1// Copyright (c) 2011 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/window_snapshot/window_snapshot.h"
6
7#include <gdk/gdkx.h>
8#include <gtk/gtk.h>
9
10#include "base/logging.h"
11#include "ui/base/x/x11_util.h"
12#include "ui/gfx/rect.h"
13
14namespace browser {
15
16static cairo_status_t SnapshotCallback(
17    void *closure, const unsigned char *data, unsigned int length) {
18  std::vector<unsigned char>* png_representation =
19      static_cast<std::vector<unsigned char>*>(closure);
20
21  size_t old_size = png_representation->size();
22  png_representation->resize(old_size + length);
23  memcpy(&(*png_representation)[old_size], data, length);
24  return CAIRO_STATUS_SUCCESS;
25}
26
27gfx::Rect GrabWindowSnapshot(gfx::NativeWindow gtk_window,
28                             std::vector<unsigned char>* png_representation) {
29  GdkWindow* gdk_window = GTK_WIDGET(gtk_window)->window;
30  Display* display = GDK_WINDOW_XDISPLAY(gdk_window);
31  XID win = GDK_WINDOW_XID(gdk_window);
32  XWindowAttributes attr;
33  if (XGetWindowAttributes(display, win, &attr) == 0) {
34    LOG(ERROR) << "Couldn't get window attributes";
35    return gfx::Rect();
36  }
37  XImage* image = XGetImage(
38      display, win, 0, 0, attr.width, attr.height, AllPlanes, ZPixmap);
39  if (!image) {
40    LOG(ERROR) << "Couldn't get image";
41    return gfx::Rect();
42  }
43  if (image->depth != 24) {
44    LOG(ERROR)<< "Unsupported image depth " << image->depth;
45    return gfx::Rect();
46  }
47  cairo_surface_t* surface =
48      cairo_image_surface_create_for_data(
49          reinterpret_cast<unsigned char*>(image->data),
50          CAIRO_FORMAT_RGB24,
51          image->width,
52          image->height,
53          image->bytes_per_line);
54
55  if (!surface) {
56    LOG(ERROR) << "Unable to create Cairo surface from XImage data";
57    return gfx::Rect();
58  }
59  cairo_surface_write_to_png_stream(
60      surface, SnapshotCallback, png_representation);
61  cairo_surface_destroy(surface);
62
63  return gfx::Rect(image->width, image->height);
64}
65
66}  // namespace browser
67