Adding file access permissions to fileBrowserHandler manifest.

chrome/common/extensions/file_browser_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/common/extensions/file_browser_handler.h"
 
+#include "base/logging.h"
 #include "chrome/common/extensions/url_pattern.h"
 #include "googleurl/src/gurl.h"
 
-FileBrowserHandler::FileBrowserHandler() {
+namespace {
+
+const char kReadAccessString[] = "read";
+const char kReadWriteAccessString[] = "read-write";
+const char kCreateAccessString[] = "create";
+
+unsigned int kPermissionsNotDefined = 0;
+unsigned int kReadPermission = 1;
+unsigned int kWritePermission = 1 << 1;
+unsigned int kCreatePermission = 1 << 2;
+unsigned int kInvalidPermission = 1 << 3;
+
+unsigned int GetAccessPermissionFlagFromString(const std::string& access_str) {
+  if (access_str == kReadAccessString)
+    return kReadPermission;
+  if (access_str == kReadWriteAccessString)
+    return kReadPermission | kWritePermission;
+  if (access_str == kCreateAccessString)
+    return kCreatePermission;
+  return kInvalidPermission;
+}
+
+}
+
+
+FileBrowserHandler::FileBrowserHandler()
+    : file_access_permission_flags_(kPermissionsNotDefined) {
 }
 
 FileBrowserHandler::~FileBrowserHandler() {
 }
 
 void FileBrowserHandler::AddPattern(const URLPattern& pattern) {
   url_set_.AddPattern(pattern);
 }
 
 void FileBrowserHandler::ClearPatterns() {
   url_set_.ClearPatterns();
 }
 
 bool FileBrowserHandler::MatchesURL(const GURL& url) const {
   return url_set_.MatchesURL(url);
 }
+
+bool FileBrowserHandler::AddFileAccessPermission(
+    const std::string& access) {
+  file_access_permission_flags_ |= GetAccessPermissionFlagFromString(access);
+  return (file_access_permission_flags_ & kInvalidPermission) != 0U;
+}
+
+bool FileBrowserHandler::InvalidateFileAccessPermissions() {
+  bool is_invalid = (file_access_permission_flags_ & kInvalidPermission) != 0U;
+  bool can_create = (file_access_permission_flags_ & kCreatePermission) != 0U;
+  bool can_read_or_write = (file_access_permission_flags_ &
+      (kReadPermission | kWritePermission)) != 0U;
+  if (is_invalid || (can_create && can_read_or_write)) {
+    file_access_permission_flags_ = kInvalidPermission;
+    return false;
+  }
+
+  if (file_access_permission_flags_ == kPermissionsNotDefined)
+    file_access_permission_flags_ = kReadPermission | kWritePermission;
+  return true;
+}
+
+bool FileBrowserHandler::CanRead() const {
+  DCHECK(!(file_access_permission_flags_ & kInvalidPermission));
+  return (file_access_permission_flags_ & kReadPermission) != 0;
+}
+
+bool FileBrowserHandler::CanWrite() const {
+  DCHECK(!(file_access_permission_flags_ & kInvalidPermission));
+  return (file_access_permission_flags_ & kWritePermission) != 0;
+}
+
+bool FileBrowserHandler::CanCreate() const {

[Yoyo Zhou, 2012/03/26 22:42:58]

Does write access imply being able to create? Do you intend for this to be used
to check "has the create file access permission" or to check "can create files"?
(In other words, if I want to be able to both edit files and create new files,
what should I specify?)

[tbarzic, 2012/03/26 23:22:51]

I plan to use this as check that the handler "has the create file access
permission".
The write permission could also imply create permission (in save as use case),
but I'm not completely sure how we're going to implement this yet (we may also
check that the handler has at least on "create" handler specified).

Maybe it would be good to rename this?

[Yoyo Zhou, 2012/03/27 00:54:20]

Yeah, my comment is along the lines of: the functionality might not match the
name, so either the name or the functionality should change.

[tbarzic, 2012/03/27 01:10:59]

Done.

+  DCHECK(!(file_access_permission_flags_ & kInvalidPermission));
+  return (file_access_permission_flags_ & kCreatePermission) != 0;
+}