gecko-dev/editor/libeditor/SplitNodeTxn.cpp

128 lines
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 "SplitNodeTxn.h"
#include "mozilla/dom/Selection.h"
#include "nsAString.h"
#include "nsDebug.h" // for NS_ASSERTION, etc
#include "nsEditor.h" // for nsEditor
#include "nsError.h" // for NS_ERROR_NOT_INITIALIZED, etc
#include "nsIContent.h" // for nsIContent
using namespace mozilla;
using namespace mozilla::dom;
// note that aEditor is not refcounted
SplitNodeTxn::SplitNodeTxn(nsEditor& aEditor, nsIContent& aNode,
int32_t aOffset)
: EditTxn()
, mEditor(aEditor)
, mExistingRightNode(&aNode)
, mOffset(aOffset)
, mNewLeftNode(nullptr)
, mParent(nullptr)
{
}
SplitNodeTxn::~SplitNodeTxn()
{
}
NS_IMPL_CYCLE_COLLECTION_INHERITED(SplitNodeTxn, EditTxn,
mParent,
mNewLeftNode)
NS_IMPL_ADDREF_INHERITED(SplitNodeTxn, EditTxn)
NS_IMPL_RELEASE_INHERITED(SplitNodeTxn, EditTxn)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SplitNodeTxn)
NS_INTERFACE_MAP_END_INHERITING(EditTxn)
NS_IMETHODIMP
SplitNodeTxn::DoTransaction()
{
// Create a new node
ErrorResult rv;
// Don't use .downcast directly because AsContent has an assertion we want
nsCOMPtr<nsINode> clone = mExistingRightNode->CloneNode(false, rv);
NS_ASSERTION(!rv.Failed() && clone, "Could not create clone");
NS_ENSURE_TRUE(!rv.Failed() && clone, rv.ErrorCode());
mNewLeftNode = dont_AddRef(clone.forget().take()->AsContent());
mEditor.MarkNodeDirty(mExistingRightNode->AsDOMNode());
// Get the parent node
mParent = mExistingRightNode->GetParentNode();
NS_ENSURE_TRUE(mParent, NS_ERROR_NULL_POINTER);
// Insert the new node
rv = mEditor.SplitNodeImpl(*mExistingRightNode, mOffset, *mNewLeftNode);
if (mEditor.GetShouldTxnSetSelection()) {
nsRefPtr<Selection> selection = mEditor.GetSelection();
NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
rv = selection->Collapse(mNewLeftNode, mOffset);
}
return rv.ErrorCode();
}
NS_IMETHODIMP
SplitNodeTxn::UndoTransaction()
{
MOZ_ASSERT(mNewLeftNode && mParent);
// This assumes Do inserted the new node in front of the prior existing node
return mEditor.JoinNodesImpl(mExistingRightNode, mNewLeftNode, mParent);
}
/* Redo cannot simply resplit the right node, because subsequent transactions
* on the redo stack may depend on the left node existing in its previous
* state.
*/
NS_IMETHODIMP
SplitNodeTxn::RedoTransaction()
{
MOZ_ASSERT(mNewLeftNode && mParent);
ErrorResult rv;
// First, massage the existing node so it is in its post-split state
if (mExistingRightNode->GetAsText()) {
rv = mExistingRightNode->GetAsText()->DeleteData(0, mOffset);
NS_ENSURE_SUCCESS(rv.ErrorCode(), rv.ErrorCode());
} else {
nsCOMPtr<nsIContent> child = mExistingRightNode->GetFirstChild();
nsCOMPtr<nsIContent> nextSibling;
for (int32_t i=0; i < mOffset; i++) {
if (rv.Failed()) {
return rv.ErrorCode();
}
if (!child) {
return NS_ERROR_NULL_POINTER;
}
nextSibling = child->GetNextSibling();
mExistingRightNode->RemoveChild(*child, rv);
if (!rv.Failed()) {
mNewLeftNode->AppendChild(*child, rv);
}
child = nextSibling;
}
}
// Second, re-insert the left node into the tree
mParent->InsertBefore(*mNewLeftNode, mExistingRightNode, rv);
return rv.ErrorCode();
}
NS_IMETHODIMP
SplitNodeTxn::GetTxnDescription(nsAString& aString)
{
aString.AssignLiteral("SplitNodeTxn");
return NS_OK;
}
nsIContent*
SplitNodeTxn::GetNewNode()
{
return mNewLeftNode;
}