Ten Little Images (or so), Part 1

Making sense of icon image requirements for iOS universal applications.

If you are developing (or considering) a “universal” application for iOS, an app that will run on all (current) iOS devices, one of the first things you have to consider are the initial branding graphics for your game.  These include the icons, in various sizes, and the launch images for each device.

The icons, of course, are displayed on the home screen of the device to represent the game, but they can also be shown (in different sizes) on the search page (as well as in Settings, if appropriate).  The launch images are stand-in graphics that are displayed in a static fashion while the app is loaded and initializes itself.  On an iPad, there need to be launch images for each orientation (portrait and landscape), while the iPhone and iPod Touch only launch in portrait orientation.  For more variety, though, the iPhone 4 and 4th generation iPod Touch have the Retina displays, with higher resolution, requiring still more images.

The assumptions here are that you are creating a “universal” application, supporting iOS 3.2 (the minimum version for iPad), and want to be sure to have your branding artwork shown in the best light on all three types of devices.  If you are supporting only iPad (no small screens or Retina displays) or only iOS 4+ (no backwards compatibility), then there are fewer conflicts and caveats, but this article should still be helpful.

Icon Artwork Specifications

All icon (and launch) images must be in PNG format (24-bit), with no transparency.  Although there are naming conventions for automatically loading different files according to the device type, arbitrary (descriptive) file names for icons are preferred and more reliable.  In our case, we use the project name (“DemolishPairs” herein) as a base name, with “ipad”, “iphone”, and “retina” used as modifiers.

For complete icon coverage, with no scaling performed by iOS, we have the following (8) icon files:

  1. DemolishPairs.png [512×512] – This is the largest (current) icon size for iOS applications; generally, the artwork should begin at this size (or larger) and be scaled down to the other sizes.
  2. DemolishPairs_ipad.png [72×72] – This is the application icon for the iPad, as shown on the home screen.
  3. DemolishPairs_ipad_small.png [50×50] – This is the application icon for iPad, displayed in search results.
  4. DemolishPairs_iphone.png [57×57] – This is the application icon for the older (non-Retina) iPhone and iPod touch.
  5. DemolishPairs_iphone_small.png [29×29] – This is the search results icon for the older iPhone and iPod touch.
  6. DemolishPairs_retina.png [114×114] – This is the application icon for the newer (Retina) iPhone and iPod touch.
  7. DemolishPairs_retina_small.png [58×58] – This is the search results icon for iPhone/iPod touch with Retina displays.
  8. iTunesArtwork [512×512] – This is (in our case) a copy of ‘DemolishPairs.png‘ with a very specific filename (note: no file extension, not even ‘.png’) for ad-hoc distribution and/or submission to the App Store.

Note that most games will not have Settings packages, but those that do can use the 29×29 icon [5] for all older displays, including iPad, and the 58×58 icon [7] for all Retina displays.  (Document icons have different requirements but are generally unnecessary for games, so they are not covered here.)

Project Configuration for Icons

Once you have the icon artwork, it is necessary to include all of the icon files in the Xcode project, so they will be copied to the compiled bundle, and then modify the project’s ‘Info.plist‘ file (by whichever name) to indicate the icon image filenames.  There are two possible entries that indicate icons, and since we are specifying multiple image files (and by Apple recommendation), we will add an ‘Icon files‘ (CFBundleIconFiles) array with six entries:

  • DemolishPairs_ipad.png
  • DemolishPairs_ipad_small.png
  • DemolishPairs_iphone.png
  • DemolishPairs_iphone_small.png
  • DemolishPairs_retina.png
  • DemolishPairs_retina_small.png

Caveat:  ‘DemolishPairs_ipad_small.png‘ must appear before ‘DemolishPairs_iphone.png‘ in the list; otherwise, iOS 3.2 (iPad) will incorrectly select the 57×57 icon instead of the 50×50 icon when displaying search results.

Although the CFBundleIconFiles array takes precedence, there is still a minor reason to add the (singular) ‘Icon file‘ (CFBundleIconFile) string, with “DemolishPairs.png” as the value.  Xcode 4 uses this image file as the default icon for the target application in the project; if it is missing or empty, the last entry in the array is used.  This (currently) has no practical impact on the application itself, but supplying a reference (512×512) icon within the bundle is not a bad thing.

Of course, if one is building an application for only iPad devices, the number of icons necessary is reduced, but I would still recommend getting a complete set of the above icon sizes from your artist anyway (just in case).  On the other hand, if one is building an application for only iPhone devices, shame on you; there is no excuse for not supporting the iPad nowadays.

Technical notes:  The above information has been thoroughly tested using Xcode 4.0, specially created test icons, and both the iOS Simulator and a variety of physical devices.  The icon images were designed to be distinguishable from each other, with single pixel borders for detecting stretching and clipping.  Results were confirmed for iOS 4 on the simulator for all three types of devices: “iPad”, “iPhone”, and “iPhone (Retina)”, as well as on an original iPad (iOS 3.2), a second generation iPod touch (iOS 4.2.1), an iPhone 4 (iOS 4.2.6), and an iPad 2 (iOS 4.3.5).  [Editor’s note: We have no plans to upgrade any device to iOS 5.x in the immediate future.]

In our next installment, Ten Little Images (or so), Part 2, I discuss the requirements and caveats of launch images in universal iOS applications.

Carbon nibs update

A spurious warning appears to be spurious.

In my last post, Carbon nibs under Lion, I gave a solution to the problem of Carbon nib (interface) files not being supported in Xcode 4, while Xcode 3 would not run under Mac OS X 10.7 (Lion).  That solution was to run Interface Build 3.2.6 and convert the nibs to a newer format.

Toward the end of the post I mentioned that many windows in the converted nib files produced a warning: “This window’s content rectangle does not lie entirely on the screen with the menu bar and may not be completely visible for all screen resolutions and configurations.”  In testing, these files did not exhibit any errant behavior, but shipping a product, even a beta, with build warnings is against our development guidelines.

Since that post (and in preparation for a proper build, without warnings), I did a little research and experimentation and discovered that the problem appears to be a minor issue with the conversion, where the resulting data is aberrant enough to generate a warning, but is handled correctly in the resulting application.  Although I did not dig deeply enough to identify the exact source of the problem, it is related to window positioning (as one may have guessed).

The solution, oddly, is simply to open the offending nib file, select the (or each) window, click on the Size (ruler) tab in the Inspector, and then drag the window position image, even slightly.  As far as I can discern, any movement (within the simulated window) fixes the problem; at least, it fixed it for all of my affected windows.  Clearly, the size of the windows was not the issue, since that was not changed, and the position should never have been a problem, either, for windows with the ‘Center’ attribute enabled (as most of mine were).  I also note that the windows I created from scratch since moving to this Lion/IB 3.2.6 setup were unaffected.

One other idiosyncrasy to note is that the build process also produces the following message: “View is clipping its content.”  It is not a warning, just a message, and I assumed that it was related to the above warning until the warnings were fixed.  It is a straightforward message, albeit with no reference to the specific view involved, so I looked into find the problem there as well.

As it turns out, there is a very useful tool with IB 3.2.6 to assist with this.  Select ‘Layout->Show Clipping Indicators’ to enable a feature that displays a small “+” at the bottom of any view that is clipping its content.  I never noticed this setting before, and it can be very handy.  Alas, it also reveals (in our case) that the messages are just pointless chatter, since they are being given for list views with extra columns that are intended to scroll horizontally.  Fortunately, they do not produce a warning message, so the messages are easily ignored; in fact, they only appear on the full build log, so I may have never noticed them had I not been debugging a nearby warning.

[The most meaningful comment that I received for the last post was (seriously), “I’ve a cockroach on my pillow.  Wanna see it?”  The days of technical development posts may be numbered.]

Carbon nibs under Lion (Mac OS X 10.7)

Apple’s overly aggressive deprecation sucks.

If you are still maintaining a Carbon application for Mac OS X, you may have stumbled upon a serious issue with handling of nib (interface) files in Xcode 4 under Lion, and if you have not yet, you probably will soon.  Hopefully, this post will help you resolve problems or avoid some of the pitfalls.

The Problems

Apple marches forward and aggressively deprecates development technology.  In this particular case, they release Xcode 4 and only allow submissions to the Mac App Store from the latest version, forcing developers to upgrade.  We are maintaining and enhancing a product that was developed using Carbon, based on Apple’s (then) recommendation for cross-platform products, and was about 90% complete when they announced its deprecation in favor of Cocoa.

Additionally, we upgraded to Lion (to properly provide customer support), unaware that the latest version of Xcode 3, version 3.2.6, would not install or run on Lion.  Instead, we could only download and install Xcode 4.1, which does not provide support for Carbon nib files.  With Snow Leopard, we could download both versions normally, but from Lion, the Xcode 3 download link is removed and Xcode 4 is only available via the Mac App Store.  More accurately, the installer is available via the Mac App Store; you still need to find it in Launchpad and run it before Xcode is ready.

There are two particular problems that occur with Carbon nibs in Xcode 4.1:

First, there is no editing capability for modifying them, so when you highlight a Carbon nib, the editing window only displays an Interface Builder icon, but (importantly and annoyingly) there is no message that editing is not supported.  Unless you already know that is the case, you will waste some amount of time attempting to figure out how to activate the “integrated” Interface Builder.

Second, the build tools provided cannot process the older nib files, so you will get a message similar to the following: ‘error: ibtool could not strip “Main.nib” because it is not a valid Interface Builder document.

Of course, there are a few obvious options here.  If you stop upgrading your development system, you can still build on Xcode 3.2.6 under Snow Leopard, except that you cannot submit to the Mac App Store.  You may be able to have both versions in parallel, but that is not an option on Lion at all, and the nib build issue still exists in Xcode 4 (although the solution to that is provided below).  Finally, you can give in to Apple’s strongarm tactics and rewrite your application to use Cocoa, but that is not always feasible, economically or otherwise.  (In our case, we are trying to maintain our products and support our customers while we rewrite it with Cocoa.)

Or, I suppose, you could flip Apple the bird and abandon their Mac platform; that has crossed my mind more than once, but it is not really an option for us.  Instead, I found a way to resolve the two main problems above, without too much effort.  (That is, it will be fairly easy for you readers; it took me significant time to figure this all out.)

The Solution

To resolve the inability to edit Carbon nib files within Xcode 4, take advantage of the fact that Interface Builder was an external tool with Xcode 3, and that it does run in Lion.  Simply copy Interface Builder 3.2.6 from a (Snow Leopard) partition on which it is installed to the Lion partition.  It should be located (by default) in the ‘/Developer/Applications’ folder, and note that it must be copied to the same directory on the Lion partition after Xcode 4.1 is installed.  (It will not run properly from a different folder, and the Xcode installer apparently removes it [so make a backup copy].)  Since Xcode will no longer launch (the external) Interface Builder automatically, you will probably want to make an alias for it in a convenient location.

Then, to resolve the build problems with the older nib files, you must use the separate Interface Builder tool to covert your nib files to a newer (XIB) format.  This is accomplished by opening each nib file in IB, selecting ‘File->Save As…’ from the menu, changing the ‘File Type’ to “Interface Build Carbon Document (XIB 3.x)”, and saving.  You will then need to open your project in Xcode, add all of the new .xib files to it, and delete the older .nib files.  Clicking on one of the .xib files in Xcode will show/edit it as an XML file (instead of just an icon) but, of course, you will probably only want to edit it in your newly installed IB3.

There may (read: probably will) be other issues, both with Xcode 4 itself and with the newer SDKs.  For example, we use one (and only 1) function defined in ‘QuickdrawAPI.h’, which has been removed from the OS X 10.7 SDK, so we had to back down to the 10.6 SDK (plus each SDK has different versions of the zlib library available).  Also, several of our windows from (converted) nib files produce a new warning: “This window’s content rectangle does not lie entirely on the screen with the menu bar and may not be completely visible for all screen resolutions and configurations.”  (We dynamically adjust most of our windows anyway, so it appears to make no difference, but we have yet to eliminate these warnings.)

Nevertheless, making the above changes will allow an older Carbon-based application to be built on Lion using Xcode 4.1, leaving you free to discover more fun and excitement.

[If you find this information useful, please leave a meaningful comment.]

10 Years of the GDcard Library

We celebrate a decade of collaboration with Goodsol.

Time really does fly when you are having fun (and doing what you love).  It was 10 years ago today that we delivered the first properly functional version of a playing card library, then named PGScard.dll, to Goodsol Development.  We have been working with them ever since, improving this library, which is used heavily in Pretty Good Solitaire, writing new games (see below), and extending the product line to include Mac OS X (and, soon, IOS), as well as our Windows products.

Back then, the whole nation was still asking questions, like ‘Where do we go from here?‘  We were facing a bit of a crisis here as well, as our primary external opportunity was stopped in the midst of economic uncertainty, and our main internal project was rendered unpalatable for release, so we were available immediately when Thomas Warfield inquired.  (The subject line of my reply was, “Work?  Did you say work? <g>“.)

In the intervening years, the library was renamed to GDcard, had numerous extensions and updates, and has been in every PGS release (for Windows) in the last decade.  The current version, GDcard 2.09, has not required any modifications in the past 4 years, but it still draws cards and provides other related functionality in the latest release, Pretty Good Solitaire 13.1.0 (with 770 games), published last week (almost 10 years to the day after the initial agreement).

This first project led to many others with Goodsol (in roughly chronological order):

… and several products to be announced later.  All of the above games have trial versions available for download (at the links provided).  We also created MahJongg Patience (a smaller version of PGMJ) for the original (retail) MahJongg Master, published in 2003 by eGames.  (I now see that we are averaging more than one new SKU per year.)

I do not expect to be exchanging diamond jewelry, or even tin or aluminum gifts, but I do look forward to much more productivity and success from this arrangement in the future.  Thanks, Thomas and Anne!

Disk Images Revisited

There are some issues under Snow Leopard.

In a blog post last year, I gave detailed instructions on Making Mac Disk Images Pretty.  Unfortunately, I have discovered that the most recent version of Mac OS X has some issues of which developers should be aware when using that technique (not that there is any obvious alternative).

I recently upgraded my development system to Mac OS X 10.6 (Snow Leopard).  Apple is fairly aggressive with requirements for its development tools,  and I need to upgrade in order to use the latest iPhone SDK.  Of course, I already had a Snow Leopard partition that I had used for testing, so I knew that our software would work, and I never experienced any previous problems.

When the time came to build an update for one of our products (FreeCell Plus 4.00/4.01), I had a few minor niggles with Xcode 3.2.1 (the latest version), described later, but I got the product built and packaged properly.  Then it was time for testing on our other supported versions of Mac OS X, Tiger (10.4) and Leopard (10.5), and I was surprised to learn that, although the software itself ran flawlessly, the disk images showed no background image when mounted, and the folder size was wrong.  The icons were in the correct locations, relative to the top left corner of the window, so the formatting was not entirely ignored, just effectively ignored.

After some research into the problem, I found the answer in this DropDMG forum thread, where it is stated that Apple has confirmed this as a bug in Snow Leopard.  I moved DropDMG over to my Leopard partition, rebooted to that version of Mac OS X (10.5), and build my packages there.  That solved the problem, and the background images showed in all supported versions of OS X.

Conclusion: In order to have background images appear in disk images on older versions of Mac OS X, you must build the disk image under Leopard or earlier, not Snow Leopard.

Caveats: Sometimes, when opening a prepared disk image under Snow Leopard, there is a blank space on the bottom (probably not coincidentally exactly the same size as the folder toolbar), which does not appear on other versions of Mac OS X.  Also under 10.6, the folder toolbar includes a slider control for quickly changing icon sizes (a.k.a., fouling up your layout).  I have not been able to determine the cause of the former issue (yet) nor the reason for the latter.  (How often does one actually change icon sizes that this is even remotely necessary?)

There were some build issues with Xcode 3.2.1 under Snow Leopard.

As I mentioned, I experienced a couple minor build issues after the upgrade to Xcode 3.2.1, both of which were addressed, albeit with differing degrees of success.

First, the default compiler in the latest version of Xcode is GNU 4.2, which is incompatible with the 10.4 (universal) SDK, and the very first build let me know that.  Faced with a choice, downgrading the compiler to GNU 4.0 versus upgrading to the 10.6 SDK, I chose the latter, which I saw as the path of least resistance (see “Apple is fairly aggressive with requirements for its development tools” above).  Unfortunately, at least for our project, the 10.6 SDK does not function as advertised and, despite properly setting the target OS to 10.4 (and obviously not using any 10.5 or 10.6 features), a product built with the 10.6 SDK will not run under Tiger (period), although it does work under Leopard.  I switched (back) to GNU 4.0 and the 10.4 SDK and all was well.

Second, the latest version of Xcode upgrades its tools (obviously), and one seemingly innocuous change to the linker was to eliminate the need for the “-mlong-branch” compile option for certain object files (generally kernel files, which means primarily for Apple and not so much for the rest of us).  Unfortunately, a warning message was added to that effect, yet Apple did not update its PPC object files accordingly.  As a result, every time one links a universal binary (supporting PPC), the linker throws this warning: “Object file compiled with -mlong-branch which is no longer needed.”  The only permanent solution is to recompile certain (protected) development files oneself, or wait until Apple fixes the problem.

The latter issue is extremely annoying to me, because now I am in the position of either ignoring linker warnings, which I never advise, or spending hours (or days) figuring out how to rebuild a portion of the development tools.  Can you say, “not my job“?  Personally, from my experience of Apple over the last few years, my bet is that this problem will soon be addressed by a campaign to suggest that developers should not continue to be stuck in the past supporting PPC systems.

Does anybody want a piece of that action?

Three Steps to Apple Help, Part 3

Accessing Apple Help from C++ Code (Carbon)

The third/final step in implementing Apple Help is programmatically displaying the main contents or individual topics within your help pages.  This, of course, assumes that you have already created a set of HTML help pages for Apple Help and then indexed and integrated these files into your Xcode project.

Accessing Apple Help from C++ using Carbon is fundamentally simple.  The Apple Help Reference contains only 4 functions (plus one constant enumeration that is no longer used).  There is a little bit of necessary mucking about with bundle references and whatnot that may be unfamiliar to programmers who have not worked with Mac development before, but it is all fairly straightforward.

In order to access Apple Help from the application, you first register your help files using the AHRegisterHelpBook() function.  This only needs to be done once, ideally during program initialization, and we do it something like this:

bool RegisterHelp ( void )

    CFBundleRef const bundle = CFBundleGetMainBundle ( );
    if ( !bundle )
        return false;

    CFURLRef const location = CFBundleCopyBundleURL ( bundle );
    if ( !location )
        return false;

    FSRef file;
    if ( !CFURLGetFSRef ( location, &file ) )
        CFRelease ( location );
        return false;

    _Error = AHRegisterHelpBook ( &file );

    CFRelease ( location );

    if ( _Error )
        return false;

    return true;


(Additional validity checking and error reporting has been stripped from this sample code for clarity.)

In the above example, most of the code is just to obtain the FSRef (file system reference) of the application bundle from which the help is to be displayed, and it assumes that you want help for the current application.  (Obviously, you could instead pass a reference to any other bundle and access a different help system, but that would be unusual.)

Once the help files are registered, you can display the main help page using the AHGotoPage() function (with default parameters), which we accomplish with a function similar to this:

void ShowHelpContents ( void )

    CFBundleRef const bundle = CFBundleGetMainBundle ( );
    if ( !bundle )

    CFStringRef const key = CFSTR( "CFBundleHelpBookName" );
    CFTypeRef const book =
        CFBundleGetValueForInfoDictionaryKey ( bundle, key );
    if ( !book )

    CFStringRef const help = (CFStringRef)book;

    _Error = AHGotoPage ( help, NULL, NULL );


(Additional validity checking and error reporting has been stripped from this sample code for clarity.)

You can also display a specific help topic by using the AHLookupAnchor() function, for which we use something like this:

void ShowHelpTopic ( CFStringRef topic )

    if ( !topic )

    CFBundleRef const bundle = CFBundleGetMainBundle ( );
    if ( !bundle )

    CFStringRef const key = CFSTR( "CFBundleHelpBookName" );
    CFTypeRef const book =
        CFBundleGetValueForInfoDictionaryKey ( bundle, key );
    if ( !book )

    CFStringRef const help = (CFStringRef)book;

    _Error = AHLookupAnchor ( help, topic );


(Additional validity checking and error reporting has been stripped from this sample code for clarity.)

In both of these last two examples, the function reads the CFBundleHelpBookName string from the main application bundle and uses that string for the name of the help system, passed as the first parameter to the appropriate Apple Help function.  (You could, of course, hard code this string, but if you were thinking that this is a good idea, shame on you.)

Accessing Apple Help from Objective-C (Cocoa)

If you are using Objective-C and Cocoa, much of the help system handling is done behind the scenes (which is, in part, why some programmers find Objective-C to be objectionable).  If you follow the steps in the previous two posts (Part 1 and Part 2) to insert your Apple Help into a Cocoa project, your main help system will work automatically.

The main help page in a Cocoa application is accessible by the user through the ‘Help->[ApplicationName] Help’ menu option by default.  If you wish to bring up the main page from your Objective-C code, you may need to reference an anchor on that page (see below) or use the Carbon method described above.

To access a specific help topic (anchor) from Objective-C and Cocoa, this is done through the shared NSHelpManager object using the openHelpAnchor:inBook: method.  For example, to open the ‘rules’ topic, you would use the following code:

    NSString *book = [[NSBundle mainBundle]
    [[NSHelpManager sharedHelpManager]
        openHelpAnchor:@"rules" inBook:book];

The documentation for NSHelpManager is quite clear that all of its functionality is simply a number of wrappers around the functions described in the first section of this post, so you could always use those functions directly, if desired.

There you have it.  At this point, you should know enough to properly implement Apple Help in your Carbon or Cocoa application for Mac OS X.  The process is a little convoluted to suss out from the documentation, so I hope this provides a decent jump start.

Three Steps to Apple Help, Part 2

Adding Help Files to an Xcode Project

The second step in implementing Apple Help is integrating the help files into an Xcode project, so they will be properly added to an application bundle, and generating an Apple Help index file.  This article describes the process continuing from the HTML files generated in the previous blog entry (Part 1).  Be sure to read the comments there, too, where Alexander Halser of Help & Manual describes an alternative (and probably quicker) method of adding the necessary ‘name’ tags.

First, transfer the entire folder containing the HTML help files to your Mac OS X development system (as/if necessary).  [A discussion of how this is done is far below the scope of this article.]  The rest of this article assumes that this folder is named “Help”; rename the folder or adjust the instructions as appropriate.

Next, you will be adding the files to the application bundle.  Open your project in Xcode.  Highlight the ‘Resources’ group, right-click (or Command-click) it, and select ‘Add->Existing Files…’ from the context menu.  Choose the ‘Help’ folder and then click the ‘Add’ button.  In the next dialog box, mark the ‘Copy items into destination group’s folder (if needed)’ check box, select the ‘Create Folder Reference for any added folders’ radio button, and then click the ‘Add’ button.  This will create a folder reference in the project, such that the entire contents of the ‘<Project>/Help’ folder will be added to the bundle as a unit.  In other words, you can add, delete, or change files in that folder from outside Xcode and those changes will be reflected in the build without explicitly adjusting the project file.

If you want to add a localized help file instead (which is not a bad idea, even if translating the help file is not in the immediate plans), the above process is slightly different.  In that case, explicitly copy (or move) the ‘Help’ folder into the appropriate project language folder, such as ‘<Project>/English.lproj’.  Follow the same procedure (‘Add->Existing Files…’), but select the ‘<Project>/English.lproj/Help’ folder, and do not (or, rather, it is unnecessary to) mark the check box, but the radio button is still important.  In this case, you will see that instead of just adding a ‘Help’ subgroup to the ‘Resources’ group, Xcode will automatically add the group as ‘Help/English’ (or whichever language).  Repeat as necessary for additional languages.

Now that the help (HTML) files will be properly copied to your application bundle(s), you need to identify these files as the Apple Help files for the project.  To do this, open the ‘Info.plist’ file for the project, a property list that contains global project settings.  Right-click (or Command-click) and select ‘Add Row’ from the context menu, choosing ‘Help Book directory path’ [or ‘CFBundleHelpBookFolder’].  Edit the value of that row to be “Help”.  Using the same procedure, add a ‘Help Book main page CONTENT attribute’ [or ‘CFBundleHelpBookName’] row, and set its value to the identical string from the “AppleTitle’ meta name (e.g., “Pretty Good Solitaire Help” [sans quotes]).  You can now close Xcode.

Creating an Apple Help Index

In order for a user to be able to search your help file, you must create an Apple Help index file.  The tool you need for this is (the enigmatically named) Help Indexer, which should already be installed on your system in the ‘/Developer/Applications/Utilities’ folder.  (I find it convenient to create an alias to this particular utility in a more accessible location.)

Launch the Help Indexer tool.  On the first execution (and thereafter as necessary), you will want to set the utility preferences (‘Help Indexer->Preferences…’), as they determine the parameters for the Apple Help index (or indices) you will create.  In the ‘Index Style’ panel, clear the ‘Generate Panther-compatible Indices’ checkbox, unless you plan to support Mac OS X 10.3 or earlier.  (At this point, we only support 10.4 [Tiger] and later [Leopard and Snow Leopard].)  I recommend selecting the ‘Errors and warnings’ radio button in the ‘Logging Options’ panel, as including the status messages for large help files simply produces too much noise that could hide any valid warning or error messages.

To actually generate the help index file, once the tool is configured, is quite simple.  Click the ‘Select…’ button, browse to select/highlight the ‘Help’ folder, and click the ‘Open’ button.  Then, click the ‘Create Index’ button, and the process begins.  When finished, review the warning/error messages (if any), and then click ‘Quit’ to close the tool.  (Note that, if you do generate a Panther-compatible index, the messages are shown in a separate tab, and you may get a ‘Warning: [filename].html — Error parsing file.  Check validity of HTML.’ message for each file.  In our experience, we were unable to eliminate these warnings, but the indexing still seemed to work properly on the older systems.)

At this point, you can open Xcode and, if you look into your ‘Help’ group (added above), you will see that a new ‘Help.helpindex’ file has been added (as well as a Panther-compatible ‘Help idx’ file, if selected).  The advantage of adding the folder as a reference group, as noted earlier, is that changes to the folder contents (such as adding the index file) are automatically reflected in the project.  The corresponding disadvantage, however, is that these changes do not necessarily trigger a bundle rebuild, so after making help file changes, you will want to either clean your target (‘Build->Clean’ or Shift-Command-K) or explicitly incorporate the changes by right-clicking (or Control-clicking) on the project group that hold the help files and selecting the ‘Preprocess’ command from the context menu.

Now you have a fully indexed Apple Help system incorporated into your project.  All that remains is to add code to programmatically access the main help content, as well as individual topics, which I will cover in the third installment, so please stay tuned.

Three Steps to Apple Help, Part 1

Building an HTML Help File

The first step in implementing Apple Help is building an HTML help file.  Apple Help is the default help system in Mac OS X, and it is fundamentally a system for displaying HTML 4.01 from an application.  In order to use some (or any) of the features of Apple Help, one must do some minor customization, which is what I intend to describe here.  (The actual writing process is left as an exercise for the reader.)

For an overview of Apple Help, see this Apple Help Programming Guide.

Any decent HTML (or text) editor can be used to produce the necessary help files, but since ours is a help system for a product available on both Mac OS X and Windows, it makes sense to start with a full-featured help editor under Windows.  In our case, we use Help & Manual, which is an excellent and capable product.  (Note that we still choose to use the older H&M 4, since version 5 added the silly ribbon toolbar interface.)

Starting with a help project appropriate for Windows HTML Help (.chm), and with a tool that either works with or exports separate HTML files, there are only a few extra steps required to make an equivalent version for Apple Help.  In H&M, you use the ‘Browser-based Help’ option to write the necessary HTML files (as described later).

The common method of accessing a topic in HTML Help (as well as in the older WinHelp format) is via help context numbers.  Apple Help, on the other hand, uses a named anchor tag for each topic that needs to be accessed directly from an application.  For example, for a topic referenced as ‘contents’, you would add the following HTML tag to the topic:

<a name="contents" />

A similar tag should be added to every desired topic page, each with a unique name.  In H&M, this can be done by using the ‘Insert|Plain HTML Code…’ menu option, or you could edit the HTML directly, of course.  I found it most useful to have the basic tag on the clipboard, paste it onto each page, and then directly edit/add the name portion.

Important Note: Do not use spaces or capital letters for the topic names. Apple Help seems to have trouble finding such tags, so context help and searching may fail.

The next step is to export the separate HTML files (if necessary).  In H&M, this is accomplished by generating ‘Browser-based Help’ (via ‘File|Compile Help File…’ or the toolbar).  First, however, you will want to click ‘Customize Browser-based Help’ and make a few changes to the default options.  On the ‘Layout’ page, select the page layout that puts everything in the same window (i.e., no frames, no scripts).  Next, on the ‘Popup Topics’ page, select ‘HTML encoded topics’, which should remove any Javascript.  Finally, on the ‘HTML Export Options’ page, change the ‘Extension for HTML topic files” to “.html” (from “.htm”).

Once your help files are together, you need to add two custom meta tags to the header of the main help page (the one you want to display when the help is opened generically).  The “AppleTitle” meta tag sets the title of the help file, and the “AppleIcon” meta tag sets the name of the help icon (described below).  For Pretty Good Solitaire Mac Edition, which has all the help files in a ‘Help’ folder, we add the following lines inside the page header (<HEAD>) of our contents page, just after the title (<TITLE></TITLE>):

<meta name="AppleTitle" content="Pretty Good Solitaire Help" />
<meta name="AppleIcon" content="Help/help.png" />

The help icon (‘help.png’, in the above example) should be a 16×16, 32-bit image (with alpha transparency) that represents the help file, usually a small version of the application icon.  Place this image in the same folder with all of the HTML files.  Note that Apple Help in recent versions of OS X do not display the help icon prominently (if at all), but help icons were important in earlier versions.

Finally, in order to appear similar to other Mac applications, you will want to change the fonts in your CSS (you did use CSS, right?) to prefer ‘Geneva’ over ‘Arial’ for the display font.  H&M generates a ‘default.css’ file, so to make this change, you need only replace each instance of “font-family: ‘Arial’;” in this file with “font-family: ‘Geneva’, ‘Arial’;” and you are done.

As a final hint, if you are using Help & Manual, you can provide a link to the keyword index (automatically generated) by manually adding a link similar to the following (for the ‘pgsme’ project):

<a href="pgsme_kwindex.html">Help Index</a>

At this point, you should have a folder containing all of the HTML files for your help system, with the necessary tags, and a help icon file.  Now, just prepare to transfer these files onto your Mac development system and wait for the second installment, in which I will explain how to generate the Apple Help index and add the help files to an Xcode project.

Where to Start

A few highlights of the original Gamecraft incarnation.

After importing all of the (250) posts from the original incarnation of this Gamecraft blog, during the editing process that was necessitated by the technology change, I had the opportunity to review many of the older posts.  I found lots of fascinating information (compared to just a few irrelevant bits), so I decided to provide a few pointers for those (i.e., most readers) who have not read the entire blog.

The most recent posting to receive attention was Making Mac Disk Images Pretty, which describes how we improved the appearance of Pretty Good Solitaire Mac Edition 2.0 [linked from C-Command Software/DropDMG].

The best series began with Quality: An Introduction (running through Quality: The Index), discussing our guiding principle of Quality as applied to (game) software development, posted in May and June 2006.

The most controversial post was my critical review of Microsoft Visual Studio 2005, which incited a debate and continued to collect comments well after VS2008 was released.

The best quote was from Voltaire: “Le mieux est l’ennemi du bien“; this translates to ‘The best is the enemy of the good.‘ [from MVP Backgammon Professional]

The worst month for posting was definitely August, during which month I only posted once over 5 years [in August 2008], a full score less than the expected (average) number of posts in that time.

This is just a small sampling from the first phase of this blog, but there is plenty more, all still available (twice over).  Now, we move forward and begin the second phase in earnest…

No Magic Numbers

Action Solitaire 1.31 is now available for download.

After the last posting, we discovered a rather significant bug in Action Solitaire. It was fortunate that it was discovered in house, but unfortunate that it was not found during beta testing and, hence, required a public update. The problem caused two of the 65 games to behave incorrectly (or even crash) when large or huge card sizes were selected, either explicitly or implicitly through automatic sizing.

The problem turned out to be magic numbers in the code. We released the first version of Action Solitaire back in 2003, which was six years of coding experience ago and at a time when I felt under some (self-imposed) pressure to get the product finished. Unlike some of the other projects, the source code for this game has not been refactored, except to the extent necessary to make updates for Vista and add new games, so I never revisited these (working) games to see the problem.

For those who do not know, a magic number is an explicit and undocumented constant in the source code for a program, so named because the value works like magic, without any proper explanation. In this particular case, the width and height of an image buffer were set to constant values, calculated (manually) to accommodate an area based on the largest card sizes supported by the game at that time. Rather than actually letting the computer determine the necessary buffer size, based on named constant values (e.g., MaxCardWidth and MaxCardHeight), the code just used constant numbers directly. When the maximum card size increased, the buffer was too small and problems ensued. Such are the dangers of magic numbers.

It did not take long to find and fix the problem, but it should not have been necessary in the first place, especially since we had standards, even back then, that discouraged the use of magic numbers. I made an exception and got burned. Ouch.

Anyway, Action Solitaire can be downloaded here, and I guarantee ample opportunity to find other bugs in this product, but the game is fun (and addictive) as well.