/// <summary>
/// Unassign the optional node.
/// </summary>
/// <param name="nodeIndex">Index of the optional node.</param>
/// <param name="isChanged">True upon return if the node was changed. False if the node was already not assigned.</param>
public virtual void Unassign(IWriteableBrowsingOptionalNodeIndex nodeIndex, out bool isChanged)
{
Contract.RequireNotNull(nodeIndex, out IWriteableBrowsingOptionalNodeIndex NodeIndex);
Debug.Assert(StateTable.ContainsKey(NodeIndex));
IWriteableOptionalNodeState State = StateTable[NodeIndex] as IWriteableOptionalNodeState;
Debug.Assert(State != null);
IWriteableOptionalInner <IWriteableBrowsingOptionalNodeIndex> Inner = State.ParentInner as IWriteableOptionalInner <IWriteableBrowsingOptionalNodeIndex>;
Debug.Assert(Inner != null);
if (Inner.IsAssigned)
{
Action <IWriteableOperation> HandlerRedo = (IWriteableOperation operation) => RedoUnassign(operation);
Action <IWriteableOperation> HandlerUndo = (IWriteableOperation operation) => UndoUnassign(operation);
WriteableAssignmentOperation Operation = CreateAssignmentOperation(Inner.Owner.Node, Inner.PropertyName, HandlerRedo, HandlerUndo, isNested: false);
Operation.Redo();
SetLastOperation(Operation);
CheckInvariant();
isChanged = true;
}
else
{
isChanged = false;
}
}
/// <summary>
/// Reduces the optional node.
/// </summary>
private protected virtual void ReduceOptional(IWriteableOptionalInner <IWriteableBrowsingOptionalNodeIndex> optionalInner, WriteableOperationList operationList, bool isNested)
{
if (optionalInner.IsAssigned && NodeHelper.IsOptionalAssignedToDefault(optionalInner.ChildState.Optional))
{
IWriteableBrowsingOptionalNodeIndex ParentIndex = optionalInner.ChildState.ParentIndex;
Action <IWriteableOperation> HandlerRedo = (IWriteableOperation operation) => RedoUnassign(operation);
Action <IWriteableOperation> HandlerUndo = (IWriteableOperation operation) => UndoUnassign(operation);
WriteableAssignmentOperation Operation = CreateAssignmentOperation(optionalInner.Owner.Node, optionalInner.PropertyName, HandlerRedo, HandlerUndo, isNested);
Operation.Redo();
operationList.Add(Operation);
}
}
private protected virtual void ClearOptional(IWriteableReplaceOperation operation)
{
INode ParentNode = Owner.Node;
WriteableBrowsingOptionalNodeIndex OldBrowsingIndex = (WriteableBrowsingOptionalNodeIndex)ChildState.ParentIndex;
INode OldNode = ChildState.Optional.HasItem ? ChildState.Node : null;
NodeTreeHelperOptional.ClearOptionalChildNode(ParentNode, PropertyName);
IWriteableBrowsingOptionalNodeIndex NewBrowsingIndex = CreateBrowsingNodeIndex();
IWriteableOptionalNodeState NewChildState = (IWriteableOptionalNodeState)CreateNodeState(NewBrowsingIndex);
SetChildState(NewChildState);
operation.Update(OldBrowsingIndex, NewBrowsingIndex, OldNode, NewChildState);
}
/// <summary>
/// Expands the optional node.
/// * If assigned, does nothing.
/// * If it has an item, assign it.
/// * Otherwise, assign the item to a default node.
/// </summary>
private protected virtual void ExpandOptional(IWriteableOptionalInner <IWriteableBrowsingOptionalNodeIndex> optionalInner, WriteableOperationList operationList)
{
if (optionalInner.IsAssigned)
{
return;
}
IWriteableBrowsingOptionalNodeIndex ParentIndex = optionalInner.ChildState.ParentIndex;
Action <IWriteableOperation> HandlerRedo = (IWriteableOperation operation) => RedoAssign(operation);
Action <IWriteableOperation> HandlerUndo = (IWriteableOperation operation) => UndoAssign(operation);
WriteableAssignmentOperation Operation = CreateAssignmentOperation(optionalInner.Owner.Node, optionalInner.PropertyName, HandlerRedo, HandlerUndo, isNested: false);
Operation.Redo();
operationList.Add(Operation);
}
private protected virtual void ReplaceOptional(IWriteableReplaceOperation operation)
{
Node ParentNode = Owner.Node;
IWriteableBrowsingOptionalNodeIndex OldBrowsingIndex = (IWriteableBrowsingOptionalNodeIndex)ChildState.ParentIndex;
Node OldNode = ChildState.Node;
if (operation.ClearNode)
{
NodeTreeHelperOptional.UnassignChildNode(ParentNode, PropertyName);
}
else
{
NodeTreeHelperOptional.SetOptionalChildNode(ParentNode, PropertyName, operation.NewNode);
}
IWriteableBrowsingOptionalNodeIndex NewBrowsingIndex = CreateBrowsingNodeIndex();
IWriteableOptionalNodeState NewChildState = (IWriteableOptionalNodeState)CreateNodeState(NewBrowsingIndex);
SetChildState(NewChildState);
operation.Update(OldBrowsingIndex, NewBrowsingIndex, OldNode, NewChildState);
}
/// <summary>
/// Initializes a new instance of the <see cref="WriteableOptionalNodeState{IInner}"/> class.
/// </summary>
/// <param name="parentIndex">The index used to create the state.</param>
public WriteableOptionalNodeState(IWriteableBrowsingOptionalNodeIndex parentIndex)
: base(parentIndex)
{
}
