You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
123 lines
4.2 KiB
C++
123 lines
4.2 KiB
C++
#include "keydecoder.h"
|
|
|
|
#include "ps2controller.h"
|
|
|
|
// Constants used for key decoding
|
|
const unsigned char BREAK_BIT = 0x80;
|
|
const unsigned char PREFIX_1 = 0xe0;
|
|
const unsigned char PREFIX_2 = 0xe1;
|
|
|
|
Key KeyDecoder::decode(unsigned char code) {
|
|
Key key = modifier;
|
|
|
|
// All keys that are introduced by the MF II keyboard (compared to the older
|
|
// AT keyboard) always send a prefix value as first byte.
|
|
if (code == PREFIX_1 || code == PREFIX_2) {
|
|
prefix = code;
|
|
} else {
|
|
// Releasing a key is, for us, only important for the modifier keys such as
|
|
// SHIFT, CTRL and ALT, For other, non-modifier keys, we ignore the break
|
|
// code.
|
|
bool pressed = (code & BREAK_BIT) == 0;
|
|
|
|
// A key's break code is identical to its make code with an additionally set
|
|
// BREAK_BIT
|
|
Key::Scancode scancode = static_cast<Key::Scancode>(code & (~BREAK_BIT));
|
|
|
|
// We ignore "new" special keys, such as the Windows key
|
|
if (scancode < Key::Scancode::KEYS) {
|
|
// save state
|
|
status[scancode] = pressed;
|
|
|
|
// Take a closer look at modifier make and break events
|
|
bool isModifier = true;
|
|
switch (scancode) {
|
|
// both shifts are handled equally
|
|
case Key::Scancode::KEY_LEFT_SHIFT:
|
|
case Key::Scancode::KEY_RIGHT_SHIFT:
|
|
modifier.shift = pressed;
|
|
break;
|
|
|
|
case Key::Scancode::KEY_LEFT_ALT:
|
|
if (prefix == PREFIX_1) {
|
|
modifier.alt_right = pressed;
|
|
} else {
|
|
modifier.alt_left = pressed;
|
|
}
|
|
break;
|
|
|
|
case Key::Scancode::KEY_LEFT_CTRL:
|
|
if (prefix == PREFIX_1) {
|
|
modifier.ctrl_right = pressed;
|
|
} else {
|
|
modifier.ctrl_left = pressed;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
isModifier = false;
|
|
}
|
|
|
|
// For keys other than modifiers, we only care about the make code
|
|
if (pressed && !isModifier) {
|
|
switch (scancode) {
|
|
case Key::Scancode::KEY_CAPS_LOCK:
|
|
modifier.caps_lock ^= 1;
|
|
setLed(PS2Controller::LED_CAPS_LOCK, modifier.caps_lock);
|
|
break;
|
|
|
|
case Key::Scancode::KEY_SCROLL_LOCK:
|
|
modifier.scroll_lock ^= 1;
|
|
setLed(PS2Controller::LED_SCROLL_LOCK, modifier.scroll_lock);
|
|
break;
|
|
|
|
case Key::Scancode::KEY_NUM_LOCK: // Can be both NumLock and pause
|
|
// On old keyboards, the pause functionality was only accessible by
|
|
// pressing Ctrl+NumLock. Modern MF-II keyboards therefore send
|
|
// exactly this code combination when the pause key was pressed.
|
|
// Normally, the pause key does not provide an ASCII code, but we
|
|
// check that anyway. In either case, we're now done decoding.
|
|
if (modifier.ctrl_left) { // pause key
|
|
key.scancode = scancode;
|
|
} else { // NumLock
|
|
modifier.num_lock ^= 1;
|
|
setLed(PS2Controller::LED_NUM_LOCK, modifier.num_lock);
|
|
}
|
|
break;
|
|
|
|
// Special case scan code 53: This code is used by both the minus key
|
|
// on the main keyboard and the division key on the number block. When
|
|
// the division key was pressed, we adjust the scancode accordingly.
|
|
case Key::Scancode::KEY_SLASH:
|
|
if (prefix == PREFIX_1) {
|
|
key.scancode = Key::Scancode::KEY_DIV;
|
|
key.shift = true;
|
|
} else {
|
|
key.scancode = scancode;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
key.scancode = scancode;
|
|
|
|
// When NumLock is enabled and a key on the keypad was pressed, we
|
|
// want return the ASCII and scan codes of the corresponding
|
|
// numerical key instead of the arrow keys. The keys on the cursor
|
|
// block (prefix == PREFIX_1), however, should remain usable.
|
|
// Therefore, as a little hack, we deactivate the NumLock for these
|
|
// keys.
|
|
if (modifier.num_lock && prefix == PREFIX_1) {
|
|
key.num_lock = false;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// The prefix is only valid for the immediately following code, which was
|
|
// just handled.
|
|
prefix = 0;
|
|
}
|
|
|
|
return key;
|
|
}
|