Looking at the code, it seems that it was always intended that you also use the keys 1 or 2 to continue to the next review (at least there is the code comment // if answer is shown, press '1' one more time to go to next). That it also worked with Enter until now was probably just an unintentional feature. But if you prefer to use Enter, you can try replacing the code with this modified version:
Modified Script
// ==UserScript==
// @name Wanikani Anki Mode
// @namespace mempo
// @version 1.7.2
// @description Anki mode for Wanikani
// @author Mempo
// @match https://www.wanikani.com/review/session*
// @match http://www.wanikani.com/review/session*
// @grant none
// @license GPL version 3 or any later version; http://www.gnu.org/copyleft/gpl.html
// ==/UserScript==
//Original author: Oleg Grishin <og402@nyu.edu>
console.log('/// WKAM begin');
// Save the original evaluator
var answerChecker = window.answerChecker;
var originalChecker = answerChecker.evaluate;
var checkerYes = function (itemType, correctValue) {
return {accurate : !0, passed: !0};
}
var checkerNo = function (itemType, correctValue) {
return {accurate : !0, passed: 0};
}
var activated = false;
var answerShown = false;
//AUTOSTART
var autostart = false;
MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
var observer = new MutationObserver(function(mutations, observer) {
$("#user-response").blur();
});
var WKANKIMODE_toggle = function () {
if (activated) {
if(autostart){
//DISABLE ANKI MODE
$("#WKANKIMODE_anki").text("Anki Mode Off");
$("#answer-form form button").prop("disabled", false);
$("#user-response").off("focus");
$("#user-response").focus();
answerChecker.evaluate = originalChecker;
observer.disconnect();
localStorage.setItem("WKANKI_autostart", false);
activated = false;
autostart = false;
console.log("back to #1");
}else{
//ENABLE AUTOSTART
activated = true;
autostart = true;
localStorage.setItem("WKANKI_autostart", true);
$("#WKANKIMODE_anki").text("Anki Mode Auto Start");
// start observer to force blur
observer.observe(document.getElementById("answer-form"), {
childList: true,
subtree: true,
attributes: true,
characterData: false
});
}
} else {
//ENABLE ANKI MODE
$("#WKANKIMODE_anki").text("Anki Mode On");
$("#answer-form form button").prop("disabled", true);
$("#user-response").on("focus", function () {
$("#user-response").blur();
});
activated = true;
autostart = false;
// start observer to force blur
observer.observe(document.getElementById("answer-form"), {
childList: true,
subtree: true,
attributes: true,
characterData: false
});
}
}
var WKANKIMODE_showAnswer = function () {
if (!$("#answer-form form fieldset").hasClass("correct") &&
!$("#answer-form form fieldset").hasClass("incorrect") &&
!answerShown ) {
var currentItem = $.jStorage.get("currentItem");
var questionType = $.jStorage.get("questionType");
if (questionType === "meaning") {
var answer = currentItem.en.join(", ");
if (currentItem.syn.length) {
answer += " (" + currentItem.syn.join(", ") + ")";
}
$("#user-response").val(answer);
} else { //READING QUESTION
var i = 0;
var answer = "";
if (currentItem.voc) {
answer += currentItem.kana[0];
} else if (currentItem.emph == 'kunyomi') {
answer += currentItem.kun[0];
} else if (currentItem.emph == 'nanori') {
answer += currentItem.nanori[0];
} else {
answer += currentItem.on[0];
}
$("#user-response").val(answer);
}
answerShown = true;
}
};
var WKANKIMODE_answerYes = function () {
if (answerShown) {
answerChecker.evaluate = checkerYes;
submitAnswer();
answerShown = false;
answerChecker.evaluate = originalChecker;
return;
}
// if answer is shown, press '1' one more time to go to next
if ($("#answer-form form fieldset").hasClass("correct") ||
$("#answer-form form fieldset").hasClass("incorrect") ) {
submitAnswer();
}
};
var WKANKIMODE_answerNo = function () {
if (answerShown) {
answerChecker.evaluate = checkerNo;
submitAnswer();
answerShown = false;
answerChecker.evaluate = originalChecker;
return;
}
if ($("#answer-form form fieldset").hasClass("correct") ||
$("#answer-form form fieldset").hasClass("incorrect") ) {
submitAnswer();
}
};
/*jshint multistr: true */
var css = "\
#WKANKIMODE_anki { \
background-color: #000099; \
margin: 0 5px; \
} \
#WKANKIMODE_yes { \
background-color: #009900; \
margin: 0 0 0 5px; \
} \
#WKANKIMODE_no { \
background-color: #990000; \
} \
.WKANKIMODE_button { \
display: inline-block; \
font-size: 0.8125em; \
color: #FFFFFF; \
cursor: pointer; \
padding: 10px; \
} \
#WKANKIMODE_anki.hidden { \
display: none; \
} ";
function addStyle(aCss) {
var head, style;
head = document.getElementsByTagName('head')[0];
if (head) {
style = document.createElement('style');
style.setAttribute('type', 'text/css');
style.textContent = aCss;
head.appendChild(style);
return style;
}
return null;
}
function submitAnswer() {
let form = $('#answer-form form');
let button = $('#answer-form button');
if ($._data(form[0], 'events').submit) form.submit();
else if ($._data(button[0], 'events').click) button.click();
}
var addButtons = function () {
//CHECK AUTOSTART
autostart = localStorage.getItem('WKANKI_autostart')==="true"?true:false;
$("<div />", {
id : "WKANKIMODE_anki",
title : "Anki Mode",
})
.text("Anki Mode Off")
.addClass("WKANKIMODE_button")
.on("click", WKANKIMODE_toggle)
.prependTo("footer");
// TO-DO
// add physical buttons to press yes/no/show answer
// var yesButton = "<div id='WKANKIMODE_yes' class='WKANKIMODE_button' title='Correct' onclick='WKANKIMODE_correct();'>Correct</div>";
// var noButton = "<div id='WKANKIMODE_no' class='WKANKIMODE_button' title='Incorrect' onclick='WKANKIMODE_incorrect();'>Incorrect</div>";
// $("footer").prepend($(noButton).hide());
// $("footer").prepend($(yesButton).hide());
};
var autostartFeature = function() {
console.log("/// WKAM: AUTOSTART = " + autostart);
if(autostart){
$("#WKANKIMODE_anki").text("Anki Mode Auto Start");
$("#answer-form form button").prop("disabled", true);
$("#user-response").on("focus", function () {
$("#user-response").blur();
});
activated = true;
// start observer to force blur
observer.observe(document.getElementById("answer-form"), {
childList: true,
subtree: true,
attributes: true,
characterData: false
});
}
}
var bindHotkeys = function () {
$(document).on("keydown.reviewScreen", function (event)
{
if (activated && $("#reviews").is(":visible") && !$("*:focus").is("textarea, input"))
{
switch (event.keyCode) {
case 13:
if ($("#answer-form form fieldset").hasClass("correct") || $("#answer-form form fieldset").hasClass("incorrect")) {
event.stopPropagation();
event.preventDefault();
document.querySelector("#answer-form input").disabled = true;
submitAnswer();
}
break;
case 32:
event.stopPropagation();
event.preventDefault();
WKANKIMODE_showAnswer();
break;
case 49:
event.stopPropagation();
event.preventDefault();
WKANKIMODE_answerYes();
break;
case 50:
event.stopPropagation();
event.preventDefault();
WKANKIMODE_answerNo();
break;
}
}
});
};
addStyle(css);
addButtons();
autostartFeature();
bindHotkeys();