Sharing on Facebook, Twitter and Google+

[FIXED]     Font of navbar.
[FIXED]     A few compile fixes.
[IMPROVED]  Made properties nonatomic.
[ADDED]     Support for facebook, twitter and google+ sharing.

External/google-plus-ios-sdk/SampleCode/GooglePlusSampleSignInViewController.m

@@ -0,0 +1,110 @@
+//
+//  GooglePlusSignInViewController.m
+//
+//  Copyright 2012 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+#import "GooglePlusSampleSignInViewController.h"
+
+#import <QuartzCore/QuartzCore.h>
+#import "GooglePlusSampleAppDelegate.h"
+#import "GooglePlusSignIn.h"
+#import "GooglePlusSignInButton.h"
+
+@implementation GooglePlusSampleSignInViewController
+
+@synthesize signInButton = signInButton_;
+@synthesize signInAuthStatus = signInAuthStatus_;
+@synthesize signOutButton = signOutButton_;
+
+- (void)dealloc {
+  [signInButton_ release];
+  [signInAuthStatus_ release];
+  [signOutButton_ release];
+  [super dealloc];
+}
+
+#pragma mark - View lifecycle
+
+- (void)reportAuthStatus {
+  GooglePlusSampleAppDelegate *appDelegate = (GooglePlusSampleAppDelegate *)
+      [[UIApplication sharedApplication] delegate];
+  if (appDelegate.auth) {
+    signInAuthStatus_.text = @"Status: Authenticated";
+  } else {
+    // To authenticate, use Google+ sign-in button.
+    signInAuthStatus_.text = @"Status: Not authenticated";
+  }
+}
+
+- (void)viewDidLoad {
+  // Set up sign-out button.
+  [[signOutButton_ layer] setCornerRadius:5];
+  [[signOutButton_ layer] setMasksToBounds:YES];
+  CGColorRef borderColor = [[UIColor colorWithWhite:203.0/255.0
+                                              alpha:1.0] CGColor];
+  [[signOutButton_ layer] setBorderColor:borderColor];
+  [[signOutButton_ layer] setBorderWidth:1.0];
+
+  // Set up sample view of Google+ sign-in.
+  signInButton_.delegate = self;
+  signInButton_.clientID = [GooglePlusSampleAppDelegate clientID];
+  signInButton_.scope = [NSArray arrayWithObjects:
+      @"https://www.googleapis.com/auth/plus.moments.write",
+      @"https://www.googleapis.com/auth/plus.me",
+      nil];
+
+  GooglePlusSampleAppDelegate *appDelegate = (GooglePlusSampleAppDelegate *)
+      [[UIApplication sharedApplication] delegate];
+  appDelegate.signInButton = signInButton_;
+  [self reportAuthStatus];
+  [super viewDidLoad];
+}
+
+- (void)viewDidUnload {
+  GooglePlusSampleAppDelegate *appDelegate = (GooglePlusSampleAppDelegate *)
+      [[UIApplication sharedApplication] delegate];
+  appDelegate.signInButton = nil;
+  [super viewDidUnload];
+}
+
+#pragma mark - GooglePlusSignInDelegate
+
+- (void)finishedWithAuth:(GTMOAuth2Authentication *)auth
+                   error:(NSError *)error {
+  if (error) {
+    signInAuthStatus_.text =
+        [NSString stringWithFormat:@"Status: Authentication error: %@", error];
+    return;
+  }
+  GooglePlusSampleAppDelegate *appDelegate = (GooglePlusSampleAppDelegate *)
+      [[UIApplication sharedApplication] delegate];
+  appDelegate.auth = auth;
+  [self reportAuthStatus];
+}
+
+#pragma mark - IBActions
+
+- (IBAction)signOut:(id)sender {
+  [[signInButton_ googlePlusSignIn] signOut];
+
+  GooglePlusSampleAppDelegate *appDelegate = (GooglePlusSampleAppDelegate *)
+      [[UIApplication sharedApplication] delegate];
+  appDelegate.auth = nil;
+
+  [self reportAuthStatus];
+}
+
+@end