toontown-keyboard-manager/main.cpp

#include <cstring>
#include <cassert>
#include <cstdio>
#include <map>
#include <X11/Xlib.h>
#define XK_MISCELLANY
#define XK_LATIN1
#include <X11/keysymdef.h>
extern "C" {
    #include <xdo.h>
}

struct KeyboardMapping {
    const char* keyseq;
    int window_index;

    static const int ALL_WINDOWS = -1;

    KeyboardMapping(const char* keyseq, int window_index)
        : keyseq(keyseq), window_index(window_index)
    {
    }
};

const std::map<KeySym, const KeyboardMapping> kbd_map = {
    {XK_w, KeyboardMapping("Up",    0)},
    {XK_a, KeyboardMapping("Left",  0)},
    {XK_s, KeyboardMapping("Down",  0)},
    {XK_d, KeyboardMapping("Right", 0)},
    {XK_Up, KeyboardMapping("Up", 1)},
    {XK_Left, KeyboardMapping("Left", 1)},
    {XK_Down, KeyboardMapping("Down", 1)},
    {XK_Right, KeyboardMapping("Right", 1)},
    {XK_Control_L, KeyboardMapping("Control_L", 0)},
    {XK_Control_R, KeyboardMapping("Control_R", 1)},
    {XK_space, KeyboardMapping("Control_R", KeyboardMapping::ALL_WINDOWS)},
    {XK_Delete, KeyboardMapping("Delete", 1)},
    {XK_v, KeyboardMapping("Delete", 0)},
};

const useconds_t KEY_DELAY = 12000; // microseconds

void search_windows_by_name(const xdo_t* xdo, const char* name_regex, Window** windowlist_ret, unsigned int* nwindows_ret) {
    xdo_search_t search;
    memset(&search, 0, sizeof(xdo_search_t));
    search.max_depth = -1;
    search.require = xdo_search::SEARCH_ALL;
    search.searchmask |= SEARCH_NAME;
    search.winname = name_regex;
    xdo_search_windows(xdo, &search, windowlist_ret, nwindows_ret);
}

class ToontownKeyboardManager {
    Display* display;
    int screen;
    Window main_window;
    xdo_t* xdo;

    void search_toontown_windows(Window** windowlist_ret, unsigned int* nwindows_ret) {
        search_windows_by_name(xdo, "^Toontown", windowlist_ret, nwindows_ret);
    }

    void send_keyseq(const KeyboardMapping* mapping, int type) {
        Window* windows;
        unsigned int nwindows;
        search_toontown_windows(&windows, &nwindows);
        for(unsigned int i=0; i<nwindows; i++) {
            if(mapping->window_index >= nwindows
                || mapping->window_index == KeyboardMapping::ALL_WINDOWS
                || mapping->window_index == i) {
                // file:///usr/share/doc/libxdo-dev/html/xdo_8h.html
                // http://www.cl.cam.ac.uk/~mgk25/ucs/keysymdef.h
                if(type == KeyPress) {
                    xdo_send_keysequence_window_down(xdo, windows[i], mapping->keyseq, KEY_DELAY);
                } else if(type == KeyRelease) {
                    xdo_send_keysequence_window_up(xdo, windows[i], mapping->keyseq, KEY_DELAY);
                }
            }
        }
        if(type == KeyPress) {
            printf("> '%s' down\n", mapping->keyseq);
        } else if(type == KeyRelease) {
            printf("> '%s' up\n", mapping->keyseq);
        }
    }

    bool handle_key(XKeyEvent* key_event) {
        // https://tronche.com/gui/x/xlib/utilities/keyboard/XLookupKeysym.html
        KeySym key_symbol = XLookupKeysym(key_event, 0);
        if(key_event->state == ControlMask && key_symbol == XK_c) {
            return false; // Ctrl-c
        } else {
            auto kbd_map_it = kbd_map.find(key_symbol);
            if(kbd_map_it != kbd_map.end()) {
                send_keyseq(&kbd_map_it->second, key_event->type);
            } else if(key_event->type == KeyPress) {
                printf(
                    "no mapping for '%s' (%#lx)\n",
                    XKeysymToString(key_symbol),
                    key_symbol
                    );

            }
            return true;
        }
    }

    static Bool key_autorepeat_predicate(Display* display, XEvent* event, XPointer arg) {
        XKeyEvent* release_event = (XKeyEvent*)arg;
        return event->type == KeyPress
            && event->xkey.keycode == release_event->keycode
            && event->xkey.time == release_event->time;
    }

    bool key_event(XKeyEvent* key_event) {
        // https://tronche.com/gui/x/xlib/events/keyboard-pointer/keyboard-pointer.html#XKeyEvent
        XEvent repeat_event;
        if(!XCheckIfEvent(display, &repeat_event, key_autorepeat_predicate, (XPointer)key_event)) {
            return handle_key(key_event);
        } else {
            // ignore auto release event
            // xcheckifevent() removed the associated auto press event
            return true;
        }
    }

    bool window_event(XEvent* event) {
        if(event->type == KeyPress || event->type == KeyRelease) {
            return key_event(&event->xkey);
        } else {
            printf("window event %d", event->type);
            return true;
        }
    }

public:
    ToontownKeyboardManager() {
        display = XOpenDisplay(NULL);
        assert(display);
        screen = XDefaultScreen(display);
        xdo = xdo_new(NULL);
        assert(xdo);

        // https://tronche.com/gui/x/xlib/window/XCreateWindow.html
        main_window = XCreateSimpleWindow(
                display,
                RootWindow(display, screen), // parent
                0, // x
                0, // y
                50, // width
                50, // height
                1, // border width
                0, // border
                0 // background
                );
        XSelectInput(display, main_window, KeyPressMask | KeyReleaseMask);
        XMapWindow(display, main_window);
    }

    void loop() {
        XEvent event;
        do {
            XNextEvent(display, &event);
        } while(window_event(&event));
    }

    ~ToontownKeyboardManager() {
        XCloseDisplay(display);
    }
};

int main() {
    // http://stackoverflow.com/questions/2100654/ignore-auto-repeat-in-x11-applications
    // XAutoRepeatOn(display);
    ToontownKeyboardManager app;
    app.loop();
    return 0;
}