Transforms the given cairo context @cr that from @widget-relative
coordinates to @window-relative coordinates.
If the @widget’s window is not an ancestor of @window, no
modification will be applied.
This is the inverse to the transformation GTK applies when
preparing an expose event to be emitted with the #GtkWidget::draw
signal. It is intended to help porting multiwindow widgets from
GTK+ 2 to the rendering architecture of GTK+ 3.
Transforms the given cairo context @cr that from @widget-relative coordinates to @window-relative coordinates. If the @widget’s window is not an ancestor of @window, no modification will be applied.
This is the inverse to the transformation GTK applies when preparing an expose event to be emitted with the #GtkWidget::draw signal. It is intended to help porting multiwindow widgets from GTK+ 2 to the rendering architecture of GTK+ 3.