cheets: add wallpaper observer to arc_wallpaper_service.

chrome/browser/chromeos/arc/arc_wallpaper_service.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_service.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 13 matching lines @@
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_util.h"
 
 using user_manager::UserManager;
 
 namespace arc {
 
 namespace {
 
+constexpr uint32_t kMinOnWallpaperChangedVersion = 1;
 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();
@@ skipping 18 matching lines @@
   // make this happen seems to do the same things as wallpaper_api.cc and
   // wallpaper_private_api.cc.
 }
 
 std::vector<uint8_t> EncodeImagePng(const gfx::ImageSkia image) {
   std::vector<uint8_t> result;
   gfx::PNGCodec::FastEncodeBGRASkBitmap(*image.bitmap(), true, &result);
   return result;
 }
 
+ash::WallpaperController* GetWallpaperController() {
+  ash::WmShell* wm_shell = ash::WmShell::Get();
+  if (wm_shell && wm_shell->wallpaper_controller()) {

[Luis Héctor Chávez, 2016/09/16 21:23:16]

Forgot this one too:

In general you want to do

if (!good_state)
  return nullptr;

// good state can be assumed from now on.

(also, elide braces :P)

[Yusuke Sato, 2016/09/16 21:23:50]

no {}

[Muyuan, 2016/09/16 21:38:48]

Done.

+    return wm_shell->wallpaper_controller();
+  }
+  return nullptr;
+}
+
 }  // namespace
 
 ArcWallpaperService::ArcWallpaperService(ArcBridgeService* bridge_service)
     : ArcService(bridge_service), binding_(this) {
   arc_bridge_service()->wallpaper()->AddObserver(this);
 }
 
 ArcWallpaperService::~ArcWallpaperService() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   // Make sure the callback is never called after destruction. It is safe to
   // call Cancel() even when there is no in-flight request.
   ImageDecoder::Cancel(this);
+  ash::WallpaperController* wc = GetWallpaperController();
+  if (wc)
+    wc->RemoveObserver(this);
   arc_bridge_service()->wallpaper()->RemoveObserver(this);
 }
 
 void ArcWallpaperService::OnInstanceReady() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   mojom::WallpaperInstance* wallpaper_instance =
       arc_bridge_service()->wallpaper()->instance();
   if (!wallpaper_instance) {
     LOG(DFATAL) << "OnWallpaperInstanceReady called, "
                 << "but no wallpaper instance found";
     return;
   }
   wallpaper_instance->Init(binding_.CreateInterfacePtrAndBind());
+  ash::WmShell::Get()->wallpaper_controller()->AddObserver(this);
+}
+
+void ArcWallpaperService::OnInstanceClosed() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  ash::WallpaperController* wc = GetWallpaperController();
+  if (wc)
+    wc->RemoveObserver(this);
 }
 
 void ArcWallpaperService::SetWallpaper(mojo::Array<uint8_t> png_data) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ImageDecoder::Cancel(this);
   ImageDecoder::StartWithOptions(this, png_data.PassStorage(),
                                  ImageDecoder::ROBUST_PNG_CODEC, true);
 }
 
 void ArcWallpaperService::GetWallpaper(const GetWallpaperCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ash::WallpaperController* wc = ash::WmShell::Get()->wallpaper_controller();
   gfx::ImageSkia wallpaper = wc->GetWallpaper();
   base::PostTaskAndReplyWithResult(
       content::BrowserThread::GetBlockingPool(), FROM_HERE,
       base::Bind(&EncodeImagePng, wallpaper), callback);
 }
 
 void ArcWallpaperService::OnImageDecoded(const SkBitmap& bitmap) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   SetBitmapAsWallpaper(bitmap);
 }
 
 void ArcWallpaperService::OnDecodeImageFailed() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   LOG(ERROR) << "Failed to decode wallpaper image.";
 }
 
+void ArcWallpaperService::OnWallpaperDataChanged() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  mojom::WallpaperInstance* instance =
+      GetWallpaperInstance(kMinOnWallpaperChangedVersion);
+  if (!instance) {

[Yusuke Sato, 2016/09/16 21:23:50]

same

+    return;
+  }
+  instance->OnWallpaperChanged();
+}
+
+mojom::WallpaperInstance* ArcWallpaperService::GetWallpaperInstance(
+    uint32_t min_version) {
+  uint32_t version = arc_bridge_service()->wallpaper()->version();
+  if (version < min_version) {
+    VLOG(1) << "ARC wallpaper instance is too old. required: " << min_version
+            << ", actual: " << version;
+    return nullptr;
+  }
+
+  mojom::WallpaperInstance* instance =
+      arc_bridge_service()->wallpaper()->instance();
+  if (!instance) {

[Yusuke Sato, 2016/09/16 21:23:50]

same

[Muyuan, 2016/09/16 21:38:49]

Done.

+    VLOG(2) << "ARC wallpaper instance is not ready.";
+  }
+
+  return instance;
+}
+
 }  // namespace arc