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

/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
 *               All right reserved.
 * Copyright (C) 2010 Google Inc. All rights reserved.
 * Copyright (C) 2014 Adobe Systems Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "core/layout/line/TrailingObjects.h"

#include "core/layout/api/LineLayoutItem.h"
#include "core/layout/line/BreakingContextInlineHeaders.h"
#include "core/layout/line/InlineIterator.h"

namespace blink {

void TrailingObjects::updateMidpointsForTrailingObjects(
    LineMidpointState& lineMidpointState,
    const InlineIterator& lBreak,
    CollapseFirstSpaceOrNot collapseFirstSpace) {
  if (!m_whitespace)
    return;

  // This object is either going to be part of the last midpoint, or it is going
  // to be the actual endpoint. In both cases we just decrease our pos by 1
  // level to exclude the space, allowing it to - in effect - collapse into the
  // newline.
  if (lineMidpointState.numMidpoints() % 2) {
    // Find the trailing space object's midpoint.
    int trailingSpaceMidpoint = lineMidpointState.numMidpoints() - 1;
    for (; trailingSpaceMidpoint > 0 &&
           lineMidpointState.midpoints()[trailingSpaceMidpoint]
                   .getLineLayoutItem() != m_whitespace;
         --trailingSpaceMidpoint) {
    }
    ASSERT(trailingSpaceMidpoint >= 0);
    if (collapseFirstSpace == CollapseFirstSpace)
      lineMidpointState.midpoints()[trailingSpaceMidpoint].setOffset(
          lineMidpointState.midpoints()[trailingSpaceMidpoint].offset() - 1);

    // Now make sure every single trailingPositionedBox following the
    // trailingSpaceMidpoint properly stops and starts ignoring spaces.
    size_t currentMidpoint = trailingSpaceMidpoint + 1;
    for (size_t i = 0; i < m_objects.size(); ++i) {
      if (currentMidpoint >= lineMidpointState.numMidpoints()) {
        // We don't have a midpoint for this box yet.
        ensureLineBoxInsideIgnoredSpaces(&lineMidpointState,
                                         LineLayoutItem(m_objects[i]));
      } else {
        ASSERT(lineMidpointState.midpoints()[currentMidpoint]
                   .getLineLayoutItem() == m_objects[i]);
        ASSERT(lineMidpointState.midpoints()[currentMidpoint + 1]
                   .getLineLayoutItem() == m_objects[i]);
      }
      currentMidpoint += 2;
    }
  } else if (!lBreak.getLineLayoutItem()) {
    ASSERT(collapseFirstSpace == CollapseFirstSpace);
    // Add a new end midpoint that stops right at the very end.
    unsigned length = m_whitespace.textLength();
    unsigned pos = length >= 2 ? length - 2 : UINT_MAX;
    InlineIterator endMid(0, m_whitespace, pos);
    lineMidpointState.startIgnoringSpaces(endMid);
    for (size_t i = 0; i < m_objects.size(); ++i) {
      ensureLineBoxInsideIgnoredSpaces(&lineMidpointState, m_objects[i]);
    }
  }
}

}  // namespace blink