Section 32. About Interactivity

32. About Interactivity

See Also

33 Create a Multimedia Link

34 Create a Navigation Link

35 Create a Menu Action Link

36 Create a Custom Button

37 Edit a Link

Interactivity is all about allowing the reader to do something with a PDF other than just read it. The primary way to allow the reader to interact with a PDF document is to add links to the document. These links can perform various actions when clicked, in much the same way that buttons on a website allow the viewer to interact with the website. In fact, the most common types of Acrobat links perform the same functions that most website buttons dothey take the viewer to another page. Navigation links are easy to create and can be extremely useful to the reader, especially in lengthy PDF documents.

In addition to simple navigation links, Acrobat offers 14 other types of links, including everything from submitting forms to executing menu commands. For the record, here are the various actions you can attach to a link and what each one does:

• Execute a menu item Executes any command from any menu in the Acrobat menu bar. This lets you add a lot of functionality to your links, and it's invaluable for full-screen presentations (especially locked, standalone presentations, such as on a trade-show kiosk), where you don't want the Acrobat interface to be displayed.

  KEY TERMS

  

  Links Clickable blocks of text or images that perform actions.

  Actions In Acrobat these include displaying specific document location, executing menu commands, playing multimedia files, running JavaScript, etc. The term specifically refers to such actions taken in response to user input, such as clicking a button.

  
  

• Go to a page view Changes the page, magnification level, and page locations displayed in the document window. This is by far the most common action for links.

• Import form data Imports data from an Acrobat PDF (form data file) document and populates existing form fields that exactly match fields in the PDF document.

• Open a file This is pretty self-explanatory. It presents the reader with a standard Open dialog box, within which he can locate and open a document.

• Open a web link Opens a prespecified URL in either Acrobat or the viewer's default browser, depending on how the user's preferences are set.

• Play a sound Plays a prespecified sound file. Acrobat supports most of the standard sound file formats, including WAV, AIFF, and MP3.

• Play media (Acrobat 5 compatible) Plays a linked video file.

• Play media (Acrobat 6 compatible) Plays a video file that can be either linked or embedded in the PDF. The main difference between Acrobat 5 and Acrobat 6 compatibility is Acrobat 6 and 7's capability to embed video files.

• Read an article Takes you to the first page of the specified article and changes your cursor to the Article tool to make it easier to navigate to additional text blocks for the same article.

• Reset a form Removes user data from fields in the current form document. A dialog box allows the user to specify which fields are to be reset.

• Run a JavaScript Runs a block of JavaScript code that you either type or paste into a JavaScript Editor dialog box.

• Set layer visibility Lets you display or hide layers that you have defined in the Layers pane.

• Show/hide a field Allows the user to show or hide prespecified form fields. This is a great way to create pop-up help text, display conditional fields, and so forth.

• Submit a form Transmits form data from the current document as PDF, XML, or HTML data to a specified URL.

You can have as many links as you want in a PDF file. The links themselves do not increase the file size significantly. You can also have multiple actions in a single link, so that a single link plays a sound, takes the viewer to a new page, plays a short video clip from that page, and then exits out of Acrobat entirely.

One key to making your PDF interactive is to make the interactivity meaningful to the reader. For interactivity to be meaningful, it must enhance either the user's enjoyment or abilities , or both. Adding a sound effect to navigation links just because you can is both pointless and annoying. If, on the other hand, your document uses a theme of some sort and you can add a sound effect that enhances that theme (and doesn't add drastically to the file size), then by all means add the sound effect.

Another key to interactivity is to make the interactive elements of your PDF accessible to the reader. Just because you add some cool interactive element doesn't mean that the reader will know it's there or what it does. Good design and clear, concise text labels or graphical icons can go a long way toward making the interactivity of a PDF document easily accessible to the reader.