|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QAbstractFileEngine
public class QAbstractFileEngine
The QAbstractFileEngine class provides an abstraction for accessing the filesystem.
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.
Nested Class Summary | |
---|---|
static class |
QAbstractFileEngine.Extension
This enum describes the types of extensions that the file engine can support. |
static class |
QAbstractFileEngine.FileFlag
The permissions and types of a file, suitable for OR'ing together. |
static class |
QAbstractFileEngine.FileFlags
This QFlag class provides flags for the int enum. |
static class |
QAbstractFileEngine.FileName
These values are used to request a file name in a particular format. |
static class |
QAbstractFileEngine.FileOwner
Press link for info on QAbstractFileEngine.FileOwner |
static class |
QAbstractFileEngine.FileTime
These are used by the fileTime function. |
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 | |
---|---|
protected |
QAbstractFileEngine()
Constructs a new QAbstractFileEngine that does not refer to any file or directory. |
Method Summary | |
---|---|
boolean |
atEnd()
Returns true if the current position is at the end of the file; otherwise, returns false. |
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 QAbstractFileEngine |
create(java.lang.String fileName)
Creates and returns a QAbstractFileEngine suitable for processing fileName. |
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. |
QFile.FileError |
error()
Returns the QFile::FileError that resulted from the last failed operation. |
java.lang.String |
errorString()
Returns the human-readable message appropriate to the current error reported by error. |
QAbstractFileEngine.FileFlags |
fileFlags()
Equivalent to fileFlags(FileInfoAll). |
QAbstractFileEngine.FileFlags |
fileFlags(QAbstractFileEngine.FileFlag... 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. |
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()
Equivalent to fileName(DefaultName). |
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 QAbstractFileEngine |
fromNativePointer(QNativePointer nativePointer)
This function returns the QAbstractFileEngine instance pointed to by nativePointer |
int |
handle()
Returns the native file handle for this file engine. |
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.OpenModeFlag... openMode)
Opens the file in the specified 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. |
boolean |
seek(long pos)
Sets the file position to the given pos. |
protected void |
setError(QFile.FileError error,
java.lang.String str)
Sets the error type to error, and the error string to str. |
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. |
long |
write(QNativePointer data,
long len)
Writes len bytes from data to the file. |
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 |
---|
protected QAbstractFileEngine()
Constructs a new QAbstractFileEngine that does not refer to any file or directory.
Method Detail |
---|
public final boolean atEnd()
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.
public final QFile.FileError error()
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.
public final java.lang.String errorString()
Returns the human-readable message appropriate to the current error reported by error. If no suitable string is available, an empty string is returned.
protected final void setError(QFile.FileError error, java.lang.String str)
Sets the error type to error, and the error string to str. Call this function to set the error values returned by the higher-level classes.
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.
public boolean close()
Closes the file, returning true if successful; otherwise returns false.
The default implementation always returns false.
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.
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.
public final QAbstractFileEngine.FileFlags fileFlags(QAbstractFileEngine.FileFlag... type)
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.
public final QAbstractFileEngine.FileFlags fileFlags()
Equivalent to fileFlags(FileInfoAll).
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.
public final java.lang.String fileName()
Equivalent to fileName(DefaultName).
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.
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.
public boolean flush()
Flushes the open file, returning true if successful; otherwise returns false.
The default implementation always returns false.
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.
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.
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.
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.
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.
public final boolean open(QIODevice.OpenModeFlag... openMode)
The \a mode is an OR combination of QIODevice::OpenMode and QIODevice::HandlingMode values.
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.
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.
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.
public long pos()
Returns the current file position.
This is the position of the data read/write head of the file.
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.
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.
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.
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.
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.
public boolean seek(long pos)
Sets the file position to the given pos. 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.
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.
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.
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.
public long size()
Returns the size of the file.
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.
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.
public static QAbstractFileEngine create(java.lang.String fileName)
Creates and returns a QAbstractFileEngine suitable for processing fileName.
You should not need to call this function; use QFile, QFileInfo or QDir directly instead.
public static QAbstractFileEngine fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |