1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "Font.h"
28
29#include "FontFallbackList.h"
30#include "GlyphBuffer.h"
31#include "GraphicsContext.h"
32#include "IntRect.h"
33#include "Logging.h"
34#include "SimpleFontData.h"
35#include "TextRun.h"
36#include "UniscribeController.h"
37#include <wtf/MathExtras.h>
38
39using namespace std;
40
41namespace WebCore {
42
43bool Font::canReturnFallbackFontsForComplexText()
44{
45    return true;
46}
47
48bool Font::canExpandAroundIdeographsInComplexText()
49{
50    return false;
51}
52
53FloatRect Font::selectionRectForComplexText(const TextRun& run, const FloatPoint& point, int h,
54                                            int from, int to) const
55{
56    UniscribeController it(this, run);
57    it.advance(from);
58    float beforeWidth = it.runWidthSoFar();
59    it.advance(to);
60    float afterWidth = it.runWidthSoFar();
61
62    // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
63    if (run.rtl()) {
64        it.advance(run.length());
65        float totalWidth = it.runWidthSoFar();
66        return FloatRect(point.x() + floorf(totalWidth - afterWidth), point.y(), roundf(totalWidth - beforeWidth) - floorf(totalWidth - afterWidth), h);
67    }
68
69    return FloatRect(point.x() + floorf(beforeWidth), point.y(), roundf(afterWidth) - floorf(beforeWidth), h);
70}
71
72float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, int from, int to, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
73{
74    if (forTextEmphasis) {
75        // FIXME: Add forTextEmphasis paremeter to UniscribeController and use it.
76        LOG_ERROR("Not implemented for text emphasis.");
77        return 0;
78    }
79
80    UniscribeController controller(this, run);
81    controller.advance(from);
82    float beforeWidth = controller.runWidthSoFar();
83    controller.advance(to, &glyphBuffer);
84
85    if (glyphBuffer.isEmpty())
86        return 0;
87
88    float afterWidth = controller.runWidthSoFar();
89
90    if (run.rtl()) {
91        controller.advance(run.length());
92        return controller.runWidthSoFar() - afterWidth;
93    }
94    return beforeWidth;
95}
96
97void Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point,
98                           int from, int to) const
99{
100    // This glyph buffer holds our glyphs + advances + font data for each glyph.
101    GlyphBuffer glyphBuffer;
102
103    float startX = point.x() + getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer);
104
105    // We couldn't generate any glyphs for the run.  Give up.
106    if (glyphBuffer.isEmpty())
107        return;
108
109    // Draw the glyph buffer now at the starting point returned in startX.
110    FloatPoint startPoint(startX, point.y());
111    drawGlyphBuffer(context, glyphBuffer, startPoint);
112}
113
114void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRun& run, const AtomicString& mark, const FloatPoint& point, int from, int to) const
115{
116    GlyphBuffer glyphBuffer;
117    float initialAdvance = getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer, ForTextEmphasis);
118
119    if (glyphBuffer.isEmpty())
120        return;
121
122    drawEmphasisMarks(context, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
123}
124
125float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
126{
127    UniscribeController controller(this, run, fallbackFonts);
128    controller.advance(run.length());
129    if (glyphOverflow) {
130        glyphOverflow->top = max<int>(glyphOverflow->top, ceilf(-controller.minGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().ascent()));
131        glyphOverflow->bottom = max<int>(glyphOverflow->bottom, ceilf(controller.maxGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0  : fontMetrics().descent()));
132        glyphOverflow->left = max<int>(0, ceilf(-controller.minGlyphBoundingBoxX()));
133        glyphOverflow->right = max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.runWidthSoFar()));
134    }
135    return controller.runWidthSoFar();
136}
137
138int Font::offsetForPositionForComplexText(const TextRun& run, float xFloat, bool includePartialGlyphs) const
139{
140    // FIXME: This truncation is not a problem for HTML, but only affects SVG, which passes floating-point numbers
141    // to Font::offsetForPosition(). Bug http://webkit.org/b/40673 tracks fixing this problem.
142    int x = static_cast<int>(xFloat);
143
144    UniscribeController controller(this, run);
145    return controller.offsetForPosition(x, includePartialGlyphs);
146}
147
148}
149