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build6/epsilon-master/ion/src/device/events.cpp 2.77 KB
6663b6c9   adorian   projet complet av...
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  #include <ion.h>
  #include <assert.h>
  
  namespace Ion {
  namespace Events {
  
  static bool sleepWithTimeout(int duration, int * timeout) {
    if (*timeout >= duration) {
      msleep(duration);
      *timeout -= duration;
      return false;
    } else {
      msleep(*timeout);
      *timeout = 0;
      return true;
    }
  }
  
  Event sLastEvent = Events::None;
  Keyboard::State sLastKeyboardState;
  bool sLastUSBPlugged = false;
  bool sLastUSBEnumerated = false;
  bool sEventIsRepeating = 0;
  constexpr int delayBeforeRepeat = 200;
  constexpr int delayBetweenRepeat = 50;
  
  bool canRepeatEvent(Event e) {
    return (e == Events::Left || e == Events::Up || e == Events::Down || e == Events::Right || e == Events::Backspace);
  }
  
  Event getEvent(int * timeout) {
    assert(*timeout > delayBeforeRepeat);
    assert(*timeout > delayBetweenRepeat);
    int time = 0;
    uint64_t keysSeenUp = 0;
    uint64_t keysSeenTransitionningFromUpToDown = 0;
    while (true) {
      // First, check if the USB plugged status has changed
      bool usbPlugged = USB::isPlugged();
      if (usbPlugged != sLastUSBPlugged) {
        sLastUSBPlugged = usbPlugged;
        return Events::USBPlug;
      }
  
      // Second, check if the USB device has been connected to an USB host
      bool usbEnumerated = USB::isEnumerated();
      if (usbEnumerated != sLastUSBEnumerated) {
        sLastUSBEnumerated = usbEnumerated;
        if (usbEnumerated) {
          return Events::USBEnumeration;
        }
      }
  
      Keyboard::State state = Keyboard::scan();
      keysSeenUp |= ~state;
      keysSeenTransitionningFromUpToDown = keysSeenUp & state;
  
      if (keysSeenTransitionningFromUpToDown != 0) {
        sEventIsRepeating = false;
        /* The key that triggered the event corresponds to the first non-zero bit
         * in "match". This is a rather simple logic operation for the which many
         * processors have an instruction (ARM thumb uses CLZ).
         * Unfortunately there's no way to express this in standard C, so we have
         * to resort to using a builtin function. */
        Keyboard::Key key = (Keyboard::Key)(63-__builtin_clzll(keysSeenTransitionningFromUpToDown));
        Event event(key, isShiftActive(), isAlphaActive());
        updateModifiersFromEvent(event);
        sLastEvent = event;
        sLastKeyboardState = state;
        return event;
      }
  
      if (sleepWithTimeout(10, timeout)) {
        // Timeout occured
        return Events::None;
      }
      time += 10;
  
      // At this point, we know that keysSeenTransitionningFromUpToDown has *always* been zero
      // In other words, no new key has been pressed
      if (canRepeatEvent(sLastEvent) && (state == sLastKeyboardState)) {
        int delay = (sEventIsRepeating ? delayBetweenRepeat : delayBeforeRepeat);
        if (time >= delay) {
          sEventIsRepeating = true;
          sLastKeyboardState = state;
          return sLastEvent;
        }
      }
    }
  }
  
  }
  }