From 955722622379930fc891372862f35390a0e16ee0 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Mon, 25 Apr 2016 14:25:14 +0900
Subject: [PATCH] Add systemPreferences.subscribeNotification

---
 .../api/atom_api_system_preferences.cc        |  6 +++
 .../browser/api/atom_api_system_preferences.h |  7 ++++
 .../api/atom_api_system_preferences_mac.mm    | 39 ++++++++++++++++++-
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/atom/browser/api/atom_api_system_preferences.cc b/atom/browser/api/atom_api_system_preferences.cc
index 6e4774c196e0..86d3484b6705 100644
--- a/atom/browser/api/atom_api_system_preferences.cc
+++ b/atom/browser/api/atom_api_system_preferences.cc
@@ -4,6 +4,7 @@
 
 #include "atom/browser/api/atom_api_system_preferences.h"
 
+#include "atom/common/native_mate_converters/callback.h"
 #include "atom/common/node_includes.h"
 #include "native_mate/dictionary.h"
 
@@ -46,6 +47,11 @@ void SystemPreferences::BuildPrototype(
   mate::ObjectTemplateBuilder(isolate, prototype)
 #if defined(OS_WIN)
       .SetMethod("isAeroGlassEnabled", &SystemPreferences::IsAeroGlassEnabled)
+#elif defined(OS_MACOSX)
+      .SetMethod("subscribeNotification",
+                 &SystemPreferences::SubscribeNotification)
+      .SetMethod("unsubscribeNotification",
+                 &SystemPreferences::UnsubscribeNotification)
 #endif
       .SetMethod("isDarkMode", &SystemPreferences::IsDarkMode);
 }
diff --git a/atom/browser/api/atom_api_system_preferences.h b/atom/browser/api/atom_api_system_preferences.h
index 993904511207..6fd7ca922dc8 100644
--- a/atom/browser/api/atom_api_system_preferences.h
+++ b/atom/browser/api/atom_api_system_preferences.h
@@ -5,7 +5,10 @@
 #ifndef ATOM_BROWSER_API_ATOM_API_SYSTEM_PREFERENCES_H_
 #define ATOM_BROWSER_API_ATOM_API_SYSTEM_PREFERENCES_H_
 
+#include <string>
+
 #include "atom/browser/api/event_emitter.h"
+#include "base/callback.h"
 #include "native_mate/handle.h"
 
 namespace atom {
@@ -21,6 +24,10 @@ class SystemPreferences : public mate::EventEmitter<SystemPreferences> {
 
 #if defined(OS_WIN)
   bool IsAeroGlassEnabled();
+#elif defined(OS_MACOSX)
+  int SubscribeNotification(const std::string& name,
+                            const base::Closure& callback);
+  void UnsubscribeNotification(int id);
 #endif
   bool IsDarkMode();
 
diff --git a/atom/browser/api/atom_api_system_preferences_mac.mm b/atom/browser/api/atom_api_system_preferences_mac.mm
index 8935ab560ec1..39eb7e6ede82 100644
--- a/atom/browser/api/atom_api_system_preferences_mac.mm
+++ b/atom/browser/api/atom_api_system_preferences_mac.mm
@@ -4,19 +4,54 @@
 
 #include "atom/browser/api/atom_api_system_preferences.h"
 
+#include <map>
+
 #import <Cocoa/Cocoa.h>
 
+#include "base/strings/sys_string_conversions.h"
+
 namespace atom {
 
 namespace api {
 
-#if defined(OS_MACOSX)
+namespace {
+
+int g_next_id = 0;
+
+// The map to convert |id| to |int|.
+std::map<int, id> g_id_map;
+
+}  // namespace
+
+int SystemPreferences::SubscribeNotification(const std::string& name,
+                                             const base::Closure& callback) {
+  int request_id = g_next_id++;
+  __block base::Closure copied_callback = callback;
+  g_id_map[request_id] = [[NSDistributedNotificationCenter defaultCenter]
+      addObserverForName:base::SysUTF8ToNSString(name)
+      object:nil
+      queue:nil
+      usingBlock:^(NSNotification* notification) {
+        copied_callback.Run();
+      }
+  ];
+  return request_id;
+}
+
+void SystemPreferences::UnsubscribeNotification(int request_id) {
+  auto iter = g_id_map.find(request_id);
+  if (iter != g_id_map.end()) {
+    id observer = iter->second;
+    [[NSDistributedNotificationCenter defaultCenter] removeObserver:observer];
+    g_id_map.erase(iter);
+  }
+}
+
 bool SystemPreferences::IsDarkMode() {
   NSString* mode = [[NSUserDefaults standardUserDefaults]
       stringForKey:@"AppleInterfaceStyle"];
   return [mode isEqualToString:@"Dark"];
 }
-#endif
 
 }  // namespace api