ImageView.hs

-- Author:     Andy Stewart <lazycat.manatee@gmail.com>
-- Maintainer: Andy Stewart <lazycat.manatee@gmail.com>
-- 
-- Copyright (C) 2010 Andy Stewart, all rights reserved.
-- 
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- any later version.
-- 
-- This program 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 General Public License for more details.
-- 
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE DeriveDataTypeable #-}
module Manatee.Extension.ImageViewer.ImageView where

import Control.Applicative
import Control.Concurrent.STM 
import Control.Monad
import Data.List
import Data.Map (Map)
import Data.ByteString.UTF8 hiding (length)
import Data.Text.Lazy (Text)
import Data.Typeable
import Graphics.UI.Gtk hiding (Statusbar, statusbarNew, get)
import Graphics.UI.Gtk.Gdk.SerializedEvent
import Manatee.Core.PageView
import Manatee.Core.Types
import Manatee.Extension.ImageViewer.ImageBuffer
import Manatee.Toolkit.GConf.GConf
import Manatee.Toolkit.General.Maybe
import Manatee.Toolkit.General.Misc
import Manatee.Toolkit.General.List
import Manatee.Toolkit.General.STM
import Manatee.Toolkit.Gtk.Concurrent
import Manatee.Toolkit.Gtk.Gtk
import Manatee.Toolkit.Gio.Gio
import Manatee.Toolkit.Gtk.ScrolledWindow
import Paths_manatee_imageviewer
import System.FilePath

import qualified Graphics.UI.Gtk.ImageView.ImageView as I
import qualified Data.Map as M

data ImageView =
    ImageView {imageViewPlugId          :: TVar PagePlugId
              ,imageViewScrolledWindow  :: ScrolledWindow
              ,imageViewView            :: I.ImageView
              ,imageViewBuffer          :: ImageBuffer
              ,imageViewBroadcastChannel:: ViewChannel String}
    deriving Typeable

instance PageBuffer ImageBuffer where
  pageBufferGetName             = readTVarIO . imageBufferPath
  pageBufferSetName a           = writeTVarIO (imageBufferPath a)
  pageBufferClient              = imageBufferClient
  pageBufferCreateView a pId    = PageViewWrap <$> imageViewNew a pId
  pageBufferMode                = imageBufferMode
  pageBufferPackageName _       = fmap takeFileName getDataDir

instance PageView ImageView where
    pageViewBuffer              = PageBufferWrap . imageViewBuffer
    pageViewPlugId              = imageViewPlugId
    pageViewFocus               = widgetGrabFocus . imageViewView
    pageViewScrolledWindow      = imageViewScrolledWindow
    pageViewHandleKeyAction     = imageViewHandleKeyAction

-- | The intervals of slide show (ms).
imageViewSlideShowInterval :: Int
imageViewSlideShowInterval = 4000

-- | New image view.
imageViewNew :: ImageBuffer -> PagePlugId -> IO ImageView
imageViewNew buffer plugId = do
  -- Create plug id.
  pId <- newTVarIO plugId

  -- Create scrolled window.
  scrolledWindow <- scrolledWindowNew_
  
  -- Load image.
  view <- I.imageViewNew
  scrolledWindow `containerAdd` view

  -- Duplicate broadcast channel.
  channel <- createViewChannel (imageBufferBroadcastChannel buffer) view

  -- Build image view.
  let imageView = ImageView pId scrolledWindow view buffer channel

  -- Listen broadcast channel.
  imageViewListenChannel imageView

  -- Draw.
  imageViewDraw imageView

  -- Update zoom status.
  view `on` I.zoomChanged $ imageViewUpdateZoomStatus imageView

  return imageView

-- | Draw image view.
imageViewDraw :: ImageView -> IO ()
imageViewDraw view = do
  -- TODO: Need find a way free old pixbuf in GtkImageView after use new pixbuf.
  -- Otherwise cause memory leak. 
  path <- readTVarIO $ imageBufferPath $ imageViewBuffer view
  pixbuf <- pixbufNewFromFile (filepathGetDisplayName (fromString path))
  I.imageViewSetPixbuf (imageViewView view) (Just pixbuf) True

-- | Browse.
imageViewBrowse :: ImageView -> FilePath -> IO ()
imageViewBrowse view path = do
  -- Update current path in ImageBuffer.
  writeTVarIO (imageBufferPath $ imageViewBuffer view) path

  -- Broadcast current path for synchronous in multiple ImageView.
  writeTChanIO (viewChannel $ imageViewBroadcastChannel view) path

-- | Listen broadcast channel for draw view synchronous.
imageViewListenChannel :: ImageView -> IO ()
imageViewListenChannel view = 
  listenViewChannel (imageViewBroadcastChannel view) $ \_ ->
      imageViewDraw view

-- | Handle key action.
imageViewHandleKeyAction :: ImageView -> Text -> SerializedEvent -> IO ()  
imageViewHandleKeyAction view keystoke sEvent = 
  case M.lookup keystoke imageViewKeymap of
    Just action -> action view
    Nothing -> widgetPropagateEvent (imageViewView view) sEvent

-- | Zoom out image.
imageViewZoomOut :: ImageView -> IO ()
imageViewZoomOut = I.imageViewZoomOut . imageViewView

-- | Zoom int image.
imageViewZoomIn :: ImageView -> IO ()
imageViewZoomIn = I.imageViewZoomIn . imageViewView

-- | Fit the window.
imageViewFit :: ImageView -> IO ()
imageViewFit view = 
  I.imageViewSetFitting (imageViewView view) True

-- | View next file.
imageViewBrowseNext :: ImageView -> IO ()
imageViewBrowseNext view = do
  currentFile <- readTVarIO $ imageBufferPath $ imageViewBuffer view
  files <- readTVarIO $ imageBufferFiles $ imageViewBuffer view
  imageViewGetNextFile currentFile files ?>= \file -> 
      imageViewBrowse view file
  
-- | View Prev file.
imageViewBrowsePrev :: ImageView -> IO ()
imageViewBrowsePrev view = do
  currentFile <- readTVarIO $ imageBufferPath $ imageViewBuffer view
  files <- readTVarIO $ imageBufferFiles $ imageViewBuffer view
  imageViewGetPrevFile currentFile files ?>= \file -> 
      imageViewBrowse view file

-- | View first file.
imageViewBrowseFirst :: ImageView -> IO ()
imageViewBrowseFirst view = do
  files <- readTVarIO $ imageBufferFiles $ imageViewBuffer view
  getFirst files ?>= \ file -> imageViewBrowse view file

-- | View last file.
imageViewBrowseLast :: ImageView -> IO ()
imageViewBrowseLast view = do
  files <- readTVarIO $ imageBufferFiles $ imageViewBuffer view
  getLast files ?>= \ file -> imageViewBrowse view file

-- | Rotate clockwise
imageViewRotateClockwise :: ImageView -> IO ()
imageViewRotateClockwise view = do
  oldPixbuf <- I.imageViewGetPixbuf $ imageViewView view
  newPixbuf <- pixbufRotateSimple oldPixbuf PixbufRotateClockwise
  I.imageViewSetPixbuf (imageViewView view) (Just newPixbuf) True

  
-- | Rotate counterclockwise.
imageViewRotateCounterclockwise :: ImageView -> IO ()
imageViewRotateCounterclockwise view = do
  oldPixbuf <- I.imageViewGetPixbuf $ imageViewView view
  newPixbuf <- pixbufRotateSimple oldPixbuf PixbufRotateCounterclockwise
  I.imageViewSetPixbuf (imageViewView view) (Just newPixbuf) True
  
-- | Rotate mirror.
imageViewRotateMirror :: ImageView -> IO ()
imageViewRotateMirror view = do
  oldPixbuf <- I.imageViewGetPixbuf $ imageViewView view
  newPixbuf <- pixbufRotateSimple oldPixbuf PixbufRotateUpsidedown
  I.imageViewSetPixbuf (imageViewView view) (Just newPixbuf) True

-- | Update zoom status.
imageViewUpdateZoomStatus :: ImageView -> IO ()
imageViewUpdateZoomStatus view = do
  zoom <- liftM (\x -> floor $ formatFloatN x 2 * 100) $ I.imageViewGetZoom $ imageViewView view
  pageViewUpdateInfoStatus view "Zoom" (" Zoom (" ++ show zoom ++ "%)")

-- | Find next image file under current directory.
imageViewGetNextFile :: FilePath -> [FilePath] -> Maybe FilePath
imageViewGetNextFile _ []  = Nothing
imageViewGetNextFile _ [_] = Nothing
imageViewGetNextFile currentFile files = 
  case findIndex (== currentFile) files of
    Just i -> 
        Just $ if i >= length files - 1
                 -- Use first image when reach last image.
                 then head files
                 -- Otherwise use next image.
                 else (!!) files (i + 1)
    Nothing -> Nothing

-- | Find previous image file under current directory.
imageViewGetPrevFile :: FilePath -> [FilePath] -> Maybe FilePath
imageViewGetPrevFile _ []  = Nothing
imageViewGetPrevFile _ [_] = Nothing
imageViewGetPrevFile currentFile files = 
  case findIndex (== currentFile) files of
    Just i -> 
        Just $ if i <= 0
                 -- Use last image when reach first image.
                 then last files
                 -- Otherwise use previous image.
                 else (!!) files (i - 1)
    Nothing -> Nothing

-- | Slide show.
imageViewSlideShow :: ImageView -> IO ()
imageViewSlideShow view@(ImageView {imageViewBuffer = 
                                        ImageBuffer {imageBufferSlideShowHanlderId = slideShowId}}) = do
  sId <- readTVarIO slideShowId
  case sId of
    -- Stop slide show.
    Just id -> do
      pageViewUpdateInfoStatus view "SlideShow" " SlideShow (off)"
      timeoutRemove id
      writeTVarIO slideShowId Nothing
    -- Start slide show.
    Nothing -> do
      pageViewUpdateInfoStatus view "SlideShow" " SlideShow (on)"
      handlerId <- timeoutAdd (imageViewBrowseNext view >> return True) imageViewSlideShowInterval
      writeTVarIO slideShowId (Just handlerId)

-- | Set as background, (just work for gnome).
imageViewSetAsBackground :: ImageView -> IO ()
imageViewSetAsBackground (ImageView {imageViewBuffer = 
                                         ImageBuffer {imageBufferPath = bufferPath}}) = do
  -- Get image path.
  path <- readTVarIO bufferPath
  setDesktopBackground path 100 Zoom

-- | Keymap.
imageViewKeymap :: Map Text (ImageView -> IO ())
imageViewKeymap = 
    M.fromList [("j",           pageViewScrollStepUp)
               ,("k",           pageViewScrollStepDown)
               ,("Down",        pageViewScrollStepUp)
               ,("Up",          pageViewScrollStepDown)
               ,("h",           pageViewScrollStepRight)
               ,("l",           pageViewScrollStepLeft)
               ,("Right",       pageViewScrollStepRight)
               ,("Left",        pageViewScrollStepLeft)
               ,(" ",           pageViewScrollPageUp)
               ,("b",           pageViewScrollPageDown)
               ,("PageDown",    pageViewScrollPageUp)
               ,("PageUp",      pageViewScrollPageDown)
               ,("J",           pageViewScrollToBottom)
               ,("K",           pageViewScrollToTop)
               ,("End",         pageViewScrollToBottom)
               ,("Home",        pageViewScrollToTop)
               ,(",",           imageViewZoomOut)
               ,(".",           imageViewZoomIn)
               ,("-",           imageViewZoomOut)
               ,("=",           imageViewZoomIn)
               ,("m",           imageViewFit)
               ,("n",           imageViewBrowseNext)
               ,("Return",      imageViewBrowseNext)
               ,("p",           imageViewBrowsePrev)
               ,("N",           imageViewBrowseLast)
               ,("P",           imageViewBrowseFirst)
               ,("<",           imageViewRotateCounterclockwise)
               ,(">",           imageViewRotateClockwise)
               ,("/",           imageViewRotateMirror)
               ,("s",           imageViewSlideShow)
               ,("B",           imageViewSetAsBackground)
               ]