gecko-dev/dom/base/RangeUtils.h

122 строки
4.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
#ifndef mozilla_RangeUtils_h
#define mozilla_RangeUtils_h
#include "mozilla/RangeBoundary.h"
#include "nsIContent.h"
#include "nsINode.h"
namespace mozilla {
namespace dom {
class AbstractRange;
} // namespace dom
class RangeUtils final {
typedef dom::AbstractRange AbstractRange;
public:
/**
* GetRawRangeBoundaryBefore() and GetRawRangeBoundaryAfter() retrieve
* RawRangeBoundary which points before or after aNode.
*/
static const RawRangeBoundary GetRawRangeBoundaryAfter(nsINode* aNode) {
MOZ_ASSERT(aNode);
if (NS_WARN_IF(!aNode->IsContent())) {
return RawRangeBoundary();
}
nsINode* parentNode = aNode->GetParentNode();
if (!parentNode) {
return RawRangeBoundary();
}
RawRangeBoundary afterNode(parentNode, aNode->AsContent());
// If aNode isn't in the child nodes of its parent node, we hit this case.
// This may occur when we're called by a mutation observer while aNode is
// removed from the parent node.
if (NS_WARN_IF(afterNode.Offset() == 0)) {
return RawRangeBoundary();
}
return afterNode;
}
static const RawRangeBoundary GetRawRangeBoundaryBefore(nsINode* aNode) {
MOZ_ASSERT(aNode);
if (NS_WARN_IF(!aNode->IsContent())) {
return RawRangeBoundary();
}
nsINode* parentNode = aNode->GetParentNode();
if (!parentNode) {
return RawRangeBoundary();
}
// If aNode isn't in the child nodes of its parent node, we hit this case.
// This may occur when we're called by a mutation observer while aNode is
// removed from the parent node.
int32_t indexInParent = parentNode->ComputeIndexOf(aNode);
if (NS_WARN_IF(indexInParent < 0)) {
return RawRangeBoundary();
}
return RawRangeBoundary(parentNode, indexInParent);
}
/**
* Compute the root node of aNode for initializing range classes.
* When aNode is in an anonymous subtree, this returns the shadow root or
* binding parent. Otherwise, the root node of the document or document
* fragment. If this returns nullptr, that means aNode can be neither the
* start container nor end container of any range.
*/
static nsINode* ComputeRootNode(nsINode* aNode);
/**
* XXX nsRange should accept 0 - UINT32_MAX as offset. However, users of
* nsRange treat offset as int32_t. Additionally, some other internal
* APIs like nsINode::ComputeIndexOf() use int32_t. Therefore,
* nsRange should accept only 0 - INT32_MAX as valid offset for now.
*/
static bool IsValidOffset(uint32_t aOffset) { return aOffset <= INT32_MAX; }
static bool IsValidOffset(nsINode* aNode, uint32_t aOffset) {
return aNode && IsValidOffset(aOffset) &&
static_cast<size_t>(aOffset) <= aNode->Length();
}
template <typename PT, typename RT>
static bool IsValidOffset(const RangeBoundaryBase<PT, RT>& aBoundary) {
return IsValidOffset(aBoundary.Container(), aBoundary.Offset());
}
/**
* Return true if aStartContainer/aStartOffset and aEndContainer/aEndOffset
* are valid start and end points for a range. Otherwise, return false.
*/
static bool IsValidPoints(nsINode* aStartContainer, uint32_t aStartOffset,
nsINode* aEndContainer, uint32_t aEndOffset) {
return IsValidPoints(RawRangeBoundary(aStartContainer, aStartOffset),
RawRangeBoundary(aEndContainer, aEndOffset));
}
template <typename SPT, typename SRT, typename EPT, typename ERT>
static bool IsValidPoints(const RangeBoundaryBase<SPT, SRT>& aStartBoundary,
const RangeBoundaryBase<EPT, ERT>& aEndBoundary);
/**
* Utility routine to detect if a content node starts before a range and/or
* ends after a range. If neither it is contained inside the range.
* Note that callers responsibility to ensure node in same doc as range.
*/
static nsresult CompareNodeToRange(nsINode* aNode,
AbstractRange* aAbstractRange,
bool* aNodeIsBeforeRange,
bool* aNodeIsAfterRange);
};
} // namespace mozilla
#endif // #ifndef mozilla_RangeUtils_h