[Download Notification] Show preview if downloaded file is image

chrome/browser/download/notification/download_notification_item.cc

Index: chrome/browser/download/notification/download_notification_item.cc
diff --git a/chrome/browser/download/notification/download_notification_item.cc b/chrome/browser/download/notification/download_notification_item.cc
index 0e3c98ab060cade1e85b81d3e788889a9baa4817..f0ec4e8eb5d7f572cbf46da29f612a4107bca292 100644
--- a/chrome/browser/download/notification/download_notification_item.cc
+++ b/chrome/browser/download/notification/download_notification_item.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/download/notification/download_notification_item.h"
 
+#include "base/files/file_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_crx_util.h"
@@ -15,6 +16,7 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
+#include "components/mime_util/mime_util.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_interrupt_reasons.h"
@@ -22,8 +24,11 @@
 #include "content/public/browser/page_navigator.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/theme_resources.h"
+#include "net/base/mime_util.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/codec/jpeg_codec.h"
+#include "ui/gfx/image/image.h"
 #include "ui/message_center/message_center.h"
 
 namespace {
@@ -31,6 +36,10 @@ namespace {
 const char kDownloadNotificationNotifierId[] =
     "chrome://downloads/notification/id-notifier";
 
+// Maximum size of preview image. If the image exceeds this size, don't show the
+// preview image.
+const int64 kMaxImagePreviewSize = 10 * 1024 * 1024;  // 10 MB
+
 }  // anonymous namespace
 
 // static
@@ -51,7 +60,7 @@ DownloadNotificationItem::NotificationWatcher::~NotificationWatcher() {
 }
 
 void DownloadNotificationItem::NotificationWatcher::Close(bool by_user) {
-  // Do nothing.
+  item_->OnNotificationClose(by_user);
 }
 
 void DownloadNotificationItem::NotificationWatcher::Click() {
@@ -77,7 +86,8 @@ DownloadNotificationItem::DownloadNotificationItem(content::DownloadItem* item,
     : profile_(profile),
       watcher_(new NotificationWatcher(this)),
       item_(item),
-      delegate_(delegate) {
+      delegate_(delegate),
+      weak_factory_(this)  {
   item->AddObserver(this);
 
   // Notify that the instance is just created.
@@ -107,6 +117,9 @@ DownloadNotificationItem::DownloadNotificationItem(content::DownloadItem* item,
 }
 
 DownloadNotificationItem::~DownloadNotificationItem() {
+  if (image_decode_status_ == IN_PROGRESS)
+    ImageDecoder::Cancel(this);
+
   if (item_)
     item_->RemoveObserver(this);
 }
@@ -164,6 +177,13 @@ void DownloadNotificationItem::OnNotificationButtonClick(int button_index) {
     UpdateNotificationData(ADD_NEW);
 }
 
+void DownloadNotificationItem::OnNotificationClose(bool by_user) {
+  if (image_decode_status_ == IN_PROGRESS) {
+    image_decode_status_ = NOT_STARTED;
+    ImageDecoder::Cancel(this);
+  }
+}
+
 // DownloadItem::Observer methods
 void DownloadNotificationItem::OnDownloadUpdated(content::DownloadItem* item) {
   DCHECK_EQ(item, item_);
@@ -200,6 +220,8 @@ void DownloadNotificationItem::CloseNotificationByUser() {
 
 void DownloadNotificationItem::UpdateNotificationData(
     NotificationUpdateType type) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
   DownloadItemModel model(item_);
   DownloadCommands command(item_);
 
@@ -217,7 +239,7 @@ void DownloadNotificationItem::UpdateNotificationData(
     notification_->set_message(GetWarningText());
 
     // Show icon.
-    SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_MALICIOUS);
+    SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_MALICIOUS);
   } else {
     notification_->set_title(GetTitle());
     notification_->set_message(model.GetStatusText());
@@ -231,9 +253,9 @@ void DownloadNotificationItem::UpdateNotificationData(
         notification_->set_progress(item_->PercentComplete());
         if (is_off_the_record) {
           // TODO(yoshiki): Replace the tentative image.
-          SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_INCOGNITO);
+          SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_INCOGNITO);
         } else {
-          SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_DOWNLOADING);
+          SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_DOWNLOADING);
         }
         break;
       case content::DownloadItem::COMPLETE:
@@ -248,9 +270,9 @@ void DownloadNotificationItem::UpdateNotificationData(
 
         if (is_off_the_record) {
           // TODO(yoshiki): Replace the tentative image.
-          SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_INCOGNITO);
+          SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_INCOGNITO);
         } else {
-          SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_DOWNLOADING);
+          SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_DOWNLOADING);
         }
         break;
       case content::DownloadItem::CANCELLED:
@@ -269,7 +291,7 @@ void DownloadNotificationItem::UpdateNotificationData(
         // be updated. (same as the case of type = COMPLETE)
         notification_->set_type(message_center::NOTIFICATION_TYPE_PROGRESS);
         notification_->set_progress(0);
-        SetNotificationImage(IDR_DOWNLOAD_NOTIFICATION_WARNING);
+        SetNotificationIcon(IDR_DOWNLOAD_NOTIFICATION_WARNING);
         break;
       case content::DownloadItem::MAX_DOWNLOAD_STATE:  // sentinel
         NOTREACHED();
@@ -290,10 +312,6 @@ void DownloadNotificationItem::UpdateNotificationData(
   }
   notification_->set_buttons(notification_actions);
 
-  if (item_->IsDone()) {
-    // TODO(yoshiki): If the downloaded file is an image, show the thumbnail.
-  }
-
   if (type == ADD_NEW) {
     notification_ui_manager()->Add(*notification_, profile_);
   } else if (type == UPDATE_EXISTING) {
@@ -315,6 +333,34 @@ void DownloadNotificationItem::UpdateNotificationData(
   }
 
   previous_download_state_ = item_->GetState();
+
+  if (item_->IsDone() && image_decode_status_ == NOT_STARTED &&
+      item_->GetReceivedBytes() <= kMaxImagePreviewSize) {
+    DCHECK(notification_->image().IsEmpty());
+
+    image_decode_status_ = IN_PROGRESS;
+
+    bool maybe_image = false;
+    if (mime_util::IsSupportedImageMimeType(item_->GetMimeType())) {
+      maybe_image = true;
+    } else {
+      std::string mime;
+      if (net::GetWellKnownMimeTypeFromExtension(
+              item_->GetTargetFilePath().FinalExtension(),
+              &mime) &&
+          mime_util::IsSupportedImageMimeType(mime)) {
+        maybe_image = true;
+      }
+    }
+
+    if (maybe_image) {
+      base::FilePath file_path = item_->GetFullPath();
+      // TODO(yoshiki): Shrink the image size to supress memory usage.
+      ImageDecoder::StartByFilePath(this, file_path);
+    } else {
+      image_decode_status_ = NOT_IMAGE;
+    }
+  }
 }
 
 void DownloadNotificationItem::OnDownloadOpened(content::DownloadItem* item) {
@@ -338,7 +384,7 @@ void DownloadNotificationItem::OnDownloadDestroyed(
   item_ = nullptr;
 }
 
-void DownloadNotificationItem::SetNotificationImage(int resource_id) {
+void DownloadNotificationItem::SetNotificationIcon(int resource_id) {
   if (image_resource_id_ == resource_id)
     return;
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
@@ -346,6 +392,19 @@ void DownloadNotificationItem::SetNotificationImage(int resource_id) {
   notification_->set_icon(bundle.GetImageNamed(image_resource_id_));
 }
 
+void DownloadNotificationItem::OnImageDecoded(const SkBitmap& decoded_image) {
+  gfx::Image image = gfx::Image::CreateFrom1xBitmap(decoded_image);
+  notification_->set_image(image);
+  image_decode_status_ = DONE;
+  UpdateNotificationData(UPDATE_EXISTING);
+}
+
+void DownloadNotificationItem::OnDecodeImageFailed() {
+  notification_->set_image(gfx::Image());
+  image_decode_status_ = FAILED;
+  UpdateNotificationData(UPDATE_EXISTING);
+}
+
 NotificationUIManager* DownloadNotificationItem::notification_ui_manager()
     const {
   if (stub_notification_ui_manager_for_testing_) {