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com.trolltech.qt.core
Class QFSFileEngine

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.core.QAbstractFileEngine
              extended by com.trolltech.qt.core.QFSFileEngine
All Implemented Interfaces:
QtJambiInterface

public class QFSFileEngine
extends QAbstractFileEngine

The QFSFileEngine class implements Qt's default file engine.

This class is part of the file engine framework in Qt. If you only want to access files or directories, use QFile, QFileInfo or QDir instead.

QFSFileEngine is the default file engine for accessing regular files. It is provided for convenience; by subclassing this class, you can alter its behavior slightly, without having to write a complete QAbstractFileEngine subclass. To install your custom file engine, you must also subclass QAbstractFileEngineHandler and create an instance of your handler.

It can also be useful to create a QFSFileEngine object directly if you need to use the local file system inside QAbstractFileEngine::create(), in order to avoid recursion (as higher-level classes tend to call QAbstractFileEngine::create()).


Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.core.QAbstractFileEngine
QAbstractFileEngine.Extension, QAbstractFileEngine.FileFlag, QAbstractFileEngine.FileFlags, QAbstractFileEngine.FileName, QAbstractFileEngine.FileOwner, QAbstractFileEngine.FileTime
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
Constructor Summary
QFSFileEngine()
          Constructs a QFSFileEngine.
QFSFileEngine(java.lang.String file)
          Constructs a QFSFileEngine for the file name file.
 
Method Summary
 QAbstractFileEngineIterator beginEntryList(QDir.Filters filters, java.util.List<java.lang.String> filterNames)
          Returns an instance of a QAbstractFileEngineIterator using filters for entry filtering and filterNames for name filtering.
 boolean caseSensitive()
          

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

 boolean close()
          

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

 boolean copy(java.lang.String newName)
          

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

static java.lang.String currentPath()
          Equivalent to currentPath(QString()).
static java.lang.String currentPath(java.lang.String path)
          Returns the canonicalized form of the current path used by the file engine for the drive specified by path.
static java.util.List<QFileInfo> drives()
          Returns the list of drives in the file system as a list of QFileInfo objects.
 QAbstractFileEngineIterator endEntryList()
          
 java.util.List<java.lang.String> entryList(QDir.Filters filters, java.util.List<java.lang.String> filterNames)
          Requests that a list of all the files matching the filters list based on the filterNames in the file engine's directory are returned.
 QAbstractFileEngine.FileFlags fileFlags(QAbstractFileEngine.FileFlags type)
          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.
 java.lang.String fileName(QAbstractFileEngine.FileName file)
          Return the file engine's current file name in the format specified by file.
 QDateTime fileTime(QAbstractFileEngine.FileTime time)
          If time is CreationTime, return when the file was created.
 boolean flush()
          

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

static QFSFileEngine fromNativePointer(QNativePointer nativePointer)
          This function returns the QFSFileEngine instance pointed to by nativePointer
 int handle()
          

Returns the native file handle for this file engine.

static java.lang.String homePath()
          Returns the home path of the current user.
 boolean isRelativePath()
          

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

 boolean isSequential()
          

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

 boolean link(java.lang.String newName)
          

Creates a link from the file currently specified by fileName to newName.

 boolean mkdir(java.lang.String dirName, boolean createParentDirectories)
          

Requests that the directory dirName be created.

 boolean open(QIODevice.OpenMode openMode)
          

Opens the file in the specified openMode.

 boolean open(QIODevice.OpenMode flags, int fd)
          Opens the file descriptor fd in flags mode.
 java.lang.String owner(QAbstractFileEngine.FileOwner arg__1)
          If arg__1 is OwnerUser return the name of the user who owns the file.
 int ownerId(QAbstractFileEngine.FileOwner arg__1)
          If arg__1 is OwnerUser return the ID of the user who owns the file.
 long pos()
          

Returns the current file position.

 long read(QNativePointer data, long maxlen)
          Reads a number of characters from the file into data.
 long readLine(QNativePointer data, long maxlen)
          This function reads one line, terminated by a '\n' character, from the file info data.
 boolean remove()
          

Requests that the file is deleted from the file system.

 boolean rename(java.lang.String newName)
          

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

 boolean rmdir(java.lang.String dirName, boolean recurseParentDirectories)
          

Requests that the directory dirName is deleted from the file system.

static java.lang.String rootPath()
          Returns the root path.
 boolean seek(long arg__1)
          Sets the file position to the given arg__1.
static boolean setCurrentPath(java.lang.String path)
          Sets the current path (e.g., for QDir), to path.
 void setFileName(java.lang.String file)
          

Sets the file engine's file name to file.

 boolean setPermissions(int perms)
          Requests that the file's permissions be set to perms.
 boolean setSize(long size)
          Requests that the file be set to size size.
 long size()
          

Returns the size of the file.

 boolean supportsExtension(QAbstractFileEngine.Extension extension)
          This virtual function returns true if the file engine supports extension; otherwise, false is returned.
static java.lang.String tempPath()
          Returns the temporary path (i.e., a path in which it is safe to store temporary files).
 long write(QNativePointer data, long len)
          Writes len bytes from data to the file.
 
Methods inherited from class com.trolltech.qt.core.QAbstractFileEngine
atEnd, create, error, errorString, fileFlags, fileFlags, fileName, open, setError
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QFSFileEngine

public QFSFileEngine()

Constructs a QFSFileEngine.


QFSFileEngine

public QFSFileEngine(java.lang.String file)

Constructs a QFSFileEngine for the file name file.

Method Detail

beginEntryList

public final QAbstractFileEngineIterator beginEntryList(QDir.Filters filters,
                                                        java.util.List<java.lang.String> filterNames)

Returns an instance of a QAbstractFileEngineIterator using filters for entry filtering and filterNames for name filtering. This function is called by QDirIterator to initiate directory iteration.

QDirIterator takes ownership of the returned instance, and deletes it when it's done.

See Also:
QDirIterator

endEntryList

public final QAbstractFileEngineIterator endEntryList()


open

public final boolean open(QIODevice.OpenMode flags,
                          int fd)

Opens the file descriptor fd in flags mode. Returns true on success; otherwise returns false.


caseSensitive

public boolean caseSensitive()

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

This virtual function must be reimplemented by all subclasses.

Overrides:
caseSensitive in class QAbstractFileEngine

close

public boolean close()

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

The default implementation always returns false.

Overrides:
close in class QAbstractFileEngine

copy

public boolean copy(java.lang.String newName)

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

Overrides:
copy in class QAbstractFileEngine

entryList

public java.util.List<java.lang.String> entryList(QDir.Filters filters,
                                                  java.util.List<java.lang.String> filterNames)

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.

This virtual function must be reimplemented by all subclasses.

Overrides:
entryList in class QAbstractFileEngine
See Also:
setFileName

fileFlags

public QAbstractFileEngine.FileFlags fileFlags(QAbstractFileEngine.FileFlags type)

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.

This virtual function must be reimplemented by all subclasses.

Overrides:
fileFlags in class QAbstractFileEngine
See Also:
setFileName

fileName

public java.lang.String fileName(QAbstractFileEngine.FileName file)

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.

Overrides:
fileName in class QAbstractFileEngine
See Also:
setFileName, FileName

fileTime

public QDateTime fileTime(QAbstractFileEngine.FileTime time)

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.

Overrides:
fileTime in class QAbstractFileEngine
See Also:
setFileName, QDateTime, QDateTime::isValid, FileTime

flush

public boolean flush()

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

The default implementation always returns false.

Overrides:
flush in class QAbstractFileEngine

handle

public int handle()

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.

Overrides:
handle in class QAbstractFileEngine

isRelativePath

public boolean isRelativePath()

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.

Overrides:
isRelativePath in class QAbstractFileEngine
See Also:
setFileName

isSequential

public boolean isSequential()

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(int) are not valid on sequential devices.

Overrides:
isSequential in class QAbstractFileEngine

link

public boolean link(java.lang.String newName)

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.

Overrides:
link in class QAbstractFileEngine

mkdir

public boolean mkdir(java.lang.String dirName,
                     boolean createParentDirectories)

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.

Overrides:
mkdir in class QAbstractFileEngine
See Also:
setFileName, rmdir, isRelativePath

open

public boolean open(QIODevice.OpenMode openMode)

Opens the file in the specified openMode. Returns true if the file was successfully opened; otherwise returns false.

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

Overrides:
open in class QAbstractFileEngine

owner

public java.lang.String owner(QAbstractFileEngine.FileOwner arg__1)

If arg__1 is OwnerUser return the name of the user who owns the file. If arg__1 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.

Overrides:
owner in class QAbstractFileEngine
See Also:
ownerId, setFileName, FileOwner

ownerId

public int ownerId(QAbstractFileEngine.FileOwner arg__1)

If arg__1 is OwnerUser return the ID of the user who owns the file. If arg__1 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.

Overrides:
ownerId in class QAbstractFileEngine
See Also:
owner, setFileName, FileOwner

pos

public long pos()

Returns the current file position.

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

Overrides:
pos in class QAbstractFileEngine

read

public long read(QNativePointer data,
                 long maxlen)

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.

Overrides:
read in class QAbstractFileEngine

readLine

public long readLine(QNativePointer data,
                     long maxlen)

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.

Overrides:
readLine in class QAbstractFileEngine

remove

public boolean remove()

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.

Overrides:
remove in class QAbstractFileEngine
See Also:
setFileName, rmdir

rename

public boolean rename(java.lang.String newName)

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.

Overrides:
rename in class QAbstractFileEngine
See Also:
setFileName

rmdir

public boolean rmdir(java.lang.String dirName,
                     boolean recurseParentDirectories)

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.

Overrides:
rmdir in class QAbstractFileEngine
See Also:
setFileName, remove, mkdir, isRelativePath

seek

public boolean seek(long arg__1)

Sets the file position to the given arg__1. 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.

Overrides:
seek in class QAbstractFileEngine
See Also:
isSequential

setFileName

public void setFileName(java.lang.String file)

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.

Overrides:
setFileName in class QAbstractFileEngine
See Also:
fileName

setPermissions

public boolean setPermissions(int perms)

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.

Overrides:
setPermissions in class QAbstractFileEngine
See Also:
size

setSize

public boolean setSize(long size)

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.

Overrides:
setSize in class QAbstractFileEngine
See Also:
size

size

public long size()

Returns the size of the file.

Overrides:
size in class QAbstractFileEngine
See Also:
setSize

supportsExtension

public boolean supportsExtension(QAbstractFileEngine.Extension extension)

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

Overrides:
supportsExtension in class QAbstractFileEngine
See Also:
extension

write

public long write(QNativePointer data,
                  long len)

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

Overrides:
write in class QAbstractFileEngine

currentPath

public static java.lang.String currentPath()

Equivalent to currentPath(QString()).


currentPath

public static java.lang.String currentPath(java.lang.String path)

Returns the canonicalized form of the current path used by the file engine for the drive specified by path.

On Windows, each drive has its own current directory, so a different path is returned for file names that include different drive names (e.g. A: or C:).

See Also:
setCurrentPath

drives

public static java.util.List<QFileInfo> drives()

Returns the list of drives in the file system as a list of QFileInfo objects. On unix and Mac OS X, only the root path is returned. On Windows, this function returns all drives (A:, C:, D:, etc.).


homePath

public static java.lang.String homePath()

Returns the home path of the current user.

See Also:
rootPath

rootPath

public static java.lang.String rootPath()

Returns the root path.

See Also:
homePath

setCurrentPath

public static boolean setCurrentPath(java.lang.String path)

Sets the current path (e.g., for QDir), to path. Returns true if the new path exists; otherwise this function does nothing, and returns false.

See Also:
currentPath

tempPath

public static java.lang.String tempPath()

Returns the temporary path (i.e., a path in which it is safe to store temporary files).


fromNativePointer

public static QFSFileEngine fromNativePointer(QNativePointer nativePointer)
This function returns the QFSFileEngine instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

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