Make the UI an observer of downloads.

chrome/browser/download/download_ui_controller.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_ui_controller.h"
+
+#include "base/stl_util.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/browser_tabstrip.h"
+#include "content/public/browser/download_item.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_delegate.h"
+
+#if defined(OS_ANDROID)
+#include "content/public/browser/android/download_controller_android.h"
+#else
+#include "chrome/browser/ui/blocked_content/blocked_content_tab_helper.h"
+#include "chrome/browser/ui/blocked_content/blocked_content_tab_helper_delegate.h"
+#endif
+
+namespace {
+
+// The presence of this UserData in a DownloadItem signals that the UI should be
+// notified of this download.
+class ShouldNotifyData : public base::SupportsUserData::Data {
+ public:
+  static void Set(content::DownloadItem* item) {
+    new ShouldNotifyData(item);
+  }
+
+  static bool IsSet(content::DownloadItem* item) {
+    return item->GetUserData(kKey) != NULL;
+  }
+
+  static void Clear(content::DownloadItem* item) {
+    item->RemoveUserData(kKey);
+  }
+
+ private:
+  explicit ShouldNotifyData(content::DownloadItem* item) {
+    item->SetUserData(kKey, this);
+  }
+
+  static const char kKey[];
+  DISALLOW_COPY_AND_ASSIGN(ShouldNotifyData);
+};
+
+const char ShouldNotifyData::kKey[] = "DownloadUIConroller ShouldNotifyData";
+
+} // namespace
+
+DownloadUIController::DownloadUIController(Profile* profile,
+                                           content::DownloadManager* manager)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(notifier_(manager, this)),
+      profile_(profile) {
+}
+
+DownloadUIController::~DownloadUIController() {
+}
+
+void DownloadUIController::OnDownloadCreated(content::DownloadManager* manager,
+                                             content::DownloadItem* item) {
+  // If this isn't a new download, there's nothing to do.
+  if (!item->IsInProgress())
+    return;
+
+  ShouldNotifyData::Set(item);
+  // SavePackage downloads are created in a state where they can be shown
+  // immediately in the browser.
+  OnDownloadUpdated(manager, item);
+}
+
+void DownloadUIController::OnDownloadUpdated(content::DownloadManager* manager,
+                                             content::DownloadItem* item) {
+
+  // Ignore if we've already notified the UI about |item| or if it isn't a new
+  // download.
+  if (!ShouldNotifyData::IsSet(item))
+    return;
+
+  // Wait until the target path is determined.
+  if (item->GetTargetFilePath().empty())
+    return;
+
+  // For a download that is in-progress, wait until the intermediate rename is
+  // complete.
+  // TODO(asanka): Get rid of remaining users of GetFullPath() in ui/.
+  if (item->IsInProgress() && item->GetFullPath().empty())
+    return;
+
+  // At this point, we expect that the download is either interrupted, or
+  // in-progress and the path is known.
+
+  // Can't be complete. That would imply that we didn't receive an
+  // OnDownloadUpdated() after the intermediate rename was completed.
+  DCHECK(!item->IsComplete());
+
+  ShouldNotifyData::Clear(item);
+  NotifyDownloadStarting(item);
+}
+
+void DownloadUIController::NotifyDownloadStarting(content::DownloadItem* item) {
+#if defined(OS_ANDROID)
+  // GET downloads are delegated to and Android DownloadManager. Chrome is only

[benjhayden, 2012/12/20 21:09:14]

to an

[asanka, 2012/12/20 22:41:19]

Done.

+  // responsible for POST downloads.
+  // See ChromeWebContentsDelegateAndroid::CanDownload().
+  content::DownloadControllerAndroid::Get()->OnPostDownloadStarted(item);
+#else
+  content::WebContents* web_contents = item->GetWebContents();
+
+  // If the tab requesting the download is a constrained popup that is not
+  // shown, treat the request as if it came from the parent.
+  if (web_contents != NULL) {
+    BlockedContentTabHelper* blocked_content_tab_helper =
+        BlockedContentTabHelper::FromWebContents(web_contents);
+    if (blocked_content_tab_helper &&
+        blocked_content_tab_helper->delegate()) {
+      content::WebContents* constraining_web_contents =
+          blocked_content_tab_helper->delegate()->
+              GetConstrainingWebContents(web_contents);
+      if (constraining_web_contents)
+        web_contents = constraining_web_contents;
+    }
+  }
+
+  Browser* browser =
+      web_contents ? chrome::FindBrowserWithWebContents(web_contents) : NULL;
+
+  // As a last resort, use the last active browser for this profile. Not ideal,
+  // but better than not showing the download at all.
+  if (browser == NULL) {
+    browser = chrome::FindLastActiveWithProfile(profile_,
+                                                chrome::GetActiveDesktop());
+  }
+
+  if (browser)
+    browser->ShowDownload(item);
+#endif
+}
+