third_party/WebKit/Source/core/layout/LayoutTextFragment.cpp

   1 /*
   2  * (C) 1999 Lars Knoll (knoll@kde.org)
   3  * (C) 2000 Dirk Mueller (mueller@kde.org)
   4  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  *
  21  */
  22
  23 #include "config.h"
  24 #include "core/layout/LayoutTextFragment.h"
  25
  26 #include "core/dom/FirstLetterPseudoElement.h"
  27 #include "core/dom/PseudoElement.h"
  28 #include "core/dom/StyleChangeReason.h"
  29 #include "core/dom/Text.h"
  30 #include "core/layout/HitTestResult.h"
  31 #include "core/layout/LayoutBlock.h"
  32
  33 namespace blink {
  34
  35 LayoutTextFragment::LayoutTextFragment(Node* node, StringImpl* str, int startOffset, int length)
  36     : LayoutText(node, str ? str->substring(startOffset, length) : PassRefPtr<StringImpl>(nullptr))
  37     , m_start(startOffset)
  38     , m_end(length)
  39     , m_isRemainingTextLayoutObject(false)
  40     , m_contentString(str)
  41     , m_firstLetterPseudoElement(nullptr)
  42 {
  43 }
  44
  45 LayoutTextFragment::LayoutTextFragment(Node* node, StringImpl* str)
  46     : LayoutText(node, str)
  47     , m_start(0)
  48     , m_end(str ? str->length() : 0)
  49     , m_isRemainingTextLayoutObject(false)
  50     , m_contentString(str)
  51     , m_firstLetterPseudoElement(nullptr)
  52 {
  53 }
  54
  55 LayoutTextFragment::~LayoutTextFragment()
  56 {
  57     ASSERT(!m_firstLetterPseudoElement);
  58 }
  59
  60 void LayoutTextFragment::willBeDestroyed()
  61 {
  62     if (m_isRemainingTextLayoutObject && m_firstLetterPseudoElement)
  63         m_firstLetterPseudoElement->setRemainingTextLayoutObject(nullptr);
  64     m_firstLetterPseudoElement = nullptr;
  65     LayoutText::willBeDestroyed();
  66 }
  67
  68 PassRefPtr<StringImpl> LayoutTextFragment::completeText() const
  69 {
  70     Text* text = associatedTextNode();
  71     return text ? text->dataImpl() : contentString();
  72 }
  73
  74 void LayoutTextFragment::setContentString(StringImpl* str)
  75 {
  76     m_contentString = str;
  77     setText(str);
  78 }
  79
  80 PassRefPtr<StringImpl> LayoutTextFragment::originalText() const
  81 {
  82     RefPtr<StringImpl> result = completeText();
  83     if (!result)
  84         return nullptr;
  85     return result->substring(start(), end());
  86 }
  87
  88 void LayoutTextFragment::setText(PassRefPtr<StringImpl> text, bool force)
  89 {
  90     LayoutText::setText(text, force);
  91
  92     m_start = 0;
  93     m_end = textLength();
  94
  95     // If we're the remaining text from a first letter then we have to tell the
  96     // first letter pseudo element to reattach itself so it can re-calculate the
  97     // correct first-letter settings.
  98     if (isRemainingTextLayoutObject()) {
  99         ASSERT(firstLetterPseudoElement());
 100         firstLetterPseudoElement()->updateTextFragments();
 101     }
 102 }
 103
 104 void LayoutTextFragment::setTextFragment(PassRefPtr<StringImpl> text, unsigned start, unsigned length)
 105 {
 106     LayoutText::setText(text, false);
 107
 108     m_start = start;
 109     m_end = length;
 110 }
 111
 112 void LayoutTextFragment::transformText()
 113 {
 114     // Note, we have to call LayoutText::setText here because, if we use our
 115     // version we will, potentially, screw up the first-letter settings where
 116     // we only use portions of the string.
 117     if (RefPtr<StringImpl> textToTransform = originalText())
 118         LayoutText::setText(textToTransform.release(), true);
 119 }
 120
 121 UChar LayoutTextFragment::previousCharacter() const
 122 {
 123     if (start()) {
 124         StringImpl* original = completeText().get();
 125         if (original && start() <= original->length())
 126             return (*original)[start() - 1];
 127     }
 128
 129     return LayoutText::previousCharacter();
 130 }
 131
 132 // If this is the layoutObject for a first-letter pseudoNode then we have to look
 133 // at the node for the remaining text to find our content.
 134 Text* LayoutTextFragment::associatedTextNode() const
 135 {
 136     Node* node = this->firstLetterPseudoElement();
 137     if (m_isRemainingTextLayoutObject || !node) {
 138         // If we don't have a node, then we aren't part of a first-letter pseudo
 139         // element, so use the actual node. Likewise, if we have a node, but
 140         // we're the remainingTextLayoutObject for a pseudo element use the real
 141         // text node.
 142         node = this->node();
 143     }
 144
 145     if (!node)
 146         return nullptr;
 147
 148     if (node->isFirstLetterPseudoElement()) {
 149         FirstLetterPseudoElement* pseudo = toFirstLetterPseudoElement(node);
 150         LayoutObject* nextLayoutObject = FirstLetterPseudoElement::firstLetterTextLayoutObject(*pseudo);
 151         if (!nextLayoutObject)
 152             return nullptr;
 153         node = nextLayoutObject->node();
 154     }
 155     return (node && node->isTextNode()) ? toText(node) : nullptr;
 156 }
 157
 158 void LayoutTextFragment::updateHitTestResult(HitTestResult& result, const LayoutPoint& point)
 159 {
 160     if (result.innerNode())
 161         return;
 162
 163     LayoutObject::updateHitTestResult(result, point);
 164
 165     // If we aren't part of a first-letter element, or if we
 166     // are part of first-letter but we're the remaining text then return.
 167     if (m_isRemainingTextLayoutObject || !firstLetterPseudoElement())
 168         return;
 169     result.setInnerNode(firstLetterPseudoElement());
 170 }
 171
 172 } // namespace blink