Added new fileBrowserPrivate and fileHandler extension APIs

chrome/browser/extensions/extension_file_browser_private_api.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/extensions/extension_file_browser_private_api.h"
 
 #include "base/json/json_writer.h"
+#include "base/stringprintf.h"
 #include "base/task.h"
 #include "base/values.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/extensions/extension_function_dispatcher.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/tab_contents/context_menu_utils.h"
+#include "chrome/browser/ui/webui/extension_icon_source.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/browser/browser_thread.h"
+#include "content/browser/child_process_security_policy.h"
+#include "content/browser/renderer_host/render_process_host.h"
+#include "content/browser/renderer_host/render_view_host.h"
+#include "content/browser/tab_contents/tab_contents.h"
+#include "webkit/fileapi/file_system_context.h"
 #include "webkit/fileapi/file_system_operation.h"
+#include "webkit/fileapi/file_system_path_manager.h"
 #include "webkit/fileapi/file_system_types.h"
+#include "webkit/glue/context_menu.h"
+
+const char kContextTaskIdSchema[] = "context-task";
+
+bool GetContextMenuItems(Profile* profile,
+                         const ContextMenuParams& params,
+                         ExtensionMenuItem::List* results) {
+  ExtensionService* service = profile->GetExtensionService();
+  if (!service)
+    return false;  // In unit-tests, we may not have an ExtensionService.
+
+  // Get a list of extension id's that have context menu items, and sort it by
+  // the extension's name.
+  ExtensionMenuManager* menu_manager = service->menu_manager();
+  std::set<std::string> ids = menu_manager->ExtensionIds();
+  std::vector<std::pair<std::string, std::string> > sorted_ids;
+  for (std::set<std::string>::iterator i = ids.begin(); i != ids.end(); ++i) {
+    const Extension* extension = service->GetExtensionById(*i, false);
+    if (extension)
+      sorted_ids.push_back(
+          std::pair<std::string, std::string>(extension->name(), *i));
+  }
+
+  if (sorted_ids.empty())
+    return true;
+
+  std::vector<std::pair<std::string, std::string> >::const_iterator i;
+  for (i = sorted_ids.begin(); i != sorted_ids.end(); ++i) {
+    const std::string& extension_id = i->second;
+    const Extension* extension = service->GetExtensionById(extension_id, false);
+    bool can_cross_incognito = service->CanCrossIncognito(extension);
+    const ExtensionMenuItem::List* all_items =
+        menu_manager->MenuItems(extension_id);
+    ExtensionMenuItem::List relevant_items =
+        ContextMenuUtils::GetRelevantExtensionItems(*all_items,
+                                                    params,
+                                                    profile,
+                                                    can_cross_incognito);
+    results->insert(results->end(), relevant_items.begin(),
+                    relevant_items.end());
+  }
+  return true;
+}
+
+void CreateContextMenuParams(const GURL& source_url,
+                             const std::string& file_url,
+                             ContextMenuParams* params) {
+  DCHECK(params);
+  params->is_image_blocked = false;
+  params->spellcheck_enabled = false;
+  params->is_editable = false;
+  params->media_flags = 0;
+  params->edit_flags = 0;
+  params->media_type = WebKit::WebContextMenuData::MediaTypeFile;
+  params->src_url = GURL(file_url);
+  params->page_url = source_url;
+}
+
+// Given the list of selected files, returns array of context menu tasks
+// that are sahred
+bool FindCommonTasks(Profile* profile,
+                     const GURL& source_url,
+                     ListValue* files_list,
+                     ExtensionMenuItem::List* common_tasks) {
+  common_tasks->clear();
+  for (size_t i = 0; i < files_list->GetSize(); ++i) {
+    std::string file_url;
+    if (!files_list->GetString(i, &file_url))
+      return false;
+
+    ContextMenuParams params;
+    CreateContextMenuParams(source_url, file_url, &params);
+
+    ExtensionMenuItem::List file_actions;
+    if (!GetContextMenuItems(profile, params, &file_actions))
+      return false;
+    // If there is nothing to do for one file, the intersection of tasks for all
+    // files will be empty at the end.
+    if (!file_actions.size()) {
+      common_tasks->clear();
+      return true;
+    }
+    // For the very first file, just copy elements.
+    if (i == 0) {
+      common_tasks->insert(common_tasks->begin(),
+                           file_actions.begin(),
+                           file_actions.end());
+      std::sort(common_tasks->begin(), common_tasks->end());
+    } else if (common_tasks->size()) {
+      // For all additional files, find intersection between the accumulated
+      // and file specific set.
+      std::sort(file_actions.begin(), file_actions.end());
+      ExtensionMenuItem::List intersection(common_tasks->size());
+      ExtensionMenuItem::List::iterator intersection_end =
+          std::set_intersection(common_tasks->begin(),
+                                common_tasks->end(),
+                                file_actions.begin(),
+                                file_actions.end(),
+                                intersection.begin());
+      common_tasks->clear();
+      common_tasks->insert(common_tasks->begin(),
+                           intersection.begin(),
+                           intersection_end);
+      std::sort(common_tasks->begin(), common_tasks->end());
+    }
+  }
+  return true;
+}
+
+// Breaks down task_id that is used between getFileTasks() and executeTask() on
+// its building blocks. task_id field the following structure:
+//     <task-type>:<extension-id>/<task-action-id>
+// Currently, the only supported task-type is of 'context'.
+bool CrackTaskIdentifier(const std::string& task_id,
+                         std::string* task_type,
+                         std::string* target_extension_id,
+                         std::string* action_id) {
+  std::string::size_type pos_col = task_id.find(':');
+  if (pos_col == std::string::npos)
+    return false;
+  *task_type = task_id.substr(0, pos_col);
+  std::string::size_type pos_slash = task_id.find('/');
+  if (pos_slash == std::string::npos)
+    return false;
+  *target_extension_id = task_id.substr(pos_col + 1, pos_slash - pos_col - 1);
+  *action_id = task_id.substr(pos_slash + 1);
+  return true;
+}
+
+std::string MakeTaskID(const char* task_schema,
+                       const char* extension_id,
+                       int action_id) {
+  return base::StringPrintf("%s:%s/%d", task_schema, extension_id, action_id);
+}
 
 class LocalFileSystemCallbackDispatcher
     : public fileapi::FileSystemCallbackDispatcher {
  public:
   explicit LocalFileSystemCallbackDispatcher(
-      RequestLocalFileSystemFunction* function) : function_(function) {
+      RequestLocalFileSystemFunctionBase* function,
+      Profile* profile,
+      int child_id,
+      const GURL& source_url,
+      const std::string& file_url)
+      : function_(function),
+        profile_(profile),
+        child_id_(child_id),
+        source_url_(source_url),
+        file_url_(file_url) {
     DCHECK(function_);
   }
   // fileapi::FileSystemCallbackDispatcher overrides.
   virtual void DidSucceed() OVERRIDE {
     NOTREACHED();
   }
   virtual void DidReadMetadata(const base::PlatformFileInfo& info) OVERRIDE {
     NOTREACHED();
   }
   virtual void DidReadDirectory(
       const std::vector<base::FileUtilProxy::Entry>& entries,
       bool has_more) OVERRIDE {
     NOTREACHED();
   }
   virtual void DidWrite(int64 bytes, bool complete) OVERRIDE {
     NOTREACHED();
   }
   virtual void DidOpenFileSystem(const std::string& name,
                                  const FilePath& path) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+    // Set up file permission access.
+    if (file_url_.length()) {
+      if (!SetupFileAccessPermissions()) {
+        DidFail(base::PLATFORM_FILE_ERROR_SECURITY);
+        return;
+      }
+    }
+
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         NewRunnableMethod(function_,
-            &RequestLocalFileSystemFunction::RespondSuccessOnUIThread,
+            &RequestLocalFileSystemFunctionBase::RespondSuccessOnUIThread,
             name,
-            path));
+            path,
+            file_url_));
   }
   virtual void DidFail(base::PlatformFileError error_code) OVERRIDE {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         NewRunnableMethod(function_,
-            &RequestLocalFileSystemFunction::RespondFailedOnUIThread,
+            &RequestLocalFileSystemFunctionBase::RespondFailedOnUIThread,
             error_code));
   }
  private:
-  RequestLocalFileSystemFunction* function_;
+
+  // Checks legitimacy of file url and grants access permissions.
+  bool SetupFileAccessPermissions() {
+    GURL file_origin_url;
+    FilePath virtual_path;
+    fileapi::FileSystemType type;
+    fileapi::FileSystemPathManager* path_manager =
+        profile_->GetFileSystemContext()->path_manager();
+    if (!path_manager->CrackFileSystemPath(FilePath(file_url_),
+                                          &file_origin_url,
+                                          &type,
+                                          &virtual_path)) {
+      return false;
+    }
+    // Make sure this url really used by the right caller extension.
+    if (source_url_.GetOrigin() != file_origin_url) {
+      DidFail(base::PLATFORM_FILE_ERROR_SECURITY);
+      return false;
+    }
+    FilePath root_path = path_manager->GetFileSystemRootPathOnFileThread(
+        file_origin_url,
+        fileapi::kFileSystemTypeLocal,
+        FilePath(virtual_path),
+        false);     // create
+    FilePath finalFilePath = root_path.Append(virtual_path);
+    // Grant read access permission to this file.
+    ChildProcessSecurityPolicy::GetInstance()->GrantReadFile(child_id_,
+                                                             finalFilePath);
+    return true;
+  }
+
+  RequestLocalFileSystemFunctionBase* function_;
+  Profile* profile_;
+  // Renderer process id.
+  int child_id_;
+  // Extension source URL.
+  GURL source_url_;
+  std::string file_url_;
   DISALLOW_COPY_AND_ASSIGN(LocalFileSystemCallbackDispatcher);
 };
 
-RequestLocalFileSystemFunction::RequestLocalFileSystemFunction() {
-}
-
-RequestLocalFileSystemFunction::~RequestLocalFileSystemFunction() {
-}
-
-bool RequestLocalFileSystemFunction::RunImpl() {
+void RequestLocalFileSystemFunctionBase::RequestOnFileThread(
+    const GURL& source_url, const std::string& file_url) {
   fileapi::FileSystemOperation* operation =
       new fileapi::FileSystemOperation(
-          new LocalFileSystemCallbackDispatcher(this),
+          new LocalFileSystemCallbackDispatcher(
+              this,
+              profile(),
+              dispatcher()->render_view_host()->process()->id(),
+              source_url,
+              file_url),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
           profile()->GetFileSystemContext(),
           NULL);
-  GURL origin_url = source_url().GetOrigin();
+  GURL origin_url = source_url.GetOrigin();
   operation->OpenFileSystem(origin_url, fileapi::kFileSystemTypeLocal,
                             false);     // create
+}
+
+bool RequestLocalFileSystemFunctionBase::RunImpl() {
+  std::string file_url;
+  if (args_->GetSize())
+    args_->GetString(0, &file_url);
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      NewRunnableMethod(this,
+          &RequestLocalFileSystemFunctionBase::RequestOnFileThread,
+          source_url_,
+          file_url));
   // Will finish asynchronously.
   return true;
 }
 
-void RequestLocalFileSystemFunction::RespondSuccessOnUIThread(
-    const std::string& name, const FilePath& path) {
+void RequestLocalFileSystemFunctionBase::RespondSuccessOnUIThread(
+    const std::string& name, const FilePath& path,
+    const std::string& file_url) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   result_.reset(new DictionaryValue());
   DictionaryValue* dict = reinterpret_cast<DictionaryValue*>(result_.get());
   dict->SetString("name", name);
   dict->SetString("path", path.value());
   dict->SetInteger("error", base::PLATFORM_FILE_OK);
+  if (file_url.size())
+    dict->SetString("fileUrl", file_url);
   SendResponse(true);
 }
 
-void RequestLocalFileSystemFunction::RespondFailedOnUIThread(
+void RequestLocalFileSystemFunctionBase::RespondFailedOnUIThread(
     base::PlatformFileError error_code) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   result_.reset(new DictionaryValue());
   DictionaryValue* dict = reinterpret_cast<DictionaryValue*>(result_.get());
   dict->SetInteger("error", static_cast<int>(error_code));
   SendResponse(true);
 }
 
+bool GetFileTasksFileBrowserFunction::RunImpl() {
+  ListValue* files_list = NULL;
+  if (!args_->GetList(0, &files_list))
+    return false;
+
+  result_.reset(new ListValue());
+  ListValue* result_list = reinterpret_cast<ListValue*>(result_.get());
+
+  ExtensionMenuItem::List common_tasks;
+  if (!FindCommonTasks(profile_, source_url_, files_list, &common_tasks))
+    return false;
+
+  ExtensionService* service = profile_->GetExtensionService();
+  for (ExtensionMenuItem::List::iterator iter = common_tasks.begin();
+       iter != common_tasks.end();
+       ++iter) {
+    if ((*iter)->type() != ExtensionMenuItem::NORMAL)
+      continue;
+    const std::string extension_id = (*iter)->extension_id();
+    const Extension* extension = service->GetExtensionById(extension_id, false);
+    if (!extension) {
+      LOG(WARNING) << "Disabled extension" << extension_id;
+      continue;
+    }
+    DictionaryValue* task = new DictionaryValue();
+    task->SetString("taskId", MakeTaskID(kContextTaskIdSchema,
+                                         extension_id.c_str(),
+                                          (*iter)->id().uid));;
+    task->SetString("title", (*iter)->title());
+    GURL icon =
+        ExtensionIconSource::GetIconURL(extension,
+                                        Extension::EXTENSION_ICON_SMALLISH,
+                                        ExtensionIconSet::MATCH_BIGGER,
+                                        false);     // grayscale
+    task->SetString("iconUrl", icon.spec());
+    result_list->Append(task);
+  }
+
+  // TODO(zelidrag, serya): Add intent content tasks to result_list once we
+  // implement that API.
+  SendResponse(true);
+  return true;
+}
+
+bool ExecuteTasksFileBrowserFunction::RunImpl() {
+  // First param is task id that was to the extension with getFileTasks call.
+  std::string task_id;
+  if (!args_->GetString(0, &task_id) || !task_id.size())
+    return false;
+
+  // The second param is the list of files that need to be executed with this
+  // task.
+  ListValue* files_list = NULL;
+  if (!args_->GetList(1, &files_list))
+    return false;
+
+  if (!files_list->GetSize())
+    return true;
+
+  std::string task_type;
+  std::string target_extension_id;
+  std::string action_id;
+  if (!CrackTaskIdentifier(task_id, &task_type, &target_extension_id,
+                           &action_id)) {
+    return false;
+  }
+
+  if (task_type == kContextTaskIdSchema) {
+    ExecuteContextMenuTasks(target_extension_id, action_id, files_list);
+  } else {
+    LOG(WARNING) << "Unsupported task type of: " << task_type;
+    // TODO(zelidrag, serya): Add intent content tasks here once we implement
+    // that API.
+    return false;
+  }
+  SendResponse(true);
+  return true;
+}
+
+std::string ExecuteTasksFileBrowserFunction::MakeFileHash(
+  const std::string& extension_id, const std::string& file_url) {
+  // TODO(zelidrag): Attach HMAC to file urls.
+  return std::string();
+}
+
+std::string ExecuteTasksFileBrowserFunction::MakeSafeFileUrl(
+  const std::string& extension_id, const std::string& origin_file_url) {
+  // Replace extension part of the url with one from the target.
+  std::string::size_type pos = origin_file_url.find("/local/");
+  if (pos == std::string::npos)
+    return std::string();
+  std::string file_url = base::StringPrintf(
+      "filesystem:chrome-extension://%s/%s",
+      extension_id.c_str(),
+      origin_file_url.substr(pos + 1).c_str());
+  return file_url.append(MakeFileHash(file_url, extension_id));

[ericu, 2011/03/31 21:31:06]

So this will look like
filesystem:chrome-extension://{id}/local/path/to/file.html{hash} ?

I'm not clear on what the part that got taken out looked like.  What was the
original origin?

[zel, 2011/04/01 03:01:35]

Yes, what I took out was the ID of the extension which initiated this API call
and replace it with the destination extension. Hash code ensures that the
destination extension is the one that can read this file url at the end.  

[ericu, 2011/04/02 01:16:05]

OK, that makes sense.  Would be nice to see a little more detail in the comments
for MakeSafeFileUrl.  Perhaps "remove the id of the file browser extension and
replace it with that of the handler extension we're invoking" or something like
that.

[zel, 2011/04/06 00:06:32]

Done.

+}
+
+bool ExecuteTasksFileBrowserFunction::ExecuteContextMenuTasks(
+    const std::string& extension_id, const std::string& action_id,
+    ListValue* files_list) {
+  ExtensionMenuManager* manager =
+      profile_->GetExtensionService()->menu_manager();
+  for (size_t i = 0; i < files_list->GetSize(); i++) {
+    std::string origin_file_url;
+    if (!files_list->GetString(i, &origin_file_url)) {
+      result_.reset(new FundamentalValue(false));
+      return false;
+    }
+    std::string file_url = MakeSafeFileUrl(extension_id, origin_file_url);
+    ContextMenuParams params;
+    CreateContextMenuParams(source_url_, file_url, &params);
+    ExtensionMenuItem::Id menuItemId(profile_, extension_id,
+                                     atoi(action_id.c_str()));
+    manager->ExecuteCommand(profile_,
+                            NULL,     // tab_contents, not needed in args.
+                            params,
+                            menuItemId);
+  }
+  result_.reset(new FundamentalValue(true));
+  return true;
+}