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

   1 /**
   2  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
   3  * Copyright (C) 2006 Apple Computer, Inc.
   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 #include "config.h"
  23 #include "core/layout/LayoutBR.h"
  24
  25 #include "core/dom/Document.h"
  26 #include "core/dom/StyleEngine.h"
  27 #include "core/editing/PositionWithAffinity.h"
  28 #include "core/layout/LayoutView.h"
  29
  30 namespace blink {
  31
  32 static PassRefPtr<StringImpl> newlineString()
  33 {
  34     DEFINE_STATIC_LOCAL(const String, string, ("\n"));
  35     return string.impl();
  36 }
  37
  38 LayoutBR::LayoutBR(Node* node)
  39     : LayoutText(node, newlineString())
  40 {
  41 }
  42
  43 LayoutBR::~LayoutBR()
  44 {
  45 }
  46
  47 LayoutRect LayoutBR::selectionRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer) const
  48 {
  49     if (!RuntimeEnabledFeatures::selectionPaintingWithoutSelectionGapsEnabled())
  50         return LayoutRect();
  51
  52     // Although line breaks contain no actual text, if we're selected we need
  53     // to return a rect that includes space to illustrate a newline.
  54     return LayoutText::selectionRectForPaintInvalidation(paintInvalidationContainer);
  55 }
  56
  57 int LayoutBR::lineHeight(bool firstLine) const
  58 {
  59     const ComputedStyle& style = styleRef(firstLine && document().styleEngine().usesFirstLineRules());
  60     return style.computedLineHeight();
  61 }
  62
  63 void LayoutBR::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
  64 {
  65     LayoutText::styleDidChange(diff, oldStyle);
  66 }
  67
  68 int LayoutBR::caretMinOffset() const
  69 {
  70     return 0;
  71 }
  72
  73 int LayoutBR::caretMaxOffset() const
  74 {
  75     return 1;
  76 }
  77
  78 PositionWithAffinity LayoutBR::positionForPoint(const LayoutPoint&)
  79 {
  80     return createPositionWithAffinity(0);
  81 }
  82
  83 } // namespace blink