/// <inheritdoc/>
public virtual void EndTransaction(string name, AggregateActionItemDelegate aggregateActionItems, bool reverseOrderOnUndo = true)
{
if (TransactionStack.Count == 0)
{
throw new InvalidOperationException(Properties.ExceptionMessages.CannotEndNoTransactionInProgress);
}
var currentTransaction = TransactionStack.Pop();
if (currentTransaction.Count > 0)
{
var result = aggregateActionItems(currentTransaction);
var aggregateActionItem = result as IAggregateActionItem;
if (aggregateActionItem != null)
{
aggregateActionItem.ReverseOrderOnUndo = reverseOrderOnUndo;
}
Add(result);
TransactionEnded?.Invoke(this, new ActionItemsEventArgs <IActionItem>(result));
}
else
{
TransactionDiscarded?.Invoke(this, new ActionItemsEventArgs <IActionItem>(new IActionItem[0]));
}
}
/// <inheritdoc/>
public virtual void DiscardTransaction()
{
if (TransactionStack.Count == 0)
{
throw new InvalidOperationException(Properties.ExceptionMessages.CannotEndNoTransactionInProgress);
}
var actions = TransactionStack.Pop();
TransactionDiscarded?.Invoke(this, new ActionItemsEventArgs <IActionItem>(actions.ToArray()));
}
/// <summary>
/// Purges the stack from the given index (included) to the top of the stack.
/// </summary>
/// <param name="index">The index from which to purge the stack.</param>
private void PurgeFromIndex(int index)
{
if (index < 0 || index > transactions.Count)
{
throw new ArgumentOutOfRangeException(nameof(index));
}
if (transactions.Count - index > 0)
{
var discardedTransactions = new IReadOnlyTransaction[transactions.Count - index];
for (var i = index; i < transactions.Count; ++i)
{
transactions[i].Interface.Freeze();
discardedTransactions[i - index] = transactions[i];
}
transactions.RemoveRange(index, transactions.Count - index);
TransactionDiscarded?.Invoke(this, new TransactionsDiscardedEventArgs(discardedTransactions, DiscardReason.StackPurged));
}
}
/// <inheritdoc/>
public virtual void EndTransaction(string name, Func <IReadOnlyCollection <IActionItem>, IActionItem> aggregateActionItems)
{
if (TransactionStack.Count == 0)
{
throw new InvalidOperationException(Properties.ExceptionMessages.CannotEndNoTransactionInProgress);
}
var currentTransaction = TransactionStack.Pop();
if (currentTransaction.Count > 0)
{
var aggregateActionItem = aggregateActionItems(currentTransaction);
Add(aggregateActionItem);
TransactionEnded?.Invoke(this, new ActionItemsEventArgs <IActionItem>(aggregateActionItem));
}
else
{
TransactionDiscarded?.Invoke(this, new ActionItemsEventArgs <IActionItem>(new IActionItem[0]));
}
}
/// <inheritdoc/>
public void CompleteTransaction(Transaction transaction)
{
lock (lockObject)
{
try
{
if (transactionsInProgress.Count == 0)
{
throw new TransactionException("There is not transaction in progress in the transaction stack.");
}
if (transaction != transactionsInProgress.Pop())
{
throw new TransactionException("The transaction being completed is not that last created transaction.");
}
// Check if we're completing the last transaction
TransactionInProgress = transactionsInProgress.Count > 0;
// Ignore the transaction if it is empty
if (transaction.IsEmpty)
{
return;
}
// If this transaction has no effect, discard it.
if (transaction.Operations.All(x => !x.HasEffect))
{
return;
}
// If we're not the last transaction, consider this transaction as an operation of its parent transaction
if (TransactionInProgress)
{
// Avoid useless nested transaction if we have a single operation inside.
PushOperation(transaction.Operations.Count == 1 ? transaction.Operations.Single() : transaction);
return;
}
// Remove transactions that will be overwritten by this one
if (currentPosition < transactions.Count)
{
PurgeFromIndex(currentPosition);
}
if (currentPosition == Capacity)
{
// If the stack has a capacity of 0, immediately freeze the new transaction.
var oldestTransaction = Capacity > 0 ? transactions[0] : transaction;
oldestTransaction.Interface.Freeze();
for (var i = 1; i < transactions.Count; ++i)
{
transactions[i - 1] = transactions[i];
}
if (Capacity > 0)
{
transactions[--currentPosition] = null;
}
TransactionDiscarded?.Invoke(this, new TransactionsDiscardedEventArgs(oldestTransaction, DiscardReason.StackFull));
}
if (Capacity > 0)
{
if (currentPosition == transactions.Count)
{
transactions.Add(transaction);
}
else
{
transactions[currentPosition] = transaction;
}
++currentPosition;
}
}
finally
{
if (!TransactionInProgress)
{
TransactionCompleted?.Invoke(this, new TransactionEventArgs(transaction));
}
}
}
}
