Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 509 insertions, 0 deletions

diff --git a/editor/txmgr/TransactionManager.cpp b/editor/txmgr/TransactionManager.cpp
new file mode 100644
index 0000000000..ad4d641d56
--- /dev/null
+++ b/editor/txmgr/TransactionManager.cpp
@@ -0,0 +1,509 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/TransactionManager.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/HTMLEditor.h"
+#include "mozilla/mozalloc.h"
+#include "mozilla/TransactionStack.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsISupports.h"
+#include "nsISupportsUtils.h"
+#include "nsITransaction.h"
+#include "nsIWeakReference.h"
+#include "TransactionItem.h"
+
+namespace mozilla {
+
+TransactionManager::TransactionManager(int32_t aMaxTransactionCount)
+    : mMaxTransactionCount(aMaxTransactionCount),
+      mDoStack(TransactionStack::FOR_UNDO),
+      mUndoStack(TransactionStack::FOR_UNDO),
+      mRedoStack(TransactionStack::FOR_REDO) {}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(TransactionManager)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(TransactionManager)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mHTMLEditor)
+  tmp->mDoStack.DoUnlink();
+  tmp->mUndoStack.DoUnlink();
+  tmp->mRedoStack.DoUnlink();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(TransactionManager)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mHTMLEditor)
+  tmp->mDoStack.DoTraverse(cb);
+  tmp->mUndoStack.DoTraverse(cb);
+  tmp->mRedoStack.DoTraverse(cb);
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TransactionManager)
+  NS_INTERFACE_MAP_ENTRY(nsITransactionManager)
+  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsITransactionManager)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TransactionManager)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TransactionManager)
+
+void TransactionManager::Attach(HTMLEditor& aHTMLEditor) {
+  mHTMLEditor = &aHTMLEditor;
+}
+
+void TransactionManager::Detach(const HTMLEditor& aHTMLEditor) {
+  MOZ_DIAGNOSTIC_ASSERT_IF(mHTMLEditor, &aHTMLEditor == mHTMLEditor);
+  if (mHTMLEditor == &aHTMLEditor) {
+    mHTMLEditor = nullptr;
+  }
+}
+
+MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
+TransactionManager::DoTransaction(nsITransaction* aTransaction) {
+  if (NS_WARN_IF(!aTransaction)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  OwningNonNull<nsITransaction> transaction = *aTransaction;
+
+  nsresult rv = BeginTransaction(transaction, nullptr);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("TransactionManager::BeginTransaction() failed");
+    DidDoNotify(transaction, rv);
+    return rv;
+  }
+
+  rv = EndTransaction(false);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionManager::EndTransaction() failed");
+
+  DidDoNotify(transaction, rv);
+  return rv;
+}
+
+MOZ_CAN_RUN_SCRIPT NS_IMETHODIMP TransactionManager::UndoTransaction() {
+  return Undo();
+}
+
+nsresult TransactionManager::Undo() {
+  // It's possible to be called Undo() again while the transaction manager is
+  // executing a transaction's DoTransaction() method.  If this happens,
+  // the Undo() request is ignored, and we return NS_ERROR_FAILURE.  This
+  // may occur if a mutation event listener calls document.execCommand("undo").
+  if (NS_WARN_IF(!mDoStack.IsEmpty())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Peek at the top of the undo stack. Don't remove the transaction
+  // until it has successfully completed.
+  RefPtr<TransactionItem> transactionItem = mUndoStack.Peek();
+  if (!transactionItem) {
+    // Bail if there's nothing on the stack.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsITransaction> transaction = transactionItem->GetTransaction();
+  nsresult rv = transactionItem->UndoTransaction(this);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionItem::UndoTransaction() failed");
+  if (NS_SUCCEEDED(rv)) {
+    transactionItem = mUndoStack.Pop();
+    mRedoStack.Push(transactionItem.forget());
+  }
+
+  if (transaction) {
+    DidUndoNotify(*transaction, rv);
+  }
+  return rv;
+}
+
+MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
+TransactionManager::RedoTransaction() {
+  return Redo();
+}
+
+nsresult TransactionManager::Redo() {
+  // It's possible to be called Redo() again while the transaction manager is
+  // executing a transaction's DoTransaction() method.  If this happens,
+  // the Redo() request is ignored, and we return NS_ERROR_FAILURE.  This
+  // may occur if a mutation event listener calls document.execCommand("redo").
+  if (NS_WARN_IF(!mDoStack.IsEmpty())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Peek at the top of the redo stack. Don't remove the transaction
+  // until it has successfully completed.
+  RefPtr<TransactionItem> transactionItem = mRedoStack.Peek();
+  if (!transactionItem) {
+    // Bail if there's nothing on the stack.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsITransaction> transaction = transactionItem->GetTransaction();
+  nsresult rv = transactionItem->RedoTransaction(this);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionItem::RedoTransaction() failed");
+  if (NS_SUCCEEDED(rv)) {
+    transactionItem = mRedoStack.Pop();
+    mUndoStack.Push(transactionItem.forget());
+  }
+
+  if (transaction) {
+    DidRedoNotify(*transaction, rv);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP TransactionManager::Clear() {
+  return NS_WARN_IF(!ClearUndoRedo()) ? NS_ERROR_FAILURE : NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::BeginBatch(nsISupports* aData) {
+  nsresult rv = BeginBatchInternal(aData);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionManager::BeginBatchInternal() failed");
+  return rv;
+}
+
+nsresult TransactionManager::BeginBatchInternal(nsISupports* aData) {
+  // We can batch independent transactions together by simply pushing
+  // a dummy transaction item on the do stack. This dummy transaction item
+  // will be popped off the do stack, and then pushed on the undo stack
+  // in EndBatch().
+  nsresult rv = BeginTransaction(nullptr, aData);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionManager::BeginTransaction() failed");
+  return rv;
+}
+
+NS_IMETHODIMP TransactionManager::EndBatch(bool aAllowEmpty) {
+  nsresult rv = EndBatchInternal(aAllowEmpty);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionManager::EndBatchInternal() failed");
+  return rv;
+}
+
+nsresult TransactionManager::EndBatchInternal(bool aAllowEmpty) {
+  // XXX: Need to add some mechanism to detect the case where the transaction
+  //      at the top of the do stack isn't the dummy transaction, so we can
+  //      throw an error!! This can happen if someone calls EndBatch() within
+  //      the DoTransaction() method of a transaction.
+  //
+  //      For now, we can detect this case by checking the value of the
+  //      dummy transaction's mTransaction field. If it is our dummy
+  //      transaction, it should be nullptr. This may not be true in the
+  //      future when we allow users to execute a transaction when beginning
+  //      a batch!!!!
+  RefPtr<TransactionItem> transactionItem = mDoStack.Peek();
+  if (NS_WARN_IF(!transactionItem)) {
+    return NS_ERROR_FAILURE;
+  }
+  nsCOMPtr<nsITransaction> transaction = transactionItem->GetTransaction();
+  if (NS_WARN_IF(transaction)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv = EndTransaction(aAllowEmpty);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                       "TransactionManager::EndTransaction() failed");
+  return rv;
+}
+
+NS_IMETHODIMP TransactionManager::GetNumberOfUndoItems(int32_t* aNumItems) {
+  *aNumItems = static_cast<int32_t>(NumberOfUndoItems());
+  MOZ_ASSERT(*aNumItems >= 0);
+  return NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::GetNumberOfRedoItems(int32_t* aNumItems) {
+  *aNumItems = static_cast<int32_t>(NumberOfRedoItems());
+  MOZ_ASSERT(*aNumItems >= 0);
+  return NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::GetMaxTransactionCount(int32_t* aMaxCount) {
+  if (NS_WARN_IF(!aMaxCount)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  *aMaxCount = mMaxTransactionCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::SetMaxTransactionCount(int32_t aMaxCount) {
+  return NS_WARN_IF(!EnableUndoRedo(aMaxCount)) ? NS_ERROR_FAILURE : NS_OK;
+}
+
+bool TransactionManager::EnableUndoRedo(int32_t aMaxTransactionCount) {
+  // It is illegal to call EnableUndoRedo() while the transaction manager is
+  // executing a transaction's DoTransaction() method because the undo and redo
+  // stacks might get pruned.  If this happens, the EnableUndoRedo() request is
+  // ignored, and we return false.
+  if (NS_WARN_IF(!mDoStack.IsEmpty())) {
+    return false;
+  }
+
+  // If aMaxTransactionCount is 0, it means to disable undo/redo.
+  if (!aMaxTransactionCount) {
+    mUndoStack.Clear();
+    mRedoStack.Clear();
+    mMaxTransactionCount = 0;
+    return true;
+  }
+
+  // If aMaxTransactionCount is less than zero, the user wants unlimited
+  // levels of undo! No need to prune the undo or redo stacks.
+  if (aMaxTransactionCount < 0) {
+    mMaxTransactionCount = -1;
+    return true;
+  }
+
+  // If new max transaction count is greater than or equal to current max
+  // transaction count, we don't need to remove any transactions.
+  if (mMaxTransactionCount >= 0 &&
+      mMaxTransactionCount <= aMaxTransactionCount) {
+    mMaxTransactionCount = aMaxTransactionCount;
+    return true;
+  }
+
+  // If aMaxTransactionCount is greater than the number of transactions that
+  // currently exist on the undo and redo stack, there is no need to prune the
+  // undo or redo stacks.
+  size_t numUndoItems = NumberOfUndoItems();
+  size_t numRedoItems = NumberOfRedoItems();
+  size_t total = numUndoItems + numRedoItems;
+  size_t newMaxTransactionCount = static_cast<size_t>(aMaxTransactionCount);
+  if (newMaxTransactionCount > total) {
+    mMaxTransactionCount = aMaxTransactionCount;
+    return true;
+  }
+
+  // Try getting rid of some transactions on the undo stack! Start at
+  // the bottom of the stack and pop towards the top.
+  for (; numUndoItems && (numRedoItems + numUndoItems) > newMaxTransactionCount;
+       numUndoItems--) {
+    RefPtr<TransactionItem> transactionItem = mUndoStack.PopBottom();
+    MOZ_ASSERT(transactionItem);
+  }
+
+  // If necessary, get rid of some transactions on the redo stack! Start at
+  // the bottom of the stack and pop towards the top.
+  for (; numRedoItems && (numRedoItems + numUndoItems) > newMaxTransactionCount;
+       numRedoItems--) {
+    RefPtr<TransactionItem> transactionItem = mRedoStack.PopBottom();
+    MOZ_ASSERT(transactionItem);
+  }
+
+  mMaxTransactionCount = aMaxTransactionCount;
+  return true;
+}
+
+NS_IMETHODIMP TransactionManager::PeekUndoStack(nsITransaction** aTransaction) {
+  MOZ_ASSERT(aTransaction);
+  *aTransaction = PeekUndoStack().take();
+  return NS_OK;
+}
+
+already_AddRefed<nsITransaction> TransactionManager::PeekUndoStack() {
+  RefPtr<TransactionItem> transactionItem = mUndoStack.Peek();
+  if (!transactionItem) {
+    return nullptr;
+  }
+  return transactionItem->GetTransaction();
+}
+
+NS_IMETHODIMP TransactionManager::PeekRedoStack(nsITransaction** aTransaction) {
+  MOZ_ASSERT(aTransaction);
+  *aTransaction = PeekRedoStack().take();
+  return NS_OK;
+}
+
+already_AddRefed<nsITransaction> TransactionManager::PeekRedoStack() {
+  RefPtr<TransactionItem> transactionItem = mRedoStack.Peek();
+  if (!transactionItem) {
+    return nullptr;
+  }
+  return transactionItem->GetTransaction();
+}
+
+nsresult TransactionManager::BatchTopUndo() {
+  if (mUndoStack.GetSize() < 2) {
+    // Not enough transactions to merge into one batch.
+    return NS_OK;
+  }
+
+  RefPtr<TransactionItem> lastUndo = mUndoStack.Pop();
+  MOZ_ASSERT(lastUndo, "There should be at least two transactions.");
+
+  RefPtr<TransactionItem> previousUndo = mUndoStack.Peek();
+  MOZ_ASSERT(previousUndo, "There should be at least two transactions.");
+
+  nsresult rv = previousUndo->AddChild(*lastUndo);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "TransactionItem::AddChild() failed");
+
+  // Transfer data from the transactions that is going to be
+  // merged to the transaction that it is being merged with.
+  nsCOMArray<nsISupports>& lastData = lastUndo->GetData();
+  nsCOMArray<nsISupports>& previousData = previousUndo->GetData();
+  if (!previousData.AppendObjects(lastData)) {
+    NS_WARNING("nsISupports::AppendObjects() failed");
+    return NS_ERROR_FAILURE;
+  }
+  lastData.Clear();
+  return rv;
+}
+
+nsresult TransactionManager::RemoveTopUndo() {
+  if (mUndoStack.IsEmpty()) {
+    return NS_OK;
+  }
+
+  RefPtr<TransactionItem> lastUndo = mUndoStack.Pop();
+  return NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::ClearUndoStack() {
+  if (NS_WARN_IF(!mDoStack.IsEmpty())) {
+    return NS_ERROR_FAILURE;
+  }
+  mUndoStack.Clear();
+  return NS_OK;
+}
+
+NS_IMETHODIMP TransactionManager::ClearRedoStack() {
+  if (NS_WARN_IF(!mDoStack.IsEmpty())) {
+    return NS_ERROR_FAILURE;
+  }
+  mRedoStack.Clear();
+  return NS_OK;
+}
+
+void TransactionManager::DidDoNotify(nsITransaction& aTransaction,
+                                     nsresult aDoResult) {
+  if (mHTMLEditor) {
+    RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+    htmlEditor->DidDoTransaction(*this, aTransaction, aDoResult);
+  }
+}
+
+void TransactionManager::DidUndoNotify(nsITransaction& aTransaction,
+                                       nsresult aUndoResult) {
+  if (mHTMLEditor) {
+    RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+    htmlEditor->DidUndoTransaction(*this, aTransaction, aUndoResult);
+  }
+}
+
+void TransactionManager::DidRedoNotify(nsITransaction& aTransaction,
+                                       nsresult aRedoResult) {
+  if (mHTMLEditor) {
+    RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+    htmlEditor->DidRedoTransaction(*this, aTransaction, aRedoResult);
+  }
+}
+
+nsresult TransactionManager::BeginTransaction(nsITransaction* aTransaction,
+                                              nsISupports* aData) {
+  // XXX: POSSIBLE OPTIMIZATION
+  //      We could use a factory that pre-allocates/recycles transaction items.
+  RefPtr<TransactionItem> transactionItem = new TransactionItem(aTransaction);
+
+  if (aData) {
+    nsCOMArray<nsISupports>& data = transactionItem->GetData();
+    data.AppendObject(aData);
+  }
+
+  mDoStack.Push(transactionItem);
+
+  nsresult rv = transactionItem->DoTransaction();
+  if (NS_FAILED(rv)) {
+    NS_WARNING("TransactionItem::DoTransaction() failed");
+    transactionItem = mDoStack.Pop();
+  }
+  return rv;
+}
+
+nsresult TransactionManager::EndTransaction(bool aAllowEmpty) {
+  RefPtr<TransactionItem> transactionItem = mDoStack.Pop();
+  if (NS_WARN_IF(!transactionItem)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsITransaction> transaction = transactionItem->GetTransaction();
+  if (!transaction && !aAllowEmpty) {
+    // If we get here, the transaction must be a dummy batch transaction
+    // created by BeginBatch(). If it contains no children, get rid of it!
+    if (!transactionItem->NumberOfChildren()) {
+      return NS_OK;
+    }
+  }
+
+  // Check if the transaction is transient. If it is, there's nothing
+  // more to do, just return.
+  if (transaction) {
+    bool isTransient = false;
+    nsresult rv = transaction->GetIsTransient(&isTransient);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("nsITransaction::GetIsTransient() failed");
+      return rv;
+    }
+    // XXX: Should we be clearing the redo stack if the transaction
+    //      is transient and there is nothing on the do stack?
+    if (isTransient) {
+      return NS_OK;
+    }
+  }
+
+  if (!mMaxTransactionCount) {
+    return NS_OK;
+  }
+
+  // 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.
+  RefPtr<TransactionItem> topTransactionItem = mDoStack.Peek();
+  if (topTransactionItem) {
+    // XXX: What do we do if this fails?
+    nsresult rv = topTransactionItem->AddChild(*transactionItem);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                         "TransactionItem::AddChild() failed");
+    return rv;
+  }
+
+  // The transaction succeeded, so clear the redo stack.
+  mRedoStack.Clear();
+
+  // Check if we can coalesce this transaction with the one at the top
+  // of the undo stack.
+  topTransactionItem = mUndoStack.Peek();
+  if (transaction && topTransactionItem) {
+    bool didMerge = false;
+    nsCOMPtr<nsITransaction> topTransaction =
+        topTransactionItem->GetTransaction();
+    if (topTransaction) {
+      nsresult rv = topTransaction->Merge(transaction, &didMerge);
+      if (didMerge) {
+        return rv;
+      }
+      NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+                           "nsITransaction::Merge() failed, but ignored");
+    }
+  }
+
+  // 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!
+  int32_t sz = mUndoStack.GetSize();
+  if (mMaxTransactionCount > 0 && sz >= mMaxTransactionCount) {
+    RefPtr<TransactionItem> overflow = mUndoStack.PopBottom();
+  }
+
+  // Push the transaction on the undo stack:
+  mUndoStack.Push(transactionItem.forget());
+  return NS_OK;
+}
+
+}  // namespace mozilla