/// <summary>
/// Moves a node around in a list or block list. In a block list, the node stays in same block.
/// </summary>
/// <param name="operation">Details of the operation performed.</param>
public virtual void Move(WriteableMoveNodeOperation operation)
{
int BlockIndex = operation.BlockIndex;
Debug.Assert(BlockIndex >= 0 && BlockIndex < BlockStateList.Count);
IWriteableBlockState BlockState = (IWriteableBlockState)BlockStateList[BlockIndex];
WriteablePlaceholderNodeStateReadOnlyList StateList = BlockState.StateList;
int MoveIndex = operation.Index;
int Direction = operation.Direction;
Debug.Assert(MoveIndex >= 0 && MoveIndex < StateList.Count);
Debug.Assert(MoveIndex + Direction >= 0 && MoveIndex + Direction < StateList.Count);
IWriteableBrowsingExistingBlockNodeIndex ExistingBlockNodeIndex = StateList[MoveIndex].ParentIndex as IWriteableBrowsingExistingBlockNodeIndex;
Debug.Assert(ExistingBlockNodeIndex != null);
BlockState.Move(ExistingBlockNodeIndex, MoveIndex, Direction);
IBlock ChildBlock = BlockState.ChildBlock;
NodeTreeHelperBlockList.MoveNode(ChildBlock, MoveIndex, Direction);
operation.Update((IWriteablePlaceholderNodeState)StateList[MoveIndex + Direction]);
if (Direction > 0)
{
for (int i = MoveIndex; i < MoveIndex + Direction; i++)
{
IWriteableBrowsingExistingBlockNodeIndex ChildNodeIndex = StateList[i].ParentIndex as IWriteableBrowsingExistingBlockNodeIndex;
Debug.Assert(ChildNodeIndex != null);
ChildNodeIndex.MoveDown();
ExistingBlockNodeIndex.MoveUp();
}
}
else if (Direction < 0)
{
for (int i = MoveIndex; i > MoveIndex + Direction; i--)
{
IWriteableBrowsingExistingBlockNodeIndex ChildNodeIndex = StateList[i].ParentIndex as IWriteableBrowsingExistingBlockNodeIndex;
Debug.Assert(ChildNodeIndex != null);
ChildNodeIndex.MoveUp();
ExistingBlockNodeIndex.MoveDown();
}
}
}
/// <summary>
/// Checks whether a node can be moved in a block list.
/// </summary>
/// <param name="nodeIndex">Index of the node that would be moved.</param>
/// <param name="direction">Direction of the move, relative to the current position of the item.</param>
public virtual bool IsMoveable(IWriteableBrowsingCollectionNodeIndex nodeIndex, int direction)
{
bool IsHandled = false;
bool Result = false;
if (nodeIndex is IWriteableBrowsingExistingBlockNodeIndex AsExistingBlockNodeIndex)
{
Debug.Assert(AsExistingBlockNodeIndex != null);
int BlockIndex = AsExistingBlockNodeIndex.BlockIndex;
Debug.Assert(BlockIndex >= 0 && BlockIndex < BlockStateList.Count);
IWriteableBlockState BlockState = (IWriteableBlockState)BlockStateList[BlockIndex];
WriteablePlaceholderNodeStateReadOnlyList StateList = BlockState.StateList;
int NewPosition = AsExistingBlockNodeIndex.Index + direction;
Result = NewPosition >= 0 && NewPosition < StateList.Count;
IsHandled = true;
}
Debug.Assert(IsHandled);
return(Result);
}
