{-# LANGUAGE DeriveDataTypeable #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  Graphics.X11.Xlib.Event
-- Copyright   :  (c) Alastair Reid, 1999-2003
-- License     :  BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer  :  libraries@haskell.org
-- Stability   :  provisional
-- Portability :  portable
--
-- A collection of FFI declarations for interfacing with Xlib Events.
--
-----------------------------------------------------------------------------

module Graphics.X11.Xlib.Event(
        QueuedMode,
        queuedAlready,
        queuedAfterFlush,
        queuedAfterReading,
        XEvent(..),
        XEventPtr,
        allocaXEvent,
        get_EventType,
        get_Window,
        XKeyEvent,
        XKeyEventPtr,
        asKeyEvent,
        XButtonEvent,
        get_KeyEvent,
        get_ButtonEvent,
        get_MotionEvent,
        XMotionEvent,
        XExposeEvent,
        get_ExposeEvent,
        XMappingEvent,
        XConfigureEvent,
        get_ConfigureEvent,
        waitForEvent,
        gettimeofday_in_milliseconds,
        -- gettimeofday_in_milliseconds_internal,
        flush,
        sync,
        pending,
        eventsQueued,
        nextEvent,
        allowEvents,
        selectInput,
        sendEvent,
        windowEvent,
        checkWindowEvent,
        maskEvent,
        checkMaskEvent,
        checkTypedEvent,
        checkTypedWindowEvent,
        putBackEvent,
        peekEvent,
        refreshKeyboardMapping,

        ) where

import Graphics.X11.Types
import Graphics.X11.Xlib.Types
import Graphics.X11.Xlib.Display( connectionNumber )

import Foreign
import Foreign.C.Types

#if __GLASGOW_HASKELL__
import Data.Data
#endif

#include "HsXlib.h"

{-# CFILES cbits/fdset.c #-}

----------------------------------------------------------------
-- Events
----------------------------------------------------------------

type   QueuedMode   = CInt
#{enum QueuedMode,
 , queuedAlready        = QueuedAlready
 , queuedAfterFlush     = QueuedAfterFlush
 , queuedAfterReading   = QueuedAfterReading
 }

-- Because of the way the corresponding C types are defined,
-- These "structs" are somewhat unusual - they omit fields which can
-- be found in more general structs.
-- For example, XAnyEvent omits type since it is in XEvent.
-- Therefore, to get the complete contents of an event one typically
-- writes:
--   do
--     ty <- get_XEvent e
--     (serial,send_event,display,window) <- get_XAnyEvent
--     window' <- get_XDestroyWindowEvent

newtype XEvent = XEvent XEventPtr
#if __GLASGOW_HASKELL__
        deriving (Eq, Ord, Show, Typeable, Data)
#else
        deriving (Eq, Ord, Show)
#endif
type XEventPtr = Ptr XEvent

allocaXEvent :: (XEventPtr -> IO a) -> IO a
allocaXEvent = allocaBytes #{size XEvent}

get_EventType :: XEventPtr -> IO EventType
get_EventType = #{peek XEvent,type}

get_Window :: XEventPtr -> IO Window
get_Window = #{peek XAnyEvent,window}

-- %struct : XAnyEvent : XAnyEvent arg1
--   Int32     : serial            # # of last request processed by server
--   Bool      : send_event        # true if this came from a SendEvent request
--   Display   : display           # Display the event was read from
--   Window    : window            # window on which event was requested in event mask

type XKeyEvent =
        ( Window    -- root window that the event occured on
        , Window    -- child window
        , Time      -- milliseconds
        , CInt       -- pointer x, y coordinates in event window
        , CInt       --
        , CInt       -- coordinates relative to root
        , CInt       --
        , Modifier  -- key or button mask
        , KeyCode   -- detail
        , Bool      -- same screen flag
        )

peekXKeyEvent :: Ptr XKeyEvent -> IO XKeyEvent
peekXKeyEvent p = do
        root            <- #{peek XKeyEvent,root} p
        subwindow       <- #{peek XKeyEvent,subwindow} p
        time            <- #{peek XKeyEvent,time} p
        x               <- #{peek XKeyEvent,x} p
        y               <- #{peek XKeyEvent,y} p
        x_root          <- #{peek XKeyEvent,x_root} p
        y_root          <- #{peek XKeyEvent,y_root} p
        state           <- (#{peek XKeyEvent,state} p) :: IO CUInt
        keycode         <- (#{peek XKeyEvent,keycode} p) :: IO CUInt
        same_screen     <- #{peek XKeyEvent,same_screen} p
        return (root, subwindow, time, x, y, x_root, y_root,
                fromIntegral state, fromIntegral keycode, same_screen)

get_KeyEvent :: XEventPtr -> IO XKeyEvent
get_KeyEvent p = peekXKeyEvent (castPtr p)

type XKeyEventPtr   = Ptr XKeyEvent

asKeyEvent :: XEventPtr -> XKeyEventPtr
asKeyEvent = castPtr

type XButtonEvent =
        ( Window    --  root window that the event occured on
        , Window    --  child window
        , Time      --  milliseconds
        , CInt       -- pointer x, y coordinates in event window
        , CInt
        , CInt       -- coordinates relative to root
        , CInt
        , Modifier  --  key or button mask
        , Button    --  detail
        , Bool      --  same screen flag
        )

peekXButtonEvent :: Ptr XButtonEvent -> IO XButtonEvent
peekXButtonEvent p = do
        root            <- #{peek XButtonEvent,root} p
        subwindow       <- #{peek XButtonEvent,subwindow} p
        time            <- #{peek XButtonEvent,time} p
        x               <- #{peek XButtonEvent,x} p
        y               <- #{peek XButtonEvent,y} p
        x_root          <- #{peek XButtonEvent,x_root} p
        y_root          <- #{peek XButtonEvent,y_root} p
        state           <- #{peek XButtonEvent,state} p
        button          <- #{peek XButtonEvent,button} p
        same_screen     <- #{peek XButtonEvent,same_screen} p
        return (root, subwindow, time, x, y, x_root, y_root,
                state, button, same_screen)

get_ButtonEvent :: XEventPtr -> IO XButtonEvent
get_ButtonEvent p = peekXButtonEvent (castPtr p)

type XMotionEvent =
        ( Window      -- root window that the event occured on
        , Window      -- child window
        , Time        -- milliseconds
        , CInt         -- pointer x, y coordinates in event window
        , CInt
        , CInt         -- coordinates relative to root
        , CInt
        , Modifier    -- key or button mask
        , NotifyMode  -- detail
        , Bool        -- same screen flag
        )

peekXMotionEvent :: Ptr XMotionEvent -> IO XMotionEvent
peekXMotionEvent p = do
        root            <- #{peek XMotionEvent,root} p
        subwindow       <- #{peek XMotionEvent,subwindow} p
        time            <- #{peek XMotionEvent,time} p
        x               <- #{peek XMotionEvent,x} p
        y               <- #{peek XMotionEvent,y} p
        x_root          <- #{peek XMotionEvent,x_root} p
        y_root          <- #{peek XMotionEvent,y_root} p
        state           <- #{peek XMotionEvent,state} p
        is_hint         <- #{peek XMotionEvent,is_hint} p
        same_screen     <- #{peek XMotionEvent,same_screen} p
        return (root, subwindow, time, x, y, x_root, y_root,
                state, is_hint, same_screen)

get_MotionEvent :: XEventPtr -> IO XMotionEvent
get_MotionEvent p = peekXMotionEvent (castPtr p)

-- %struct : XCrossingEvent : XCrossingEvent arg1
--   Window       : root                # root window that the event occured on
--   Window       : subwindow   # child window
--   Time         : time                # milliseconds
--   Int          : x           # pointer x, y coordinates in event window
--   Int          : y
--   Int          : x_root              # coordinates relative to root
--   Int          : y_root
--   NotifyMode   : mode
--   NotifyDetail : detail
--   Bool         : same_screen # same screen flag
--   Bool         : focus               # boolean focus
--   Modifier     : state               # key or button mask
--
-- %struct : XFocusChangeEvent : XFocusChangeEvent arg1
--   NotifyMode   : mode
--   NotifyDetail : detail
--
-- -- omitted: should be translated into bitmaps
-- -- PURE void getKeymapEvent(event)
-- -- IN XEvent*        event
-- -- OUT Window        window          = ((XKeymapEvent*)event)->window
-- -- OUT array[32] Char key_vector     = ((XKeymapEvent*)event)->key_vector
-- -- RESULT:

type XExposeEvent =
        ( Position      -- x
        , Position      -- y
        , Dimension     -- width
        , Dimension     -- height
        , CInt          -- count
        )

peekXExposeEvent :: Ptr XExposeEvent -> IO XExposeEvent
peekXExposeEvent p = do
        x       <- #{peek XExposeEvent,x} p
        y       <- #{peek XExposeEvent,y} p
        width   <- #{peek XExposeEvent,width} p
        height  <- #{peek XExposeEvent,height} p
        count   <- #{peek XExposeEvent,count} p
        return (x, y, width, height, count)

get_ExposeEvent :: XEventPtr -> IO XExposeEvent
get_ExposeEvent p = peekXExposeEvent (castPtr p)

-- %struct : XGraphicsExposeEvent : XGraphicsExposeEvent arg1
--   Position   : x
--   Position   : y
--   Dimension  : width         .
--   Dimension  : height
--   Int                : count
--   Int                : major_code
--   Int                : minor_code
--
-- %struct : XCirculateEvent : XCirculateEvent arg1
--   Window     : window
--   Place              : place
--
-- %struct : XConfigureEvent : XConfigureEvent arg1
--   Window     : window
--   Position   : x
--   Position   : y
--   Dimension  : width
--   Dimension  : height
--   Dimension  : border_width
--   Window     : above
--   Bool               : override_redirect
--
-- %struct : XCreateWindowEvent : XCreateWindowEvent arg1
--   Window     : window
--   Position   : x
--   Position   : y
--   Dimension  : width
--   Dimension  : height
--   Dimension  : border_width
--   Bool               : override_redirect
--
-- %struct : XDestroyWindowEvent : XDestroyWindowEvent arg1
--   Window     : window
--
-- %struct : XGravityEvent : XGravityEvent arg1
--   Window     : window
--   Position   : x
--   Position   : y
--
-- %struct : XMapEvent : XMapEvent arg1
--   Bool               : override_redirect

type XMappingEvent =
        ( MappingRequest  -- request
        , KeyCode         -- first_keycode
        , CInt            -- count
        )

withXMappingEvent :: XMappingEvent -> (Ptr XMappingEvent -> IO a) -> IO a
withXMappingEvent event_map f =
        allocaBytes #{size XMappingEvent} $ \ event_map_ptr -> do
        pokeXMappingEvent event_map_ptr event_map
        f event_map_ptr

pokeXMappingEvent :: Ptr XMappingEvent -> XMappingEvent -> IO ()
pokeXMappingEvent p (request, first_keycode, count) = do
        #{poke XMappingEvent,request}           p request
        #{poke XMappingEvent,first_keycode}     p first_keycode
        #{poke XMappingEvent,count}             p count

type XConfigureEvent =
        ( Position
        , Position
        , Dimension
        , Dimension
        )

peekXConfigureEvent :: Ptr XConfigureEvent -> IO XConfigureEvent
peekXConfigureEvent p = do
        x       <- #{peek XConfigureEvent,x} p
        y       <- #{peek XConfigureEvent,y} p
        width   <- #{peek XConfigureEvent,width} p
        height  <- #{peek XConfigureEvent,height} p
        return (x, y, width, height)

get_ConfigureEvent :: XEventPtr -> IO XConfigureEvent
get_ConfigureEvent p = peekXConfigureEvent (castPtr p)

-- %struct : XResizeRequestEvent : XResizeRequestEvent arg1
--   Dimension  : width
--   Dimension  : height
--

-- %struct : XReparentEvent : XReparentEvent arg1
--   Window     : window
--   Window     : parent
--   Position   : x
--   Position   : y
--   Bool               : override_redirect
--
-- %struct : XUnmapEvent : XUnmapEvent arg1
--   Window     : window
--   Bool               : from_configure
--
-- %struct : XVisibilityEvent : XVisibilityEvent arg1
--   Visibility : state
--
-- %struct : XCirculateRequestEvent : XCirculateRequestEvent arg1
--   Place              : place
--
-- -- omitted because valuemask looks tricky
-- -- %struct : XConfigureRequestEvent : XConfigureRequestEvent arg1
-- --   Window   : window
-- --   Position         : x
-- --   Position         : y
-- --   Dimension        : width
-- --   Dimension        : height
-- --   Dimension        : border_width
-- --   Window   : above
-- --   StackingMethod : detail
-- --   ???              : valuemask
--
-- %struct : XMapRequestEvent : XMapRequestEvent arg1
--   Window     : window
--
-- %struct : XColormapEvent : XColormapEvent arg1
--   Colormap           : colormap
--   Bool                       : new
--   ColormapNotification       : state
--
-- -- getClientMessageEvent omitted
-- -- getPropertyEvent omitted
-- -- getSelectionClearEvent omitted
-- -- getSelectionRequestEvent omitted
-- -- getSelectionEvent omitted
-- -- xrrScreenChangeNotifyEvent omitted

-- functions

-- The following is useful if you want to do a read with timeout.

-- | Reads an event with a timeout (in microseconds).
-- Returns True if timeout occurs.
waitForEvent :: Display -> Word32 -> IO Bool
waitForEvent display usecs =
        with (TimeVal (usecs `div` 1000000) (usecs `mod` 1000000)) $ \ tv_ptr ->
        allocaBytes #{size fd_set} $ \ readfds ->
        allocaBytes #{size fd_set} $ \ nofds -> do
        let fd = connectionNumber display
        fdZero readfds
        fdZero nofds
        fdSet (fromIntegral fd) readfds
        n <- select ((fromIntegral fd)+1) readfds nofds nofds tv_ptr
        return (n == 0)

newtype FdSet = FdSet (Ptr FdSet)
#if __GLASGOW_HASKELL__
        deriving (Eq, Ord, Show, Typeable, Data)
#else
        deriving (Eq, Ord, Show)
#endif

foreign import ccall unsafe "HsXlib.h" fdZero :: Ptr FdSet -> IO ()
foreign import ccall unsafe "HsXlib.h" fdSet :: CInt -> Ptr FdSet -> IO ()

foreign import ccall unsafe "HsXlib.h" select ::
        CInt -> Ptr FdSet -> Ptr FdSet -> Ptr FdSet -> Ptr TimeVal -> IO CInt

-- | This function is somewhat compatible with Win32's @TimeGetTime()@
gettimeofday_in_milliseconds :: IO Integer
gettimeofday_in_milliseconds =
        alloca $ \ tv_ptr -> do
        _rc <- gettimeofday tv_ptr nullPtr
        TimeVal sec usec <- peek tv_ptr
        return (toInteger sec * 1000 + toInteger usec `div` 1000)

data TimeVal = TimeVal Word32 Word32

instance Storable TimeVal where
        alignment _ = #{size int}
        sizeOf _ = #{size struct timeval}
        peek p = do
                sec <- #{peek struct timeval,tv_sec} p
                usec <- #{peek struct timeval,tv_usec} p
                return (TimeVal sec usec)
        poke p (TimeVal sec usec) = do
                #{poke struct timeval,tv_sec} p sec
                #{poke struct timeval,tv_usec} p usec

newtype TimeZone = TimeZone (Ptr TimeZone)
#if __GLASGOW_HASKELL__
        deriving (Eq, Ord, Show, Typeable, Data)
#else
        deriving (Eq, Ord, Show)
#endif

foreign import ccall unsafe "HsXlib.h"
        gettimeofday :: Ptr TimeVal -> Ptr TimeZone -> IO ()

-- | interface to the X11 library function @XFlush()@.
foreign import ccall unsafe "HsXlib.h XFlush"
        flush        :: Display ->               IO ()

-- | interface to the X11 library function @XSync()@.
foreign import ccall safe "HsXlib.h XSync"
        sync         :: Display -> Bool ->       IO ()

-- | interface to the X11 library function @XPending()@.
foreign import ccall unsafe "HsXlib.h XPending"
        pending      :: Display ->               IO CInt

-- | interface to the X11 library function @XEventsQueued()@.
foreign import ccall unsafe "HsXlib.h XEventsQueued"
        eventsQueued :: Display -> QueuedMode -> IO CInt

-- | interface to the X11 library function @XNextEvent()@.
foreign import ccall safe "HsXlib.h XNextEvent"
        nextEvent    :: Display -> XEventPtr  -> IO ()

-- | interface to the X11 library function @XAllowEvents()@.
foreign import ccall unsafe "HsXlib.h XAllowEvents"
        allowEvents  :: Display -> AllowEvents -> Time -> IO ()

-- ToDo: XFree(res1) after constructing result
-- %fun XGetMotionEvents :: Display -> Window -> Time -> Time -> IO ListXTimeCoord
-- %code res1 = XGetMotionEvents(arg1,arg2,arg3,arg4,&res1_size)

-- | interface to the X11 library function @XSelectInput()@.
foreign import ccall unsafe "HsXlib.h XSelectInput"
        selectInput :: Display -> Window -> EventMask -> IO ()

-- | interface to the X11 library function @XSendEvent()@.
sendEvent :: Display -> Window -> Bool -> EventMask -> XEventPtr -> IO ()
sendEvent display w propagate event_mask event_send =
        throwIfZero "sendEvent" $
                xSendEvent display w propagate event_mask event_send
foreign import ccall unsafe "HsXlib.h XSendEvent"
        xSendEvent :: Display -> Window -> Bool -> EventMask ->
                XEventPtr -> IO Status

-- | interface to the X11 library function @XWindowEvent()@.
foreign import ccall unsafe "HsXlib.h XWindowEvent"
        windowEvent :: Display -> Window -> EventMask -> XEventPtr -> IO ()

-- | interface to the X11 library function @XCheckWindowEvent()@.
foreign import ccall unsafe "HsXlib.h XCheckWindowEvent"
        checkWindowEvent :: Display -> Window -> EventMask ->
                XEventPtr -> IO Bool

-- | interface to the X11 library function @XMaskEvent()@.
foreign import ccall unsafe "HsXlib.h XMaskEvent"
        maskEvent :: Display -> EventMask -> XEventPtr -> IO ()

-- | interface to the X11 library function @XCheckMaskEvent()@.
foreign import ccall unsafe "HsXlib.h XCheckMaskEvent"
        checkMaskEvent :: Display -> EventMask -> XEventPtr -> IO Bool

-- | interface to the X11 library function @XCheckTypedEvent()@.
foreign import ccall unsafe "HsXlib.h XCheckTypedEvent"
        checkTypedEvent :: Display -> EventType -> XEventPtr -> IO Bool

-- | interface to the X11 library function @XCheckTypedWindowEvent()@.
foreign import ccall unsafe "HsXlib.h XCheckTypedWindowEvent"
        checkTypedWindowEvent :: Display -> Window -> EventType ->
                XEventPtr -> IO Bool

-- | interface to the X11 library function @XPutBackEvent()@.
foreign import ccall unsafe "HsXlib.h XPutBackEvent"
        putBackEvent :: Display -> XEventPtr -> IO ()

-- | interface to the X11 library function @XPeekEvent()@.
foreign import ccall unsafe "HsXlib.h XPeekEvent"
        peekEvent :: Display -> XEventPtr -> IO ()

-- XFilterEvent omitted (can't find documentation)
-- XIfEvent omitted (can't pass predicates (yet))
-- XCheckIfEvent omitted (can't pass predicates (yet))
-- XPeekIfEvent omitted (can't pass predicates (yet))

-- | interface to the X11 library function @XRefreshKeyboardMapping()@.
refreshKeyboardMapping :: XMappingEvent -> IO ()
refreshKeyboardMapping event_map =
        withXMappingEvent event_map $ \ event_map_ptr ->
        xRefreshKeyboardMapping event_map_ptr
foreign import ccall unsafe "HsXlib.h XRefreshKeyboardMapping"
        xRefreshKeyboardMapping :: Ptr XMappingEvent -> IO ()

-- XSynchronize omitted (returns C function)
-- XSetAfterFunction omitted (can't pass functions (yet))

----------------------------------------------------------------
-- End
----------------------------------------------------------------