Detect removed files and reflect the state in chrome://downloads and the download shelf

chrome/browser/ui/webui/downloads_dom_handler.cc

 // Copyright (c) 2011 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/downloads_dom_handler.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/basictypes.h"
@@ skipping 102 matching lines @@
 
 // A download has started or been deleted. Query our DownloadManager for the
 // current set of downloads.
 void DownloadsDOMHandler::ModelChanged() {
   ClearDownloadItems();
   download_manager_->SearchDownloads(WideToUTF16(search_text_),
                                      &download_items_);
   sort(download_items_.begin(), download_items_.end(), DownloadItemSorter());
 
   // Scan for any in progress downloads and add ourself to them as an observer.
   for (OrderedDownloads::iterator it = download_items_.begin();

[Paweł Hajdan Jr., 2011/05/10 11:37:51]

Oh, the loop is now empty and the comment is also misleading. I think the code
can stay here, just always call AddObserver. You shouldn't need HasObservers,
because this is the only place that adds something to download_items_.

Also, adding observers in SendCurrentDownloads is a surprising side effect. I
think the best place for observer adding code is here, in ModelChanged.

        it != download_items_.end(); ++it) {
     if (static_cast<int>(it - download_items_.begin()) > kMaxDownloads)
       break;
-
-    DownloadItem* download = *it;
-    if (download->IsInProgress()) {
-      // We want to know what happens as the download progresses.
-      download->AddObserver(this);
-    } else if (download->safety_state() == DownloadItem::DANGEROUS) {
-      // We need to be notified when the user validates the dangerous download.
-      download->AddObserver(this);
-    }
   }
 
   SendCurrentDownloads();
 }
 
 void DownloadsDOMHandler::HandleGetDownloads(const ListValue* args) {
   std::wstring new_search = UTF16ToWideHack(ExtractStringValue(args));
   if (search_text_.compare(new_search) != 0) {
     search_text_ = new_search;
     ModelChanged();
   } else {
     SendCurrentDownloads();
   }
+
+  download_manager_->CheckForFilesRemoval();
 }
 
 void DownloadsDOMHandler::HandleOpenFile(const ListValue* args) {
   DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->OpenDownload();
 }
 
 void DownloadsDOMHandler::HandleDrag(const ListValue* args) {
   DownloadItem* file = GetDownloadByValue(args);
@@ skipping 45 matching lines @@
 void DownloadsDOMHandler::HandleClearAll(const ListValue* args) {
   download_manager_->RemoveAllDownloads();
 }
 
 // DownloadsDOMHandler, private: ----------------------------------------------
 
 void DownloadsDOMHandler::SendCurrentDownloads() {
   ListValue results_value;
   for (OrderedDownloads::iterator it = download_items_.begin();
       it != download_items_.end(); ++it) {
+    // Add observers for all download items just once
+    if (!(*it)->HasObserver(this))
+      (*it)->AddObserver(this);
     int index = static_cast<int>(it - download_items_.begin());
     if (index > kMaxDownloads)
       break;
     results_value.Append(download_util::CreateDownloadItemValue(*it, index));
   }
 
   web_ui_->CallJavascriptFunction("downloadsList", results_value);
 }
 
 void DownloadsDOMHandler::ClearDownloadItems() {
@@ skipping 16 matching lines @@
   return NULL;
 }
 
 DownloadItem* DownloadsDOMHandler::GetDownloadByValue(const ListValue* args) {
   int id;
   if (ExtractIntegerValue(args, &id)) {
     return GetDownloadById(id);
   }
   return NULL;
 }