RenderBR.cpp revision 8e35f3cfc7fba1d1c829dc557ebad6409cbe16a2 
1/**
2 * This file is part of the DOM implementation for KDE.
3 *
4 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
5 * Copyright (C) 2006 Apple Computer, 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 "RenderBR.h"
26
27#include "Document.h"
28#include "InlineTextBox.h"
29#include "VisiblePosition.h"
30
31namespace WebCore {
32
33RenderBR::RenderBR(Node* node)
34    : RenderText(node, StringImpl::create("\n"))
35    , m_lineHeight(-1)
36{
37}
38
39RenderBR::~RenderBR()
40{
41}
42
43InlineBox* RenderBR::createInlineBox(bool makePlaceholder, bool isRootLineBox, bool isOnlyRun)
44{
45    // We only treat a box as text for a <br> if we are on a line by ourself or in strict mode
46    // (Note the use of strict mode.  In "almost strict" mode, we don't treat the box for <br> as text.)
47    InlineTextBox* box = static_cast<InlineTextBox*>(RenderText::createInlineBox(makePlaceholder, isRootLineBox, isOnlyRun));
48    box->setIsText(isOnlyRun || document()->inStrictMode());
49    return box;
50}
51
52int RenderBR::baselinePosition(bool firstLine, bool isRootLineBox) const
53{
54    if (firstTextBox() && !firstTextBox()->isText())
55        return 0;
56    return RenderText::baselinePosition(firstLine, isRootLineBox);
57}
58
59int RenderBR::lineHeight(bool firstLine, bool isRootLineBox) const
60{
61    if (firstTextBox() && !firstTextBox()->isText())
62        return 0;
63
64    if (firstLine) {
65        RenderStyle* s = style(firstLine);
66        Length lh = s->lineHeight();
67        if (lh.isNegative()) {
68            if (s == style()) {
69                if (m_lineHeight == -1)
70                    m_lineHeight = RenderObject::lineHeight(false);
71                return m_lineHeight;
72            }
73            return s->font().lineSpacing();
74        }
75        if (lh.isPercent())
76            return lh.calcMinValue(s->fontSize());
77        return lh.value();
78    }
79
80    if (m_lineHeight == -1)
81        m_lineHeight = RenderObject::lineHeight(false);
82    return m_lineHeight;
83}
84
85void RenderBR::styleDidChange(RenderStyle::Diff diff, const RenderStyle* oldStyle)
86{
87    RenderText::styleDidChange(diff, oldStyle);
88    m_lineHeight = -1;
89}
90
91int RenderBR::caretMinOffset() const
92{
93    return 0;
94}
95
96int RenderBR::caretMaxOffset() const
97{
98    return 1;
99}
100
101unsigned RenderBR::caretMaxRenderedOffset() const
102{
103    return 1;
104}
105
106VisiblePosition RenderBR::positionForCoordinates(int /*x*/, int /*y*/)
107{
108    return VisiblePosition(element(), 0, DOWNSTREAM);
109}
110
111} // namespace WebCore
112