Left-Handedness and Right-Handedness

Overview of left-handedness and right-handedness.

Tablet PC has system settings that specify whether the user is left handed or right handed. Your application should take advantage of these settings so that a user's hand does not obscure user interface (UI) elements and objects that display important information or functions.

Microsoft® Windows® XP Tablet PC Edition includes an application programming interface (API) that can be used to check the users handedness:

[C++]SystemParametersInfo (SPI_GETMENUDROPALIGNMENT, 0, &gfRightHanded, 0)

If the returned value in the gfRightHanded parameter is true, it implies that the user has specified right-handedness. Otherwise, left-handedness is implied.

For more information on using the SystemParametersInfo API, see the MSDN® reference topic on SystemParametersInfo and the How to Use SystemParametersInfo API for Control Panel Settings Knowledge Base article.

For example, custom menus or ToolTips for your application can appear on the side of the control opposite the users primary hand. Left-handed users continue to see current behavior, in which ToolTips and menus appear to the right of the mouse cursor or the active menu title.

The following figure shows a ToolTip for a left-handed Tablet PC user.

The following figure shows a menu for a left-handed Tablet PC user.

Right-handed users see these on-screen objects in a more convenient place that is not beneath their pen hand. However, controls that are left-justified, such as menus, do not benefit from this. A left-justified control does not appear further to the left than the edge of the window.