Portability | portable (depends on GHC) |
---|---|
Stability | provisional |
Maintainer | gtk2hs-users@lists.sourceforge.net |
Graphics.UI.Gtk.Windows.OffscreenWindow
Contents
Description
A toplevel container widget used to manage offscreen rendering of child widgets.
- Module available since Gtk+ version 2.20
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.