gecko-dev/layout/base/nsGenConList.h
Emilio Cobos Álvarez 6759592377 Bug 1552719 - Make nsBulletFrame::Ordinal() O(1) again. r=mats
I did this instead of just (ab)using the fact that every list item has at least
one counter-increment node because:

 * I don't have the bullet frame around by the time we initially compute the
   counter increment, which means that I'd need to grow nsBlockFrame / add a
   frame property for the list item ordinal, which I think would be unfortunate.

 * It feels more consistent with the way regular CSS counters work and with the
   way we want ::marker to eventually work.

Differential Revision: https://phabricator.services.mozilla.com/D31990

--HG--
extra : moz-landing-system : lando
2019-05-21 17:30:42 +00:00

144 lines
5.1 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/. */
/* base class for nsCounterList and nsQuoteList */
#ifndef nsGenConList_h___
#define nsGenConList_h___
#include "mozilla/LinkedList.h"
#include "nsIFrame.h"
#include "nsStyleStruct.h"
#include "nsCSSPseudoElements.h"
#include "nsTextNode.h"
class nsGenConList;
struct nsGenConNode : public mozilla::LinkedListElement<nsGenConNode> {
using StyleContentType = mozilla::StyleContentType;
// The wrapper frame for all of the pseudo-element's content. This
// frame generally has useful style data and has the
// NS_FRAME_GENERATED_CONTENT bit set (so we use it to track removal),
// but does not necessarily for |nsCounterChangeNode|s.
nsIFrame* mPseudoFrame;
// Index within the list of things specified by the 'content' property,
// which is needed to do 'content: open-quote open-quote' correctly,
// and needed for similar cases for counters.
const int32_t mContentIndex;
// null for:
// * content: no-open-quote / content: no-close-quote
// * counter nodes for increments and resets
// * counter nodes for bullets (mPseudoFrame->IsBulletFrame()).
RefPtr<nsTextNode> mText;
explicit nsGenConNode(int32_t aContentIndex)
: mPseudoFrame(nullptr), mContentIndex(aContentIndex) {}
/**
* Finish initializing the generated content node once we know the
* relevant text frame. This must be called just after
* the textframe has been initialized. This need not be called at all
* for nodes that don't generate text. This will generally set the
* mPseudoFrame, insert the node into aList, and set aTextFrame up
* with the correct text.
* @param aList the list the node belongs to
* @param aPseudoFrame the :before or :after frame
* @param aTextFrame the textframe where the node contents will render
* @return true iff this marked the list dirty
*/
virtual bool InitTextFrame(nsGenConList* aList, nsIFrame* aPseudoFrame,
nsIFrame* aTextFrame) {
mPseudoFrame = aPseudoFrame;
CheckFrameAssertions();
return false;
}
virtual ~nsGenConNode() {} // XXX Avoid, perhaps?
protected:
void CheckFrameAssertions() {
NS_ASSERTION(
mContentIndex < int32_t(mPseudoFrame->StyleContent()->ContentCount()) ||
// Special-case for the use node created for the legacy markers,
// which don't use the content property.
(mPseudoFrame->IsBulletFrame() && mContentIndex == 0 &&
mPseudoFrame->Style()->GetPseudoType() ==
mozilla::PseudoStyleType::marker &&
!mPseudoFrame->StyleContent()->ContentCount()),
"index out of range");
// We allow negative values of mContentIndex for 'counter-reset' and
// 'counter-increment'.
NS_ASSERTION(mContentIndex < 0 ||
mPseudoFrame->Style()->GetPseudoType() ==
mozilla::PseudoStyleType::before ||
mPseudoFrame->Style()->GetPseudoType() ==
mozilla::PseudoStyleType::after ||
mPseudoFrame->Style()->GetPseudoType() ==
mozilla::PseudoStyleType::marker,
"not CSS generated content and not counter change");
NS_ASSERTION(mContentIndex < 0 ||
mPseudoFrame->GetStateBits() & NS_FRAME_GENERATED_CONTENT,
"not generated content and not counter change");
}
};
class nsGenConList {
protected:
mozilla::LinkedList<nsGenConNode> mList;
uint32_t mSize;
public:
nsGenConList() : mSize(0), mLastInserted(nullptr) {}
~nsGenConList() { Clear(); }
void Clear();
static nsGenConNode* Next(nsGenConNode* aNode) {
MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
return aNode->getNext();
}
static nsGenConNode* Prev(nsGenConNode* aNode) {
MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
return aNode->getPrevious();
}
void Insert(nsGenConNode* aNode);
// Destroy all nodes with aFrame as parent. Returns true if some nodes
// have been destroyed; otherwise false.
bool DestroyNodesFor(nsIFrame* aFrame);
// Return true if |aNode1| is after |aNode2|.
static bool NodeAfter(const nsGenConNode* aNode1, const nsGenConNode* aNode2);
bool IsFirst(nsGenConNode* aNode) {
MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
return aNode == mList.getFirst();
}
bool IsLast(nsGenConNode* aNode) {
MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
return aNode == mList.getLast();
}
private:
void Destroy(nsGenConNode* aNode) {
MOZ_ASSERT(aNode, "aNode cannot be nullptr!");
delete aNode;
mSize--;
}
// Map from frame to the first nsGenConNode of it in the list.
nsDataHashtable<nsPtrHashKey<nsIFrame>, nsGenConNode*> mNodes;
// A weak pointer to the node most recently inserted, used to avoid repeated
// list traversals in Insert().
nsGenConNode* mLastInserted;
};
#endif /* nsGenConList_h___ */