gecko-dev/layout/base/nsQuoteList.h
Martin Robinson f85b73bf84 Bug 1463600 - Implement CSS 'contain: style' r=emilio
Add an implementation of CSS `contain: style`. This introduces two new
data structures, the ContainStyleScope and ContainStyleScopeManager.

ContainStyleScope manages one `contain: style` "world" which has its own
counter and quote lists. The contents of these lists depend on their
parent scopes, but are not affected by their children.
ContainStyleScopeManager manages a tree of scopes starting at a root
scope which is outside of any `contain: style` element.

Scopes are stored in a hash table that is keyed off of the nsIContent
which establishes the `contain: style` scope. When modifying quote or
content lists, the ContainStyleScopeManager is responsible for finding
the appropriate `contain: style` scope to modify.

Perhaps the most complex part of this is that counters and quotes have
read access to the state of counters and quotes that are in ancestor
`contain: style` scopes. In the case of counters, USE nodes that are at
the beginning of counter lists might have a counter scope that starts in
an ancestor `contain: style` scope. When nsCounterNode::SetScope() is
called, the code may look upward in the `contain: style` scope tree to
find the start of the counter scope. In the case of quotes, the first
node in the quote list must look for the state of quotes in ancestor
`contain: style` scopes.

Differential Revision: https://phabricator.services.mozilla.com/D149508
2022-06-22 16:16:59 +00:00

101 lines
3.1 KiB
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/* -*- 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/. */
/* implementation of quotes for the CSS 'content' property */
#ifndef nsQuoteList_h___
#define nsQuoteList_h___
#include "mozilla/Attributes.h"
#include "nsGenConList.h"
namespace mozilla {
class ContainStyleScope;
} // namespace mozilla
struct nsQuoteNode : public nsGenConNode {
// open-quote, close-quote, no-open-quote, or no-close-quote
const StyleContentType mType;
// Quote depth before this quote, which is always non-negative.
int32_t mDepthBefore;
nsQuoteNode(StyleContentType aType, uint32_t aContentIndex)
: nsGenConNode(aContentIndex), mType(aType), mDepthBefore(0) {
NS_ASSERTION(aType == StyleContentType::OpenQuote ||
aType == StyleContentType::CloseQuote ||
aType == StyleContentType::NoOpenQuote ||
aType == StyleContentType::NoCloseQuote,
"incorrect type");
NS_ASSERTION(aContentIndex <= INT32_MAX, "out of range");
}
virtual bool InitTextFrame(nsGenConList* aList, nsIFrame* aPseudoFrame,
nsIFrame* aTextFrame) override;
// is this 'open-quote' or 'no-open-quote'?
bool IsOpenQuote() {
return mType == StyleContentType::OpenQuote ||
mType == StyleContentType::NoOpenQuote;
}
// is this 'close-quote' or 'no-close-quote'?
bool IsCloseQuote() { return !IsOpenQuote(); }
// is this 'open-quote' or 'close-quote'?
bool IsRealQuote() {
return mType == StyleContentType::OpenQuote ||
mType == StyleContentType::CloseQuote;
}
// Depth of the quote for *this* node. Either non-negative or -1.
// -1 means this is a closing quote that tried to decrement the
// counter below zero (which means no quote should be rendered).
int32_t Depth() { return IsOpenQuote() ? mDepthBefore : mDepthBefore - 1; }
// always non-negative
int32_t DepthAfter() {
return IsOpenQuote() ? mDepthBefore + 1
: (mDepthBefore == 0 ? 0 : mDepthBefore - 1);
}
// The text that should be displayed for this quote.
nsString Text();
};
class nsQuoteList : public nsGenConList {
private:
nsQuoteNode* FirstNode() {
return static_cast<nsQuoteNode*>(mList.getFirst());
}
public:
explicit nsQuoteList(mozilla::ContainStyleScope* aScope) : mScope(aScope) {}
// assign the correct |mDepthBefore| value to a node that has been inserted
// Should be called immediately after calling |Insert|.
void Calc(nsQuoteNode* aNode);
nsQuoteNode* Next(nsQuoteNode* aNode) {
return static_cast<nsQuoteNode*>(nsGenConList::Next(aNode));
}
nsQuoteNode* Prev(nsQuoteNode* aNode) {
return static_cast<nsQuoteNode*>(nsGenConList::Prev(aNode));
}
void RecalcAll();
#ifdef DEBUG
void PrintChain();
#endif
private:
mozilla::ContainStyleScope* mScope;
};
#endif /* nsQuoteList_h___ */