TweetFollow Us on Twitter

Enhancing Your Application with NSStatusItem

Volume Number: 24 (2008)
Issue Number: 07
Column Tag: Application Development

Enhancing Your Application with NSStatusItem

How to utilize the NSStatusItem API to add functionalitys

by Marcus S. Zarra

Introduction

The user interface is arguably the hardest part of any application. This is especially true on OS X because we, as users, demand more of the developers of our applications. If the developer adds too many features and UI elements, then the application feels too busy or complicated. However if too few features are added then application is too primitive or simple.

Fortunately there are some choices. An application that would be considered too simple for the Dock might be perfect on the Dashboard or on the Menu Bar. Likewise, an application that is too busy to be a Dashboard widget might very well be perfectly at home in the Dock. But what if you are in the grey area between the Dock and the Menu Bar? While the design choices between these options ischoices between these options are beyond the scope of this article, I will present how to add a Menu Bar item – also known as a menu extra, menu item or menulet – to to your application and how to control it.

Menu Bar Items: Two Different Beasts

There are two different kinds of objects that can be placed on the menu bar in the upper right corner. First there is the kind that only Apple is allowedallows. The API is private and at the time of this article, third party developers are discouraged from using them.

The second kind that developers are encouraged to use is the NSStatusItem API. The NSStatusItem behaves decidedly different than the internal API that Apple uses. First, NSStatusItem objects cannot be dragged around the menu bar; second they cannot be removed from the menu bar with the mouse; and lastly, they are more "sluggish" than the Apple internal items when another item on the bar is moved or removed.

However, they are still an extremely useful UI element that can be utilized to great effect. The basic concept behind them is that they are a menu with an icon. In that respect, their behavior is very similar to NSMenuItem objects.

Building an NSStatusItem

While it is possible to build an NSStatusItem 100% in code, I prefer to use Interface Builder wherever whenever possible. This makes localizations easier and reduces the amount of code I need to maintain. Therefore, the first step to building an NSStatusItem is to build its menu in Interface Builder.

Building the Menu

To add a new menu to the project, I open the MainMenu.xib file and drag in a new NSMenu object (See Image 1). I normally rename the new menu to "Status Menu" or something similar to keep it clear which menu is which.


Image 1: Drag a new NSMenu into the nib

When an NSMenu is first added it contains three menu items. These items can be added to, removed from and changed as needed. For this example, I have changed the menu so that it has four items: Status, a separator, About and Quit. When I am done the menu looks like Image 2.


Image 2: The finished menu in IB

Now that the menu itself is complete it is time to write some code. For this example, the AppDelegate of my project will be responsible for the NSStatusItem. First, the header:

AppDelegate.h
#import <Cocoa/Cocoa.h>
@interface AppDelegate : NSObject {
   NSStatusItem *myStatusItem;
   IBOutlet NSMenu *myStatusMenu;
   IBOutlet NSMenuItem *myMenuStatusItem;
}
@end

Since both the about menu item and the quit menu item can be handled outside of the AppDelegate in this example, I have not added IBAction methods for them. Once the header has been written, it is time to go back to Interface Builder and link the references as shown in Image 3.

As for the About and Quit menus, they are linked to the Application object as follows:

About -> NSApplication -orderFrontStandardAboutPanel:
Quit -> NSApplication -terminate:

Once all of the linking is complete, I am done withwith the work with Interface Builder is complete;. tTime to move on to the AppDelegate. In this situation I prefer to initialize the NSStatusItem in the applicationDidFinishLaunching: method so that it appears as soon as the application is ready to start receiving events. Depending on an applications particular situation the initialization code can be placed in other locations.

AppDelegate.m
#import "AppDelegate.h"
@implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification*)notification
{
   myStatusItem = [[[NSStatusBar systemStatusBar] statusItemWithLength:NSSquareStatusItemLength] retain];
   
   NSImage *statusImage = [NSImage imageNamed:@"TheZ.tiff"];
   [myStatusItem setImage:statusImage];
   [myStatusItem setHighlightMode:YES];
   
   [myStatusItem setMenu:myStatusMenu];
   
   [myMenuStatusItem setTitle:NSLocalizedString(@"Special Status", @"status menu item text")];
}
@end

The first thing to notice in this code block is that NSStatusItem objects are not initialized directly. Rather, they are requested from an NSStatusBar object. The NSStatusBar object has a class level method that returns the system status bar from which I one can request a NSStatusItem.

Once I have my newthe NSStatusItem request is complete, it is possibleI am able to set its image, highlight mode and menu. The image is the image that is displayed on the Menu Bar and is has a 16x16 resolutionimage. The highlight mode determines whether or not the image is highlighted when clicked. The default is "NO", which is not appropriate when a menu is attached so I have set it to YES in the sample code. The last call to myStatusItem passes it the menu that isI constructed and referenced in Interface Builder. This will be the menu that the NSStatusItem displays when it is clicked.

The last line of the applicationDidFinishLaunching: method is a call to the status menu item that isI referenced from Interface Builder. This call changes the text of that menu item. Note that the sample code doesI have not disabled this menu. Since it does not have a target or action it will be displayed grayed out already so there is no need to disable it.

Controlling The Menu

In various situations it is appropriate to make changes to the NSStatusItem or one of its menu items. In this example, I have intentionally linked the *myStatusMenuItem ivar to one of the NSMenuItem objects on the menu so that it can be changed during the life of the program. To illustrate this change, I added a button to the main window that when clicked would change this menu item:


Image 3: Linking the AppDelegate to the Menu

AppDelegate.h
-(IBAction)changeMenu:(id)sender;
AppDelegate.m
-(IBAction)changeMenu:(id)sender;
{
  [myMenuStatusItem setTitle:NSLocalizedString(@"Changed Status", @"statuc menu item changed text")];
}

With this addition to the application, the status menu item will change to "Changed Status".

It is also possible to change the image that is displayed on the Menu Bar

AppDelegate.h
-(IBAction)purpleZ:(id)sender;
-(IBAction)blackZ:(id)sender;
AppDelegate.m
-(IBAction)purpleZ:(id)sender;
{
   [myStatusItem setImage:[NSImage imageNamed:@"ThePurpleZ.tiff"]];
}
-(IBAction)blackZ:(id)sender;
{
   [myStatusItem setImage:[NSImage imageNamed:@"TheZ.tiff"]];
}

In the example application, I added these actions are added to the Format menu rather than buttons on the main window.

Lastly, if it is desired to have the NSStatusItem as an option rather than a requirement in the application, it is possible to remove the menu item from the bar:

AppDelegate.h
-(IBAction)removeStatusItem:(id)sender;
-(IBAction)addStatusItem:(id)sender;
AppDelegate.m
-(IBAction)removeStatusItem:(id)sender;
{
   [[NSStatusBar systemStatusBar] removeStatusItem:myStatusItem];
   myStatusItem = nil;
}
-(IBAction)addStatusItem:(id)sender;
{
   if (myStatusItem) return;
   myStatusItem = [[[NSStatusBar systemStatusBar] statusItemWithLength:NSVariableStatusItemLength] retain];
   
   [myStatusItem setImage:[NSImage imageNamed:@"TheZ.tiff"]];
   [myStatusItem setHighlightMode:YES];
   [myStatusItem setMenu:myStatusMenu];
   
   [myMenuStatusItem setTitle:NSLocalizedString(@"Special Status", @"status menu item text")];
}
-(BOOL)validateMenuItem:(NSMenuItem*)item
{
   if ([item action] == @selector(removeStatusItem:)) {
      return (myStatusItem != nil);
   }
   if ([item action] == @selector(addStatusItem:)) {
      return (myStatusItem == nil);
   }
   return YES;
}

The code to remove the status item is very simple. Just one call to NSStatusBar -removeStatusItem: and it is gone. Since there is no way to add the existing item back to the bar it is prudent to set the ivar to nil at this time.

To add the NSStatusItem back to the bar, the example I simply copiesd the code from the applicationDidFinishLaunching: method. Ideally this should be abstracted so that the code is not duplicated.

Lastly, I addedthere is a -validateMenuItem: method to make sure that only one status item is ever added and just as importantly, that the application is not trying to remove a non-existent item I do not try to remove a non-existent item.

Now, with the addition of a checkbox in the preferences linked to NSUserDefaults, it is trivial to add a user preference on whether or not to show the status item. OneI could then add logic to the applicationDidFinishLaunching: method to decide whether or not a NSStatusItem needs to be initialized based on the NSUserDefault.

Conclusion

That is all there is to the NSStatusItem API. Hopefully, one day, Apple will allow third party developers to utilize their internal status items so that we can legitimately produce menu bar items that are feature comparable to the system items. Until then, NSStatusItem is a solid API that we can utilize.

As a parting comment, if I wanted my entire application to run as a menu bar item (without a Dock icon ala Twitterific), that only requires one small addition to the Info.plist:

Info.plist
<key>LSUIElement</key>
<string>1</string>

And the application will not bounce in the dock at all. I do not recommend that for this example application as it is not designed to run in that manner but there are plenty of applications that this is perfectly suited for.

NOTE: This change cannot be made to an application on the fly. So if you wanted to make the Dock icon optional also it would require an application restart and probably some trickery with the Finder as the Finder does tend to "cache" the Info.plist file for applications.


Marcus S. Zarra is the owner of Zarra Studios, based out of Colorado Springs, Colorado. He has been developing Cocoa software since 2003, Java software since 1996, and has been in the industry since 1985. Currently Marcus is producing software for OS X. In addition to writing software, he assists other developers by blogging about development and supplying code samples.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Coda 2.5.11 - One-window Web development...
Coda is a powerful Web editor that puts everything in one place. An editor. Terminal. CSS. Files. With Coda 2, we went beyond expectations. With loads of new, much-requested features, a few surprises... Read more
Bookends 12.5.7 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Access the power of Bookends directly from Mellel, Nisus Writer Pro, or MS Word (... Read more
Maya 2016 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
RapidWeaver 6.2.3 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
MacFamilyTree 7.5.2 - Create and explore...
MacFamilyTree gives genealogy a facelift: it's modern, interactive, incredibly fast, and easy to use. We're convinced that generations of chroniclers would have loved to trade in their genealogy... Read more
Paragraphs 1.0.1 - Writing tool just for...
Paragraphs is an app just for writers. It was built for one thing and one thing only: writing. It gives you everything you need to create brilliant prose and does away with the rest. Everything in... Read more
BlueStacks App Player 0.9.21 - Run Andro...
BlueStacks App Player lets you run your Android apps fast and fullscreen on your Mac. Version 0.9.21: Note: Now requires OS X 10.8 or later running on a 64-bit Intel processor. Initial stable... Read more
Tweetbot 2.0.2 - Popular Twitter client....
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
Apple iBooks Author 2.3 - Create and pub...
Apple iBooks Author helps you create and publish amazing Multi-Touch books for iPad. Now anyone can create stunning iBooks textbooks, cookbooks, history books, picture books, and more for iPad. All... Read more
NeoOffice 2014.12 - Mac-tailored, OpenOf...
NeoOffice is a complete office suite for OS X. With NeoOffice, users can view, edit, and save OpenOffice documents, PDF files, and most Microsoft Word, Excel, and PowerPoint documents. NeoOffice 3.x... Read more

Rage of Bahamut is Giving Almost All of...
The App Store isn't what it used to be back in 2012, so it's not unexpected to see some games changing their structures with the times. Now we can add Rage of Bahamut to that list with the recent announcement that the game is severely cutting back... | Read more »
Adventures of Pip (Games)
Adventures of Pip 1.0 Device: iOS iPhone Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: ** ONE WEEK ONLY — 66% OFF! *** “Adventures of Pip is a delightful little platformer full of charm, challenge and impeccable... | Read more »
Divide By Sheep - Tips, Tricks, and Stre...
Who would have thought splitting up sheep could be so involved? Anyone who’s played Divide by Sheep, that’s who! While we’re not about to give you complete solutions to everything (because that’s just cheating), we will happily give you some... | Read more »
NaturalMotion and Zynga Have Started Tea...
An official sequel to 2012's CSR Racing is officially on the way, with Zynga and NaturalMotion releasing a short teaser trailer to get everyone excited. Well, as excited as one can get from a trailer with no gameplay footage, anyway. [Read more] | Read more »
Grab a Friend and Pick up Overkill 3, Be...
Overkill 3 is a pretty enjoyable third-person shooter that was sort of begging for some online multiplayer. Fortunately the begging can stop, because its newest update has added an online co-op mode. [Read more] | Read more »
Scanner Pro's Newest Update Adds Au...
Scanner Pro is one of the most popular document scanning apps on iOS, thanks in no small part to its near-constant updates, I'm sure. Now we're up to update number six, and it adds some pretty handy new features. [Read more] | Read more »
Heroki (Games)
Heroki 1.0 Device: iOS Universal Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: CLEAR THE SKIES FOR A NEW HERO!The peaceful sky village of Levantia is in danger! The dastardly Dr. N. Forchin and his accomplice,... | Read more »
Wars of the Roses (Games)
Wars of the Roses 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
TapMon Battle (Games)
TapMon Battle 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: It's time to battle!Tap! Tap! Tap! Try tap a egg to hatch a Tapmon!Do a battle with another tapmons using your hatched tapmons! *... | Read more »
Alchemic Dungeons (Games)
Alchemic Dungeons 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: ### Release Event! ### 2.99$->0.99$ for limited time! ### Roguelike Role Playing Game! ### Alchemic Dungeons is roguelike... | Read more »

Price Scanner via MacPrices.net

15-inch 2.5GHz Retina MacBook Pro on sale for...
Amazon.com has the 15″ 2.5GHz Retina MacBook Pro on sale for $2274 including free shipping. Their price is $225 off MSRP, and it’s the lowest price available for this model. Read more
Logo Pop Free Vector Logo Design App For OS X...
128bit Technologies has released of Logo Pop Free 1.2 for Mac OS X, a vector based, full-fledged, logo design app available exclusively on the Mac App Store for the agreeable price of absolutely free... Read more
21-inch 1.4GHz iMac on sale for $999, save $1...
B&H Photo has new 21″ 1.4GHz iMac on sale for $999 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Best Buy has the 21″ 1.4GHz iMac on sale for $999.99 on their... Read more
16GB iPad mini 3 on sale for $339, save $60
B&H Photo has the 16GB iPad mini 3 WiFi on sale for $339 including free shipping plus NY tax only. Their price is $60 off MSRP. Read more
Save up to $40 on iPad Air 2, NY tax only, fr...
B&H Photo has iPad Air 2s on sale for up to $40 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $489 $10 off - 64GB iPad Air 2 WiFi: $559 $40 off - 128GB iPad Air... Read more
Apple Releases OS X 10.10.4 With WIFi Fix, iO...
On Tuesday, Apple released final versions of OS X 10.10.4 and iOS 8.4, as well as updates for the Safari browser for OS X Yosemite, Mavericks, and Mountain Lion. The OS X 10.10.4 update focuses on... Read more
Dual-Band High-Gain Antennas for Home Wi-Fi N...
Linksys has announced what it claims are the first dual-band, omni-directional high-gain antennas for the consumer market. The new Linksys high-gain antennas available in a 2- and 4-pack (WRT004ANT... Read more
Apple refurbished 2014 15-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 15″ 2.2GHz Retina MacBook Pros available for $1609, $390 off original MSRP. Apple’s one-year warranty is included, and shipping is free. They have... Read more
Clearance 2014 MacBook Airs available for up...
Adorama has 2014 MacBook Airs on sale for up to $301 off original MSRP including NY + NJ sales tax and free shipping: - 11″ 256GB MacBook Air: $798 $301 off original MSRP - 13″ 128GB MacBook Air: $... Read more
5K iMacs on sale for $100 off MSRP, free ship...
B&H Photo has the new 27″ 3.3GHz 5K iMac on sale for $1899.99 including free shipping plus NY tax only. Their price is $100 off MSRP. They have the 27″ 3.5GHz 5K iMac on sale for $2199, also $100... Read more

Jobs Board

*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Fulfillment Operations Execution Ana...
**Job Summary** The AMR Apple Fulfillment Operations Team is seeking a talented team player to drive the Apple Online Store (AOS) fulfillment performance to ensure a Read more
Localization Producer - *Apple* HR and Reta...
…project manager to support the Retail Globalization team. You will participate in Apple exponential inte ational growth and drive global project initiatives for the Read more
*Apple* Online Store UAT Lead - Apple (Unite...
**Job Summary** The Apple Online Store is a fast paced and ever evolving business environment. A UAT lead in this organization is able to have a direct impact on one of Read more
Senior Payments Security Manager - *Apple*...
**Job Summary** Apple , Inc. is looking for a highly motivated, innovative and hands-on senior payments security manager to join the Apple Pay security team. You will Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.