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

   1 /*
   2  * Copyright (C) 2009 Google Inc. All rights reserved.
   3  * Copyright (C) 2011 Apple Inc. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  *     * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "config.h"
  33
  34 #include "core/layout/LayoutRubyText.h"
  35
  36 namespace blink {
  37
  38 LayoutRubyText::LayoutRubyText(Element* element)
  39     : LayoutBlockFlow(element)
  40 {
  41 }
  42
  43 LayoutRubyText::~LayoutRubyText()
  44 {
  45 }
  46
  47 bool LayoutRubyText::isChildAllowed(LayoutObject* child, const ComputedStyle&) const
  48 {
  49     return child->isInline();
  50 }
  51
  52 ETextAlign LayoutRubyText::textAlignmentForLine(bool endsWithSoftBreak) const
  53 {
  54     ETextAlign textAlign = style()->textAlign();
  55     // FIXME: This check is bogus since user can set the initial value.
  56     if (textAlign != ComputedStyle::initialTextAlign())
  57         return LayoutBlockFlow::textAlignmentForLine(endsWithSoftBreak);
  58
  59     // The default behavior is to allow ruby text to expand if it is shorter than the ruby base.
  60     return JUSTIFY;
  61 }
  62
  63 void LayoutRubyText::adjustInlineDirectionLineBounds(unsigned expansionOpportunityCount, LayoutUnit& logicalLeft, LayoutUnit& logicalWidth) const
  64 {
  65     ETextAlign textAlign = style()->textAlign();
  66     // FIXME: This check is bogus since user can set the initial value.
  67     if (textAlign != ComputedStyle::initialTextAlign())
  68         return LayoutBlockFlow::adjustInlineDirectionLineBounds(expansionOpportunityCount, logicalLeft, logicalWidth);
  69
  70     int maxPreferredLogicalWidth = this->maxPreferredLogicalWidth();
  71     if (maxPreferredLogicalWidth >= logicalWidth)
  72         return;
  73
  74     // Inset the ruby text by half the inter-ideograph expansion amount, but no more than a full-width
  75     // ruby character on each side.
  76     LayoutUnit inset = (logicalWidth - maxPreferredLogicalWidth) / (expansionOpportunityCount + 1);
  77     if (expansionOpportunityCount)
  78         inset = std::min(LayoutUnit(2 * style()->fontSize()), inset);
  79
  80     logicalLeft += inset / 2;
  81     logicalWidth -= inset;
  82 }
  83
  84 bool LayoutRubyText::avoidsFloats() const
  85 {
  86     return true;
  87 }
  88
  89 } // namespace blink