values are used to request a file name in a particular format. More...
 
enum  FileOwner { OwnerUser , OwnerGroup }
 \value OwnerUser The user who owns the file. More...
 
enum  Extension { AtEndExtension , FastReadLineExtension , MapExtension , UnMapExtension }
 
typedef QAbstractFileEngineIterator Iterator
 
using IteratorUniquePtr = std::unique_ptr<Iterator>
 

Public Member Functions

virtual ~QAbstractFileEngine ()
 Destroys the QAbstractFileEngine.
 
virtual bool open (QIODevice::OpenMode openMode, std::optional< QFile::Permissions > permissions=std::nullopt)
 Opens the file in the specified mode.
 
virtual bool close ()
 Closes the file, returning true if successful; otherwise returns false.
 
virtual bool flush ()
 Flushes the open file, returning true if successful; otherwise returns false.
 
virtual bool syncToDisk ()
 
virtual qint64 size () const
 Returns the size of the file.
 
virtual qint64 pos () const
 Returns the current file position.
 
virtual bool seek (qint64 pos)
 Sets the file position to the given offset.
 
virtual bool isSequential () const
 Returns true if the file is a sequential access device; returns false if the file is a direct access device.
 
virtual bool remove ()
 Requests that the file is deleted from the file system.
 
virtual bool copy (const QString &newName)
 Copies the contents of this file to a file with the name newName.
 
virtual bool rename (const QString &newName)
 Requests that the file be renamed to newName in the file system.
 
virtual bool renameOverwrite (const QString &newName)
 
virtual bool link (const QString &newName)
 Creates a link from the file currently specified by fileName() to newName.
 
virtual bool mkdir (const QString &dirName, bool createParentDirectories, std::optional< QFile::Permissions > permissions=std::nullopt) const
 Requests that the directory dirName be created with the specified permissions.
 
virtual bool rmdir (const QString &dirName, bool recurseParentDirectories) const
 Requests that the directory dirName is deleted from the file system.
 
virtual bool setSize (qint64 size)
 Requests that the file be set to size size.
 
virtual bool caseSensitive () const
 Should return true if the underlying file system is case-sensitive; otherwise return false.
 
virtual bool isRelativePath () const
 Return true if the file referred to by this file engine has a relative path; otherwise return false.
 
virtual QStringList entryList (QDir::Filters filters, const QStringList &filterNames) const
 Requests that a list of all the files matching the filters list based on the filterNames in the file engine's directory are returned.
 
virtual FileFlags fileFlags (FileFlags type=FileInfoAll) const
 This function should return the set of OR'd flags that are true for the file engine's file, and that are in the type's OR'd members.
 
virtual bool setPermissions (uint perms)
 Requests that the file's permissions be set to perms.
 
virtual QByteArray id () const
 
virtual QString fileName (FileName file=DefaultName) const
 Return the file engine's current file name in the format specified by file.
 
virtual uint ownerId (FileOwner) const
 If owner is OwnerUser return the ID of the user who owns the file.
 
virtual QString owner (FileOwner) const
 If owner is OwnerUser return the name of the user who owns the file.
 
virtual bool setFileTime (const QDateTime &newDate, QFile::FileTime time)
 
virtual QDateTime fileTime (QFile::FileTime time) const
 If time is BirthTime, return when the file was born (created).
 
virtual void setFileName (const QString &file)
 Sets the file engine's file name to file.
 
virtual int handle () const
 Returns the native file handle for this file engine.
 
virtual bool cloneTo (QAbstractFileEngine *target)
 
bool atEnd () const
 
ucharmap (qint64 offset, qint64 size, QFile::MemoryMapFlags flags)
 
bool unmap (uchar *ptr)
 
virtual IteratorUniquePtr beginEntryList (const QString &path, QDir::Filters filters, const QStringList &filterNames)
 Returns a QAbstractFileEngine::IteratorUniquePtr, that can be used to iterate over the entries in path, using filters for entry filtering and filterNames for name filtering.
 
virtual IteratorUniquePtr endEntryList ()
 
virtual qint64 read (char *data, qint64 maxlen)
 Reads a number of characters from the file into data.
 
virtual qint64 readLine (char *data, qint64 maxlen)
 This function reads one line, terminated by a '\n' character, from the file info data.
 
virtual qint64 write (const char *data, qint64 len)
 Writes len bytes from data to the file.
 
QFile::FileError error () const
 Returns the QFile::FileError that resulted from the last failed operation.
 
QString errorString () const
 Returns the human-readable message appropriate to the current error reported by error().
 
virtual bool extension (Extension extension, const ExtensionOption *option=nullptr, ExtensionReturn *output=nullptr)
 
virtual bool supportsExtension (Extension extension) const
 

Static Public Member Functions

static std::unique_ptr< QAbstractFileEnginecreate (const QString &fileName)
 Creates and returns a QAbstractFileEngine suitable for processing fileName.
 

Protected Member Functions

void setError (QFile::FileError error, const QString &str)
 Sets the error type to error, and the error string to errorString.
 
 QAbstractFileEngine ()
 Constructs a new QAbstractFileEngine that does not refer to any file or directory.
 
 QAbstractFileEngine (QAbstractFileEnginePrivate &)
 

Protected Attributes

QScopedPointer< QAbstractFileEnginePrivated_ptr
 

Detailed Description

\inmodule QtCore \reentrant

The QAbstractFileEngine class provides an abstraction for accessing the filesystem.

Since
4.1

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

A QAbstractFileEngine 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(), and entryList() functions are applicable. In all cases the caseSensitive(), isRelativePath(), fileFlags(), ownerId(), owner(), and fileTime() functions are applicable.

A 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
QAbstractFileEngineHandler

Definition at line 35 of file qabstractfileengine_p.h.

Member Typedef Documentation

◆ Iterator

Since
4.3

Synonym for QAbstractFileEngineIterator.

Definition at line 124 of file qabstractfileengine_p.h.

◆ IteratorUniquePtr

Since
6.8

Synonym for std::unique_ptr<Iterator> (that is a std::unique_ptr<QAbstractFileEngineIterator>).

Definition at line 125 of file qabstractfileengine_p.h.

Member Enumeration Documentation

◆ Extension

Since
4.3

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 supportsExtension()).

\value 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.

\value FastReadLineExtension Whether the file engine provides a fast implementation for readLine() or not. If readLine() remains unimplemented in the file engine, QAbstractFileEngine will provide an implementation based on calling read() repeatedly. If supportsExtension() returns false for this extension, however, QIODevice can provide a faster implementation by making use of its internal buffer. For engines that already provide a fast readLine() implementation, returning false for this extension can avoid unnecessary double-buffering in QIODevice.

\value MapExtension Whether the file engine provides the ability to map a file to memory.

\value UnMapExtension Whether the file engine provides the ability to unmap memory that was previously mapped.

Enumerator
AtEndExtension 
FastReadLineExtension 
MapExtension 
UnMapExtension 

Definition at line 138 of file qabstractfileengine_p.h.

◆ FileFlag

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

\value ReadOwnerPerm The owner of the file has permission to read it. \value WriteOwnerPerm The owner of the file has permission to write to it. \value ExeOwnerPerm The owner of the file has permission to execute it. \value ReadUserPerm The current user has permission to read the file. \value WriteUserPerm The current user has permission to write to the file. \value ExeUserPerm The current user has permission to execute the file. \value ReadGroupPerm Members of the current user's group have permission to read the file. \value WriteGroupPerm Members of the current user's group have permission to write to the file. \value ExeGroupPerm Members of the current user's group have permission to execute the file. \value ReadOtherPerm All users have permission to read the file. \value WriteOtherPerm All users have permission to write to the file. \value ExeOtherPerm All users have permission to execute the file.

\value LinkType The file is a link to another file (or link) in the file system (i.e. not a file or directory). \value FileType The file is a regular file to the file system (i.e. not a link or directory) \value BundleType \macos and iOS: the file is a bundle; implies DirectoryType \value DirectoryType The file is a directory in the file system (i.e. not a link or file).

\value HiddenFlag The file is hidden. \value ExistsFlag The file actually exists in the file system. \value RootFlag The file or the file pointed to is the root of the filesystem. \value LocalDiskFlag The file resides on the local disk and can be passed to standard file functions. \value Refresh Passing this flag will force the file engine to refresh all flags.

\omitvalue PermsMask \omitvalue TypesMask \omitvalue FlagsMask \omitvalue FileInfoAll

See also
fileFlags(), setFileName()
Enumerator
ReadOwnerPerm 
WriteOwnerPerm 
ExeOwnerPerm 
ReadUserPerm 
WriteUserPerm 
ExeUserPerm 
ReadGroupPerm 
WriteGroupPerm 
ExeGroupPerm 
ReadOtherPerm 
WriteOtherPerm 
ExeOtherPerm 
LinkType 
FileType 
DirectoryType 
BundleType 
HiddenFlag 
LocalDiskFlag 
ExistsFlag 
RootFlag 
Refresh 
PermsMask 
TypesMask 
FlagsMask 
FileInfoAll 

Definition at line 38 of file qabstractfileengine_p.h.

◆ FileName

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

\value DefaultName The same filename that was passed to the QAbstractFileEngine. \value BaseName The name of the file excluding the path. \value PathName The path to the file excluding the base name. \value AbsoluteName The absolute path to the file (including the base name). \value AbsolutePathName The absolute path to the file (excluding the base name). \value AbsoluteLinkTarget 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.) \value RawLinkPath The raw link path of the file that this file is a link to. (This will be empty if this file is not a link.) \value CanonicalName Often very similar to AbsoluteLinkTarget. Will return the true path to the file. \value CanonicalPathName Same as CanonicalName, excluding the base name. \value BundleName Returns the name of the bundle implies BundleType is set. \value JunctionName The full name of the directory that this NTFS junction is linked to. (This will be empty if this file is not an NTFS junction.)

\omitvalue NFileNames

See also
fileName(), setFileName()
Enumerator
DefaultName 
BaseName 
PathName 
AbsoluteName 
AbsolutePathName 
AbsoluteLinkTarget 
CanonicalName 
CanonicalPathName 
BundleName 
JunctionName 
RawLinkPath 
NFileNames 

Definition at line 66 of file qabstractfileengine_p.h.

◆ FileOwner

\value OwnerUser The user who owns the file.

\value OwnerGroup The group who owns the file.

See also
owner(), ownerId(), setFileName()
Enumerator
OwnerUser 
OwnerGroup 

Definition at line 80 of file qabstractfileengine_p.h.

Constructor & Destructor Documentation

◆ ~QAbstractFileEngine()

QAbstractFileEngine::~QAbstractFileEngine ( )
virtual

Destroys the QAbstractFileEngine.

Definition at line 339 of file qabstractfileengine.cpp.

◆ QAbstractFileEngine() [1/2]

QAbstractFileEngine::QAbstractFileEngine ( )
protected

Constructs a new QAbstractFileEngine that does not refer to any file or directory.

See also
setFileName()

Definition at line 321 of file qabstractfileengine.cpp.

References d_ptr, and QAbstractFileEnginePrivate::q_ptr.

◆ QAbstractFileEngine() [2/2]

QAbstractFileEngine::QAbstractFileEngine ( QAbstractFileEnginePrivate & dd)
protected

Constructs a QAbstractFileEngine.

Definition at line 331 of file qabstractfileengine.cpp.

References d_ptr, and QAbstractFileEnginePrivate::q_ptr.

Member Function Documentation

◆ atEnd()

bool QAbstractFileEngine::atEnd ( ) const
Since
4.3

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(), supportsExtension(), QFile::atEnd()

Definition at line 759 of file qabstractfileengine.cpp.

References AtEndExtension, and extension().

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◆ beginEntryList()

QAbstractFileEngine::IteratorUniquePtr QAbstractFileEngine::beginEntryList ( const QString & path,
QDir::Filters filters,
const QStringList & filterNames )
virtual

Returns a QAbstractFileEngine::IteratorUniquePtr, that can be used to iterate over the entries in path, using filters for entry filtering and filterNames for name filtering.

This function is called by QDirListing to initiate directory iteration.

See also
QDirListing

Reimplemented in AndroidAbstractFileEngine, QFSFileEngine, QResourceFileEngine, AndroidContentFileEngine, QIOSFileEngineAssetsLibrary, and QQmlPreviewFileEngine.

Definition at line 1011 of file qabstractfileengine.cpp.

References filters, and Q_UNUSED.

◆ caseSensitive()

bool QAbstractFileEngine::caseSensitive ( ) const
virtual

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

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidContentFileEngine, AndroidAbstractFileEngine, and QQmlPreviewFileEngine.

Definition at line 565 of file qabstractfileengine.cpp.

◆ cloneTo()

bool QAbstractFileEngine::cloneTo ( QAbstractFileEngine * target)
virtual
Since
5.10

Duplicates the contents of this file (starting from the current position) to the file specified by the engine target.

Returns true on success; otherwise, false is returned.

Reimplemented in QFSFileEngine.

Definition at line 815 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ close()

bool QAbstractFileEngine::close ( )
virtual

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

The default implementation always returns false.

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidContentFileEngine, AndroidAbstractFileEngine, QIOSFileEngineAssetsLibrary, and QQmlPreviewFileEngine.

Definition at line 369 of file qabstractfileengine.cpp.

◆ copy()

bool QAbstractFileEngine::copy ( const QString & newName)
virtual

Copies the contents of this file to a file with the name newName.

Returns true on success; otherwise, false is returned.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 460 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ create()

std::unique_ptr< QAbstractFileEngine > QAbstractFileEngine::create ( const QString & fileName)
static

Creates and returns a QAbstractFileEngine suitable for processing fileName.

You should not need to call this function; use QFile, QFileInfo or 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.

See also
QAbstractFileEngineHandler

Definition at line 182 of file qabstractfileengine.cpp.

References QFileSystemEngine::createLegacyEngine(), engine, and fileName.

Referenced by QFilePrivate::engine().

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◆ endEntryList()

virtual IteratorUniquePtr QAbstractFileEngine::endEntryList ( )
inlinevirtual

Reimplemented in QQmlPreviewFileEngine.

Definition at line 129 of file qabstractfileengine_p.h.

◆ entryList()

QStringList QAbstractFileEngine::entryList ( QDir::Filters filters,
const QStringList & filterNames ) const
virtual

Requests that a list of all the files matching the filters list based on the filterNames 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.

See also
setFileName()

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 592 of file qabstractfileengine.cpp.

References fileName, filters, Q_UNUSED, and ret.

Referenced by QFSFileEngine::entryList(), and QQmlPreviewFileEngine::entryList().

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◆ error()

QFile::FileError QAbstractFileEngine::error ( ) const

Returns the QFile::FileError that resulted from the last failed operation.

If QFile::UnspecifiedError is returned, QFile will use its own idea of the error status.

See also
QFile::FileError, errorString()

Definition at line 1167 of file qabstractfileengine.cpp.

References d.

Referenced by QFSFileEngine::copy(), QFSFileEngine::link(), QIOSFileEngineAssetsLibrary::read(), QFSFileEngine::remove(), QIOSFileEngineAssetsLibrary::setError(), QFSFileEngine::setFileTime(), and QFSFileEngine::setPermissions().

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◆ errorString()

QString QAbstractFileEngine::errorString ( ) const

Returns the human-readable message appropriate to the current error reported by error().

If no suitable string is available, an empty string is returned.

See also
error()

Definition at line 1180 of file qabstractfileengine.cpp.

References d.

Referenced by setError().

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◆ extension()

bool QAbstractFileEngine::extension ( Extension extension,
const ExtensionOption * option = nullptr,
ExtensionReturn * output = nullptr )
virtual
Since
4.3

This virtual function can be reimplemented in a QAbstractFileEngine subclass to provide support for extensions. The option argument is provided as input to the extension, and this function can store output results in output.

The behavior of this function is determined by extension; see the Extension documentation for details.

You can call supportsExtension() to check if an extension is supported by the file engine.

By default, no extensions are supported, and this function returns false.

See also
supportsExtension(), Extension

Reimplemented in QQmlPreviewFileEngine, QFSFileEngine, and QResourceFileEngine.

Definition at line 1137 of file qabstractfileengine.cpp.

References extension(), output, and Q_UNUSED.

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◆ fileFlags()

QAbstractFileEngine::FileFlags QAbstractFileEngine::fileFlags ( FileFlags type = FileInfoAll) const
virtual

This function should return the set of OR'd flags 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.

See also
setFileName()

Reimplemented in QFSFileEngine, QResourceFileEngine, QIOSFileEngineAssetsLibrary, QQmlPreviewFileEngine, AndroidContentFileEngine, and AndroidAbstractFileEngine.

Definition at line 619 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ fileName()

QString QAbstractFileEngine::fileName ( FileName file = DefaultName) const
virtual

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.

See also
setFileName(), FileName

Reimplemented in QFSFileEngine, QIOSFileEngineAssetsLibrary, AndroidContentFileEngine, AndroidAbstractFileEngine, QResourceFileEngine, and QQmlPreviewFileEngine.

Definition at line 661 of file qabstractfileengine.cpp.

References file, and Q_UNUSED.

◆ fileTime()

QDateTime QAbstractFileEngine::fileTime ( QFile::FileTime time) const
virtual

If time is BirthTime, return when the file was born (created).

If time is MetadataChangeTime, return when the file's metadata was last changed. 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).

See also
setFileName(), QDateTime, QDateTime::isValid(), FileTime

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 720 of file qabstractfileengine.cpp.

References Q_UNUSED, and time.

◆ flush()

bool QAbstractFileEngine::flush ( )
virtual

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

The default implementation always returns false.

Reimplemented in QFSFileEngine, QResourceFileEngine, and QQmlPreviewFileEngine.

Definition at line 393 of file qabstractfileengine.cpp.

◆ handle()

int QAbstractFileEngine::handle ( ) const
virtual

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.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 742 of file qabstractfileengine.cpp.

◆ id()

QByteArray QAbstractFileEngine::id ( ) const
virtual
Since
5.9

Return an identifier that (hopefully) uniquely identifies this file in the system. Returns an invalid QByteArray() if that cannot be calculated.

Reimplemented in QFSFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 646 of file qabstractfileengine.cpp.

References QByteArray().

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◆ isRelativePath()

bool QAbstractFileEngine::isRelativePath ( ) const
virtual

Return true if the file referred to by this file engine has a relative path; otherwise return false.

See also
setFileName()

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 576 of file qabstractfileengine.cpp.

◆ isSequential()

bool QAbstractFileEngine::isSequential ( ) const
virtual

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

Operations involving size() and seek(qint64) are not valid on sequential devices.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 440 of file qabstractfileengine.cpp.

◆ link()

bool QAbstractFileEngine::link ( const QString & newName)
virtual

Creates a link from the file currently specified by 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.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 501 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ map()

uchar * QAbstractFileEngine::map ( qint64 offset,
qint64 size,
QFile::MemoryMapFlags flags )
Since
4.4

Maps size bytes of the file into memory starting at offset. Returns a pointer to the memory if successful; otherwise returns false if, for example, an error occurs.

This function bases its behavior on calling extension() with MapExtensionOption. If the engine does not support this extension, 0 is returned.

flags is currently not used, but could be used in the future.

See also
unmap(), supportsExtension()

Definition at line 780 of file qabstractfileengine.cpp.

References QAbstractFileEngine::MapExtensionReturn::address, extension(), and MapExtension.

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◆ mkdir()

bool QAbstractFileEngine::mkdir ( const QString & dirName,
bool createParentDirectories,
std::optional< QFile::Permissions > permissions = std::nullopt ) const
virtual

Requests that the directory dirName be created with the specified permissions.

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.

If permissions is null then implementation-specific default permissions are used.

See also
setFileName(), rmdir(), isRelativePath()

Reimplemented in QFSFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 520 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ open()

bool QAbstractFileEngine::open ( QIODevice::OpenMode openMode,
std::optional< QFile::Permissions > permissions = std::nullopt )
virtual

Opens the file in the specified mode.

Returns true if the file was successfully opened; otherwise returns false.

The mode is an OR combination of QIODevice::OpenMode and QIODevice::HandlingMode values.

If the file is created as a result of this call, its permissions are set according to permissision. Null value means an implementation- specific default.

Reimplemented in QResourceFileEngine, QQmlPreviewFileEngine, QFSFileEngine, AndroidContentFileEngine, AndroidAbstractFileEngine, and QIOSFileEngineAssetsLibrary.

Definition at line 356 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ owner()

QString QAbstractFileEngine::owner ( FileOwner owner) const
virtual

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().

See also
ownerId(), setFileName(), FileOwner

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 688 of file qabstractfileengine.cpp.

References owner(), and Q_UNUSED.

Referenced by owner(), and ownerId().

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◆ ownerId()

uint QAbstractFileEngine::ownerId ( FileOwner owner) const
virtual

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.

See also
owner(), setFileName(), FileOwner

Reimplemented in QFSFileEngine, QResourceFileEngine, and QQmlPreviewFileEngine.

Definition at line 674 of file qabstractfileengine.cpp.

References owner(), and Q_UNUSED.

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◆ pos()

qint64 QAbstractFileEngine::pos ( ) const
virtual

Returns the current file position.

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

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidAbstractFileEngine, QIOSFileEngineAssetsLibrary, and QQmlPreviewFileEngine.

Definition at line 411 of file qabstractfileengine.cpp.

Referenced by seek().

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◆ read()

qint64 QAbstractFileEngine::read ( char * data,
qint64 maxlen )
virtual

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.

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidAbstractFileEngine, QIOSFileEngineAssetsLibrary, and QQmlPreviewFileEngine.

Definition at line 1027 of file qabstractfileengine.cpp.

References Q_UNUSED.

Referenced by readLine().

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◆ readLine()

qint64 QAbstractFileEngine::readLine ( char * data,
qint64 maxlen )
virtual

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.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 1050 of file qabstractfileengine.cpp.

References read().

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◆ remove()

bool QAbstractFileEngine::remove ( )
virtual

Requests that the file is deleted from the file system.

If the operation succeeds return true; otherwise return false.

See also
setFileName(), rmdir()

Reimplemented in QFSFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 451 of file qabstractfileengine.cpp.

◆ rename()

bool QAbstractFileEngine::rename ( const QString & newName)
virtual

Requests that the file be renamed to newName in the file system.

If the operation succeeds return true; otherwise return false.

See also
setFileName()

Reimplemented in QFSFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 473 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ renameOverwrite()

bool QAbstractFileEngine::renameOverwrite ( const QString & newName)
virtual
Since
5.1

Requests that the file be renamed to newName in the file system. If the new name already exists, it must be overwritten. If the operation succeeds, returns true; otherwise returns false.

See also
setFileName()

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 489 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ rmdir()

bool QAbstractFileEngine::rmdir ( const QString & dirName,
bool recurseParentDirectories ) const
virtual

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.

See also
setFileName(), remove(), mkdir(), isRelativePath()

Reimplemented in QFSFileEngine, AndroidContentFileEngine, and QQmlPreviewFileEngine.

Definition at line 540 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ seek()

bool QAbstractFileEngine::seek ( qint64 offset)
virtual

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.

See also
isSequential()

Reimplemented in AndroidAbstractFileEngine, QIOSFileEngineAssetsLibrary, QFSFileEngine, QResourceFileEngine, and QQmlPreviewFileEngine.

Definition at line 427 of file qabstractfileengine.cpp.

References pos(), and Q_UNUSED.

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◆ setError()

void QAbstractFileEngine::setError ( QFile::FileError error,
const QString & errorString )
protected

Sets the error type to error, and the error string to errorString.

Call this function to set the error values returned by the higher-level classes.

See also
QFile::error(), QIODevice::errorString(), QIODevice::setErrorString()

Definition at line 1193 of file qabstractfileengine.cpp.

References d, error, and errorString().

Referenced by QFSFileEngine::copy(), QFSFileEngine::link(), QFSFileEngine::open(), QFSFileEngine::open(), QFSFileEngine::open(), QFSFileEngine::remove(), QIOSFileEngineAssetsLibrary::setError(), QFSFileEngine::setFileTime(), QFSFileEngine::setPermissions(), and QFSFileEngine::setSize().

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◆ setFileName()

void QAbstractFileEngine::setFileName ( const QString & file)
virtual

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.

See also
rename()

Reimplemented in QFSFileEngine, QResourceFileEngine, AndroidAbstractFileEngine, QIOSFileEngineAssetsLibrary, and QQmlPreviewFileEngine.

Definition at line 732 of file qabstractfileengine.cpp.

References file, and Q_UNUSED.

◆ setFileTime()

bool QAbstractFileEngine::setFileTime ( const QDateTime & newDate,
QFile::FileTime time )
virtual
Since
5.10

Sets the file time to newDate, returning true if successful; otherwise returns false.

See also
fileTime()

Reimplemented in QFSFileEngine.

Definition at line 703 of file qabstractfileengine.cpp.

References Q_UNUSED, and time.

◆ setPermissions()

bool QAbstractFileEngine::setPermissions ( uint perms)
virtual

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;

See also
size()

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 634 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ setSize()

bool QAbstractFileEngine::setSize ( qint64 size)
virtual

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;

See also
size()

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 555 of file qabstractfileengine.cpp.

References Q_UNUSED.

◆ size()

qint64 QAbstractFileEngine::size ( ) const
virtual

◆ supportsExtension()

bool QAbstractFileEngine::supportsExtension ( Extension extension) const
virtual
Since
4.3

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

See also
extension()

Reimplemented in QFSFileEngine, QResourceFileEngine, and QQmlPreviewFileEngine.

Definition at line 1154 of file qabstractfileengine.cpp.

References extension(), and Q_UNUSED.

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◆ syncToDisk()

bool QAbstractFileEngine::syncToDisk ( )
virtual
Since
5.1

Flushes and syncs the file to disk.

Returns true if successful; otherwise returns false. The default implementation always returns false.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 382 of file qabstractfileengine.cpp.

◆ unmap()

bool QAbstractFileEngine::unmap ( uchar * address)
Since
4.4

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.

See also
map(), supportsExtension()

Definition at line 801 of file qabstractfileengine.cpp.

References extension(), and UnMapExtension.

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◆ write()

qint64 QAbstractFileEngine::write ( const char * data,
qint64 len )
virtual

Writes len bytes from data to the file.

Returns the number of characters written on success; otherwise returns -1.

Reimplemented in QFSFileEngine, and QQmlPreviewFileEngine.

Definition at line 1038 of file qabstractfileengine.cpp.

References Q_UNUSED.

Member Data Documentation

◆ d_ptr

QScopedPointer<QAbstractFileEnginePrivate> QAbstractFileEngine::d_ptr
protected

Definition at line 184 of file qabstractfileengine_p.h.

Referenced by QAbstractFileEngine(), and QAbstractFileEngine().


The documentation for this class was generated from the following files: