1/*
2 * Copyright (C) 2010 Igalia S.L.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser 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 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include "config.h"
20#include "ImageBuffer.h"
21
22#include "CairoUtilities.h"
23#include "GRefPtrGtk.h"
24#include "GdkCairoUtilities.h"
25#include "MIMETypeRegistry.h"
26#include <cairo.h>
27#include <gtk/gtk.h>
28#include <wtf/glib/GUniquePtr.h>
29#include <wtf/text/Base64.h>
30#include <wtf/text/CString.h>
31#include <wtf/text/WTFString.h>
32
33namespace WebCore {
34
35static bool encodeImage(cairo_surface_t* surface, const String& mimeType, Optional<double> quality, GUniqueOutPtr<gchar>& buffer, gsize& bufferSize)
36{
37 // List of supported image encoding types comes from the GdkPixbuf documentation.
38 // http://developer.gnome.org/gdk-pixbuf/stable/gdk-pixbuf-File-saving.html#gdk-pixbuf-save-to-bufferv
39
40 String type = mimeType.substring(sizeof "image");
41 if (type != "jpeg" && type != "png" && type != "tiff" && type != "ico" && type != "bmp")
42 return false;
43
44 GRefPtr<GdkPixbuf> pixbuf;
45 if (type == "jpeg") {
46 // JPEG doesn't support alpha channel. The <canvas> spec states that toDataURL() must encode a Porter-Duff
47 // composite source-over black for image types that do not support alpha.
48 RefPtr<cairo_surface_t> newSurface;
49 if (cairo_surface_get_type(surface) == CAIRO_SURFACE_TYPE_IMAGE) {
50 newSurface = adoptRef(cairo_image_surface_create_for_data(cairo_image_surface_get_data(surface),
51 CAIRO_FORMAT_RGB24,
52 cairo_image_surface_get_width(surface),
53 cairo_image_surface_get_height(surface),
54 cairo_image_surface_get_stride(surface)));
55 } else {
56 IntSize size = cairoSurfaceSize(surface);
57 newSurface = adoptRef(cairo_image_surface_create(CAIRO_FORMAT_RGB24, size.width(), size.height()));
58 RefPtr<cairo_t> cr = adoptRef(cairo_create(newSurface.get()));
59 cairo_set_source_surface(cr.get(), surface, 0, 0);
60 cairo_paint(cr.get());
61 }
62 pixbuf = adoptGRef(cairoSurfaceToGdkPixbuf(newSurface.get()));
63 } else
64 pixbuf = adoptGRef(cairoSurfaceToGdkPixbuf(surface));
65 if (!pixbuf)
66 return false;
67
68 GUniqueOutPtr<GError> error;
69 if (type == "jpeg" && quality && *quality >= 0.0 && *quality <= 1.0) {
70 String qualityString = String::number(static_cast<int>(*quality * 100.0 + 0.5));
71 gdk_pixbuf_save_to_buffer(pixbuf.get(), &buffer.outPtr(), &bufferSize, type.utf8().data(), &error.outPtr(), "quality", qualityString.utf8().data(), NULL);
72 } else
73 gdk_pixbuf_save_to_buffer(pixbuf.get(), &buffer.outPtr(), &bufferSize, type.utf8().data(), &error.outPtr(), NULL);
74
75 return !error;
76}
77
78String ImageBuffer::toDataURL(const String& mimeType, Optional<double> quality, PreserveResolution) const
79{
80 Vector<uint8_t> imageData = toData(mimeType, quality);
81 if (imageData.isEmpty())
82 return "data:,";
83
84 Vector<char> base64Data;
85 base64Encode(imageData.data(), imageData.size(), base64Data);
86
87 return "data:" + mimeType + ";base64," + base64Data;
88}
89
90Vector<uint8_t> ImageBuffer::toData(const String& mimeType, Optional<double> quality) const
91{
92 ASSERT(MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType));
93
94 GUniqueOutPtr<gchar> buffer;
95 gsize bufferSize;
96 if (!encodeImage(m_data.m_surface.get(), mimeType, quality, buffer, bufferSize))
97 return { };
98
99 Vector<uint8_t> imageData;
100 imageData.append(buffer.get(), bufferSize);
101 return imageData;
102}
103
104}
105