[CUPS] Implement the Print Job notification.

chrome/browser/chromeos/printing/cups_print_job_notification_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/cups_print_job_notification_manager.h"
+
+#include "chrome/browser/chromeos/printing/cups_print_job.h"
+#include "chrome/browser/profiles/profile.h"
+
+namespace chromeos {
+
+CupsPrintJobNotificationManager::CupsPrintJobNotificationManager(
+    Profile* profile,
+    CupsPrintJobManager* print_job_manager)
+    : print_job_manager_(print_job_manager), profile_(profile) {
+  if (print_job_manager_)
+    print_job_manager_->AddObserver(this);
+}
+
+CupsPrintJobNotificationManager::~CupsPrintJobNotificationManager() {
+  if (print_job_manager_)
+    print_job_manager_->RemoveObserver(this);
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobCreated(CupsPrintJob* job) {
+  if (notification_map_.find(job) != notification_map_.end())

[skau, 2016/10/27 01:43:01]

you can use base::ContainsKey() for this.  It's a bit nicer.

[xdai1, 2016/10/28 23:59:54]

Done.

+    return;
+  notification_map_[job] =
+      base::MakeUnique<CupsPrintJobNotification>(job, profile_);
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobStarted(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();

[skau, 2016/10/27 01:43:01]

If we end up extracting all the information from the job anyway, should we just
have a OnPrintJobStatusChanged() method instead of all the different changes? 
Also, should we pass the job object to the notification here?

[xdai1, 2016/10/28 23:59:54]

I think it's nicer to have different changes other than a single status change
here. We might have different observers in the future so having different
changes also might benefit future cases. I don't see the reason why we should
pass the job object to the notification, could you elaborate? 

[skau, 2016/10/31 15:39:05]

Okay.  I was wondering if OnPrintJobStatusUpdated() should be passed the pointer
to the job or at least the status.  Otherwise, when reading this code, we're
forced to remember or assume that the notification has a pointer to the correct
print job object.  Semantically, it's the same.

+}
+
+void CupsPrintJobNotificationManager::OnPrintJobUpdated(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobSuspended(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobResumed(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobDone(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();
+}
+
+void CupsPrintJobNotificationManager::OnPrintJobError(CupsPrintJob* job) {
+  DCHECK(notification_map_.find(job) != notification_map_.end());
+  notification_map_[job]->OnPrintJobStatusUpdated();
+}
+
+}  // namespace chromeos