Provide Ample Target Space

The pen often proves an inaccurate pointing device. The well-behaved pen application allows ample margin for pointing errors from the user, who can easily miss a small button or other target. Consider the following suggestions to make your pen-based application friendly to the user with poor aim:

  • Create targets as large as practical.

  • Space toolbar buttons so that they have gaps between them.

  • Avoid crowding dialog boxes with controls placed near one another.

  • Pen-down events falling within a few pixels of a button should be treated as a press of that button. Always increase the effective size of a control by sending the HE_SETINFLATE submessage, as described in the "HE_SETINFLATE Submessage" section in Chapter 3, "The Writing Process."

  • Compensate for the pixel sizes of different displays. Use GetDeviceCaps to determine sizes and maintain uniform dimensions for on-screen targets.

Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
Unix Manual Pages
Delphi Examples
Databases for Amazon shops developers
Amazon Categories Database
Browse Nodes Database