To understand different modes of screen readers, Let us first understand how screen readers work with browsers.
Screen reader interaction on browser
Once the page loads on the browser, screen reader analyzes the content and presents the same in a linear passion called virtual buffer. The screen reader in fact interact with this virtual buffer and share content to the user.
When the screen reader interacts with this virtual buffer the general windows key strokes on browser have different impact. For example left and right arrow navigates to previous character and next character while up and down arrow navigates to previous and next lines. This cursor movement will even not visible and hence it is called virtual cursor.
Browse or virtual Mode:
Interacting with this virtual buffer is also called as browse mode or virtual mode in screen readers. The entire interaction of the keyboard is taken over by screen reader in this mode. Screen reader implement general navigation and quick navigation commands in this mode.
User can navigate to next interactive element with tab and previous interactive element with shift + tab. The directional arrows will navigate user character by character, word by word, sentence by sentence even to non-interactive elements. Quick navigation keys “h†navigate user to next heading and “shift + h†to previous heading, similarly f for form elements, g for images etc. Here are full list of screen reader commands for different screen readers.
Forms or Focus Mode
While the quick navigation keys work with virtual mode, when the user have to type some text in a editable text field or to select an option in a dropdown the keys has to be directly passed on to the browser instead of virtual mode. The keys interacting directly to the browser can be referred as forms or focus mode.
When the user navigates with the tab key most of the screen readers directly pass the keys to the browser and acts as forms or focus mode. When the arrow keys are used some screen readers can detect the forms or focus mode automatically and allows the user to act accordingly. For some screen readers users should explicitly change the mode manually.
In NVDA and JAWS in case user has to switch the mode press Insert + space. Insert key is mapped as JAWS key for JAWS screen reader and NVDA key for NVDA screen reader.
Application Mode
As discussed in the previous sections, either the elements on the page or it’s interaction method are responsible for changing the screen reader modes. With the introduction of rich internet applications, users are expected to change the modes to accurately interact with certain widgets. For example to move between the tabs in a tab list left and right arrows are used, but in a virtual mode these keys navigate to previous and next characters. To accomplish this content authors should forcefully change the screen reader mode to a more comfortable mode. This mode is more or less similar to focus mode, sometimes this mode is also referred as application mode.
Content authors may be using ARIA roles such as role=â€application†or other similar techniques to force screen reader to switch to application mode. Understanding these screen reader modes will help you in learning the next module.