{-# LINE 2 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} -- -*-haskell-*- -- GIMP Toolkit (GTK) Widget OffscreenWindow -- -- Author : Andy Stewart -- -- Created: 25 Mar 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) -- -- A toplevel container widget used to manage offscreen rendering of child widgets. -- -- * Module available since Gtk+ version 2.20 -- module Graphics.UI.Gtk.Windows.OffscreenWindow ( -- * Detail -- | 'OffscreenWindow' is strictly intended to be used for obtaining snapshots of widgets that are not -- part of a normal widget hierarchy. It differs from 'widgetGetSnapshot' in that the widget you -- want to get a snapshot of need not be displayed on the user's screen as a part of a widget -- hierarchy. However, since 'OffscreenWindow' is a toplevel widget you cannot obtain snapshots of a -- full window with it since you cannot pack a toplevel widget in another toplevel. -- -- The idea is to take a widget and manually set the state of it, add it to a 'OffscreenWindow' and -- then retrieve the snapshot as a 'Pixmap' or 'Pixbuf'. -- -- 'OffscreenWindow' derives from 'Window' only as an implementation detail. Applications should not -- use any API specific to 'Window' to operate on this object. It should be treated as a 'Bin' that -- has no parent widget. -- -- When contained offscreen widgets are redrawn, 'OffscreenWindow' will emit a 'damageEvent' signal. -- * Class Hierarchy -- | -- @ -- | 'GObject' -- | +----'Object' -- | +----'Widget' -- | +----'Container' -- | +----'Bin' -- | +----Window -- | +----'OffscreenWindow' -- @ -- * Types OffscreenWindow, OffscreenWindowClass, castToOffscreenWindow, gTypeOffscreenWindow, toOffscreenWindow, -- * Constructors offscreenWindowNew, -- * Methods offscreenWindowGetPixmap, offscreenWindowGetPixbuf, ) where import Control.Monad (liftM) import System.Glib.FFI import Graphics.UI.Gtk.Abstract.Object (makeNewObject) import Graphics.UI.Gtk.Types {-# LINE 82 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} {-# LINE 84 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} -- | Creates a toplevel container widget that is used to retrieve snapshots of widgets without showing -- them on the screen. For widgets that are on the screen and part of a normal widget hierarchy, -- 'widgetGetSnapshot' can be used instead. -- -- * Available since Gtk+ version 2.20 -- offscreenWindowNew :: IO OffscreenWindow offscreenWindowNew = makeNewObject mkOffscreenWindow $ liftM (castPtr :: Ptr Widget -> Ptr OffscreenWindow) $ gtk_offscreen_window_new {-# LINE 97 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} -- | Retrieves a snapshot of the contained widget in the form of a 'Pixmap'. If you need to keep this -- around over window resizes then you should add a reference to it. -- -- * Available since Gtk+ version 2.20 -- offscreenWindowGetPixmap :: OffscreenWindowClass self => self -- ^ @offscreen@ the 'OffscreenWindow' contained widget. -> IO (Maybe Pixmap) -- ^ returns A 'Pixmap' pointer to the offscreen pixmap, or 'Nothing'. offscreenWindowGetPixmap offscreen = maybeNull (makeNewGObject mkPixmap) $ (\(OffscreenWindow arg1) -> withForeignPtr arg1 $ \argPtr1 ->gtk_offscreen_window_get_pixmap argPtr1) {-# LINE 110 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} (toOffscreenWindow offscreen) -- | Retrieves a snapshot of the contained widget in the form of a 'Pixbuf'. -- -- * Available since Gtk+ version 2.20 -- offscreenWindowGetPixbuf :: OffscreenWindowClass self => self -- ^ @offscreen@ the 'OffscreenWindow' contained widget. -> IO (Maybe Pixbuf) -- ^ returns A 'Pixbuf' pointer to the offscreen pixbuf, or 'Nothing'. offscreenWindowGetPixbuf offscreen = maybeNull (wrapNewGObject mkPixbuf) $ (\(OffscreenWindow arg1) -> withForeignPtr arg1 $ \argPtr1 ->gtk_offscreen_window_get_pixbuf argPtr1) {-# LINE 123 "./Graphics/UI/Gtk/Windows/OffscreenWindow.chs" #-} (toOffscreenWindow offscreen) foreign import ccall safe "gtk_offscreen_window_new" gtk_offscreen_window_new :: (IO (Ptr Widget)) foreign import ccall safe "gtk_offscreen_window_get_pixmap" gtk_offscreen_window_get_pixmap :: ((Ptr OffscreenWindow) -> (IO (Ptr Pixmap))) foreign import ccall safe "gtk_offscreen_window_get_pixbuf" gtk_offscreen_window_get_pixbuf :: ((Ptr OffscreenWindow) -> (IO (Ptr Pixbuf)))