Implement a JavaScript API for document scanning

chrome/browser/extensions/api/document_scan/document_scan_api.cc

+// Copyright 2014 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/api/document_scan/document_scan_api.h"
+
+#include "base/file_util.h"
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/strings/stringprintf.h"
+#include "chrome/browser/download/download_prefs.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/login/login_state.h"
+#include "content/public/browser/browser_thread.h"
+#include "extensions/browser/extension_system.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+
+using chromeos::DBusThreadManager;
+using chromeos::LorgnetteManagerClient;
+using content::BrowserThread;
+
+namespace extensions {
+
+namespace api {
+
+DocumentScanListScannersFunction::DocumentScanListScannersFunction() {}
+
+DocumentScanListScannersFunction::~DocumentScanListScannersFunction() {}
+
+bool DocumentScanListScannersFunction::Prepare() {
+  set_work_thread_id(BrowserThread::FILE);
+  return true;
+}
+
+void DocumentScanListScannersFunction::AsyncWorkStart() {
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+#if !defined(OS_CHROMEOS)
+  results_ = document_scan::ListScanners::Results::Create(
+      std::vector<linked_ptr<document_scan::ScannerInfo> >());
+  AsyncWorkCompleted();
+#else  // OS_CHROMEOS
+  DBusThreadManager::Get()->GetLorgnetteManagerClient()->
+       ListScanners(base::Bind(
+           &DocumentScanListScannersFunction::OnScannerListReceived,
+           base::Unretained(this)));
+
+  // Add a reference, which is balanced in OnScannerListReceived to keep the
+  // object around and allow the callback to be invoked.
+  AddRef();
+#endif  // OS_CHROMEOS
+}
+
+void DocumentScanListScannersFunction::OnScannerListReceived(
+    bool succeeded, const LorgnetteManagerClient::ScannerTable &scanners) {
+  std::vector<linked_ptr<document_scan::ScannerInfo> > out_scanners;
+  for (LorgnetteManagerClient::ScannerTable::const_iterator iter =
+           scanners.begin();
+       iter != scanners.end();
+       ++iter) {
+    const std::string &name = iter->first;
+    const LorgnetteManagerClient::ScannerTableEntry &entry = iter->second;
+    linked_ptr<document_scan::ScannerInfo> info(new document_scan::ScannerInfo);
+    info->name = name;
+    LorgnetteManagerClient::ScannerTableEntry::const_iterator info_it;
+    info_it = entry.find(lorgnette::kScannerPropertyManufacturer);
+    if (info_it != entry.end()) {
+      info->manufacturer = info_it->second;
+    }
+    info_it = entry.find(lorgnette::kScannerPropertyModel);
+    if (info_it != entry.end()) {
+      info->model = info_it->second;
+    }
+    info_it = entry.find(lorgnette::kScannerPropertyType);
+    if (info_it != entry.end()) {
+      info->type = info_it->second;
+    }
+    out_scanners.push_back(info);
+  }
+
+  results_ = document_scan::ListScanners::Results::Create(out_scanners);
+  AsyncWorkCompleted();
+
+  // Balance the AddRef in AsyncWorkStart().
+  Release();
+}
+
+bool DocumentScanListScannersFunction::Respond() {
+  return true;
+}
+
+DocumentScanScanFunction::DocumentScanScanFunction() {}
+
+DocumentScanScanFunction::~DocumentScanScanFunction() {}
+
+bool DocumentScanScanFunction::Prepare() {
+  set_work_thread_id(BrowserThread::FILE);
+  params_ = document_scan::Scan::Params::Create(*args_);
+  EXTENSION_FUNCTION_VALIDATE(params_.get());
+  return true;
+}
+
+bool DocumentScanScanFunction::GetDocumentScanFilename(
+    base::FilePath* filename) {
+  base::FilePath directory;
+
+  if (chromeos::LoginState::Get()->IsUserLoggedIn()) {
+    DownloadPrefs* download_prefs = DownloadPrefs::FromBrowserContext(
+        ProfileManager::GetActiveUserProfile());
+    directory = download_prefs->DownloadPath();
+  } else  {
+    if (!base::GetTempDir(&directory)) {
+      LOG(ERROR) << "Failed to find temporary directory.";
+      return false;
+    }
+  }
+
+  base::Time::Exploded now;
+  base::Time::Now().LocalExplode(&now);
+
+  std::string basename = base::StringPrintf(
+      "Document Scan %d-%02d-%02d at %02d.%02d.%02d",
+      now.year, now.month, now.day_of_month, now.hour, now.minute, now.second);
+
+  *filename = directory.AppendASCII(basename + ".png");
+  return true;
+}
+
+void DocumentScanScanFunction::AsyncWorkStart() {
+#if !defined(OS_CHROMEOS)
+  results_ = document_scan::Scan::Results::Create(false, "");
+  AsyncWorkCompleted();
+  return;
+#endif  // OS_CHROMEOS
+
+  LOG(WARNING) << "Choosing scanner " << params_->scanner;
+  LorgnetteManagerClient::ScanProperties properties;
+  if (params_->options.mode.get()) {
+    properties.mode = *params_->options.mode.get();
+  }
+
+  if (params_->options.resolution_dpi.get()) {
+    properties.resolution_dpi = *params_->options.resolution_dpi.get();
+  }
+
+  base::FilePath scan_filename;
+  if (!GetDocumentScanFilename(&scan_filename)) {
+    LOG(WARNING) << "Could not find document scan directory";
+    return;
+  }
+
+  base::File file(
+      scan_filename,
+      base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE);
+  if (!file.IsValid()) {
+    LOG(WARNING) << "Could not open file " << scan_filename.value();
+    return;
+  }
+
+  base::PlatformFile platform_file = file.TakePlatformFile();
+  LOG(WARNING) << "ScanImage platform_file is " << platform_file;
+  DBusThreadManager::Get()->GetLorgnetteManagerClient()->
+       ScanImage(params_->scanner, platform_file, properties,
+                 base::Bind(&DocumentScanScanFunction::ScanImageCallback,
+                            base::Unretained(this),
+                            scan_filename));
+
+  // Add a reference, which is balanced in ScanImageCallback to keep the
+  // object around and allow the callback to be invoked.
+  AddRef();
+}
+
+void DocumentScanScanFunction::ScanImageCallback(
+    const base::FilePath& filename, bool succeeded) {
+  LOG(WARNING) << "ScanImage returns " << succeeded;
+  std::string image_data;
+  if (!base::ReadFileToString(filename, &image_data)) {
+    LOG(WARNING) << "Unable to read image data at " << filename.value();
+  }
+  results_ = document_scan::Scan::Results::Create(succeeded, image_data);
+  AsyncWorkCompleted();
+
+  // Balance the AddRef in AsyncWorkStart().
+  Release();
+}
+
+bool DocumentScanScanFunction::Respond() {
+  return true;
+}
+
+}  // namespace api
+
+}  // namespace extensions