Pen Gestures

When using the pen for writing, certain ink patterns are interpreted as gestures. Using one of these specially drawn symbols invokes a particular operation, such as deleting text, or produces a nonprinting text character, such as a carriage return or a tab. For example, a circled X gesture is equivalent to the Cut command. After the system interprets a gesture, the gesture's ink is removed from the display.

Note
For more information about common gestures and their interpretation, see Chapter 5, "General Interaction Techniques."

All gestures include a circular stroke to distinguish them from ordinary characters. Most gestures also operate positionally; in other words, they act upon the objects on which they are drawn. Determining the position of the specific gesture depends on either the area surrounded by the gesture or a single point — the hot spot of the gesture.

Pen gestures usually cannot be combined with ink (writing or drawing actions) within the same recognition sequence. For example, the user cannot draw a few characters, immediately followed by a gesture, followed by more characters.

The rapidity of gestural commands is one of the key advantages of the pen. Do not rely on gestures as the only or primary way to perform commands, however, because gestures require memorization by users. Regard gestures as a quick access, shortcut method for operations adequately supported elsewhere in the interface, such as in menus or buttons. If the pen extensions are installed, you can optionally place a bitmap of the gesture next to the corresponding command (in place of the keyboard shortcut text) to help the user learn particular gestures.

In addition, avoid using gestures when they interfere with common functionality or make operations with parallel input devices, such as the mouse or keyboard, more cumbersome. For example, although writing a character gesture in a list box could be used as a way to scroll automatically within the list, it would interfere with the basic and more frequent user action of selecting an item in the list. A better technique is to provide a text input field where the user can write and, based on the letters entered, scroll the list.