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|
{-# LANGUAGE CPP #-}
-- GIMP Toolkit (GTK) Binding for Haskell: binding to gstreamer -*-haskell-*-
--
-- Author : Peter Gavin
-- Created: 1-Apr-2007
--
-- Copyright (c) 2007 Peter Gavin
--
-- 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/>.
--
-- GStreamer, 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 GStreamer documentation.
--
-- |
-- Maintainer : gtk2hs-devel\@lists.sourceforge.net
-- Stability : alpha
-- Portability : portable (depends on GHC)
--
-- An object describing events that are passed up and down a pipeline.
module Media.Streaming.GStreamer.Core.Event (
-- * Detail
-- | An 'Event' is a message that is passed up and down a pipeline.
--
-- There are a number of predefined events and functions returning
-- events. To send an event an application will usually use
-- 'Media.Streaming.GStreamer.Core.Element.elementSendEvent', and
-- elements will use
-- 'Media.Streaming.GStreamer.Core.Pad.padSendEvent' or
-- 'Media.Streaming.GStreamer.Core.padPushEvent'.
--
--
-- * Types
Event,
EventClass,
EventType(..),
SeekFlags(..),
SeekType(..),
-- * Event Operations
eventType,
eventNewCustom,
eventNewEOS,
eventNewFlushStart,
eventNewFlushStop,
#if GST_CHECK_VERSION(0,10,12)
eventNewLatency,
#endif
eventNewNavigation,
eventNewNewSegment,
eventNewNewSegmentFull,
eventNewQOS,
eventNewSeek,
eventNewTag,
eventParseBufferSize,
#if GST_CHECK_VERSION(0,10,12)
eventParseLatency,
#endif
eventParseNewSegment,
eventParseNewSegmentFull,
eventParseQOS,
eventParseSeek,
eventParseTag,
eventTypeGetName,
eventTypeGetFlags,
) where
import Control.Monad (liftM)
{#import Media.Streaming.GStreamer.Core.Types#}
import System.Glib.FFI
import System.Glib.GObject
import System.Glib.UTFString
import System.Glib.GError
{# context lib = "gstreamer" prefix = "gst" #}
eventType :: EventClass event
=> event
-> EventType
eventType event =
cToEnum $ unsafePerformIO $ withMiniObject (toEvent event) cEventType
foreign import ccall unsafe "_hs_gst_event_type"
cEventType :: Ptr Event
-> IO {# type GstEventType #}
eventNewCustom :: EventType
-> Structure
-> IO Event
eventNewCustom eventType structure =
{# call event_new_custom #} (cFromEnum eventType)
structure >>=
takeMiniObject
eventNewEOS, eventNewFlushStart, eventNewFlushStop :: IO Event
eventNewEOS = {# call event_new_eos #} >>= takeMiniObject
eventNewFlushStart = {# call event_new_flush_start #} >>= takeMiniObject
eventNewFlushStop = {# call event_new_flush_stop #} >>= takeMiniObject
#if GST_CHECK_VERSION(0,10,12)
eventNewLatency :: ClockTime
-> IO Event
eventNewLatency latency =
{# call event_new_latency #} (fromIntegral latency) >>=
takeMiniObject
#endif
eventNewNavigation :: Structure
-> IO Event
eventNewNavigation structure =
{# call event_new_navigation #} structure >>=
takeMiniObject
eventNewNewSegment :: Bool
-> Double
-> Format
-> Int64
-> Int64
-> Int64
-> IO Event
eventNewNewSegment update rate format start stop position =
{# call event_new_new_segment #} (fromBool update)
(realToFrac rate)
(fromIntegral $ fromFormat format)
(fromIntegral start)
(fromIntegral stop)
(fromIntegral position) >>=
takeMiniObject
eventNewNewSegmentFull :: Bool
-> Double
-> Double
-> Format
-> Int64
-> Int64
-> Int64
-> IO Event
eventNewNewSegmentFull update appliedRate rate format start stop position =
{# call event_new_new_segment_full #} (fromBool update)
(realToFrac rate)
(realToFrac appliedRate)
(fromIntegral $ fromFormat format)
(fromIntegral start)
(fromIntegral stop)
(fromIntegral position) >>=
takeMiniObject
eventNewQOS :: Double
-> ClockTimeDiff
-> ClockTime
-> IO Event
eventNewQOS proportion diff timestamp =
{# call event_new_qos #} (realToFrac proportion)
(fromIntegral diff)
(fromIntegral timestamp) >>=
takeMiniObject
eventNewSeek :: Double
-> Format
-> [SeekFlags]
-> SeekType
-> Int64
-> SeekType
-> Int64
-> IO Event
eventNewSeek rate format flags startType start stopType stop =
{# call event_new_seek #} (realToFrac rate)
(fromIntegral $ fromFormat format)
(cFromFlags flags)
(cFromEnum startType)
(fromIntegral start)
(cFromEnum stopType)
(fromIntegral stop) >>=
takeMiniObject
eventNewTag :: TagList
-> IO Event
eventNewTag tagList =
withTagList tagList ({# call event_new_tag #} . castPtr) >>=
takeMiniObject
eventParseBufferSize :: EventClass event
=> event
-> Maybe (Format, Int64, Int64, Bool)
eventParseBufferSize event | eventType event == EventBufferSize =
Just $ unsafePerformIO $ alloca $ \formatPtr -> alloca $ \minSizePtr ->
alloca $ \maxSizePtr -> alloca $ \asyncPtr ->
do {# call event_parse_buffer_size #} (toEvent event)
formatPtr
minSizePtr
maxSizePtr
asyncPtr
format <- liftM (toFormat . fromIntegral) $ peek formatPtr
minSize <- liftM fromIntegral $ peek minSizePtr
maxSize <- liftM fromIntegral $ peek maxSizePtr
async <- liftM toBool $ peek asyncPtr
return (format, minSize, maxSize, async)
| otherwise = Nothing
#if GST_CHECK_VERSION(0,10,12)
eventParseLatency :: EventClass event
=> event
-> Maybe ClockTime
eventParseLatency event | eventType event == EventLatency =
Just $ unsafePerformIO $ alloca $ \latencyPtr ->
do {# call event_parse_latency #} (toEvent event)
latencyPtr
liftM fromIntegral $ peek latencyPtr
| otherwise = Nothing
#endif
eventParseNewSegment :: EventClass event
=> event
-> Maybe (Bool, Double, Format, Int64, Int64, Int64)
eventParseNewSegment event | eventType event == EventNewSegment =
Just $ unsafePerformIO $ alloca $ \updatePtr ->
alloca $ \ratePtr -> alloca $ \formatPtr ->
alloca $ \startPtr -> alloca $ \stopPtr ->
alloca $ \positionPtr ->
do {# call event_parse_new_segment #} (toEvent event)
ratePtr
updatePtr
formatPtr
startPtr
stopPtr
positionPtr
update <- liftM toBool $ peek updatePtr
rate <- liftM realToFrac $ peek ratePtr
format <- liftM (toFormat . fromIntegral) $ peek formatPtr
start <- liftM fromIntegral $ peek startPtr
stop <- liftM fromIntegral $ peek stopPtr
position <- liftM fromIntegral $ peek positionPtr
return (update, rate, format, start, stop, position)
| otherwise = Nothing
eventParseNewSegmentFull :: EventClass event
=> event
-> Maybe (Bool, Double, Double, Format, Int64, Int64, Int64)
eventParseNewSegmentFull event | eventType event == EventNewSegment =
Just $ unsafePerformIO $ alloca $ \updatePtr ->
alloca $ \ratePtr -> alloca $ \appliedRatePtr ->
alloca $ \formatPtr -> alloca $ \startPtr ->
alloca $ \stopPtr -> alloca $ \positionPtr ->
do {# call event_parse_new_segment_full #} (toEvent event)
ratePtr
appliedRatePtr
updatePtr
formatPtr
startPtr
stopPtr
positionPtr
update <- liftM toBool $ peek updatePtr
rate <- liftM realToFrac $ peek ratePtr
appliedRate <- liftM realToFrac $ peek appliedRatePtr
format <- liftM (toFormat . fromIntegral) $ peek formatPtr
start <- liftM fromIntegral $ peek startPtr
stop <- liftM fromIntegral $ peek stopPtr
position <- liftM fromIntegral $ peek positionPtr
return (update, rate, appliedRate, format, start, stop, position)
| otherwise = Nothing
eventParseQOS :: EventClass event
=> event
-> Maybe (Double, ClockTimeDiff, ClockTime)
eventParseQOS event | eventType event == EventQOS =
Just $ unsafePerformIO $ alloca $ \proportionPtr ->
alloca $ \diffPtr -> alloca $ \timestampPtr ->
do {# call event_parse_qos #} (toEvent event)
proportionPtr
diffPtr
timestampPtr
proportion <- liftM realToFrac $ peek proportionPtr
diff <- liftM fromIntegral $ peek diffPtr
timestamp <- liftM fromIntegral $ peek timestampPtr
return (proportion, diff, timestamp)
| otherwise = Nothing
eventParseSeek :: EventClass event
=> event
-> Maybe (Double, Format, [SeekFlags], SeekType, Int64, SeekType, Int64)
eventParseSeek event | eventType event == EventSeek =
Just $ unsafePerformIO $ alloca $ \ratePtr ->
alloca $ \formatPtr -> alloca $ \flagsPtr ->
alloca $ \startTypePtr -> alloca $ \startPtr ->
alloca $ \stopTypePtr -> alloca $ \stopPtr ->
do {# call event_parse_seek #} (toEvent event)
ratePtr
formatPtr
flagsPtr
startTypePtr
startPtr
stopTypePtr
stopPtr
rate <- liftM realToFrac $ peek ratePtr
format <- liftM (toFormat . fromIntegral) $ peek formatPtr
flags <- liftM cToFlags $ peek flagsPtr
startType <- liftM cToEnum $ peek startTypePtr
start <- liftM fromIntegral $ peek startPtr
stopType <- liftM cToEnum $ peek stopTypePtr
stop <- liftM fromIntegral $ peek stopPtr
return (rate, format, flags, startType, start, stopType, stop)
| otherwise = Nothing
eventParseTag :: EventClass event
=> event
-> Maybe TagList
eventParseTag event | eventType event == EventTag =
Just $ unsafePerformIO $ alloca $ \tagListPtr ->
do {# call event_parse_tag #} (toEvent event) (castPtr tagListPtr)
peek tagListPtr >>= peekTagList
| otherwise = Nothing
eventTypeGetName :: EventType
-> String
eventTypeGetName eventType =
unsafePerformIO $
{# call event_type_get_name #} (cFromEnum eventType) >>=
peekUTFString
eventTypeGetFlags :: EventType
-> [EventTypeFlags]
eventTypeGetFlags =
cToFlags . {# call fun event_type_get_flags #} . cFromEnum
|
