TweetFollow Us on Twitter


Volume Number: 19 (2003)
Issue Number: 5
Column Tag: Programming

Getting Started


by Dave Mark

When I first started programming the Mac, lo those many years ago, one of the earliest programs I wrote was a teeny app called PictViewer. PictViewer put up a standard document window, with scroll bars and a grow box, and drew a pict image, centered in the window. The first version just displayed the image, clipping it to the window FrameRect as needed. The scroll bars were mere decoration. When I tackled a more advanced version of PictViewer, I added the callback routines and other code to bring the scroll bars to life. In still a later incarnation, I added the ability to drag and drop an image on a PictViewer window.

As I was putting the finishing touches on this project, I remember thinking, "gee, it sure would be nice if all this was just a bit easier." Frameworks like PowerPlant did go a long way towards stringing all the pieces together, but there was still a lot of hand-coding to be done and lots of room for error.

As you'll see in this month's program, TinyViewer, the combination of the Objective-C runtime and tools like Interface Builder and Project Builder take working with objects to the next level.

Getters, Setters, and Key Value Coding

Before we dig into TinyViewer, I'd like to take a moment to emphasize a point I made in my March column. The issue was a naming convention for accessor functions. I suggested that you name your getter methods to match the name of the instance variable being retrieved, then put the word "set" in front of that (be sure to cap the first letter after the word "set") to name the setter function. Here's the example I gave:

- (int)height;        // Returns the value of the height field
- (void)setHeight:(int)h;    // Sets the height field to
                                     // the value in h

Bill Cheeseman, famous ex-attorney (remember the John Travolta movie A Civil Action? Bruce Norris played Bill in the movie. True.) and Cocoa aficionado (I highly recommend his most excellent book, Cocoa Recipes for Mac OS X: The Vermont Recipes), took the time to discuss the importance of this convention with me.

In a nutshell, consider this naming convention mandatory, not optional. In Bill's words:

    "The -height and -setHeight: getter and setter naming conventions are expected by many features of the AppKit and Foundation. While these are optional naming "conventions" from the perspective of Objective-C as a language, they are effectively mandatory if you want to use the Cocoa frameworks. You will lose a lot of important Cocoa framework functionality if you don't follow these naming conventions.

    The most important aspect of the Cocoa frameworks that depends on following these naming conventions is the key-value coding protocol. Look up key-value coding in the Cocoa documentation, and read the class reference document for the NSKeyValueCoding informal protocol in the Foundation frameworks. Several important Cocoa technologies use key-value coding, such as AppleScript. If you don't follow this naming convention for your accessors, you will not be able to take advantage of Cocoa's automatic support for AppleScriptability. There are several other areas where similar dependence on key-value coding requires you to follow these naming conventions.

    Basically, key-value coding lets you write code that calls methods by giving the names of instance variables as strings. This enables you to write a single method which will call other methods based on the strings you provide, rather than having to make actual method calls (er, "to send actual messages") in a long case statement. Because of this, the actual method calls ("messages") can be determined at run time, not hard-coded at compile time. Furthermore, key-value coding gives the separate, added benefit of providing the data in the correct type without your having to code type coercions in a case statement."

Thanks, Bill! As you develop more confidence with Objective-C and Cocoa, spend some time digging through the key-value coding doc and examples. Here's a good link to start with:

OK, let's get back to this month's program...


Every time I sit down to tackle a new Mac programming environment or methodology, I always seem to find myself coming back to PictViewer. How am I going to get PictViewer up and running with this new setup. As soon as I had my first working version of Project Builder installed, the first thing I did was dig through the Cocoa doc, looking for the classes I'd need to master to create a resizable window, with scrollbars, I could usein which I could display an image. Once I figured that out, I'd then tackle some drag-and-drop classes so I could add that feature to the program.

Little did I know how easy (and cool) this would turn out to be.

Create the TinyViewer Project

Launch Project Builder and create a new project of type Cocoa Application. Name the app TinyViewer and save. In the Project Builder Files pane, click to open the triangle to the left of Resources, then open the triangle to the left of MainMenu.nib. This will reveal an item named English (assuming you are on an English-based Mac).

The .nib file is an Interface Builder file. Interface Builder is sort of like ResEdit on steroids. With it, you can customize all your favorite objects and encode them for later decoding when your program is actually run. The item named English in the Project Builder Files tab refers to the English-localized nib file. Figure 1 shows the Finder listing of my version of TinyViewer. Notice the directory named English.lproj and the file MainMenu.nib within that directory. That's the English version of the nib file, the one we'll be working with in this column.

Figure 1. The English.lproj folder inside the project folder.

Figure 2 shows a Terminal listing showing a localized application on my hard drive. I start by going into the /Applications directory, the doing a cd into the sub-directory If I looked at /Applications in a Finder window, would just appear as a single application file. In reality, your packaged applications are a series of files, all rolled under a single directory, in this case named As Figure 2 shows, if you make your way down into /Applications/, you'll see a number of different files and directories, including a directory for each localized version of the app. You should definitely fire up Terminal and try this for yourself. Dive down into your favorite app, then look for English.lproj.

Figure 2. Follow the terminal commands to find your way to the localized .nib files

Editing the .nib File

Double-click on TinyViewer/Resources/MainMenu.nib/English in the project window Files tab. This will open your .nib file in Interface Builder. You'll likely see 4 Interface Builder windows appear. The window labeled Window (Figure 3) represents your app's main window. The window labeled MainMenu.nib - MainMenu (Figure 4) contains your app's menu bar. The window labeled MainMenu.nib (Figure 5) acts as a central repository for the resources/instances you'll be creating. And the window labeled Cocoa - Other (Figure 6) is a palette window.

Figure 3. The default TinyViewer window, shrunk for convenience.

Figure 4. The default application menubar.

Figure 5. The main .nib file navigation window.

Figure 6. The palettes window.

Note the row of icons at the top of the palette window (Figure 6). Clicking on one of the icons changes the set of items available from that section of the palette. Currently, there are 10 palette icons. In order, they are Menus, Views, Other, Windows, Data, Containers, GraphicsViews, AppleScript, MSFFormatterPalette, and Sherlock. Our focus will be on the third icon from the left, the Other palette. Click on the Other icon and your palette window should look like the one shown in Figure 6.

Click and drag an NSImageView out of the palette window into the window named Window. If you hover your cursor over an item in the palette window, a "tool tip" will appear that tells you the item type. Drag the NSImageView towards the upper-left corner of the Window window until a pair of crossed blue lines appear (see Figure 7).

Figure 7. Dragging an NSImageView onto your main window.

Next, click on the NSImageView icon to select it. 8 grow handles will appear. Drag the lower right grow handle to grow the NSImageView until the crossed blue lines appear as you approach the lower right corner of the window. The net result will be an NSImageView inset in the window about the thickness of a scrollbar on all four sides.

Now, let's bring up an inspector window and customize our NSImageView. Select Show Info from the Tools menu. The NSImageView Info window will appear (Figure 8). The Info window allows you to modify the currently selected object. In this case, we're inspecting our NSImageView object.

Figure 8. The Info window for our NSImageView.

Take a look at Figure 8. Your settings should look like this. Be sure the Editable checkbox is checked. This will enable "drag and drop". In fact, when you take the interface for a spin, try testing the interface with and without the Editable checkbox checked.

Next, select Size from the popup menu and compare your settings to those shown in Figure 9. Note that the Layout Rect fields will not necessarily match. Not to worry. It's just the difference between our window sizes. What's important is the Autosizing settings. To change those, click on the two lines in the inner square till each line turns into a pair of springs. Again, when you test the interface, play with these settings. Try it with one line and one spring, just to see what affect this has.

Figure 9. The NSImageView Info window, this time showing the Size settings.

Testing the Interface

OK, now let's take the interface for a spin. Select Test Interface from the File menu. Your window will appear, with an NSImageView area centered in the window. Click on a picture and drag it to the NSImageView field. The image should appear centered in the window. When you resize the window, the image should resize until it reaches its full size.

Play, play, play. Drag the image back out of the window and onto the desktop. A clipping file should appear. Double-click it and you can view your image directly in the Finder. Cool!

To exit the application, just select Quit from the File menu.

You should now be back in Interface Builder. Select Save from the File menu to save the .nib file. Now go back into Project Builder and run TinyViewer. Notice that TinyViewer appears in the dock as an icon, the main menu is titled "TinyViewer", your window appears, and is fully functional. Very cool!!

    There's a terrific new Cocoa book out there you should definitely check out. It's called Cocoa Programming by Scott Anguish, Erik M. Buuck, and Donald A. Yacktman, published by Sams. You can find it at

    I can't say enough about Cocoa Programming. Chapter 1 has one of the clearest breakdowns of the Mac OS X development universe I've yet read. There's great coverage of Objective C, design patterns, memory management, strings, encoding/decoding, exhaustive coverage of the Cocoa frameworks, and just about anything else you might think of. And there, nestled in Chapter 3 you'll find the Cocoa Programming treatment of an NSImageView app. Great stuff. My highest recommendation.

Till Next Month...

Next month, we'll do more with Interface Builder, including exploring the details of the Info window and customizing the menu bar. See you then...

Dave Mark is a long-time Mac developer and author and has written a number of books on Macintosh development, including Learn C on the Macintosh, Learn C++ on the Macintosh, and The Macintosh Programming Primer series. Be sure to check out Dave's web site at


Community Search:
MacTech Search:

Software Updates via MacUpdate

Garmin Express - Manage your Gar...
Garmin Express is your essential tool for managing your Garmin devices. Update maps, golf courses and device software. You can even register your device. Update maps Update software Register your... Read more
Duet - Use your iPad as an exter...
Duet is the first app that allows you to use your iDevice as an extra display for your Mac using the Lightning or 30-pin cable. Note: This app requires a $14.99 iOS companion app. Version Read more
Apple iTunes 12.5.2 - Play Apple Music a...
Apple iTunes lets you organize and stream Apple Music, download and watch video and listen to Podcasts. It can automatically download new music, app, and book purchases across all your devices and... Read more
Pinegrow Web Designer 2.95 - Mockup and...
Pinegrow Web Designer is desktop app that lets you mockup and design webpages faster with multi-page editing, CSS and LESS styling, and smart components for Bootstrap, Foundation, Angular JS, and... Read more
jAlbum Pro 13.6 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. You can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly... Read more
jAlbum 13.6 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results - Simply drag and drop photos into groups, choose a design... Read more
TextMate 2.0-beta.12.26 - Code/markup ed...
TextMate is a versatile plain text editor with a unique and innovative feature set which caused it to win an Apple Design Award for Best Mac OS X Developer Tool in August 2006. A rapidly growing... Read more
VMware Fusion 8.5.1 - Run Windows apps a...
VMware Fusion 8 and Fusion 8 Pro--the latest versions of its virtualization software for running Windows on a Mac without rebooting--include full support for Windows 10, OS X El Capitan, and the... Read more
Apple Final Cut Pro X 10.3 - Professiona...
Apple Final Cut Pro X is a professional video editing solution.Completely redesigned from the ground up, Final Cut Pro adds extraordinary speed, quality, and flexibility to every part of the post-... Read more
Civilization VI 1.0.0 - Next iteration o...
Sid Meier’s Civilization VI is the next entry in the popular Civilization franchise. Originally created by legendary game designer Sid Meier, Civilization is a strategy game in which you attempt to... Read more

Latest Forum Discussions

See All

Plants vs. Zombies Heroes guide: How to...
Plants vs. Zombies Heroes might look cute and cuddly, but it's actually a very complex deck builder that requires a lot of time to master. While there's a bit of a learning curve, it's easy for people of any skill level to have fun with the game. | Read more »
Roofbot: Puzzler On The Roof (Games)
Roofbot: Puzzler On The Roof 1.0.2 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.2 (iTunes) Description: Guide Roofie through gorgeous, meditative rooftops and try to get the right color energy balls into the... | Read more »
The 4 best food delivery apps
As the temperatures continue to drop, so does the motivation to venture outside. Sometimes you still want to eat a nice meal from that sushi place down the road though. Thankfully in these trying times, there are a number of fine food delivery... | Read more »
Toca Life: Farm (Education)
Toca Life: Farm 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: Work and play the farmer's way! Milk your cow, gather eggs from your hens and raise your crops. Have a picnic, play the... | Read more »
The Lost Shield (Games)
The Lost Shield 1.0.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0.0 (iTunes) Description: The Lost shield is a brick break/adventure game. You play as a hero who must return a powerful but dangerous magic shield... | Read more »
The Forgotten Room (Games)
The Forgotten Room 1.0.1 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0.1 (iTunes) Description: Play as paranormal investigator John “Buster of Ghosts” Murr as he explores yet another mysteriously creepy house. This... | Read more »
5 Halloween mobile games for wimps
If you're anything like me, horror games are a great way to have nightly nightmares for the next decade or three. They're off limits, but perhaps you want to get in on the Halloween celebrations in some way. Fortunately not all Halloween themed... | Read more »
The 5 scariest mobile games
It's the most wonderful time of the year for people who enjoy scaring themselves silly with haunted houses, movies, video games, and what have you. Mobile might not be the first platform you'd turn to for quality scares, but rest assured there are... | Read more »
Lifeline: Flatline (Games)
Lifeline: Flatline 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: The Lifeline series takes a terrifying turn in this interactive horror experience. Every decision you make could help... | Read more »
Game of Dice is now available on Faceboo...
After celebrating its anniversary in style with a brand new update, there’s even more excitement in store for Game of Dice has after just being launched on Facebook Gameroom. A relatively new platform, Facebook Gameroom has been designed for PC... | Read more »

Price Scanner via

WaterField Unveils Syde MacBook Pro Touch Bar...
The new WaterField Designs Syde Case for Apple’s new MacBook Pro Touch Bar combines the top-notch laptop protection of a sleeve with the functionality and handsome look of an over-the-shoulder or... Read more
Apple Unveils Redesigned MacBook Pro With Tou...
October 27, 2016 – Apple today introduced the thinnest and lightest MacBook Pro yet, along with a new interface innovation that replaces the traditional row of function keys with a Retina-quality... Read more
Apple Unveils New TV App for Apple TV, iPhone...
October 27, 2016 – Apple today introduced a new TV app, offering a unified experience for discovering and accessing TV shows and movies from multiple apps on Apple TV, iPhone and iPad. The TV app... Read more
Price drops on select refurbished 2015 13″ Re...
Apple dropped prices on select Certified Refurbished 2015 13″ Retina MacBook Pros by as much as $90. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz/256GB... Read more
Apple reveals new next-generation 15″ and 13″...
Apple today revealed their next-generation 15″ and 13″ MacBook Pros. The new models are thinner and lighter than before with a new aluminum design featuring an enhanced keyboard with retina, multi-... Read more
Worldwide Smartphone Shipments Up 1.0% Year o...
According to preliminary results from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, vendors shipped a total of 362.9 million smartphones worldwide in the third... Read more
TuneBand Arm Band For iPhone 7 and 7 Plus Rel...
Grantwood Technology has added the TuneBand for iPhone 7 and 7 Plus to its smartphone armband series. The TuneBand provides a lightweight and comfortable way to wear the iPhone while running,... Read more
1.4GHz Mac mini on sale for $449, save $50
Adorama has the 1.4GHz Mac mini on sale for $50 off MSRP including free shipping plus NY & NJ sales tax only: - 1.4GHz Mac mini (Apple sku# MGEM2LL/A): $449 $50 off MSRP To purchase a mini at... Read more
21-inch 1.6GHz iMac on sale for $999, save $1...
B&H has the 21″ 1.6GHz Apple iMac on sale for $999 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Read more
Macs’ Superior Enterprise Deployment Cost Eco...
IBM’s debunking of conventional wisdom and popular mythology about the relative cost of using Apple Mac computers as opposed to PCs running Microsoft Windows at the sixth annual Jamf Nation User... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 52812906 Houston, Texas, United States Posted: Oct. 18, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC is an Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 52812872 Houston, Texas, United States Posted: Oct. 18, 2016 Weekly Hours: 40.00 **Job Summary** As an Apple Solutions Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Software Engineering Intern: UI Applications...
Job Summary Apple is currently seeking enthusiastic interns who can work full-time for a minimum of 12-weeks between Fall 2015 and Summer 2016. Our software Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.