// Adds this element to the selection
void ISelectionItemProvider.AddToSelection()
{
// Make sure that the control is enabled
if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
{
throw new ElementNotEnabledException();
}
// simple case: object already selected
if (WindowsListView.IsItemSelected(_hwnd, _item))
{
return;
}
// object does not support multi-selection
if (!WindowsListView.MultiSelected(_hwnd))
{
IRawElementProviderSimple container = ((ISelectionItemProvider)this).SelectionContainer;
bool selectionRequired = container != null ? ((ISelectionProvider)container).IsSelectionRequired : true;
// For single selection containers that IsSelectionRequired == false and nothing is selected
// an AddToSelection is valid.
if (selectionRequired || WindowsListView.GetSelectedItemCount(_hwnd) > 0)
{
throw new InvalidOperationException(SR.Get(SRID.DoesNotSupportMultipleSelection));
}
}
// At this point we know: Item either supports multiple selection or nothing
// is selected in the list
// Try to select an item
if (!WindowsListView.SelectItem(_hwnd, _item))
{
throw new InvalidOperationException(SR.Get(SRID.OperationCannotBePerformed));
}
}
