[Resumption 11/12] Support resuming interrupted downloads from the downloads shelf.

chrome/browser/download/download_shelf_context_menu.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/download/download_shelf_context_menu.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_crx_util.h"
 #include "chrome/browser/download/download_item_model.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/safe_browsing/download_protection_service.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/page_navigator.h"
+#include "content/public/common/content_switches.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using content::DownloadItem;
 using extensions::Extension;
 
+namespace {
+
+// Returns true if downloads resumption is enabled.
+bool IsDownloadResumptionEnabled() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  return command_line.HasSwitch(switches::kEnableDownloadResumption);
+}
+
+} // namespace
+
 DownloadShelfContextMenu::~DownloadShelfContextMenu() {
   DetachFromDownloadItem();
 }
 
 DownloadShelfContextMenu::DownloadShelfContextMenu(
     DownloadItem* download_item,
     content::PageNavigator* navigator)
     : download_item_(download_item),
       navigator_(navigator) {
   DCHECK(download_item_);
@@ skipping 35 matching lines @@
     case ALWAYS_OPEN_TYPE:
       // For temporary downloads, the target filename might be a temporary
       // filename. Don't base an "Always open" decision based on it. Also
       // exclude extensions.
       return download_item_->CanOpenDownload() &&
           !download_crx_util::IsExtensionDownload(*download_item_);
     case CANCEL:
       return download_item_->IsPartialDownload();
     case TOGGLE_PAUSE:
       return download_item_->GetState() == DownloadItem::IN_PROGRESS;
+    case RESUME_INTERRUPTED:
+      return download_item_->IsInterrupted() && download_item_->CanResume();

[Randy Smith (Not in Mondays), 2013/06/05 20:12:55]

Actually, an extra high-level question: Why not just expand the TOGGLE_PAUSE
item to do the resume interrupted functionality?  (Not blocking landing; just
curious as to why you made this design choice.)

[asanka, 2013/06/05 20:29:17]

Good question. I did it that way the first time around, and TOGGLE_PAUSE seemed
like the wrong action to trigger a resumption for an interrupted download. Back
when this CL was started, resumption was via
DownloadItem::ResumeInterruptedDownload().

I'll change it back to TOGGLE_PAUSE with appropriate documentation.

     case DISCARD:
     case KEEP:
     case LEARN_MORE_SCANNING:
     case LEARN_MORE_INTERRUPTED:
       return true;
   }
   return false;
 }
 
 bool DownloadShelfContextMenu::IsCommandIdChecked(int command_id) const {
@@ skipping 40 matching lines @@
       // It is possible for the download to complete before the user clicks the
       // menu item, recheck if the download is in progress state before toggling
       // pause.
       if (download_item_->GetState() == DownloadItem::IN_PROGRESS) {
         if (download_item_->IsPaused())
           download_item_->Resume();
         else
           download_item_->Pause();
       }
       break;
+    case RESUME_INTERRUPTED:
+      download_item_->Resume();
+      break;
     case DISCARD:
       download_item_->Remove();
       break;
     case KEEP:
       download_item_->ValidateDangerousDownload();
       break;
     case LEARN_MORE_SCANNING: {
 #if defined(FULL_SAFE_BROWSING)
       using safe_browsing::DownloadProtectionService;
       SafeBrowsingService* sb_service =
@@ skipping 38 matching lines @@
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_OPEN_WHEN_COMPLETE);
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_OPEN);
     case ALWAYS_OPEN_TYPE:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_ALWAYS_OPEN_TYPE);
     case CANCEL:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_CANCEL);
     case TOGGLE_PAUSE:
       if (download_item_ && download_item_->IsPaused())
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_PAUSE_ITEM);
+    case RESUME_INTERRUPTED:
+      return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
     case DISCARD:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_DISCARD);
     case KEEP:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_KEEP);
     case LEARN_MORE_SCANNING:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_LEARN_MORE_SCANNING);
     case LEARN_MORE_INTERRUPTED:
       return l10n_util::GetStringUTF16(
           IDS_DOWNLOAD_MENU_LEARN_MORE_INTERRUPTED);
   }
@@ skipping 50 matching lines @@
   finished_download_menu_model_->AddItemWithStringId(
       SHOW_IN_FOLDER, IDS_DOWNLOAD_MENU_SHOW);
   finished_download_menu_model_->AddSeparator(ui::NORMAL_SEPARATOR);
   finished_download_menu_model_->AddItemWithStringId(
       CANCEL, IDS_DOWNLOAD_MENU_CANCEL);
 
   return finished_download_menu_model_.get();
 }
 
 ui::SimpleMenuModel* DownloadShelfContextMenu::GetInterruptedMenuModel() {
-#if defined(OS_WIN)
-  // The Help Center article is currently Windows specific.
-  // TODO(asanka): Enable this for other platforms when the article is expanded
-  // for other platforms.
+#if !defined(OS_WIN)
+  // If resumption isn't enabled and we aren't on Windows, then none of the
+  // options here are applicable.
+  if (!IsDownloadResumptionEnabled())
+    return GetInProgressMenuModel();
+#endif
+
   if (interrupted_download_menu_model_)
     return interrupted_download_menu_model_.get();
 
   interrupted_download_menu_model_.reset(new ui::SimpleMenuModel(this));
 
+  if (IsDownloadResumptionEnabled()) {
+    interrupted_download_menu_model_->AddItemWithStringId(
+        RESUME_INTERRUPTED, IDS_DOWNLOAD_MENU_RESUME_ITEM);
+  }
+#if defined(OS_WIN)
+  // The Help Center article is currently Windows specific.
+  // TODO(asanka): Enable this for other platforms when the article is expanded
+  // for other platforms.
   interrupted_download_menu_model_->AddItemWithStringId(
       LEARN_MORE_INTERRUPTED, IDS_DOWNLOAD_MENU_LEARN_MORE_INTERRUPTED);
+#endif
+  if (IsDownloadResumptionEnabled()) {
+    interrupted_download_menu_model_->AddSeparator(ui::NORMAL_SEPARATOR);
+    interrupted_download_menu_model_->AddItemWithStringId(
+        CANCEL, IDS_DOWNLOAD_MENU_CANCEL);
+  }
 
   return interrupted_download_menu_model_.get();
-#else
-  return GetInProgressMenuModel();
-#endif
 }
 
 ui::SimpleMenuModel* DownloadShelfContextMenu::GetMaliciousMenuModel() {
   if (malicious_download_menu_model_)
     return malicious_download_menu_model_.get();
 
   malicious_download_menu_model_.reset(new ui::SimpleMenuModel(this));
 
   malicious_download_menu_model_->AddItemWithStringId(
       DISCARD, IDS_DOWNLOAD_MENU_DISCARD);
   malicious_download_menu_model_->AddItemWithStringId(
       KEEP, IDS_DOWNLOAD_MENU_KEEP);
   malicious_download_menu_model_->AddSeparator(ui::NORMAL_SEPARATOR);
   malicious_download_menu_model_->AddItemWithStringId(
       LEARN_MORE_SCANNING, IDS_DOWNLOAD_MENU_LEARN_MORE_SCANNING);
 
   return malicious_download_menu_model_.get();
 }