Register and select printer on click.

chrome/browser/chromeos/printing/printer_pref_manager.cc

 // Copyright 2016 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/chromeos/printing/printer_pref_manager.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 13 matching lines @@
 namespace chromeos {
 
 namespace {
 
 const base::ListValue* GetPrinterList(Profile* profile) {
   return profile->GetPrefs()->GetList(prefs::kPrintingDevices);
 }
 
 // Returns the printer with the matching |id| from the list |values|.  The
 // returned value is mutable and |values| could be modified.
-base::DictionaryValue* FindPrinterPref(base::ListValue* values,
+base::DictionaryValue* FindPrinterPref(const base::ListValue* values,
                                        const std::string& id) {
   for (const auto& value : *values) {
     base::DictionaryValue* printer_dictionary;
     if (!value->GetAsDictionary(&printer_dictionary))
       continue;
 
     std::string printer_id;
     if (printer_dictionary->GetString(printing::kPrinterId, &printer_id) &&
         id == printer_id)
       return printer_dictionary;
@@ skipping 44 matching lines @@
 
     std::unique_ptr<Printer> printer =
         printing::PrefToPrinter(*printer_dictionary);
     if (printer)
       printers.push_back(std::move(printer));
   }
 
   return printers;
 }
 
+std::unique_ptr<Printer> PrinterPrefManager::GetPrinter(
+    const std::string& printer_id) const {
+  const base::ListValue* values = GetPrinterList(profile_);
+  const base::DictionaryValue* printer = FindPrinterPref(values, printer_id);
+
+  return printer ? printing::PrefToPrinter(*printer) : nullptr;
+}
+
 void PrinterPrefManager::RegisterPrinter(std::unique_ptr<Printer> printer) {
   if (printer->id().empty())
     printer->set_id(base::GenerateGUID());
 
   std::unique_ptr<base::DictionaryValue> updated_printer =
-      printing::PrinterToPref(*(printer.get()));
+      printing::PrinterToPref(*printer);
   UpdatePrinterPref(profile_, printer->id(), std::move(updated_printer));
 }
 
 bool PrinterPrefManager::RemovePrinter(const std::string& printer_id) {
   DCHECK(!printer_id.empty());
   ListPrefUpdate update(profile_->GetPrefs(), prefs::kPrintingDevices);
   base::ListValue* printer_list = update.Get();
   DCHECK(printer_list) << "Printer preference not registered";
   base::DictionaryValue* printer = FindPrinterPref(printer_list, printer_id);
 
   return printer && printer_list->Remove(*printer, nullptr);
 }
 
 }  // namespace chromeos