third_party/WebKit/Source/core/layout/LayoutQuote.h

   1 /*
   2  * Copyright (C) 2011 Nokia Inc. All rights reserved.
   3  * Copyright (C) 2012 Google Inc. All rights reserved.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public License
  16  * along with this library; see the file COPYING.LIB.  If not, write to
  17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18  * Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #ifndef LayoutQuote_h
  23 #define LayoutQuote_h
  24
  25 #include "core/layout/LayoutInline.h"
  26 #include "core/style/ComputedStyle.h"
  27 #include "core/style/ComputedStyleConstants.h"
  28 #include "core/style/QuotesData.h"
  29
  30 namespace blink {
  31
  32 class Document;
  33 class LayoutTextFragment;
  34
  35 // LayoutQuote is the layout object associated with generated quotes
  36 // ("content: open-quote | close-quote | no-open-quote | no-close-quote").
  37 // http://www.w3.org/TR/CSS2/generate.html#quotes-insert
  38 //
  39 // This object is generated thus always anonymous.
  40 //
  41 // For performance reasons, LayoutQuotes form a doubly-linked list. See |m_next|
  42 // and |m_previous| below.
  43 class LayoutQuote final : public LayoutInline {
  44 public:
  45     LayoutQuote(Document*, const QuoteType);
  46     ~LayoutQuote() override;
  47     void attachQuote();
  48
  49     const char* name() const override { return "LayoutQuote"; }
  50
  51 private:
  52     void detachQuote();
  53
  54     void willBeDestroyed() override;
  55     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectQuote || LayoutInline::isOfType(type); }
  56     void styleDidChange(StyleDifference, const ComputedStyle*) override;
  57     void willBeRemovedFromTree() override;
  58
  59     String computeText() const;
  60     void updateText();
  61     const QuotesData* quotesData() const;
  62     void updateDepth();
  63     bool isAttached() { return m_attached; }
  64
  65     LayoutTextFragment* findFragmentChild() const;
  66
  67     // Type of this LayoutQuote: open-quote, close-quote, no-open-quote,
  68     // no-close-quote.
  69     QuoteType m_type;
  70
  71     // Number of open quotes in the tree. Also called the nesting level
  72     // in CSS 2.1.
  73     // Used to determine if a LayoutQuote is invalid (closing quote without a
  74     // matching opening quote) and which quote character to use (see the 'quote'
  75     // property that is used to define quote character pairs).
  76     int m_depth;
  77
  78     // The next and previous LayoutQuote in layout tree order.
  79     // LayoutQuotes are linked together by this doubly-linked list.
  80     // Those are used to compute |m_depth| in an efficient manner.
  81     LayoutQuote* m_next;
  82     LayoutQuote* m_previous;
  83
  84     // This tracks whether this LayoutQuote was inserted into the layout tree
  85     // and its position in the linked list is correct (m_next and m_previous).
  86     // It's used for both performance (avoid unneeded tree walks to find the
  87     // previous and next quotes) and conformance (|m_depth| relies on an
  88     // up-to-date linked list positions).
  89     bool m_attached;
  90
  91     // Cached text for this quote.
  92     String m_text;
  93 };
  94
  95 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutQuote, isQuote());
  96
  97 } // namespace blink
  98
  99 #endif // LayoutQuote_h