home | |||
links |
|
||
developer's mag main page article part 1 part 2 part 3 part 4 part 5 part 6 part 7 part 8 |
2 - About Keys and Event LoopsUltimately, all ebm GUI programs rely heavily on the message loop. In the familiar MsgHandler() function, the MSG_TYPE value 'MSG_KEY' is the message relating to keystrokes, with the actual key code stored in the data value (the S32 parameter).The key message loop doesn't just handle ordinary keystrokes entered via the bottom text entry pad. Several other objects on the ebm masquerade as keys, allowing you to use the same message loop to monitor these extra user interfaces. To avoid confusing them with character codes, the special values are larger than 255. The silk-screened display at the bottom and the jog wheel each have specific key codes associated with them, and are defined in /franklin/SDK/sneak32/include/gui_types.h. Firstly, the jog wheel can be detected with the following:
The silk-screened cursor pad at the bottom right has the following keys associated with it:
Additional pad key codes are:
There are also key codes associated with data entry, which need no description:
To round out the list of defines, there are several that you should never encounter with the ebm's hardware, but which you might see mentioned from time to time:
Previous Section Next Section |
||
Copyright © 2001-2006 ebmDevMag.com - Legal Notice |