Implement user selected wallpaper feature.

chrome/browser/ui/webui/options2/chromeos/wallpaper_thumbnail_source2.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/ui/webui/options2/chromeos/wallpaper_thumbnail_source2.h"
 
 #include "ash/desktop_background/desktop_background_resources.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/singleton.h"
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
+#include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "grit/ui_resources.h"
 #include "net/base/mime_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/codec/png_codec.h"
 
 namespace chromeos {
 namespace options2 {
 
 namespace {
 
 const char kDefaultWallpaperPrefix[] = "default_";
+const char kCustomWallpaperPrefix[] = "custom_";
 
 // Parse an integer from |path| and save it to |index|. For example, deafult_20
 // will set |index| to 20.
 // |path| and |index| must not be NULL.
 bool ParseIndexFromPath(const std::string& path, int* index) {
   // TODO(bshe): We should probably save a string instead of index for
   // extensibility. Remove this function when we migrate to string preference.
   DCHECK(index);
   if (!StartsWithASCII(path, kDefaultWallpaperPrefix, false))
     return false;
   return base::StringToInt(base::StringPiece(path.begin() +
       strlen(kDefaultWallpaperPrefix), path.end()), index);
 }
 
 // Convert |path| to corresponding IDR. Return -1 if the path is invalid.
 // |path| must not be NULL.
 int PathToIDR(const std::string& path) {
   int idr = -1;
   int index = ash::GetInvalidWallpaperIndex();
   if (ParseIndexFromPath(path, &index))
     idr = ash::GetWallpaperInfo(index).thumb_id;
   return idr;
 }
 
+// True if |path| is a custom wallpaper thumbnail URL and set |email| parsed
+// from |path|.
+// custom url = "custom_|email|?date" where date is current time.
+bool IsCustomWallpaperPath(const std::string& path, std::string* email) {
+  if (!StartsWithASCII(path, kCustomWallpaperPrefix, false) ||
+      path.find_first_of("?") == std::string::npos)

[flackr, 2012/05/09 21:26:16]

Not having a ? doesn't mean it's definitely not a custom wallpaper path, even
though the convention is that we always put the ? in. Can you move the check for
? to change the substr?

[bshe, 2012/05/10 16:10:26]

Done.

+    return false;
+  *email = path.substr(strlen(kCustomWallpaperPrefix),
+      path.find_first_of("?") - strlen(kCustomWallpaperPrefix));

[flackr, 2012/05/09 21:26:16]

std::string::substr can take just start position, this will be much cleaner.

[bshe, 2012/05/10 16:10:26]

Done.

+  return true;
+}
+
 }  // namespace
 
 std::string GetDefaultWallpaperThumbnailURL(int index) {
   return StringPrintf("%s%s%d", chrome::kChromeUIWallpaperThumbnailURL,
                       kDefaultWallpaperPrefix, index);
 }
 
 bool IsDefaultWallpaperURL(const std::string url, int* wallpaper_index) {
   DCHECK(wallpaper_index);
   *wallpaper_index = ash::GetInvalidWallpaperIndex();
   if (!StartsWithASCII(url, chrome::kChromeUIWallpaperThumbnailURL, false))
       return false;
   std::string sub_path = url.substr(strlen(
       chrome::kChromeUIWallpaperThumbnailURL));
   return ParseIndexFromPath(sub_path, wallpaper_index);
 }
 
 WallpaperThumbnailSource::WallpaperThumbnailSource()
     : DataSource(chrome::kChromeUIWallpaperThumbnailHost, NULL) {
 }
 
 WallpaperThumbnailSource::~WallpaperThumbnailSource() {
 }
 
 void WallpaperThumbnailSource::StartDataRequest(const std::string& path,
                                                 bool is_incognito,
                                                 int request_id) {
+  std::string email;
+  if (IsCustomWallpaperPath(path, &email)) {
+    const chromeos::User* user = chromeos::UserManager::Get()->FindUser(email);
+    if (user) {
+      std::vector<unsigned char> data;
+      gfx::PNGCodec::EncodeBGRASkBitmap(user->wallpaper_thumb(), false, &data);
+      SendResponse(request_id, new base::RefCountedBytes(data));
+      return;
+    }
+  }
   int idr = PathToIDR(path);
   if (idr != -1) {
     DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
     const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     SendResponse(request_id, rb.LoadDataResourceBytes(idr));
   }
 }
 
 std::string WallpaperThumbnailSource::GetMimeType(const std::string&) const {
   return "images/png";
 }
 
 }  // namespace options2
 }  // namespace chromeos