nsresult
nsTransactionManager::EndTransaction()
{
nsCOMPtr<nsITransaction> tint;
nsRefPtr<nsTransactionItem> tx;
nsresult result = NS_OK;
// No need for LOCK/UNLOCK_TX_MANAGER() calls since the calling routine
// should have done this already!
result = mDoStack.Pop(getter_AddRefs(tx));
if (NS_FAILED(result) || !tx)
return result;
result = tx->GetTransaction(getter_AddRefs(tint));
if (NS_FAILED(result)) {
// XXX: What do we do with the transaction item at this point?
return result;
}
if (!tint) {
PRInt32 nc = 0;
// If we get here, the transaction must be a dummy batch transaction
// created by BeginBatch(). If it contains no children, get rid of it!
tx->GetNumberOfChildren(&nc);
if (!nc) {
return result;
}
}
// Check if the transaction is transient. If it is, there's nothing
// more to do, just return.
PRBool isTransient = PR_FALSE;
if (tint)
result = tint->GetIsTransient(&isTransient);
if (NS_FAILED(result) || isTransient || !mMaxTransactionCount) {
// XXX: Should we be clearing the redo stack if the transaction
// is transient and there is nothing on the do stack?
return result;
}
nsRefPtr<nsTransactionItem> top;
// Check if there is a transaction on the do stack. If there is,
// the current transaction is a "sub" transaction, and should
// be added to the transaction at the top of the do stack.
result = mDoStack.Peek(getter_AddRefs(top));
if (top) {
result = top->AddChild(tx);
// XXX: What do we do if this fails?
return result;
}
// The transaction succeeded, so clear the redo stack.
result = ClearRedoStack();
if (NS_FAILED(result)) {
// XXX: What do we do if this fails?
}
// Check if we can coalesce this transaction with the one at the top
// of the undo stack.
top = 0;
result = mUndoStack.Peek(getter_AddRefs(top));
if (tint && top) {
PRBool didMerge = PR_FALSE;
nsCOMPtr<nsITransaction> topTransaction;
result = top->GetTransaction(getter_AddRefs(topTransaction));
if (topTransaction) {
PRBool doInterrupt = PR_FALSE;
result = WillMergeNotify(topTransaction, tint, &doInterrupt);
NS_ENSURE_SUCCESS(result, result);
if (!doInterrupt) {
result = topTransaction->Merge(tint, &didMerge);
nsresult result2 = DidMergeNotify(topTransaction, tint, didMerge, result);
if (NS_SUCCEEDED(result))
result = result2;
if (NS_FAILED(result)) {
// XXX: What do we do if this fails?
}
if (didMerge) {
return result;
}
}
}
}
// Check to see if we've hit the max level of undo. If so,
// pop the bottom transaction off the undo stack and release it!
PRInt32 sz = 0;
result = mUndoStack.GetSize(&sz);
if (mMaxTransactionCount > 0 && sz >= mMaxTransactionCount) {
nsRefPtr<nsTransactionItem> overflow;
result = mUndoStack.PopBottom(getter_AddRefs(overflow));
// XXX: What do we do in the case where this fails?
}
// Push the transaction on the undo stack:
result = mUndoStack.Push(tx);
if (NS_FAILED(result)) {
// XXX: What do we do in the case where a clear fails?
// Remove the transaction from the stack, and release it?
}
return result;
}
nsresult
nsTransactionManager::EndTransaction()
{
nsresult result = NS_OK;
nsRefPtr<nsTransactionItem> tx = mDoStack.Pop();
if (!tx)
return NS_ERROR_FAILURE;
nsCOMPtr<nsITransaction> tint = tx->GetTransaction();
if (!tint) {
PRInt32 nc = 0;
// If we get here, the transaction must be a dummy batch transaction
// created by BeginBatch(). If it contains no children, get rid of it!
tx->GetNumberOfChildren(&nc);
if (!nc) {
return result;
}
}
// Check if the transaction is transient. If it is, there's nothing
// more to do, just return.
bool isTransient = false;
if (tint)
result = tint->GetIsTransient(&isTransient);
if (NS_FAILED(result) || isTransient || !mMaxTransactionCount) {
// XXX: Should we be clearing the redo stack if the transaction
// is transient and there is nothing on the do stack?
return result;
}
// Check if there is a transaction on the do stack. If there is,
// the current transaction is a "sub" transaction, and should
// be added to the transaction at the top of the do stack.
nsRefPtr<nsTransactionItem> top = mDoStack.Peek();
if (top) {
result = top->AddChild(tx);
// XXX: What do we do if this fails?
return result;
}
// The transaction succeeded, so clear the redo stack.
result = ClearRedoStack();
if (NS_FAILED(result)) {
// XXX: What do we do if this fails?
}
// Check if we can coalesce this transaction with the one at the top
// of the undo stack.
top = mUndoStack.Peek();
if (tint && top) {
bool didMerge = false;
nsCOMPtr<nsITransaction> topTransaction = top->GetTransaction();
if (topTransaction) {
bool doInterrupt = false;
result = WillMergeNotify(topTransaction, tint, &doInterrupt);
NS_ENSURE_SUCCESS(result, result);
if (!doInterrupt) {
result = topTransaction->Merge(tint, &didMerge);
nsresult result2 = DidMergeNotify(topTransaction, tint, didMerge, result);
if (NS_SUCCEEDED(result))
result = result2;
if (NS_FAILED(result)) {
// XXX: What do we do if this fails?
}
if (didMerge) {
return result;
}
}
}
}
// Check to see if we've hit the max level of undo. If so,
// pop the bottom transaction off the undo stack and release it!
PRInt32 sz = mUndoStack.GetSize();
if (mMaxTransactionCount > 0 && sz >= mMaxTransactionCount) {
nsRefPtr<nsTransactionItem> overflow = mUndoStack.PopBottom();
}
// Push the transaction on the undo stack:
mUndoStack.Push(tx);
return NS_OK;
}