gi-gio-2.0.18: Gio bindings

CopyrightWill Thompson Iñaki García Etxebarria and Jonas Platte
LicenseLGPL-2.1
MaintainerIñaki García Etxebarria (garetxe@gmail.com)
Safe HaskellNone
LanguageHaskell2010

GI.Gio.Objects.FileEnumerator

Contents

Description

FileEnumerator allows you to operate on a set of GFiles, returning a FileInfo structure for each file enumerated (e.g. fileEnumerateChildren will return a FileEnumerator for each of the children within a directory).

To get the next file's information from a FileEnumerator, use fileEnumeratorNextFile or its asynchronous version, fileEnumeratorNextFilesAsync. Note that the asynchronous version will return a list of GFileInfos, whereas the synchronous will only return the next file in the enumerator.

The ordering of returned files is unspecified for non-Unix platforms; for more information, see dirReadName. On Unix, when operating on local files, returned files will be sorted by inode number. Effectively you can assume that the ordering of returned files will be stable between successive calls (and applications) assuming the directory is unchanged.

If your application needs a specific ordering, such as by name or modification time, you will have to implement that in your application code.

To close a FileEnumerator, use fileEnumeratorClose, or its asynchronous version, fileEnumeratorCloseAsync. Once a FileEnumerator is closed, no further actions may be performed on it, and it should be freed with objectUnref.

Synopsis

Exported types

newtype FileEnumerator Source #

Memory-managed wrapper type.

class GObject o => IsFileEnumerator o Source #

Type class for types which can be safely cast to FileEnumerator, for instance with toFileEnumerator.

toFileEnumerator :: (MonadIO m, IsFileEnumerator o) => o -> m FileEnumerator Source #

Cast to FileEnumerator, for types for which this is known to be safe. For general casts, use castTo.

Methods

close

fileEnumeratorClose Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) 
=> a

enumerator: a FileEnumerator.

-> Maybe b

cancellable: optional Cancellable object, Nothing to ignore.

-> m ()

(Can throw GError)

Releases all resources used by this enumerator, making the enumerator return IOErrorEnumClosed on all calls.

This will be automatically called when the last reference is dropped, but you might want to call this function to make sure resources are released as early as possible.

closeAsync

fileEnumeratorCloseAsync Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) 
=> a

enumerator: a FileEnumerator.

-> Int32

ioPriority: the [I/O priority][io-priority] of the request

-> Maybe b

cancellable: optional Cancellable object, Nothing to ignore.

-> Maybe AsyncReadyCallback

callback: a AsyncReadyCallback to call when the request is satisfied

-> m () 

Asynchronously closes the file enumerator.

If cancellable is not Nothing, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error IOErrorEnumCancelled will be returned in fileEnumeratorCloseFinish.

closeFinish

fileEnumeratorCloseFinish Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) 
=> a

enumerator: a FileEnumerator.

-> b

result: a AsyncResult.

-> m ()

(Can throw GError)

Finishes closing a file enumerator, started from fileEnumeratorCloseAsync.

If the file enumerator was already closed when fileEnumeratorCloseAsync was called, then this function will report IOErrorEnumClosed in error, and return False. If the file enumerator had pending operation when the close operation was started, then this function will report IOErrorEnumPending, and return False. If cancellable was not Nothing, then the operation may have been cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error IOErrorEnumCancelled will be set, and False will be returned.

getChild

fileEnumeratorGetChild Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsFileInfo b) 
=> a

enumerator: a FileEnumerator

-> b

info: a FileInfo gotten from fileEnumeratorNextFile or the async equivalents.

-> m File

Returns: a File for the FileInfo passed it.

Return a new File which refers to the file named by info in the source directory of enumerator. This function is primarily intended to be used inside loops with fileEnumeratorNextFile.

This is a convenience method that's equivalent to:

C code

 gchar *name = g_file_info_get_name (info);
 GFile *child = g_file_get_child (g_file_enumerator_get_container (enumr),
                                  name);

Since: 2.36

getContainer

fileEnumeratorGetContainer Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a) 
=> a

enumerator: a FileEnumerator

-> m File

Returns: the File which is being enumerated.

Get the File container which is being enumerated.

Since: 2.18

hasPending

fileEnumeratorHasPending Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a) 
=> a

enumerator: a FileEnumerator.

-> m Bool

Returns: True if the enumerator has pending operations.

Checks if the file enumerator has pending operations.

isClosed

fileEnumeratorIsClosed Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a) 
=> a

enumerator: a FileEnumerator.

-> m Bool

Returns: True if the enumerator is closed.

Checks if the file enumerator has been closed.

iterate

fileEnumeratorIterate Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) 
=> a

direnum: an open FileEnumerator

-> Maybe b

cancellable: a Cancellable

-> m (FileInfo, File)

(Can throw GError)

This is a version of fileEnumeratorNextFile that's easier to use correctly from C programs. With fileEnumeratorNextFile, the gboolean return value signifies "end of iteration or error", which requires allocation of a temporary GError.

In contrast, with this function, a False return from fileEnumeratorIterate *always* means "error". End of iteration is signaled by outInfo or outChild being Nothing.

Another crucial difference is that the references for outInfo and outChild are owned by direnum (they are cached as hidden properties). You must not unref them in your own code. This makes memory management significantly easier for C code in combination with loops.

Finally, this function optionally allows retrieving a File as well.

You must specify at least one of outInfo or outChild.

The code pattern for correctly using fileEnumeratorIterate from C is:

direnum = g_file_enumerate_children (file, ...);
while (TRUE)
  {
    GFileInfo *info;
    if (!g_file_enumerator_iterate (direnum, &info, NULL, cancellable, error))
      goto out;
    if (!info)
      break;
    ... do stuff with "info"; do not unref it! ...
  }

out:
  g_object_unref (direnum); // Note: frees the last @info

Since: 2.44

nextFile

fileEnumeratorNextFile Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) 
=> a

enumerator: a FileEnumerator.

-> Maybe b

cancellable: optional Cancellable object, Nothing to ignore.

-> m (Maybe FileInfo)

Returns: A FileInfo or Nothing on error or end of enumerator. Free the returned object with objectUnref when no longer needed. (Can throw GError)

Returns information for the next file in the enumerated object. Will block until the information is available. The FileInfo returned from this function will contain attributes that match the attribute string that was passed when the FileEnumerator was created.

See the documentation of FileEnumerator for information about the order of returned files.

On error, returns Nothing and sets error to the error. If the enumerator is at the end, Nothing will be returned and error will be unset.

nextFilesAsync

fileEnumeratorNextFilesAsync Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) 
=> a

enumerator: a FileEnumerator.

-> Int32

numFiles: the number of file info objects to request

-> Int32

ioPriority: the [I/O priority][io-priority] of the request

-> Maybe b

cancellable: optional Cancellable object, Nothing to ignore.

-> Maybe AsyncReadyCallback

callback: a AsyncReadyCallback to call when the request is satisfied

-> m () 

Request information for a number of files from the enumerator asynchronously. When all i/o for the operation is finished the callback will be called with the requested information.

See the documentation of FileEnumerator for information about the order of returned files.

The callback can be called with less than numFiles files in case of error or at the end of the enumerator. In case of a partial error the callback will be called with any succeeding items and no error, and on the next request the error will be reported. If a request is cancelled the callback will be called with IOErrorEnumCancelled.

During an async request no other sync and async calls are allowed, and will result in IOErrorEnumPending errors.

Any outstanding i/o request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is PRIORITY_DEFAULT.

nextFilesFinish

fileEnumeratorNextFilesFinish Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) 
=> a

enumerator: a FileEnumerator.

-> b

result: a AsyncResult.

-> m [FileInfo]

Returns: a List of GFileInfos. You must free the list with g_list_free() and unref the infos with objectUnref when you're done with them. (Can throw GError)

Finishes the asynchronous operation started with fileEnumeratorNextFilesAsync.

setPending

fileEnumeratorSetPending Source #

Arguments

:: (HasCallStack, MonadIO m, IsFileEnumerator a) 
=> a

enumerator: a FileEnumerator.

-> Bool

pending: a boolean value.

-> m () 

Sets the file enumerator as having pending operations.

Properties

container

No description available in the introspection data.

constructFileEnumeratorContainer :: (IsFileEnumerator o, IsFile a) => a -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “container” property. This is rarely needed directly, but it is used by new.