arc: IPC method to set custom wallpaper.

chrome/browser/chromeos/arc/arc_wallpaper_handler.cc

+// Copyright 2016 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/arc/arc_wallpaper_handler.h"
+
+#include <string>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.h"
+#include "components/signin/core/account_id/account_id.h"
+#include "components/user_manager/user_manager.h"
+#include "components/wallpaper/wallpaper_files_id.h"
+#include "components/wallpaper/wallpaper_layout.h"
+#include "ui/gfx/image/image_skia.h"
+
+namespace arc {
+
+namespace {
+
+constexpr char kAndroidWallpaperFilename[] = "android.jpg";
+
+// Sets a decoded bitmap as the wallpaper.
+void SetBitmapAsWallpaper(const SkBitmap& bitmap) {
+  // Make the SkBitmap immutable as we won't modify it. This is important
+  // because otherwise it gets duplicated during painting, wasting memory.
+  SkBitmap immutable_bitmap(bitmap);
+  immutable_bitmap.setImmutable();
+  gfx::ImageSkia image = gfx::ImageSkia::CreateFrom1xBitmap(immutable_bitmap);
+  image.MakeThreadSafe();
+
+  chromeos::WallpaperManager* wallpaper_manager =
+      chromeos::WallpaperManager::Get();
+
+  const AccountId& account_id =
+      user_manager::UserManager::Get()->GetPrimaryUser()->GetAccountId();
+  wallpaper::WallpaperFilesId wallpaper_files_id =
+      wallpaper_manager->GetFilesId(account_id);
+  bool update_wallpaper =
+      account_id ==
+      user_manager::UserManager::Get()->GetActiveUser()->GetAccountId();
+  // TODO(crbug.com/618922): Allow specifying layout.
+  wallpaper_manager->SetCustomWallpaper(
+      account_id, wallpaper_files_id, kAndroidWallpaperFilename,
+      wallpaper::WALLPAPER_LAYOUT_STRETCH, user_manager::User::CUSTOMIZED,
+      image, update_wallpaper);
+
+  // TODO(crbug.com/618922): Register the wallpaper to Chrome OS wallpaper
+  // picker. Currently the new wallpaper does not appear there. The best way to
+  // make this happen seems to do the same things as wallpaper_api.cc and
+  // wallpaper_private_api.cc.
+}
+
+}  // namespace
+
+// An implementation of ImageDecoder::ImageRequest that just calls back
+// ArcWallpaperHandler.
+class ArcWallpaperHandler::ImageRequestImpl
+    : public ImageDecoder::ImageRequest {
+ public:
+  // |handler| outlives this instance.
+  explicit ImageRequestImpl(ArcWallpaperHandler* handler) : handler_(handler) {}
+
+  // ImageDecoder::ImageRequest implementation.
+  void OnImageDecoded(const SkBitmap& bitmap) override {
+    handler_->OnImageDecoded(this, bitmap);
+  }
+  void OnDecodeImageFailed() override { handler_->OnDecodeImageFailed(this); }
+
+ private:
+  ArcWallpaperHandler* handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageRequestImpl);
+};
+
+ArcWallpaperHandler::ArcWallpaperHandler() = default;
+
+ArcWallpaperHandler::~ArcWallpaperHandler() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // Cancel in-flight requests.
+  for (ImageRequestImpl* request : inflight_requests_) {
+    ImageDecoder::Cancel(request);
+    delete request;
+  }
+  inflight_requests_.clear();
+}
+
+void ArcWallpaperHandler::SetWallpaper(const std::vector<uint8_t>& jpeg_data) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  std::unique_ptr<ImageRequestImpl> request =
+      base::MakeUnique<ImageRequestImpl>(this);
+  // TODO(nya): Improve ImageDecoder to minimize copy.
+  std::string jpeg_data_as_string(reinterpret_cast<const char*>(jpeg_data[0]),
+                                  jpeg_data.size());
+  ImageDecoder::StartWithOptions(request.get(), jpeg_data_as_string,
+                                 ImageDecoder::ROBUST_JPEG_CODEC, true);
+  inflight_requests_.insert(request.release());
+}
+
+void ArcWallpaperHandler::OnImageDecoded(ImageRequestImpl* request,
+                                         const SkBitmap& bitmap) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  inflight_requests_.erase(request);
+  delete request;

[dcheng, 2016/06/17 13:23:27]

Just curious, but do we really need to handle multiple in-flight requests? I
think we can just remember one and Cancel() the previous? Then we don't need the
container at all.

[Shuhei Takahashi, 2016/06/20 12:10:30]

You're right. That sounds better. Let me address it in another patch.

+  SetBitmapAsWallpaper(bitmap);
+}
+
+void ArcWallpaperHandler::OnDecodeImageFailed(ImageRequestImpl* request) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  inflight_requests_.erase(request);
+  delete request;
+  LOG(ERROR) << "Failed to decode wallpaper image.";
+}
+
+}  // namespace arc