4 Data Variables and Data handling
Eloquence keyboard handling
Two statement groups allow better control of the Eloquence keyboard processing.
NOTE: These keywords are not available when working with graphical user interface.
Eloquence normally rejects any key pressed while it is busy with a beep signal. The TYPEAHEAD statement enables the program to control Eloquence keyboard handling
The typeahead statement adjusts the keyboard mode. Changing the keyboard mode implies a TYPEHEAD CLEAR operation.
In TYPEAHEAD mode 1, the program must be aware, that there may be some saved keystrokes, if reacting upon a function key.
- n = 0
- Default behavior. Any key pressed while Eloquence is not in input state will be rejected.
- n = 1
- Partial typeahead. Any key, which is not a function key is saved in a typeahead buffer for later processing.
- Function keys are executed immediately.
- n = 2
- Full typeahead. All keys are saved in the typeahead buffer for later processing.
In TYPEAHEAD mode 2, it's not possible to interrupt a program (for example abort a very long printout) using a function key. Function keys loose their meaning, while not in INPUT mode.
Clear the typeahead buffer. If a character is currently in typeahead buffer, a
beep is output to indicate the loss of input.
The typeahead function returns the number of characters currently in typeahead buffer.
Eloquence Language Manual - 19 DEC 2002