//=====================================================================
/// <summary>
/// This is used to update the change policy based on the owning data list or data navigator
/// </summary>
/// <param name="canAdd">If true and the data source permits it, allow additions</param>
/// <param name="canEdit">If true and the data source permits it, allow edits</param>
/// <param name="canDelete">If true and the data source permits it, allow deletes</param>
internal void UpdatePolicy(bool canAdd, bool canEdit, bool canDelete)
{
bool listCanAdd, listCanEdit, listCanDelete, listChangeNotify, oldAdd = this.AllowAdditions,
oldEdit = this.AllowEdits, oldDelete = this.AllowDeletes;
CurrencyManager listManager = (dataList != null) ? dataList.ListManager : dataNav.ListManager;
if (listManager == null)
{
this.AllowAdditions = canAdd;
this.AllowEdits = canEdit;
this.AllowDeletes = canDelete;
}
else
{
IBindingList bl = (listManager.List as IBindingList);
if (bl != null)
{
listCanAdd = bl.AllowNew;
listCanEdit = bl.AllowEdit;
listCanDelete = bl.AllowRemove;
listChangeNotify = bl.SupportsChangeNotification;
}
else
{
listCanAdd = listCanDelete = (!listManager.List.IsReadOnly && !listManager.List.IsFixedSize);
listCanEdit = !listManager.List.IsReadOnly;
listChangeNotify = false;
}
this.AllowAdditions = (canAdd && listCanAdd && listChangeNotify);
this.AllowEdits = (canEdit && listCanEdit);
this.AllowDeletes = (canDelete && listCanDelete && listChangeNotify);
}
// If the change policy was modified, raise the ChangePolicyModified event on the owner
if (dataList != null)
{
if (this.AllowAdditions != oldAdd || this.AllowEdits != oldEdit || this.AllowDeletes != oldDelete)
{
dataList.OnChangePolicyModified(new ChangePolicyEventArgs(this.AllowAdditions,
this.AllowEdits, this.AllowDeletes));
}
else
{
// Enable or disable Add and Delete based on the policy
dataList.btnAdd.Enabled = (this.AllowAdditions && listManager != null);
dataList.btnDelete.Enabled = (this.AllowDeletes && listManager != null &&
listManager.Count > 0);
}
}
else
if (this.AllowAdditions != oldAdd || this.AllowEdits != oldEdit || this.AllowDeletes != oldDelete)
{
dataNav.OnChangePolicyModified(new ChangePolicyEventArgs(this.AllowAdditions, this.AllowEdits,
this.AllowDeletes));
}
else
{
// Enable or disable Add and Delete based on the policy
dataNav.btnAdd.Enabled = (this.AllowAdditions && listManager != null);
dataNav.btnDelete.Enabled = (this.AllowDeletes && listManager != null && listManager.Count > 0);
}
}
