[Gtk2hs-commit] (main branch): Fix crash bug of treeViewColumnGetWidget.

[Andy S. <And...@co...>]

Sat May  8 09:06:57 EDT 2010  Andy Stewart <laz...@gm...>
  * Fix crash bug of treeViewColumnGetWidget.
  Ignore-this: bf8dc177526ddc4a3af03ee2c5b2013d
  
  When you first call treeViewColumnGetWidget will got error "main: user error (makeNewObject: object is NULL)"
  Details see : http://library.gnome.org/devel/gtk/stable/GtkTreeViewColumn.html#gtk-tree-view-column-get-widget

    hunk ./gtk/Graphics/UI/Gtk/ModelView/TreeViewColumn.chs 379
    - -> widget
    + -> Maybe widget
    hunk ./gtk/Graphics/UI/Gtk/ModelView/TreeViewColumn.chs 384
    -    (toWidget widget)
    +    (maybe (Widget nullForeignPtr) toWidget widget)
    hunk ./gtk/Graphics/UI/Gtk/ModelView/TreeViewColumn.chs 390
    -treeViewColumnGetWidget :: TreeViewColumn -> IO Widget
    -treeViewColumnGetWidget self =
    -  makeNewObject mkWidget $
    -  {# call unsafe tree_view_column_get_widget #}
    -    self
    +treeViewColumnGetWidget :: TreeViewColumn [_$_]
    + -> IO (Maybe Widget) -- ^ returns the 'Widget' in the column header, or 'Nothing'
    +treeViewColumnGetWidget self = do
    +  widgetPtr <- {# call unsafe tree_view_column_get_widget #} self
    +  if widgetPtr == nullPtr
    +     then return Nothing
    +     else liftM Just $ makeNewObject mkWidget (return widgetPtr)
    hunk ./gtk/Graphics/UI/Gtk/ModelView/TreeViewColumn.chs 688
    -treeViewColumnWidget :: WidgetClass widget => ReadWriteAttr TreeViewColumn Widget widget
    +treeViewColumnWidget :: WidgetClass widget => ReadWriteAttr TreeViewColumn (Maybe Widget) (Maybe widget)