[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..5ca4cb83d928720f3ce35c492e85b5981818b44f 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"
@@ -22,8 +23,12 @@
 #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 "third_party/skia/include/core/SkBitmap.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 +36,27 @@ 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
+
+std::string ReadNotificationImage(
+    const std::string type, const base::FilePath file_path) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
+
+  gfx::Image image;
+
+  std::string data;
+  bool ret = base::ReadFileToString(file_path, &data);
+  if (!ret)
+    return std::string();
+
+  if (data.size() > kMaxImagePreviewSize)

[asanka, 2015/06/09 00:13:38]

Check the size of the file rather than checking the size of |data|.

[yoshiki, 2015/06/10 15:05:04]

The file size is checked at l.336 in the patchset #4.

+    return std::string();
+
+  return data;
+}
+
 }  // anonymous namespace
 
 // static
@@ -77,7 +103,8 @@ 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.
@@ -200,6 +227,8 @@ void DownloadNotificationItem::CloseNotificationByUser() {
 
 void DownloadNotificationItem::UpdateNotificationData(
     NotificationUpdateType type) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
   DownloadItemModel model(item_);
   DownloadCommands command(item_);
 
@@ -217,7 +246,7 @@ 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 +260,9 @@ 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 +277,9 @@ 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 +298,7 @@ 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 +319,6 @@ 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 +340,43 @@ void DownloadNotificationItem::UpdateNotificationData(
   }
 
   previous_download_state_ = item_->GetState();
+
+  if (item_->IsDone() && !set_image_ &&
+      item_->GetTotalBytes() <= kMaxImagePreviewSize) {
+    DCHECK(notification_->image().IsEmpty());
+
+    set_image_ = true;
+
+    std::string type;
+    std::string mime_topleveltype;
+    std::string mime_subtype;
+    if (net::ParseMimeTypeWithoutParameter(

[asanka, 2015/06/09 00:13:38]

Use mime_util::IsSupportedImageMimeType()

[yoshiki, 2015/06/10 15:05:04]

Done.

+            item_->GetMimeType(), &mime_topleveltype, &mime_subtype) &&
+        mime_topleveltype == "image" &&
+        (mime_subtype == "png" || mime_subtype == "jpg" ||
+         mime_subtype == "jpeg")) {
+      type = mime_subtype;
+    } else {
+      std::string dot_extension = item_->GetTargetFilePath().FinalExtension();

[asanka, 2015/06/09 00:13:38]

Use net::GetMimeTypeFromFile(). Note that this can cause IO. So ideally, you'd
pass the MIMe type to ReadNotificationImage() and have it deal with MIME types.

[yoshiki, 2015/06/10 15:05:04]

I think we don't need to check the file contents for all downloaded file. Just
checking the extension is enough. WDYT?

+      if (!dot_extension.empty()) {
+        std::string extension = dot_extension.substr(1);
+        if (extension == "png" || extension == "jpg" || extension == "jpeg")
+          type = extension;
+      }
+    }
+
+    if (!type.empty()) {
+      base::FilePath file_path = item_->GetFullPath();
+      content::BrowserThread::PostTaskAndReplyWithResult(
+          content::BrowserThread::FILE,
+          FROM_HERE,
+          base::Bind(&ReadNotificationImage,
+                     type,
+                     file_path),
+          base::Bind(&DownloadNotificationItem::OnImageLoaded,
+                     weak_factory_.GetWeakPtr()));
+    }
+  }
 }
 
 void DownloadNotificationItem::OnDownloadOpened(content::DownloadItem* item) {
@@ -338,7 +400,7 @@ 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 +408,25 @@ void DownloadNotificationItem::SetNotificationImage(int resource_id) {
   notification_->set_icon(bundle.GetImageNamed(image_resource_id_));
 }
 
+void DownloadNotificationItem::OnImageLoaded(std::string image_data) {
+  if (image_data.empty())
+    return;
+
+  // TODO(yoshiki): Set option to reduce the image size to supress memory usage.

[asanka, 2015/06/09 00:13:38]

No. We should be passing a file handle over to the utility process and have it
read + decode + resize the image before sending us the image bits.

See SandboxedZipAnalyzer for example.

[yoshiki, 2015/06/10 15:05:04]

Done. Resizing will be implemented later.

+  ImageDecoder::Start(this, image_data);

[asanka, 2015/06/09 00:13:38]

You should call ImageDecoder::Cancel() if the notification item is going away.

[yoshiki, 2015/06/10 15:05:04]

Done.

+}
+
+void DownloadNotificationItem::OnImageDecoded(const SkBitmap& decoded_image) {
+  gfx::Image image = gfx::Image::CreateFrom1xBitmap(decoded_image);
+  notification_->set_image(image);
+  UpdateNotificationData(UPDATE_EXISTING);
+}
+
+void DownloadNotificationItem::OnDecodeImageFailed() {
+  notification_->set_image(gfx::Image());
+  UpdateNotificationData(UPDATE_EXISTING);
+}
+
 NotificationUIManager* DownloadNotificationItem::notification_ui_manager()
     const {
   if (stub_notification_ui_manager_for_testing_) {