Orca--Take the Killer Whale for a Ride

Let's take Orca for a test ride and try a dialog containing components you might encounter in a traditional window: gedit's Open Files dialog. First, run the gedit application, which typically is found as the Text Editor menu item under the Accessories menu. Then, press Ctrl-O to open the Open Files dialog.

Figure 5. gedit's Open Files Dialog

When the Open Files dialog first appears, focus is on the text area labeled Location:. Orca automatically should present this information to you. With speech, you will hear “Location: text”, which is Orca telling you the name, contents and role of the text area. As you type in this area, speech and Braille automatically should update.

Note to application developers: one of the main trouble areas for accessibility is forgetting to bind labels to the things they are labeling. The reason Orca knew to present the Location: label for the text area is that the gedit developers took care to set the L of Location as a mnemonic to get to the text area via Alt-L. Using mnemonics is not just useful for keyboard-only users, it also lets the accessibility infrastructure know there is a binding between the label and the text area. In the event a mnemonic is not something you can use, you can set the Label For and Labeled By properties on associated components using the accessibility properties tab in Glade.

As you arrow down through the file list, Orca presents each line to you. To get out of the file list, press Tab to navigate to the other objects on the page. As you do so, Orca presents information about where you are. Notice how the Character Coding label is presented when you tab to that combo box. Mnemonics and quality keyboard traversal are good friends to a screen reader.

Now, let's try accessing the relatively rich Web page at linuxjournal.com. This will not only provide you with an example of accessing rich content with Orca, but it also will give you an idea of the power of scripting with Orca. The Orca team has worked closely with the Mozilla team to provide much better accessibility for Firefox 3. Orca's script for Firefox 3 also provides a number of custom mechanisms for accessing Web content. In this example, we'll demonstrate how a typical user might browse Web content.

Note: you must use the latest Firefox 3 nightly builds. See the “Firefox” page of the Orca Wiki for more information on obtaining the latest Firefox 3 nightly builds.

When you run Firefox 3, go to linuxjournal.com by pressing Ctrl-L and then typing the URL. Once Firefox loads the page, Orca should start reading it automatically. You can stop the automatic reading at any time by pressing any key on the keyboard.

At this point, you can tab around to focusable items on the page, such as links. There is much more important information on the page than links, however, and Orca's script for Firefox provides convenience mechanisms to get to the information.

Pressing the arrow keys gives you traditional caret navigation, but the Orca script for Firefox also provides more sophisticated structural navigation. Press O and Shift-O to jump to the next and previous “large objects” on the page. On linuxjournal.com, these happen to be the article summaries. You also can press H and Shift-H to move by header and L and Shift-L to move by list. The “Firefox” page of the Orca Wiki has more complete documentation on accessing Web content via Firefox and Orca.

This introduction should give you enough information to begin experimenting with the Orca screen reader, both as an end user or as a developer wishing to make your application more accessible. The Orca help facility, available via the Help button on the Orca main window, and the Orca Wiki provide much more information than can be covered here.

We also encourage users and application developers to join the Orca users' list. It is a list with a culture geared toward constructive and helpful comments. Much of the Orca user community hangs out and participates on this list.