ATK, GAIL and Selection Notification

["Padraig O'Briain" <Padraig Obriain Sun COM>]

We currently use a property accessible-selection to provide notification of 
selection changes. There are two types of selection changes; when text is
selected in, for example, a GtkTreeview or a GtkEntry, and when an item is
selected in a tree, list or table.

In gailtextview.c a notification of property change is emitted when the cursor
position is moved and text is selected. However the text which is selected is
not provided as part of the notification. It can be obtained by 
atk_text_get_selection().

No notification is generated when text is selected in a GtkEntry. I think we
can implement that by listening for notification of "text-changed" property of
the GtkEntry. However bug 62636 will prevent the selected text being reported 
correctly.

For selectable labels, it is not currently possible to report the selected 
text. Bug 62148 will need to be fixed.

I do not think that it is possible for the text in a cell to be selected.

For trees, lists, tables, menus and notebook, a change in the 
ACCESSIBLE_SELECTION property should mean that there has been a change in 
the selected children. The child selected or deselected should emit a change 
notification of the accessible-state property. To determine what is currently 
selected the AtkSelection interface can be used.

I am aware that the current GAIL implementation does not do this properly.

Padraig