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{-# LANGUAGE CPP #-}
-- GIMP Toolkit (GTK) Binding for Haskell: binding to gio -*-haskell-*-
--
-- Author : Andy Stewart
-- Created: 30-Apirl-2010
--
-- Copyright (c) 2010 Andy Stewart
--
-- This library is free software: you can redistribute it and/or
-- modify it under the terms of the GNU Lesser General Public License
-- as published by the Free Software Foundation, either version 3 of
-- the License, or (at your option) any later version.
--
-- This library is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-- Lesser General Public License for more details.
--
-- You should have received a copy of the GNU Lesser General Public
-- License along with this program. If not, see
-- <http://www.gnu.org/licenses/>.
--
-- GIO, the C library which this Haskell library depends on, is
-- available under LGPL Version 2. The documentation included with
-- this library is based on the original GIO documentation.
--
-- | Maintainer : gtk2hs-devel@lists.sourceforge.net
-- Stability : alpha
-- Portability : portable (depends on GHC)
module System.GIO.File.FileEnumerator (
-- * Details
--
-- | 'FileEnumerator' allows you to operate on a set of 'File's, 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 'FileInfo', whereas the synchronous will only return the next file in the
-- enumerator.
--
-- To close a 'FileEnumerator', use 'fileEnumeratorClose', or its asynchronous version,
-- 'fileEnumeratorCloseAsync'.
--
-- * Types
FileEnumerator (..),
FileEnumeratorClass,
-- * Methods
fileEnumeratorNextFile,
fileEnumeratorClose,
fileEnumeratorNextFilesAsync,
fileEnumeratorNextFilesFinish,
fileEnumeratorCloseAsync,
fileEnumeratorCloseFinish,
fileEnumeratorIsClosed,
fileEnumeratorHasPending,
fileEnumeratorSetPending,
#if GLIB_CHECK_VERSION(2,18,0)
fileEnumeratorGetContainer,
#endif
) where
import Control.Monad
import Data.Maybe (fromMaybe)
import System.GIO.Enums
import System.Glib.FFI
import System.Glib.Flags
import System.Glib.GError
import System.Glib.GList
import System.Glib.GObject
import System.Glib.UTFString
{#import System.GIO.Async.AsyncResult#}
{#import System.GIO.Types#}
{# context lib = "gio" prefix = "g" #}
-- | 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.
--
-- On error, a 'GError' is thrown. If the enumerator is at the end, 'Nothing' will be
-- returned.
fileEnumeratorNextFile :: FileEnumeratorClass enumerator => enumerator
-> Maybe Cancellable -- ^ @cancellable@ optional 'Cancellable' object, 'Nothing' to ignore.
-> IO (Maybe FileInfo) -- ^ returns A 'FileInfo' or 'Nothing' on error or end of enumerator.
fileEnumeratorNextFile enumerator cancellable =
checkGError ( \gErrorPtr ->
maybeNull (makeNewGObject mkFileInfo) $
{#call g_file_enumerator_next_file #}
(toFileEnumerator enumerator)
(fromMaybe (Cancellable nullForeignPtr) cancellable)
gErrorPtr)
(\ _ -> return Nothing)
-- | Releases all resources used by this enumerator, making the enumerator return GIoErrorClosed 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.
--
-- Throws a 'GError' if an error occurs.
fileEnumeratorClose :: FileEnumeratorClass enumerator => enumerator
-> Maybe Cancellable -- ^ @cancellable@ optional 'Cancellable' object, 'Nothing' to ignore.
-> IO ()
fileEnumeratorClose enumerator cancellable =
propagateGError $ \gErrorPtr -> do
{#call g_file_enumerator_close#}
(toFileEnumerator enumerator)
(fromMaybe (Cancellable nullForeignPtr) cancellable)
gErrorPtr
return ()
-- | 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.
--
-- 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 'IoErrorCancelled'.
--
-- During an async request no other sync and async calls are allowed, and will result in
-- 'IoErrorPending' 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 GPriorityDefault.
fileEnumeratorNextFilesAsync :: FileEnumeratorClass enumerator
=> enumerator
-> Int -- ^ @numFiles@ the number of file info objects to request
-> Int -- ^ @ioPriority@ the io priority of the request.
-> Maybe Cancellable -- ^ @cancellable@ optional 'Cancellable' object, 'Nothing' to ignore.
-> AsyncReadyCallback -- ^ @callback@ a 'AsyncReadyCallback' to call when the request is satisfied
-> IO ()
fileEnumeratorNextFilesAsync enumerator numFiles ioPriority cancellable callback = do
cCallback <- marshalAsyncReadyCallback callback
{#call g_file_enumerator_next_files_async #}
(toFileEnumerator enumerator)
(fromIntegral numFiles)
(fromIntegral ioPriority)
(fromMaybe (Cancellable nullForeignPtr) cancellable)
cCallback
(castFunPtrToPtr cCallback)
-- | Finishes the asynchronous operation started with 'fileEnumeratorNextFilesAsync'.
fileEnumeratorNextFilesFinish :: FileEnumeratorClass enumerator => enumerator
-> AsyncResult
-> IO [FileInfo]
fileEnumeratorNextFilesFinish enumerator asyncResult =
propagateGError ({# call g_file_enumerator_next_files_finish #} (toFileEnumerator enumerator) asyncResult)
>>= \glistPtr -> do
infoPtrs <- fromGList glistPtr
mapM (makeNewGObject mkFileInfo . return) infoPtrs
-- | 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 'IoErrorCancelled' will be returned
-- in 'fileEnumeratorCloseFinish'.
fileEnumeratorCloseAsync :: FileEnumeratorClass enumerator
=> enumerator
-> Int -- ^ @ioPriority@ the I/O priority of the request.
-> Maybe Cancellable -- ^ @cancellable@ optional 'Cancellable' object, 'Nothing' to ignore.
-> AsyncReadyCallback -- ^ @callback@ a 'AsyncReadyCallback' to call when the request is satisfied
-> IO ()
fileEnumeratorCloseAsync enumerator ioPriority mbCancellable callback = do
cCallback <- marshalAsyncReadyCallback callback
{#call g_file_enumerator_close_async #}
(toFileEnumerator enumerator)
(fromIntegral ioPriority)
(fromMaybe (Cancellable nullForeignPtr) mbCancellable)
cCallback
(castFunPtrToPtr cCallback)
-- | Finishes closing a file enumerator, started from 'fileEnumeratorCloseAsync'.
--
-- If the file enumerator was already closed when 'fileEnumeratorCloseAsync' was called, then this
-- function will report GIoErrorClosed in error, and return 'False'. If the file enumerator had
-- pending operation when the close operation was started, then this function will report
-- 'IoErrorPending', 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 'GError' 'IoErrorCancelled' will be thrown.
fileEnumeratorCloseFinish :: FileEnumeratorClass enumerator => enumerator
-> AsyncResult
-> IO ()
fileEnumeratorCloseFinish enumerator asyncResult =
propagateGError (\gErrorPtr -> do
{# call g_file_enumerator_close_finish #}
(toFileEnumerator enumerator)
asyncResult
gErrorPtr
return ())
-- | Checks if the file enumerator has been closed.
fileEnumeratorIsClosed :: FileEnumeratorClass enumerator => enumerator
-> IO Bool -- ^ returns 'True' if the enumerator is closed.
fileEnumeratorIsClosed enumerator =
liftM toBool $
{#call g_file_enumerator_is_closed#} (toFileEnumerator enumerator)
-- | Checks if the file enumerator has pending operations.
fileEnumeratorHasPending :: FileEnumeratorClass enumerator => enumerator
-> IO Bool -- ^ returns 'True' if the enumerator has pending operations.
fileEnumeratorHasPending enumerator =
liftM toBool $
{#call g_file_enumerator_has_pending#} (toFileEnumerator enumerator)
-- | Sets the file enumerator as having pending operations.
fileEnumeratorSetPending :: FileEnumeratorClass enumerator => enumerator
-> Bool
-> IO ()
fileEnumeratorSetPending enumerator pending =
{#call g_file_enumerator_set_pending#} (toFileEnumerator enumerator) (fromBool pending)
#if GLIB_CHECK_VERSION(2,18,0)
-- | Get the 'File' container which is being enumerated.
fileEnumeratorGetContainer :: FileEnumeratorClass enumerator => enumerator
-> IO File
fileEnumeratorGetContainer enumerator =
makeNewGObject mkFile $
{#call g_file_enumerator_get_container#} (toFileEnumerator enumerator)
#endif
|
