macdevcenter.com
oreilly.comSafari Books Online.Conferences.

advertisement

AddThis Social Bookmark Button

Building Interactive iPod Experiences

by Erica Sadun
11/28/2006

The interactive multimedia presentation is one of the least-trumpeted features of the iPod. Nearly everyone knows about podcasting, which is a way of providing linear audio and video presentations. You download a podcast, listen to or watch it, and you're done. Beginning, middle, end. In contrast, relatively few people know about, or even use, an iPod's nonlinear abilities. These features allow listeners to interact with text and audio and visual materials, making decisions on where they want to go next and what material interests them.

This interaction is often called "museum mode," as if to suggest the listener were wandering through a museum and wanted to pick and choose which paintings or exhibits to learn about. You're certainly not limited to visiting museums, though. Interactive presentations can be used for any kind of learning and exploration, whether you're providing content for hands-on labs, building an interactive "brochure" for high-end real estate, creating a multimedia reference guide, and so forth.

If you can get past the fact that iPods are some of the most frequently stolen consumer devices on Earth, and you might consider developing and providing material on this platform, interactive presentations add a great new spin to an already amazing device. This article will introduce you to the basics of interactive iPod design and show where you can learn more about iPod multimedia development.

iPod Notes

You may have encountered iPod Notes before. (They're located in Extras -> Notes, off your main iPod menu.) Maybe you've used them to keep a few text items on-hand on your iPod. You may have used a utility like Text2iPod X to convert a text file from the Gutenberg project so it can be viewed on the iPod. Or perhaps you've seen this feature and dismissed it as not particularly interesting or useful. As you certainly have guessed by now, it's this very iPod Notes feature that allows you to build interactive presentations.

Notes provide interaction through the use of a very simple, very limited markup language. Markup languages, like HTML or XML, add angle-bracketed tags to text files to indicate style and layout directions for those files and establish connections between files. Apple's iPod note markups offer a very limited, very specific subset of these tags. You won't have the flexibility and precision you'd expect while authoring web pages, but you do get enough directives that you can tell the iPod to create interactive links to audio, video, images, and text.

In fact, the development process feels very much like creating a website. To build your presentation, you gather all of your multimedia assets, load them onto the iPod, and design the text files that tell the iPod how they are joined together. The iPod interprets these text-based "notes" and presents them to the user.

Preparing the iPod for Disk Use

If you want to develop content for iPod Notes, you must enable disk access. This provides direct access to the iPod hard drive so you can develop and save your source material. In iTunes, select your iPod in the DEVICES list and select the Summary tab in the main iTunes window. Locate the "Enable disk use" checkbox in the Options pane and select it (Figure 1).

Figure 1
Figure 1. You must enable disk use to create notes on your iPod.

iTunes may warn you at this point that "Enabling the iPod for disk use requires manually ejecting the iPod before each disconnect, even when automatically updating music." If this dialog appears, click OK.

Click Apply. After a second or two, an iPod icon appears on your desktop. Double-click this icon to open a file browser window. Once you've set the disk use option in iTunes, the iPod will mount on your desktop whenever you dock it.

Creating Simple Content

The first, and easiest, content you can add to your iPod Notes is--surprisingly enough--pictures. In your iPod's browser window in the Finder, check to see if a Notes folder exists. If not, create one. Drag several JPEG images to the Notes folder and remove any other files. Then dismount your iPod so you can interact with it directly.

Tip: JPEG is the only supported image format.

Figure 2
Figure 2. Adding JPEG images to your Notes folder allows you to select each image and view it.

On the iPod side of things, navigate to Extras -> Notes. There you'll discover a list of the JPEG images you added to the Notes folder (Figure 3). Select any file name to display it. After, click MENU to return to the list. When you are done exploring the images, redock your iPod and allow it to mount on your desktop.

Figure 3a Figure 3b
Figure 3. It's easy to create a list of JPEG files that displays in the iPod Notes interface.

Next on the list of easy-to-create content is the simple text file. Fire up TextEdit and create a new file with the contents "Hello World." Save it as helloworld.txt in your Notes folder on the iPod hard drive. Dismount the iPod and return to Extras -> Notes.

The new helloworld.txt file joins the JPEG images already in your Notes folder. Select it to display its contents (Figure 4). Notice how the title bar displays the name of the text file, as it displayed the names of the JPEG files when you displayed them (Figure 3).

Figure 4a Figure 4b
Figure 4. Add any text file to the Notes folder for easy display.

Notes can display up to 4,096 characters each, which is roughly four pages of printed text. As Figure 5 shows, after you add more than one page of text, a scroll bar automatically appears, allowing you to use the scroll wheel to navigate up and down the page. In addition, most simple spacing is preserved. The line breaks seen in Figure 5 were added by pressing the return key twice after paragraphs in TextEdit. This makes it extremely easy to paste text into new text files and display them on the iPod using notes.

Figure 5
Figure 5. The iPod automatically handles scrolling by adding a scroll bar to each text page that exceeds the size of a single window.

Finally, as far as simple things are concerned, you can add folders to iPod Notes. Folders allow you to organize your notes and pictures in a basic hierarchy, which you can navigate as you would any other menu on the Mac or iPod. For example, putting all the pictures from the first example into a subfolder creates a new folder item on the Notes menu, as shown in Figure 6. Notice the ">" sign to the right of My Pictures that indicates this is a folder.

Figure 6a Figure 6b
Figure 6. The Notes interface allows you to group items by folder.

Tip: You are allowed to add up to 1,000 notes per iPod. When you add more, only the first 1,000 are loaded.

Pages: 1, 2

Next Pagearrow