{-# LANGUAGE CPP #-}
-- -*-haskell-*-
--  GIMP Toolkit (GTK) Widget AnimView
--
--  Author : Andy Stewart
--
--  Created: 19 Aug 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 2.1 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.
--
-- |
-- Maintainer  : gtk2hs-users@lists.sourceforge.net
-- Stability   : provisional
-- Portability : portable (depends on GHC)
--
module Graphics.UI.Gtk.ImageView.AnimView (
-- * Details
-- | 'AnimView' subclasses 'ImageView'. It has the same look and feel as its parent but is also capable
-- of displaying GIF animations.

-- * Tyeps  
   AnimView,
   AnimViewClass,

-- * Methods
   animViewNew,
   animViewGetAnim,
   animViewSetAnim,
   animViewSetIsPlaying,
   animViewGetIsPlaying,
   animViewStep,

-- * Signals
   step,
   toggleRunning,
) where

import Control.Monad	(liftM)
import Data.Maybe    (fromMaybe)

import Graphics.UI.Gtk.Abstract.Object	(makeNewObject)
import Graphics.UI.Gtk.ImageView.Enums
import System.Glib.Attributes
import System.Glib.FFI
import System.Glib.UTFString

{#import Graphics.UI.Gtk.ImageView.Signals#}
{#import Graphics.UI.Gtk.ImageView.Types#}
{#import System.Glib.Properties#}

{# context lib="gtk" prefix="gtk" #}

-- | Creates a new 'AnimView' with default values. The default values are:
-- 
-- * anim : 'Nothing'
-- * @isPlaying@ : 'False'
animViewNew = 
  makeNewObject mkAnimView $
  liftM (castPtr :: Ptr Widget -> Ptr AnimView) $
  {# call unsafe gtk_anim_view_new #}

-- | Returns the current animation of the view.
animViewGetAnim :: AnimViewClass view => view 
                -> IO PixbufAnimation -- ^ returns the current animation 
animViewGetAnim view =
  wrapNewGObject mkPixbufAnimation $
  {#call gtk_anim_view_get_anim #}
    (toAnimView view)

-- | Sets the pixbuf animation to play, or 'Nothing' to not play any animation.
-- 
-- If the animation is a static image or only has one frame, then the static image will be displayed
-- instead. If more frames are loaded into the animation, then 'AnimView' will automatically animate
-- to those frames.
-- 
-- The effect of this method is analoguous to 'imageViewSetPixbuf'. Fit mode is reset to
-- 'FitSizeIfLarger' so that the whole area of the animation fits in the view. Three signals are
-- emitted, first the 'ImageView' will emit 'zoomChanged' and then 'pixbufChanged', second,
-- 'AnimView' itself will emit 'animChanged'.
-- 
-- The default pixbuf animation is 'Nothing'.
animViewSetAnim :: AnimViewClass view => view
                -> Maybe PixbufAnimation -- ^ @anim@  A pixbuf animation to play. 
                -> IO ()
animViewSetAnim view anim = 
    {#call gtk_anim_view_set_anim #}
      (toAnimView view)
      (fromMaybe (PixbufAnimation nullForeignPtr) anim)

-- | Sets whether the animation should play or not. If there is no current animation this method does not
-- have any effect.
animViewSetIsPlaying :: AnimViewClass view => view
                     -> Bool -- ^ @playing@ 'True' to play the animation, 'False' otherwise 
                     -> IO ()
animViewSetIsPlaying view playing =
  {#call gtk_anim_view_set_is_playing #}
    (toAnimView view)
    (fromBool playing)

-- | Returns whether the animation is playing or not. If there is no current animation, this method will
-- always returns 'False'.
animViewGetIsPlaying :: AnimViewClass view => view
                     -> IO Bool -- ^ returns 'True' if an animation is playing, 'False' otherwise. 
animViewGetIsPlaying view =
  liftM toBool $
  {#call gtk_anim_view_get_is_playing #}
      (toAnimView view)
    
-- | Steps the animation one frame forward. If the animation is playing it will be stopped. Will it wrap
-- around if the animation is at its last frame?
animViewStep :: AnimViewClass view => view -> IO ()
animViewStep view =
  {#call gtk_anim_view_step #}
      (toAnimView view)

-- | Steps the animation one frame forward. If the animation is playing it will first be stopped. 'step'
-- is a keybinding signal emitted when GDK_j is pressed on the widget and should not be used by clients
-- of this library.
step :: AnimViewClass view => Signal view (IO ())
step = Signal (connect_NONE__NONE "step")

-- | Stops the animation if it was playing or resumes it, if it was playing. 'toggleRunning' is a
-- keybinding signal emitted when GDK_p is pressed on the widget and should not be used by clients of
-- this library.
toggleRunning :: AnimViewClass view => Signal view (IO ())
toggleRunning = Signal (connect_NONE__NONE "toggle-running")