gecko-dev/editor/libeditor/base/JoinElementTxn.cpp

142 lines
4.4 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 <stdio.h> // for printf
#include "JoinElementTxn.h"
#include "nsAString.h"
#include "nsDebug.h" // for NS_ASSERTION, etc
#include "nsEditor.h" // for nsEditor
#include "nsError.h" // for NS_ERROR_NULL_POINTER, etc
#include "nsIContent.h" // for nsIContent
#include "nsIDOMCharacterData.h" // for nsIDOMCharacterData
#include "nsIEditor.h" // for nsEditor::IsModifiableNode
#include "nsISupportsImpl.h" // for EditTxn::QueryInterface, etc
using namespace mozilla;
#ifdef DEBUG
static bool gNoisy = false;
#endif
JoinElementTxn::JoinElementTxn()
: EditTxn()
{
}
NS_IMPL_CYCLE_COLLECTION_INHERITED_3(JoinElementTxn, EditTxn,
mLeftNode,
mRightNode,
mParent)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JoinElementTxn)
NS_INTERFACE_MAP_END_INHERITING(EditTxn)
NS_IMETHODIMP JoinElementTxn::Init(nsEditor *aEditor,
nsINode *aLeftNode,
nsINode *aRightNode)
{
NS_PRECONDITION((aEditor && aLeftNode && aRightNode), "null arg");
if (!aEditor || !aLeftNode || !aRightNode) { return NS_ERROR_NULL_POINTER; }
mEditor = aEditor;
mLeftNode = aLeftNode;
nsCOMPtr<nsINode> leftParent = mLeftNode->GetParentNode();
if (!mEditor->IsModifiableNode(leftParent)) {
return NS_ERROR_FAILURE;
}
mRightNode = aRightNode;
mOffset = 0;
return NS_OK;
}
// After DoTransaction() and RedoTransaction(), the left node is removed from the content tree and right node remains.
NS_IMETHODIMP JoinElementTxn::DoTransaction(void)
{
#ifdef DEBUG
if (gNoisy)
{
printf("%p Do Join of %p and %p\n",
static_cast<void*>(this),
static_cast<void*>(mLeftNode.get()),
static_cast<void*>(mRightNode.get()));
}
#endif
NS_PRECONDITION((mEditor && mLeftNode && mRightNode), "null arg");
if (!mEditor || !mLeftNode || !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
nsCOMPtr<nsINode> rightParent = mRightNode->GetParentNode();
NS_ENSURE_TRUE(rightParent, NS_ERROR_NULL_POINTER);
if (leftParent != rightParent) {
NS_ASSERTION(false, "2 nodes do not have same parent");
return NS_ERROR_INVALID_ARG;
}
// set this instance mParent.
// Other methods will see a non-null mParent and know all is well
mParent = leftParent;
mOffset = mLeftNode->Length();
nsresult rv = mEditor->JoinNodesImpl(mRightNode, mLeftNode, mParent);
#ifdef DEBUG
if (NS_SUCCEEDED(rv) && gNoisy) {
printf(" left node = %p removed\n", static_cast<void*>(mLeftNode.get()));
}
#endif
return rv;
}
//XXX: what if instead of split, we just deleted the unneeded children of mRight
// and re-inserted mLeft?
NS_IMETHODIMP JoinElementTxn::UndoTransaction(void)
{
#ifdef DEBUG
if (gNoisy)
{
printf("%p Undo Join, right node = %p\n",
static_cast<void*>(this),
static_cast<void*>(mRightNode.get()));
}
#endif
NS_ASSERTION(mRightNode && mLeftNode && mParent, "bad state");
if (!mRightNode || !mLeftNode || !mParent) { return NS_ERROR_NOT_INITIALIZED; }
// first, massage the existing node so it is in its post-split state
nsCOMPtr<nsIDOMCharacterData>rightNodeAsText = do_QueryInterface(mRightNode);
ErrorResult rv;
if (rightNodeAsText)
{
rv = rightNodeAsText->DeleteData(0, mOffset);
NS_ENSURE_SUCCESS(rv.ErrorCode(), rv.ErrorCode());
}
else
{
for (nsCOMPtr<nsINode> child = mRightNode->GetFirstChild();
child;
child = child->GetNextSibling())
{
mLeftNode->AppendChild(*child, rv);
NS_ENSURE_SUCCESS(rv.ErrorCode(), rv.ErrorCode());
}
}
// second, re-insert the left node into the tree
mParent->InsertBefore(*mLeftNode, mRightNode, rv);
return rv.ErrorCode();
}
NS_IMETHODIMP JoinElementTxn::GetTxnDescription(nsAString& aString)
{
aString.AssignLiteral("JoinElementTxn");
return NS_OK;
}