Filling out an Input Struct

[cuppajoeman]

So I'm trying to convert a gui editor to a terminal one. The editor logic is like a black box that consumes the keyboards input state (InputKeyState) and returns the new state of the editor; that is we have to fill out this struct and send it to the black box:

enum class InputKey {
    a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z,

    SPACE,
    GRAVE_ACCENT,
    TILDE,

    ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, ZERO,
    MINUS, EQUAL,

    EXCLAMATION_POINT, AT_SIGN, NUMBER_SIGN, DOLLAR_SIGN, PERCENT_SIGN,
    CARET, AMPERSAND, ASTERISK, LEFT_PARENTHESIS, RIGHT_PARENTHESIS,
    UNDERSCORE, PLUS,

    LEFT_SQUARE_BRACKET, RIGHT_SQUARE_BRACKET,
    LEFT_CURLY_BRACKET, RIGHT_CURLY_BRACKET,

    COMMA, PERIOD, LESS_THAN, GREATER_THAN,

    CAPS_LOCK, ESCAPE, ENTER, TAB, BACKSPACE, INSERT, DELETE,

    RIGHT, LEFT, UP, DOWN,

    SLASH, QUESTION_MARK, BACKSLASH, PIPE,
    COLON, SEMICOLON, SINGLE_QUOTE, DOUBLE_QUOTE,

    LEFT_SHIFT, RIGHT_SHIFT,
    LEFT_CONTROL, RIGHT_CONTROL,
    LEFT_ALT, RIGHT_ALT,
    LEFT_SUPER, RIGHT_SUPER,

    FUNCTION_KEY, MENU_KEY,

    LEFT_MOUSE_BUTTON, RIGHT_MOUSE_BUTTON, MIDDLE_MOUSE_BUTTON,
    SCROLL_UP, SCROLL_DOWN,

    DUMMY
};

struct InputKeyState {
    std::unordered_map<InputKey, bool> input_key_to_is_pressed;
    std::unordered_map<InputKey, bool> input_key_to_is_pressed_prev;
    std::unordered_map<InputKey, bool> input_key_to_just_pressed;
};

---

Now I'm in the context of fxtui and so I need to get the required information to fill out the struct, the way I'm trying to do this is by making the following:

  component |= CatchEvent([&](Event event) {
...
}

which occurs when an event occurs, I looked at the definition of event here:

struct Event {

...

  // --- Arrow ---
  static const Event ArrowLeft;
  static const Event ArrowRight;
  static const Event ArrowUp;
  static const Event ArrowDown;

  static const Event ArrowLeftCtrl;
  static const Event ArrowRightCtrl;
  static const Event ArrowUpCtrl;
  static const Event ArrowDownCtrl;

  // --- Other ---
  static const Event Backspace;
  static const Event Delete;
  static const Event Return;
  static const Event Escape;
  static const Event Tab;
  static const Event TabReverse;

  // --- Navigation keys ---
  static const Event Insert;
  static const Event Home;
  static const Event End;
  static const Event PageUp;
  static const Event PageDown;

  // --- Function keys ---
  static const Event F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12;

  // --- Control keys ---
  static const Event a, A, CtrlA, AltA, CtrlAltA;
  static const Event b, B, CtrlB, AltB, CtrlAltB;
  static const Event c, C, CtrlC, AltC, CtrlAltC;
  static const Event d, D, CtrlD, AltD, CtrlAltD;
  static const Event e, E, CtrlE, AltE, CtrlAltE;
  static const Event f, F, CtrlF, AltF, CtrlAltF;
  static const Event g, G, CtrlG, AltG, CtrlAltG;
  static const Event h, H, CtrlH, AltH, CtrlAltH;
  static const Event i, I, CtrlI, AltI, CtrlAltI;
  static const Event j, J, CtrlJ, AltJ, CtrlAltJ;
  static const Event k, K, CtrlK, AltK, CtrlAltK;
  static const Event l, L, CtrlL, AltL, CtrlAltL;
  static const Event m, M, CtrlM, AltM, CtrlAltM;
  static const Event n, N, CtrlN, AltN, CtrlAltN;
  static const Event o, O, CtrlO, AltO, CtrlAltO;
  static const Event p, P, CtrlP, AltP, CtrlAltP;
  static const Event q, Q, CtrlQ, AltQ, CtrlAltQ;
  static const Event r, R, CtrlR, AltR, CtrlAltR;
  static const Event s, S, CtrlS, AltS, CtrlAltS;
  static const Event t, T, CtrlT, AltT, CtrlAltT;
  static const Event u, U, CtrlU, AltU, CtrlAltU;
  static const Event v, V, CtrlV, AltV, CtrlAltV;
  static const Event w, W, CtrlW, AltW, CtrlAltW;
  static const Event x, X, CtrlX, AltX, CtrlAltX;
  static const Event y, Y, CtrlY, AltY, CtrlAltY;
  static const Event z, Z, CtrlZ, AltZ, CtrlAltZ;

  ...
  
};

Which looks okay, but I don't really see how I can isolate the pressing of the key LEFT_SHIFT, RIGHT_SHIFT, LEFT_CONTROL, RIGHT_CONTROL, MENU_KEY, LEFT_SUPER_KEY, RIGHT_SUPER_KEY, etc...

It seems like alot of those modifiers are baked into a specific key like this static const Event z, Z, CtrlZ, AltZ, CtrlAltZ;, so how can I explicitly check for those events?

[cuppajoeman]

@ArthurSonzogni any ideas for this? Still haven't been able to figure it out

[ArthurSonzogni]

Sorry, the terminal API doesn't doesn't expose a single "shift" key. It always comes combined with another key.

I guess you will have to decombine manually to recover what you need.

[cuppajoeman]

Sorry, the terminal API doesn't doesn't expose a single "shift" key. It always comes combined with another key.

I guess you will have to decombine manually to recover what you need.

Ok, that's good to know, for the combined keys I can do this:

{Event::a, {InputKey::a}},
{Event::A, {InputKey::LEFT_SHIFT, InputKey::a}},
{Event::CtrlA, {InputKey::LEFT_CONTROL, InputKey::a}},
{Event::AltA, {InputKey::LEFT_ALT, InputKey::a}},
{Event::CtrlAltA, {InputKey::LEFT_CONTROL, InputKey::LEFT_ALT, InputKey::a}},

But there's still an issue which is that the editor heavily uses SHIFT + SPACE to launch menus, which I think is currently impossible with the current API.

Also Im curious why you took this combined key approach, was there some advantage over just exposing each key separately? Would you be open to modifying the API so that we could get isolated key presses ?

[cuppajoeman]

Hmm, I did some research of my own and also couldn't really figure out how to detect shift space with ncurses and other options. Maybe I'll just have to change some of the keybinds.