chrome/browser/ui/libgtk2ui/gtk2_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/libgtk2ui/gtk2_util.h"
   6
   7 #include <gtk/gtk.h>
   8
   9 #include "base/command_line.h"
  10 #include "base/logging.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "skia/ext/platform_canvas.h"
  13 #include "third_party/skia/include/core/SkBitmap.h"
  14 #include "ui/gfx/canvas.h"
  15 #include "ui/gfx/size.h"
  16
  17 namespace {
  18
  19 void CommonInitFromCommandLine(const CommandLine& command_line,
  20                                void (*init_func)(gint*, gchar***)) {
  21   const std::vector<std::string>& args = command_line.argv();
  22   int argc = args.size();
  23   scoped_array<char *> argv(new char *[argc + 1]);
  24   for (size_t i = 0; i < args.size(); ++i) {
  25     // TODO(piman@google.com): can gtk_init modify argv? Just being safe
  26     // here.
  27     argv[i] = strdup(args[i].c_str());
  28   }
  29   argv[argc] = NULL;
  30   char **argv_pointer = argv.get();
  31
  32   init_func(&argc, &argv_pointer);
  33   for (size_t i = 0; i < args.size(); ++i) {
  34     free(argv[i]);
  35   }
  36 }
  37
  38 }  // namespace
  39
  40 namespace libgtk2ui {
  41
  42 void GtkInitFromCommandLine(const CommandLine& command_line) {
  43   CommonInitFromCommandLine(command_line, gtk_init);
  44 }
  45
  46 const SkBitmap GdkPixbufToImageSkia(GdkPixbuf* pixbuf) {
  47   // TODO(erg): What do we do in the case where the pixbuf fails these dchecks?
  48   // I would prefer to use our gtk based canvas, but that would require
  49   // recompiling half of our skia extensions with gtk support, which we can't
  50   // do in this build.
  51   DCHECK_EQ(GDK_COLORSPACE_RGB, gdk_pixbuf_get_colorspace(pixbuf));
  52
  53   int n_channels = gdk_pixbuf_get_n_channels(pixbuf);
  54   int w = gdk_pixbuf_get_width(pixbuf);
  55   int h = gdk_pixbuf_get_height(pixbuf);
  56
  57   SkBitmap ret;
  58   ret.setConfig(SkBitmap::kARGB_8888_Config, w, h);
  59   ret.allocPixels();
  60   ret.eraseColor(0);
  61
  62   uint32_t* skia_data = static_cast<uint32_t*>(ret.getAddr(0, 0));
  63
  64   if (n_channels == 4) {
  65     int total_length = w * h;
  66     guchar* gdk_pixels = gdk_pixbuf_get_pixels(pixbuf);
  67
  68     // Now here's the trick: we need to convert the gdk data (which is RGBA and
  69     // isn't premultiplied) to skia (which can be anything and premultiplied).
  70     for (int i = 0; i < total_length; ++i, gdk_pixels += 4) {
  71       const unsigned char& red = gdk_pixels[0];
  72       const unsigned char& green = gdk_pixels[1];
  73       const unsigned char& blue = gdk_pixels[2];
  74       const unsigned char& alpha = gdk_pixels[3];
  75
  76       skia_data[i] = SkPreMultiplyARGB(alpha, red, green, blue);
  77     }
  78   } else if (n_channels == 3) {
  79     // Because GDK makes rowstrides word aligned, we need to do something a bit
  80     // more complex when a pixel isn't perfectly a word of memory.
  81     int rowstride = gdk_pixbuf_get_rowstride(pixbuf);
  82     guchar* gdk_pixels = gdk_pixbuf_get_pixels(pixbuf);
  83     for (int y = 0; y < h; ++y) {
  84       int row = y * rowstride;
  85
  86       for (int x = 0; x < w; ++x) {
  87         guchar* pixel = gdk_pixels + row + (x * 3);
  88         const unsigned char& red = pixel[0];
  89         const unsigned char& green = pixel[1];
  90         const unsigned char& blue = pixel[2];
  91
  92         skia_data[y * w + x] = SkPreMultiplyARGB(255, red, green, blue);
  93       }
  94     }
  95   } else {
  96     NOTREACHED();
  97   }
  98
  99   return ret;
 100 }
 101
 102 }  // namespace libgtk2ui