third_party/WebKit/Source/core/layout/line/TrailingObjects.cpp

   1 /*
   2  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
   3  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
   4  * Copyright (C) 2010 Google Inc. All rights reserved.
   5  * Copyright (C) 2014 Adobe Systems Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public License
  18  * along with this library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20  * Boston, MA 02110-1301, USA.
  21  *
  22  */
  23
  24 #include "config.h"
  25 #include "core/layout/line/TrailingObjects.h"
  26
  27 #include "core/layout/api/LineLayoutItem.h"
  28 #include "core/layout/line/BreakingContextInlineHeaders.h"
  29 #include "core/layout/line/InlineIterator.h"
  30
  31 namespace blink {
  32
  33 void TrailingObjects::updateMidpointsForTrailingObjects(LineMidpointState& lineMidpointState, const InlineIterator& lBreak, CollapseFirstSpaceOrNot collapseFirstSpace)
  34 {
  35     if (!m_whitespace)
  36         return;
  37
  38     // This object is either going to be part of the last midpoint, or it is going to be the actual endpoint.
  39     // In both cases we just decrease our pos by 1 level to exclude the space, allowing it to - in effect - collapse into the newline.
  40     if (lineMidpointState.numMidpoints() % 2) {
  41         // Find the trailing space object's midpoint.
  42         int trailingSpaceMidpoint = lineMidpointState.numMidpoints() - 1;
  43         for ( ; trailingSpaceMidpoint > 0 && lineMidpointState.midpoints()[trailingSpaceMidpoint].object() != m_whitespace; --trailingSpaceMidpoint) { }
  44         ASSERT(trailingSpaceMidpoint >= 0);
  45         if (collapseFirstSpace == CollapseFirstSpace)
  46             lineMidpointState.midpoints()[trailingSpaceMidpoint].setOffset(lineMidpointState.midpoints()[trailingSpaceMidpoint].offset() -1);
  47
  48         // Now make sure every single trailingPositionedBox following the trailingSpaceMidpoint properly stops and starts
  49         // ignoring spaces.
  50         size_t currentMidpoint = trailingSpaceMidpoint + 1;
  51         for (size_t i = 0; i < m_objects.size(); ++i) {
  52             if (currentMidpoint >= lineMidpointState.numMidpoints()) {
  53                 // We don't have a midpoint for this box yet.
  54                 ensureLineBoxInsideIgnoredSpaces(&lineMidpointState, LineLayoutItem(m_objects[i]));
  55             } else {
  56                 ASSERT(lineMidpointState.midpoints()[currentMidpoint].object() == m_objects[i]);
  57                 ASSERT(lineMidpointState.midpoints()[currentMidpoint + 1].object() == m_objects[i]);
  58             }
  59             currentMidpoint += 2;
  60         }
  61     } else if (!lBreak.object()) {
  62         ASSERT(collapseFirstSpace == CollapseFirstSpace);
  63         // Add a new end midpoint that stops right at the very end.
  64         unsigned length = m_whitespace.textLength();
  65         unsigned pos = length >= 2 ? length - 2 : UINT_MAX;
  66         InlineIterator endMid(0, m_whitespace, pos);
  67         lineMidpointState.startIgnoringSpaces(endMid);
  68         for (size_t i = 0; i < m_objects.size(); ++i) {
  69             ensureLineBoxInsideIgnoredSpaces(&lineMidpointState, m_objects[i]);
  70         }
  71     }
  72 }
  73
  74 }