1/*
2 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20#include "config.h"
21
22#if ENABLE(SVG)
23#include "SVGTextMetrics.h"
24
25#include "RenderSVGInlineText.h"
26#include "TextRun.h"
27
28namespace WebCore {
29
30SVGTextMetrics::SVGTextMetrics()
31    : m_width(0)
32    , m_height(0)
33    , m_length(0)
34{
35}
36
37SVGTextMetrics::SVGTextMetrics(RenderSVGInlineText* textRenderer, const TextRun& run, unsigned position, unsigned textLength)
38{
39    ASSERT(textRenderer);
40
41    float scalingFactor = textRenderer->scalingFactor();
42    ASSERT(scalingFactor);
43
44    const Font& scaledFont = textRenderer->scaledFont();
45
46    int extraCharsAvailable = textLength - (position + run.length());
47    int length = 0;
48
49    // Calculate width/height using the scaled font, divide this result by the scalingFactor afterwards.
50    m_width = scaledFont.width(run, extraCharsAvailable, length, m_glyph.name) / scalingFactor;
51    m_height = scaledFont.fontMetrics().floatHeight() / scalingFactor;
52
53    m_glyph.unicodeString = String(run.characters(), length);
54    m_glyph.isValid = true;
55
56    ASSERT(length >= 0);
57    m_length = static_cast<unsigned>(length);
58}
59
60bool SVGTextMetrics::operator==(const SVGTextMetrics& other)
61{
62    return m_width == other.m_width
63        && m_height == other.m_height
64        && m_length == other.m_length
65        && m_glyph == other.m_glyph;
66}
67
68SVGTextMetrics SVGTextMetrics::emptyMetrics()
69{
70    DEFINE_STATIC_LOCAL(SVGTextMetrics, s_emptyMetrics, ());
71    s_emptyMetrics.m_length = 1;
72    return s_emptyMetrics;
73}
74
75static TextRun constructTextRun(RenderSVGInlineText* text, const UChar* characters, unsigned position, unsigned length)
76{
77    RenderStyle* style = text->style();
78    ASSERT(style);
79
80    TextRun run(characters + position
81                , length
82                , false /* allowTabs */
83                , 0 /* xPos, only relevant with allowTabs=true */
84                , 0 /* padding, only relevant for justified text, not relevant for SVG */
85                , TextRun::AllowTrailingExpansion
86                , !style->isLeftToRightDirection()
87                , style->unicodeBidi() == Override /* directionalOverride */);
88
89#if ENABLE(SVG_FONTS)
90    run.setReferencingRenderObject(text);
91#endif
92
93    // We handle letter & word spacing ourselves.
94    run.disableSpacing();
95    return run;
96}
97
98SVGTextMetrics SVGTextMetrics::measureCharacterRange(RenderSVGInlineText* text, unsigned position, unsigned length)
99{
100    ASSERT(text);
101    TextRun run(constructTextRun(text, text->characters(), position, length));
102    return SVGTextMetrics(text, run, position, text->textLength());
103}
104
105}
106
107#endif // ENABLE(SVG)
108