Copyright | Will Thompson Iñaki García Etxebarria and Jonas Platte |
---|---|
License | LGPL-2.1 |
Maintainer | Iñaki García Etxebarria (garetxe@gmail.com) |
Safe Haskell | None |
Language | Haskell2010 |
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
- newtype FileEnumerator = FileEnumerator (ManagedPtr FileEnumerator)
- class GObject o => IsFileEnumerator o
- toFileEnumerator :: (MonadIO m, IsFileEnumerator o) => o -> m FileEnumerator
- noFileEnumerator :: Maybe FileEnumerator
- fileEnumeratorClose :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) => a -> Maybe b -> m ()
- fileEnumeratorCloseAsync :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) => a -> Int32 -> Maybe b -> Maybe AsyncReadyCallback -> m ()
- fileEnumeratorCloseFinish :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) => a -> b -> m ()
- fileEnumeratorGetChild :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsFileInfo b) => a -> b -> m File
- fileEnumeratorGetContainer :: (HasCallStack, MonadIO m, IsFileEnumerator a) => a -> m File
- fileEnumeratorHasPending :: (HasCallStack, MonadIO m, IsFileEnumerator a) => a -> m Bool
- fileEnumeratorIsClosed :: (HasCallStack, MonadIO m, IsFileEnumerator a) => a -> m Bool
- fileEnumeratorIterate :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) => a -> Maybe b -> m (FileInfo, File)
- fileEnumeratorNextFile :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) => a -> Maybe b -> m (Maybe FileInfo)
- fileEnumeratorNextFilesAsync :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) => a -> Int32 -> Int32 -> Maybe b -> Maybe AsyncReadyCallback -> m ()
- fileEnumeratorNextFilesFinish :: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) => a -> b -> m [FileInfo]
- fileEnumeratorSetPending :: (HasCallStack, MonadIO m, IsFileEnumerator a) => a -> Bool -> m ()
- constructFileEnumeratorContainer :: (IsFileEnumerator o, IsFile a) => a -> IO (GValueConstruct o)
Exported types
newtype FileEnumerator Source #
Memory-managed wrapper type.
Instances
GObject FileEnumerator Source # | |
Defined in GI.Gio.Objects.FileEnumerator gobjectType :: FileEnumerator -> IO GType # | |
IsObject FileEnumerator Source # | |
Defined in GI.Gio.Objects.FileEnumerator | |
IsFileEnumerator FileEnumerator Source # | |
Defined in GI.Gio.Objects.FileEnumerator |
class GObject o => IsFileEnumerator o Source #
Type class for types which can be safely cast to FileEnumerator
, for instance with toFileEnumerator
.
Instances
(GObject a, (UnknownAncestorError FileEnumerator a :: Constraint)) => IsFileEnumerator a Source # | |
Defined in GI.Gio.Objects.FileEnumerator | |
IsFileEnumerator FileEnumerator Source # | |
Defined in GI.Gio.Objects.FileEnumerator |
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
.
noFileEnumerator :: Maybe FileEnumerator Source #
A convenience alias for Nothing
:: Maybe
FileEnumerator
.
Methods
close
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) | |
=> a |
|
-> Maybe b |
|
-> m () | (Can throw |
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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) | |
=> a |
|
-> Int32 |
|
-> Maybe b |
|
-> Maybe AsyncReadyCallback |
|
-> 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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) | |
=> a |
|
-> b |
|
-> m () | (Can throw |
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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsFileInfo b) | |
=> a |
|
-> b |
|
-> m File |
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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a) | |
=> a |
|
-> m File | Returns: the |
Get the File
container which is being enumerated.
Since: 2.18
hasPending
fileEnumeratorHasPending Source #
:: (HasCallStack, MonadIO m, IsFileEnumerator a) | |
=> a |
|
-> m Bool | Returns: |
Checks if the file enumerator has pending operations.
isClosed
fileEnumeratorIsClosed Source #
:: (HasCallStack, MonadIO m, IsFileEnumerator a) | |
=> a |
|
-> m Bool | Returns: |
Checks if the file enumerator has been closed.
iterate
fileEnumeratorIterate Source #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) | |
=> a |
|
-> Maybe b |
|
-> m (FileInfo, File) | (Can throw |
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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) | |
=> a |
|
-> Maybe b |
|
-> m (Maybe FileInfo) | Returns: A |
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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsCancellable b) | |
=> a |
|
-> Int32 |
|
-> Int32 |
|
-> Maybe b |
|
-> Maybe AsyncReadyCallback |
|
-> 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 #
:: (HasCallStack, MonadIO m, IsFileEnumerator a, IsAsyncResult b) | |
=> a |
|
-> b |
|
-> m [FileInfo] | Returns: a |
Finishes the asynchronous operation started with fileEnumeratorNextFilesAsync
.
setPending
fileEnumeratorSetPending Source #
:: (HasCallStack, MonadIO m, IsFileEnumerator a) | |
=> a |
|
-> Bool |
|
-> 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
.