gecko-dev/editor/libeditor/JoinNodeTransaction.cpp

124 строки
3.8 KiB
C++

/* -*- 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 "mozilla/EditorBase.h" // for EditorBase
#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 "nsIDOMCharacterData.h" // for nsIDOMCharacterData
#include "nsIEditor.h" // for EditorBase::IsModifiableNode
#include "nsISupportsImpl.h" // for QueryInterface, etc.
namespace mozilla {
using namespace dom;
JoinNodeTransaction::JoinNodeTransaction(EditorBase& aEditorBase,
nsINode& aLeftNode,
nsINode& aRightNode)
: mEditorBase(&aEditorBase)
, mLeftNode(&aLeftNode)
, mRightNode(&aRightNode)
, mOffset(0)
{
}
NS_IMPL_CYCLE_COLLECTION_INHERITED(JoinNodeTransaction, EditTransactionBase,
mEditorBase,
mLeftNode,
mRightNode,
mParent)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JoinNodeTransaction)
NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
bool
JoinNodeTransaction::CanDoIt() const
{
if (NS_WARN_IF(!mLeftNode) ||
NS_WARN_IF(!mRightNode) ||
NS_WARN_IF(!mEditorBase) ||
!mLeftNode->GetParentNode()) {
return false;
}
return mEditorBase->IsModifiableNode(mLeftNode->GetParentNode());
}
// 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(!mEditorBase) ||
NS_WARN_IF(!mLeftNode) ||
NS_WARN_IF(!mRightNode)) {
return NS_ERROR_NOT_INITIALIZED;
}
// Get the parent node
nsCOMPtr<nsINode> leftParent = mLeftNode->GetParentNode();
NS_ENSURE_TRUE(leftParent, NS_ERROR_NULL_POINTER);
// Verify that mLeftNode and mRightNode have the same parent
if (leftParent != mRightNode->GetParentNode()) {
NS_ASSERTION(false, "Nodes do not have same parent");
return NS_ERROR_INVALID_ARG;
}
// Set this instance's mParent. Other methods will see a non-null mParent
// and know all is well
mParent = leftParent;
mOffset = mLeftNode->Length();
return mEditorBase->JoinNodesImpl(mRightNode, mLeftNode, mParent);
}
//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(!mParent) ||
NS_WARN_IF(!mLeftNode) ||
NS_WARN_IF(!mRightNode)) {
return NS_ERROR_NOT_INITIALIZED;
}
// First, massage the existing node so it is in its post-split state
ErrorResult rv;
if (mRightNode->GetAsText()) {
rv = mRightNode->GetAsText()->DeleteData(0, mOffset);
} else {
nsCOMPtr<nsIContent> child = mRightNode->GetFirstChild();
for (uint32_t i = 0; i < mOffset; i++) {
if (rv.Failed()) {
return rv.StealNSResult();
}
if (!child) {
return NS_ERROR_NULL_POINTER;
}
nsCOMPtr<nsIContent> nextSibling = child->GetNextSibling();
mLeftNode->AppendChild(*child, rv);
child = nextSibling;
}
}
// Second, re-insert the left node into the tree
nsCOMPtr<nsINode> refNode = mRightNode;
mParent->InsertBefore(*mLeftNode, refNode, rv);
return rv.StealNSResult();
}
NS_IMETHODIMP
JoinNodeTransaction::GetTxnDescription(nsAString& aString)
{
aString.AssignLiteral("JoinNodeTransaction");
return NS_OK;
}
} // namespace mozilla