Drag and dropping text, parsable as url

chrome/browser/ui/views/toolbar/home_button.cc

 // Copyright 2013 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/views/toolbar/home_button.h"
 
 #include "base/macros.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/prefs/pref_service.h"
 #include "components/user_prefs/user_prefs.h"
+#include "ui/base/dragdrop/drag_and_drop_url_utils.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/link.h"
 #include "ui/views/controls/link_listener.h"
 #include "ui/views/layout/grid_layout.h"
 #include "ui/views/layout/layout_constants.h"
 #include "ui/views/widget/widget.h"
 
 // HomePageUndoBubble --------------------------------------------------------
@@ skipping 128 matching lines @@
 }
 
 bool HomeButton::GetDropFormats(
     int* formats,
     std::set<ui::Clipboard::FormatType>* format_types) {
   *formats = ui::OSExchangeData::URL;
   return true;
 }
 
 bool HomeButton::CanDrop(const OSExchangeData& data) {
-  return data.HasURL(ui::OSExchangeData::CONVERT_FILENAMES);
+  return ui::CanBeInterpretedAsURL(data, ui::OSExchangeData::CONVERT_FILENAMES);

[dyaroshev, 2016/09/14 17:12:05]

Here we don't check for URL validity, but in OnPerformDrop we do. Do we ever
want to get and invalid URL out of drag and drop?

[Peter Kasting, 2016/09/15 21:26:53]

I would suggest that:

* CanBeInterpretedAsURL() should only return true if the extracted URL would be
valid.
* TryToInterpretAsURL() should, similarly, include "and the URL is valid" as
part of what it's returning.
* Thus, callers of these should not need to check .is_valid().

The rationale for this is that a URL that is !is_valid() is not really a URL. 
So if the text cannot be interpreted as a valid URL, it cannot be interpreted as
a URL at all.

 }
 
 int HomeButton::OnDragUpdated(const ui::DropTargetEvent& event) {
   return event.source_operations();
 }
 
 int HomeButton::OnPerformDrop(const ui::DropTargetEvent& event) {
-  GURL new_homepage_url;
-  base::string16 title;
-  if (event.data().GetURLAndTitle(
-          ui::OSExchangeData::CONVERT_FILENAMES, &new_homepage_url, &title) &&
-      new_homepage_url.is_valid()) {
+  auto url_and_title = ui::TryToInterpretAsURL(
+      event.data(), ui::OSExchangeData::CONVERT_FILENAMES);
+  if (!url_and_title)
+    return ui::DragDropTypes::DRAG_NONE;
+
+  GURL& new_homepage_url = url_and_title->first;
+  if (new_homepage_url.is_valid()) {
     PrefService* prefs = browser_->profile()->GetPrefs();
     bool old_is_ntp = prefs->GetBoolean(prefs::kHomePageIsNewTabPage);
     GURL old_homepage(prefs->GetString(prefs::kHomePage));
 
     prefs->SetBoolean(prefs::kHomePageIsNewTabPage, false);
     prefs->SetString(prefs::kHomePage, new_homepage_url.spec());
 
     HomePageUndoBubble::ShowBubble(browser_, old_is_ntp, old_homepage, this);
   }
   return ui::DragDropTypes::DRAG_NONE;
 }