1 files changed, 142 insertions, 0 deletions
diff --git a/editor/libeditor/JoinNodeTransaction.cpp b/editor/libeditor/JoinNodeTransaction.cpp
new file mode 100644
index 0000000000..5e1fde74cb
--- /dev/null
+++ b/editor/libeditor/JoinNodeTransaction.cpp
@@ -0,0 +1,142 @@
+/* -*- 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 "JoinNodeTransaction.h"
+
+#include "HTMLEditUtils.h"
+#include "mozilla/HTMLEditor.h"  // for HTMLEditor
+#include "mozilla/dom/Text.h"
+#include "nsAString.h"
+#include "nsDebug.h"          // for NS_ASSERTION, etc.
+#include "nsError.h"          // for NS_ERROR_NULL_POINTER, etc.
+#include "nsIContent.h"       // for nsIContent
+#include "nsISupportsImpl.h"  // for QueryInterface, etc.
+
+namespace mozilla {
+
+using namespace dom;
+
+// static
+already_AddRefed<JoinNodeTransaction> JoinNodeTransaction::MaybeCreate(
+    HTMLEditor& aHTMLEditor, nsIContent& aLeftContent,
+    nsIContent& aRightContent) {
+  RefPtr<JoinNodeTransaction> transaction =
+      new JoinNodeTransaction(aHTMLEditor, aLeftContent, aRightContent);
+  if (NS_WARN_IF(!transaction->CanDoIt())) {
+    return nullptr;
+  }
+  return transaction.forget();
+}
+
+JoinNodeTransaction::JoinNodeTransaction(HTMLEditor& aHTMLEditor,
+                                         nsIContent& aLeftContent,
+                                         nsIContent& aRightContent)
+    : mHTMLEditor(&aHTMLEditor),
+      mLeftContent(&aLeftContent),
+      mRightContent(&aRightContent),
+      mOffset(0) {}
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(JoinNodeTransaction, EditTransactionBase,
+                                   mHTMLEditor, mLeftContent, mRightContent,
+                                   mParentNode)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JoinNodeTransaction)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
+
+bool JoinNodeTransaction::CanDoIt() const {
+  if (NS_WARN_IF(!mLeftContent) || NS_WARN_IF(!mRightContent) ||
+      NS_WARN_IF(!mHTMLEditor) || !mLeftContent->GetParentNode()) {
+    return false;
+  }
+  return HTMLEditUtils::IsRemovableFromParentNode(*mLeftContent);
+}
+
+// After DoTransaction() and RedoTransaction(), the left node is removed from
+// the content tree and right node remains.
+NS_IMETHODIMP JoinNodeTransaction::DoTransaction() {
+  if (NS_WARN_IF(!mHTMLEditor) || NS_WARN_IF(!mLeftContent) ||
+      NS_WARN_IF(!mRightContent)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Get the parent node
+  nsINode* leftContentParent = mLeftContent->GetParentNode();
+  if (NS_WARN_IF(!leftContentParent)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Verify that mLeftContent and mRightContent have the same parent
+  if (leftContentParent != mRightContent->GetParentNode()) {
+    NS_ASSERTION(false, "Nodes do not have same parent");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Set this instance's mParentNode.  Other methods will see a non-null
+  // mParentNode and know all is well
+  mParentNode = leftContentParent;
+  mOffset = mLeftContent->Length();
+
+  OwningNonNull<HTMLEditor> htmlEditor = *mHTMLEditor;
+  OwningNonNull<nsIContent> leftContent = *mLeftContent;
+  OwningNonNull<nsIContent> rightContent = *mRightContent;
+  nsresult rv = htmlEditor->DoJoinNodes(rightContent, leftContent);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "HTMLEditor::DoJoinNodes() failed");
+  return rv;
+}
+
+// XXX: What if instead of split, we just deleted the unneeded children of
+//     mRight and re-inserted mLeft?
+NS_IMETHODIMP JoinNodeTransaction::UndoTransaction() {
+  if (NS_WARN_IF(!mParentNode) || NS_WARN_IF(!mLeftContent) ||
+      NS_WARN_IF(!mRightContent) || NS_WARN_IF(!mHTMLEditor)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  OwningNonNull<nsIContent> leftContent = *mLeftContent;
+  OwningNonNull<nsIContent> rightContent = *mRightContent;
+  OwningNonNull<nsINode> parentNode = *mParentNode;
+
+  // First, massage the existing node so it is in its post-split state
+  ErrorResult error;
+  if (Text* rightTextNode = rightContent->GetAsText()) {
+    OwningNonNull<HTMLEditor> htmlEditor = *mHTMLEditor;
+    htmlEditor->DoDeleteText(MOZ_KnownLive(*rightTextNode), 0, mOffset, error);
+    if (error.Failed()) {
+      NS_WARNING("EditorBase::DoDeleteText() failed");
+      return error.StealNSResult();
+    }
+  } else {
+    AutoTArray<OwningNonNull<nsIContent>, 24> movingChildren;
+    if (nsIContent* child = mRightContent->GetFirstChild()) {
+      movingChildren.AppendElement(*child);
+      for (uint32_t i = 0; i < mOffset; i++) {
+        child = child->GetNextSibling();
+        if (!child) {
+          break;
+        }
+        movingChildren.AppendElement(*child);
+      }
+    }
+    for (OwningNonNull<nsIContent>& child : movingChildren) {
+      leftContent->AppendChild(child, error);
+      if (error.Failed()) {
+        NS_WARNING("nsINode::AppendChild() failed");
+        return error.StealNSResult();
+      }
+    }
+  }
+
+  NS_WARNING_ASSERTION(!error.Failed(), "The previous error was ignored");
+
+  // Second, re-insert the left node into the tree
+  parentNode->InsertBefore(leftContent, rightContent, error);
+  // InsertBefore() may call MightThrowJSException() even if there is no
+  // error. We don't need the flag here.
+  error.WouldReportJSException();
+  NS_WARNING_ASSERTION(!error.Failed(), "nsINode::InsertBefore() failed");
+  return error.StealNSResult();
+}
+
+}  // namespace mozilla