TweetFollow Us on Twitter

TinyViewer

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

Getting Started

TinyViewer

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:

http://developer.apple.com/techpubs/macosx...

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

TinyViewer

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 Clock.app. If I looked at /Applications in a Finder window, Clock.app 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 Clock.app. As Figure 2 shows, if you make your way down into /Applications/Clock.app/Contents/, 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 http://www.devdepot.com/books.html.

    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 http://www.spiderworks.com.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Live Home 3D Pro 3.2.2 - $69.99
Live Home 3D Pro, a successor of Live Interior 3D, is the powerful yet intuitive home design software that lets you build the house of your dreams right on your Mac. It has every feature of Live Home... Read more
Live Home 3D Pro 3.2.2 - $69.99
Live Home 3D Pro, a successor of Live Interior 3D, is the powerful yet intuitive home design software that lets you build the house of your dreams right on your Mac. It has every feature of Live Home... Read more
FileZilla 3.27.0.1 - Fast and reliable F...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.27.0.1: MSW: Add misssing file to .zip binary package... Read more
Spotify 1.0.59.395. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
Sierra Cache Cleaner 11.0.6 - Clear cach...
Sierra Cache Cleaner is an award-winning general purpose tool for macOS X. SCC makes system maintenance simple with an easy point-and-click interface to many macOS X functions. Novice and expert... Read more
DiskCatalogMaker 7.1.2 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Live Home 3D Pro 3.1.2 - $69.99
Live Home 3D Pro, a successor of Live Interior 3D, is the powerful yet intuitive home design software that lets you build the house of your dreams right on your Mac. It has every feature of Live Home... Read more
Deeper 2.2.1 - Enable hidden features in...
Deeper is a personalization utility for macOS which allows you to enable and disable the hidden functions of the Finder, Dock, QuickTime, Safari, iTunes, login window, Spotlight, and many of Apple's... Read more
Pinegrow 3.04 - Mockup and design webpag...
Pinegrow (was 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,... Read more
Deeper 2.2.1 - Enable hidden features in...
Deeper is a personalization utility for macOS which allows you to enable and disable the hidden functions of the Finder, Dock, QuickTime, Safari, iTunes, login window, Spotlight, and many of Apple's... Read more

Latest Forum Discussions

See All

The best deals on the App Store this wee...
There are quite a few truly superb games on sale on the App Store this week. If you haven't played some of these, many of which are true classics, now's the time to jump on the bandwagon. Here are the deals you need to know about. [Read more] | Read more »
Realpolitiks Mobile (Games)
Realpolitiks Mobile 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: PLEASE NOTE: The game might not work properly on discontinued 1GB of RAM devices (iPhone 5s, iPhone 6, iPhone 6 Plus, iPad... | Read more »
Layton’s Mystery Journey (Games)
Layton’s Mystery Journey 1.0.0 Device: iOS Universal Category: Games Price: $15.99, Version: 1.0.0 (iTunes) Description: THE MUCH-LOVED LAYTON SERIES IS BACK WITH A 10TH ANNIVERSARY INSTALLMENT! Developed by LEVEL-5, LAYTON’S... | Read more »
Full Throttle Remastered (Games)
Full Throttle Remastered 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Originally released by LucasArts in 1995, Full Throttle is a classic graphic adventure game from industry legend Tim... | Read more »
Stunning shooter Morphite gets a new tra...
Morphite is officially landing on iOS in September. The game looks like the space shooter we've been needing on mobile, and we're going to see if it fits the bill quite shortly. The game's a collaborative effort between Blowfish Studios, We're Five... | Read more »
Layton's Mystery Journey arrives to...
As you might recall, Layton's Mystery Journey is headed to iOS and Android -- tomorrow! To celebrate the impending launch, Level-5's released a new trailer, complete with an adorable hamster. [Read more] | Read more »
Sidewords (Games)
Sidewords 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Grab a cup of coffee and relax with Sidewords. Sidewords is part logic puzzle, part word game, all original. No timers. No... | Read more »
Noodlecake Games' 'Leap On!...
Noodlecake Games is always good for some light-hearted arcade fun, and its latest project, Leap On! could carry on that tradition. It's a bit like high stakes tetherball in a way. Your job is to guide a cute little blob around a series of floating... | Read more »
RuneScape goes mobile later this year
Yes, RuneScape still exists. In fact, it's coming to iOS and Android in just a few short months. Jagex, creators of the hit fantasy MMORPG of yesteryear, is releasing RuneScape Mobile and Old School RuneScape for mobile devices, complete with... | Read more »
Crash of Cars wants you to capture the c...
Crash of Cars is going full on medieval in its latest update, introducing castles and all manner of new cars and skins fresh from the Dark Ages. The update introduces a new castle-themed map (complete with catapults) and a gladiator-style battle... | Read more »

Price Scanner via MacPrices.net

Clearance 2016 12-inch Retina MacBooks, Apple...
Apple recently dropped prices on Certified Refurbished 2016 12″ Retina MacBooks, with models now available starting at $1019. Apple will include a standard one-year warranty with each MacBook, and... Read more
Save or Share
FotoJet Designer, is a simple but powerful new graphic design apps available on both Mac and Windows. With FotoJet Designer’s 900+ templates, thousands of resources, and powerful editing tools you... Read more
Logo Maker Shop iOS App Lets Businesses Get C...
A newly released app is designed to help business owners to get creative with their branding by designing their own logos. With more than 1,000 editable templates, Logo Maker Shop 1.0 provides the... Read more
Sale! New 15-inch MacBook Pros for up to $150...
Amazon has the new 2017 15″ MacBook Pros on sale for up to $150 off MSRP including free shipping: – 15″ 2.8GHz MacBook Pro Space Gray: $2249 $150 off MSRP – 15″ 2.89Hz MacBook Pro Space Gray: $2779 $... Read more
DEVONthink To Go 2.1.7 For iOS Brings Usabili...
DEVONtechnologies has updated DEVONthink To Go, the iOS companion to DEVONthink for Mac, with enhancements and bug fixes. Version 2.1.7 adds an option to clear the Global Inbox and makes the grid... Read more
15-inch 2.2GHz Retina MacBook Pro, Apple refu...
Apple has Certified Refurbished 2015 15″ 2.2GHz Retina MacBook Pros available for $1699. That’s $300 off MSRP, and it’s the lowest price available for a 15″ MacBook Pro. An Apple one-year warranty is... Read more
13-inch 2.3GHz Silver MacBook Pro on sale for...
B&H Photo has the new 2017 13″ 2.3GHz/256GB Silver MacBook Pro (MPXU2LL/A) on sale for $1399 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
Apple Tackles Distracted Driving With iOS 11...
One of the most important new features coming in iOS 11 is Do Not Disturb while driving, intended to help drivers stay more focused on the road. With Do Not Disturb while driving, your iPhone can... Read more
iMazing Mini for Mac: Free Automatic and Priv...
Geneva, Switzerland-based indie developer DigiDNA has released iMazing Mini, their free macOS utility designed to automatically back up iOS devices over any local Wi-Fi network. The app offers users... Read more
Clearance 2016 13-inch MacBook Airs, Apple re...
Apple dropped prices recently on Certified Refurbished 2016 13″ MacBook Airs, with models now available starting at $809. An Apple one-year warranty is included with each MacBook, and shipping is... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions - Apple...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Senior Payments Architect - *Apple* Pay - A...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
Frameworks Engineering Manager, *Apple* Wat...
Frameworks Engineering Manager, Apple Watch Job Number: 41632321 Santa Clara Valley, California, United States Posted: Jun. 15, 2017 Weekly Hours: 40.00 Job Summary Read more
Manager, *Apple* Media Products - Apple Inc...
Job Summary The Apple Media Products Discovery, Fraud and Abuse team is responsible for protecting the integrity of Apple services. As a manager of the team, you Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.