Resize and save custom wallpaper to large and small size

chrome/browser/chromeos/login/simple_png_encoder.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/login/simple_png_encoder.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/threading/worker_pool.h"
+#include "chrome/browser/chromeos/login/user_manager.h"
+#include "chrome/common/url_constants.h"
+#include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/size.h"
+#include "ui/gfx/skia_util.h"
+
+#if defined(USE_SYSTEM_ZLIB)
+#include <zlib.h>
+#else
+#include "third_party/zlib/zlib.h"
+#endif
+
+namespace chromeos {
+
+SimplePngEncoder::SimplePngEncoder(
+    scoped_refptr<base::RefCountedBytes> data,
+    SkBitmap image)
+    : data_(data),
+      image_(image) {
+}
+
+void SimplePngEncoder::Run(EncoderCallback callback) {
+  base::WorkerPool::PostTaskAndReply(
+      FROM_HERE,
+      base::Bind(&SimplePngEncoder::EncodeWallpaper, this),
+      base::Bind(callback, data_),
+      true /* task_is_slow */);
+}
+
+void SimplePngEncoder::EncodeWallpaper() {
+  if (cancel_flag_.IsSet())
+    return;
+  SkAutoLockPixels lock_input(image_);
+  // Avoid compression to make things faster.
+  gfx::PNGCodec::EncodeWithCompressionLevel(
+      reinterpret_cast<unsigned char*>(image_.getAddr32(0, 0)),
+      gfx::PNGCodec::FORMAT_SkBitmap,
+      gfx::Size(image_.width(), image_.height()),
+      image_.width() * image_.bytesPerPixel(),
+      false,
+      std::vector<gfx::PNGCodec::Comment>(),
+      Z_NO_COMPRESSION,
+      &data_->data());
+}
+
+void SimplePngEncoder::Cancel() {
+  cancel_flag_.Set();
+}
+
+SimplePngEncoder::~SimplePngEncoder() {
+}
+
+}  // namespace chromeos