When the download folder does not exist, change the download folder to a user's "Downloads"

chrome/browser/download/download_util.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.
 //
 // Download utility implementation
 
 #include "chrome/browser/download/download_util.h"
 
 #if defined(OS_WIN)
 #include <shobjidl.h>
@@ skipping 185 matching lines @@
 
   DCHECK(!generated_name->empty());
 
   GenerateSafeFileName(mime_type, generated_name);
 }
 
 }  // namespace
 
 // Download temporary file creation --------------------------------------------
 
-class DefaultDownloadDirectory {
- public:
-  const FilePath& path() const { return path_; }
- private:
-  DefaultDownloadDirectory() {
-    if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &path_)) {
+ScopedDefaultDownloadDirectory::ScopedDefaultDownloadDirectory() {
+  DefaultDownloadDirectory::override_path_.clear();
+}
+
+ScopedDefaultDownloadDirectory::~ScopedDefaultDownloadDirectory() {
+  DefaultDownloadDirectory::override_path_.clear();
+}
+
+void ScopedDefaultDownloadDirectory::Override(const FilePath& override_path) {
+  DefaultDownloadDirectory::override_path_ = override_path;

[Paweł Hajdan Jr., 2011/06/09 19:10:38]

We should still update the pref here, as said before. It has a default value in
DownloadPrefs based on DefaultDownloadDirectory::Get, and we should keep those
in sync to avoid weirdness.

[haraken1, 2011/06/14 11:10:05]

I see. Now, DownloadPrefs::OverrideDefaultDownloadDirectory() updates those
values. 

+}
+
+void ScopedDefaultDownloadDirectory::UnOverride() {
+  DefaultDownloadDirectory::override_path_.clear();
+}
+
+FilePath DefaultDownloadDirectory::override_path_;
+
+const FilePath DefaultDownloadDirectory::Get() {
+  if (!override_path_.empty()) {
+    return override_path_;
+  }
+  FilePath path;
+  if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &path))
+    NOTREACHED();
+  if (DownloadPathIsDangerous(path)) {
+    if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS_SAFE, &path))
       NOTREACHED();
+  }
+  return path;
+}
+
+bool ChooseSavableDirectory(const FilePath& website_save_dir,
+                            const FilePath& download_save_dir,
+                            const FilePath& default_downloads_dir,
+                            FilePath* save_dir) {
+  bool prompt_dialog = false;
+  if (file_util::PathIsWritable(website_save_dir)) {
+    // If the default html/websites save folder exists,
+    // then use the default h5Btml/websites save folder.
+    *save_dir = website_save_dir;
+  } else if (file_util::PathIsWritable(download_save_dir)) {
+    // If the default html/websites save folder does not exist
+    // but the default download folder exists,
+    // then use the default download folder.
+    *save_dir = download_save_dir;
+  } else {
+    // If both the above folders do not exist,
+    // use the user's "Downloads" folder.
+    *save_dir = download_util::DefaultDownloadDirectory::Get();
+    prompt_dialog = true;
+    if (!file_util::PathIsWritable(*save_dir)) {
+      VLOG(1) << "Cannot find the user's writable \"Downloads\" folder.";
+      // Create the |download_save_dir| folder if we cannot get
+      // the user's writable "Downloads" folder (This will be a rare case).
+      *save_dir = download_save_dir;
     }
-    if (DownloadPathIsDangerous(path_)) {
-      if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS_SAFE, &path_)) {
-        NOTREACHED();
-      }
-    }
+    // Make sure that the folder does exist.
+    if (!file_util::CreateDirectory(*save_dir))
+      LOG(ERROR) << "Failed to create " << (*save_dir).value();
   }
-  friend struct base::DefaultLazyInstanceTraits<DefaultDownloadDirectory>;
-  FilePath path_;
-};
-
-static base::LazyInstance<DefaultDownloadDirectory>
-    g_default_download_directory(base::LINKER_INITIALIZED);
-
-const FilePath& GetDefaultDownloadDirectory() {
-  return g_default_download_directory.Get().path();
+  return prompt_dialog;
 }
 
 bool CreateTemporaryFileForDownload(FilePath* temp_file) {
-  if (file_util::CreateTemporaryFileInDir(GetDefaultDownloadDirectory(),
-                                          temp_file))
+  FilePath path = DefaultDownloadDirectory::Get();
+  if (file_util::CreateTemporaryFileInDir(path, temp_file))
     return true;
   return file_util::CreateTemporaryFile(temp_file);
 }
 
 bool DownloadPathIsDangerous(const FilePath& download_path) {
   FilePath desktop_dir;
   if (!PathService::Get(chrome::DIR_USER_DESKTOP, &desktop_dir)) {
     NOTREACHED();
     return false;
   }
@@ skipping 679 matching lines @@
 FilePath GetCrDownloadPath(const FilePath& suggested_path) {
   FilePath::StringType file_name;
   base::SStringPrintf(
       &file_name,
       PRFilePathLiteral FILE_PATH_LITERAL(".crdownload"),
       suggested_path.value().c_str());
   return FilePath(file_name);
 }
 
 }  // namespace download_util