window.inputLanguageAssistant = {

    init: function() {

        let urlbar = document.getElementById('urlbar-input'); // Since FF 68-70 (I don't know exact version)
        if (!urlbar)
            urlbar = document.getElementById('urlbar');
        if (!urlbar)
            return;

        try {
            Components.utils.import("resource://gre/modules/ctypes.jsm");
            this.lib = ctypes.open("user32.dll");
            this.ActivateKeyboardLayout = this.lib.declare("ActivateKeyboardLayout",
                                                           ctypes.winapi_abi,
                                                           ctypes.voidptr_t,  // return HKL
                                                           ctypes.voidptr_t,  // HKL hkl
                                                           ctypes.uint32_t);  // UINT Flags
            this.KLF_SETFORPROCESS = 0x00000100;
            this.HKL_ENGLISH = ctypes.voidptr_t(0x00000409); // United States (US)
        }
        catch (err) {
            // console.log(err);
        }

        urlbar.addEventListener('focus', function(e) {
            window.inputLanguageAssistant.focus();
        });

        urlbar.addEventListener('blur', function(e) {
            window.inputLanguageAssistant.blur();
        });

    },

    focus: function() {
        try {
            if (this.ActivateKeyboardLayout) {
                this.hkl = this.ActivateKeyboardLayout(this.HKL_ENGLISH, this.KLF_SETFORPROCESS);
            }
        }
        catch (err) {
            // console.log(err);
        }
    },

    blur: function() {
        try {
            if (this.ActivateKeyboardLayout && this.hkl) {
                this.ActivateKeyboardLayout(this.hkl, this.KLF_SETFORPROCESS);
            }
        }
        catch (err) {
            // console.log(err);
        }
    }
};

window.inputLanguageAssistant.init();