14.9 Processing Events
The routine in Example 14-12
processes events. The top portion of takeEvents
converts key events to the corresponding button event, and then the
bottom sets the colors and flags and draws the button in the new color.
Key codes are mapped to ASCII with XLookupString()
,
and keyToWin
is called to get the offset into
windata
that is represented by this key. When key
events occur, the appropriate pad is flashed.
Example 14-12. basecalc — the takeEvents routine
takeEvents () { XEvent Event; register int win; register int Pressed = False; register int inWindow = False; char buffer[10]; register char *keyChars = buffer; register int keyDown = False; int i, nbytes; while (1) { /* Get event if key not down */ if (!keyDown) XNextEvent (display, &Event); else Event.type = KeyRelease; /* Map keyboard events to window events */ if (Event.type == KeyPress || Event.type == KeyRelease) { nbytes = XLookupString (&Event, buffer, sizeof(buffer), NULL, NULL); if (Event.type == KeyPress) { Event.type = ButtonPress; keyDown = True; } else { for (i=0; i<60000; i++) ; /* Wait */ Event.type = ButtonRelease; } if ((Event.xbutton.window = keyToWin (keyChars, nbytes)) == None){ keyDown = False; continue; } } for (win=0; win < NBUTTONS; win++) if (Buttons[win].ID == Event.xbutton.window) break; switch (Event.type) { case ButtonPress: if (windata[win].color == disabledColor) break; Pressed = win; if (!keyDown) inWindow = True; windata[win].color = pressedColor; drawButton (win, 0); break; ...
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