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kbhit |
Function (ROM Call 0x52) |
Checks for unread keystrokes.
kbhit checks to see if a keystroke is currently available. Any available keystrokes can be
retrieved with ngetchx. If a keystroke is available, kbhit returns a
nonzero integer (in fact, it returns the exactly same value as
ngetchx); if not, it returns 0. Note that kbhit does not pick a
keystroke from the keyboard queue. So, kbhit will continue to return non-zero value until
"keypress" flag is reset by calling ngetchx,
GKeyFlush or GKeyIn.
Note: kbhit function is slow, because it also handles receiving eventual bytes from the
link port (used mainly internally in TIOS when the calculator is in the Home screen). See kbd_queue
for much faster way to check the keyboard state.
Uses: HomeAlone, OSCheckSilentLink, OSLinkCmd, OSqinquire, OSSetSR
Used by: GKeyDown, GKeyFlush, pushkey, cmd_disptbl, cmd_pause, push_getkey, EV_eventLoop, EV_getc, GS_PlotAll, GZ_Stat, Regraph
See also: ngetchx, GKeyIn, kbd_queue, OSFastArrows