Use distributed notifications instead of polling to determine success/failure of the preference pan…

remoting/host/me2me_preference_pane.mm

 // Copyright (c) 2012 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.
 
 #import "remoting/host/me2me_preference_pane.h"
 
 #import <Cocoa/Cocoa.h>
 #include <launch.h>
 #import <PreferencePanes/PreferencePanes.h>
 #import <SecurityInterface/SFAuthorizationView.h>
@@ skipping 10 matching lines @@
 #include "base/memory/scoped_ptr.h"
 #include "base/stringprintf.h"
 #include "base/sys_string_conversions.h"
 #include "remoting/host/host_config.h"
 #include "remoting/host/json_host_config.h"
 #include "remoting/protocol/me2me_host_authenticator_factory.h"
 
 namespace {
 // The name of the Remoting Host service that is registered with launchd.
 #define kServiceName "org.chromium.chromoting"
+
+#define kUpdateCompleteNotificationName kServiceName ".update_complete"
 #define kConfigDir "/Library/PrivilegedHelperTools/"
 
 // This helper script is executed as root.  It is passed a command-line option
 // (--enable or --disable), which causes it to create or remove a file that
 // informs the host's launch script of whether the host is enabled or disabled.
 const char kHelperTool[] = kConfigDir kServiceName ".me2me.sh";
 
 bool GetTemporaryConfigFilePath(FilePath* path) {
   if (!file_util::GetTempDir(path))
     return false;
@@ skipping 55 matching lines @@
 }
 
 - (void)willUnselect {
   NSDistributedNotificationCenter* center =
       [NSDistributedNotificationCenter defaultCenter];
   [center removeObserver:self];
 
   [service_status_timer_ invalidate];
   [service_status_timer_ release];
   service_status_timer_ = nil;
+  if (have_new_config_) {
+    [self notifyPlugin: @"CANCEL"];
+  }
 }
 
 - (void)onApply:(id)sender {
   if (!have_new_config_) {
     // It shouldn't be possible to hit the button if there is no config to
     // apply, but check anyway just in case it happens somehow.
     return;
   }
 
   // Ensure the authorization token is up-to-date before using it.
@@ skipping 168 matching lines @@
     pid_t job_pid = base::mac::PIDForJob(kServiceName);
     if (job_pid > 0) {
       kill(job_pid, SIGHUP);
     } else {
       LOG(ERROR) << "Failed to obtain PID of service " << kServiceName;
       [self showError];
     }
   } else {
     [self sendJobControlMessage:LAUNCH_KEY_STARTJOB];
   }
+
+  // Broadcast a distributed notification to inform the plugin that the
+  // configuration has been applied.
+  [self notifyPlugin: @"OK"];
 }
 
 - (BOOL)runHelperAsRootWithCommand:(const char*)command
                          inputData:(const std::string&)input_data {
   AuthorizationRef authorization =
       [[authorization_view_ authorization] authorizationRef];
   if (!authorization) {
     LOG(ERROR) << "Failed to obtain authorizationRef";
     return NO;
   }
@@ skipping 89 matching lines @@
 
   int error = launch_data_get_errno(response.get());
   if (error) {
     LOG(ERROR) << "launchd returned error: " << error;
     [self showError];
     return NO;
   }
   return YES;
 }
 
+- (void)notifyPlugin:(NSString*)result {
+  NSDistributedNotificationCenter* center =
+      [NSDistributedNotificationCenter defaultCenter];
+  NSString* name =
+      [[NSString alloc] initWithUTF8String:kUpdateCompleteNotificationName];

[Lambros, 2012/05/15 18:55:35]

nit: stringWithUTF8String might be easier (and doesn't require releasing the
string, I think).

[Jamie, 2012/05/15 20:53:50]

Thanks, I wasn't aware of that.

+  NSDictionary* result_dictionary =
+      [NSDictionary dictionaryWithObject:result
+                                  forKey:@"result"];
+  [center postNotificationName:name
+                        object:nil
+                      userInfo:result_dictionary];
+}
+
 @end