Scancodes Windows Linux

Evgeny Siberia · wrote on 27 May 2021, 15:15

Hi. I need to receive the current button clicked. Conditions: Linux\Win + any keyboard layout.
My code doesn't correct in Win:

enum class Keys {

    F1      = 67,
    F2      = 68,
    F3      = 69,
    F4      = 70,
    F5      = 71,
    F6      = 72,
    F7      = 73,
    F8      = 74,
    F9      = 75,
    F10     = 76,
    F11     = 95,
    F12     = 96,
    CAPS    = 66,
    LSHIFT  = 50,
    RSHIFT  = 62,
    LCTRL   = 37,
    RCTRL   = 105,
    LALT    = 64,
    RALT    = 108,
    ENTER   = 36,
    BACKSPACE = 22,
    Q   = 24,
    W   = 25,
    E   = 26,
    R   = 27,
    T   = 28,
    Y   = 29,
    U   = 30,
    I   = 31,
    O   = 32,
    P   = 33,
    A   = 38,
    S   = 39,
    D   = 40,
    F   = 41,
    G   = 42,
    H   = 43,
    J   = 44,
    K   = 45,
    L   = 46,
    Z   = 52,
    X   = 53,
    C   = 54,
    V   = 55,
    B   = 56,
    N   = 57,
    M   = 58,
    LSqBracket      = 34,
    RSqBracket      = 35,
    VerticalLine    = 51,
    COLON           = 47,
    QuotationMark   = 48,
    LAngleBracket   = 59,
    RAngleBracket   = 60,
    Question        = 61,
    SlantLine       = 106,
    Asterick        = 63,
    Minus           = 82,
    Plus            = 86,
    NLEnter         = 104,
    NLDel           = 91,
    Zero        = 19,
    One         = 10,
    Two         = 11,
    Three       = 12,
    Four        = 13,
    Five        = 14,
    Six         = 15,
    Seven       = 16,
    Eight       = 17,
    Nine        = 18,
    NLZero      = 90,
    NLOne       = 87,
    NLTwo       = 88,
    NLThree     = 89,
    NLFour      = 83,
    NLFive      = 84,
    NLSix       = 85,
    NLSeven     = 79,
    NLEight     = 80,
    NLNine      = 81
};

Values in Windows and Linux are different. This code only for Linux. If use QKeyEvent::key() for a different keyboard layout (for example - Russian layout) , then any key() below will be ignored (except Key_Escape):

void Form::keyPressEvent(QKeyEvent *e)
{
    if(e->key() == Qt::Key_C){
        buttonClicked("C");
        return;
    }
}

How do solve this?

Christian Ehrlicher · 27 May 2021, 16:56

@Evgeny-Siberia said in Scancodes Windows Linux:

How do solve this?

By taking a look into the documentation you will find enough functions which gives you a scan code instead the key.

Evgeny Siberia · wrote on 27 May 2021, 16:56

@Christian-Ehrlicher I know it. But values in enum class Keys are QKeyEvent::nativeScanCode() const. It didn't work in Windows.

Christian Ehrlicher · 27 May 2021, 18:18

@Evgeny-Siberia said in Scancodes Windows Linux:

But values in enum class Keys are QKeyEvent::nativeScanCode()

What does this mean? nativeScanCode() returns an uint32, not an enum...

Evgeny Siberia · wrote on 27 May 2021, 18:18

@Christian-Ehrlicher

void Form::keyPressEvent(QKeyEvent *e) {
    qDebug() << QString("Key=%1 Scan=%2").arg(e->text()).arg(e->nativeScanCode());
}

and we'll receive these nums, which I wrote in enum.

Evgeny Siberia · 27 May 2021, 18:46

I rewrote it for Win and Linux, but I'm sure there is a simpler solution.

#ifndef NATIVESCANCODES_H
#define NATIVESCANCODES_H

enum class Keys {
#if defined(Q_OS_LINUX)
    F1      = 67,
    F2      = 68,
    F3      = 69,
    F4      = 70,
    F5      = 71,
    F6      = 72,
    F7      = 73,
    F8      = 74,
    F9      = 75,
    F10     = 76,
    F11     = 95,
    F12     = 96,
    CAPS    = 66,
    LSHIFT  = 50,
    RSHIFT  = 62,
    LCTRL   = 37,
    RCTRL   = 105,
    LALT    = 64,
    RALT    = 108,
    ENTER   = 36,
    BACKSPACE = 22,
    Q   = 24,
    W   = 25,
    E   = 26,
    R   = 27,
    T   = 28,
    Y   = 29,
    U   = 30,
    I   = 31,
    O   = 32,
    P   = 33,
    A   = 38,
    S   = 39,
    D   = 40,
    F   = 41,
    G   = 42,
    H   = 43,
    J   = 44,
    K   = 45,
    L   = 46,
    Z   = 52,
    X   = 53,
    C   = 54,
    V   = 55,
    B   = 56,
    N   = 57,
    M   = 58,
    LSqBracket      = 34,
    RSqBracket      = 35,
    VerticalLine    = 51,
    COLON           = 47,
    QuotationMark   = 48,
    LAngleBracket   = 59,
    RAngleBracket   = 60,
    Question        = 61,
    SlantLine       = 106,
    Asterick        = 63,
    Minus           = 82,
    Plus            = 86,
    NLEnter         = 104,
    NLDel           = 91,
    Zero        = 19,
    One         = 10,
    Two         = 11,
    Three       = 12,
    Four        = 13,
    Five        = 14,
    Six         = 15,
    Seven       = 16,
    Eight       = 17,
    Nine        = 18,
    NLZero      = 90,
    NLOne       = 87,
    NLTwo       = 88,
    NLThree     = 89,
    NLFour      = 83,
    NLFive      = 84,
    NLSix       = 85,
    NLSeven     = 79,
    NLEight     = 80,
    NLNine      = 81
#elif defined(Q_OS_WIN)
    F1      = 59,
    F2      = 60,
    F3      = 61,
    F4      = 62,
    F5      = 63,
    F6      = 64,
    F7      = 65,
    F8      = 66,
    F9      = 67,
    F10     = 68,
    F11     = 87,
    F12     = 88,
    CAPS    = 58,
    LSHIFT  = 42,
    RSHIFT  = 54,
    LCTRL   = 29,
    RCTRL   = 285,
    LALT    = 56,
    RALT    = 312,
    ENTER   = 28,
    BACKSPACE = 14,
    Q   = 16,
    W   = 17,
    E   = 18,
    R   = 19,
    T   = 20,
    Y   = 21,
    U   = 22,
    I   = 23,
    O   = 24,
    P   = 25,
    A   = 30,
    S   = 31,
    D   = 32,
    F   = 33,
    G   = 34,
    H   = 35,
    J   = 36,
    K   = 37,
    L   = 38,
    Z   = 44,
    X   = 45,
    C   = 46,
    V   = 47,
    B   = 48,
    N   = 49,
    M   = 50,
    LSqBracket      = 26,
    RSqBracket      = 27,
    VerticalLine    = 43,
    COLON           = 39,
    QuotationMark   = 40,
    LAngleBracket   = 51,
    RAngleBracket   = 52,
    Question        = 53,
    SlantLine       = 309,
    Asterick        = 55,
    Minus           = 74,
    Plus            = 78,
    NLEnter         = 284,
    NLDel           = 83,
    Zero        = 11,
    One         = 2,
    Two         = 3,
    Three       = 4,
    Four        = 5,
    Five        = 6,
    Six         = 7,
    Seven       = 8,
    Eight       = 9,
    Nine        = 10,
    NLZero      = 82,
    NLOne       = 79,
    NLTwo       = 80,
    NLThree     = 81,
    NLFour      = 75,
    NLFive      = 76,
    NLSix       = 77,
    NLSeven     = 71,
    NLEight     = 72,
    NLNine      = 73
#endif

};

#endif // NATIVESCANCODES_H

artwaw · 27 May 2021, 19:01

@Evgeny-Siberia why enum?

const QMap<uint32,QString> keyNames = {
{scancode1:"1"},
{scancode2:"2"},
...
}

Evgeny Siberia · 27 May 2021, 19:03

@artwaw
"why enum?" - I thought about this earlier but decided that enum is easy to read. I will use it in a project.

switch (e->nativeScanCode()) {
    case static_cast<quint32>(Keys::F1):
...

Here we can see that it was F1 that was pressed. For more convenient use.

artwaw · 27 May 2021, 19:07

@Evgeny-Siberia I fail to see the improvement of rewriting Qt::Keys - especially that those are already platform independent. You are, of course, most welcome to do as you wish.

EDIT:
I mean, there already is Qt::key_F1, replacing it with key::whatever... But it's your code.

Evgeny Siberia · A artwaw 27 May 2021, 19:03

@artwaw thx, I will change it may be.