GregMat Cover Answer Choices

Hide answer choices on GregMat

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         GregMat Cover Answer Choices
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Hide answer choices on GregMat
// @author       ganeshh123
// @match        https://www.gregmat.com/problems/*
// @grant        none
// @license MIT
// ==/UserScript==

(function () {
  "use strict";

  // Your code here...
  const hideAnswerButtonText = "Cover Answer Choices";
  const showAnswerButtonText = "Show Answer Choices";

  let answersHidden = false;

  const buildElement = (type, attributes, ...children) => {
    const newElement = document.createElement(type);

    Object.keys(attributes).forEach((key) => {
      newElement.setAttribute(key, attributes[key]);
    });

    children.forEach((child) => {
      if (typeof child === "string") {
        newElement.appendChild(document.createTextNode(child));
      } else if (child instanceof HTMLElement) {
        newElement.appendChild(child);
      }
    });

    return newElement;
  };

  const showHideAnswerChoices = (shouldHide) => {
    const labels = [...document.querySelectorAll("label")];

    labels.forEach((label) => {
      label.style.opacity = shouldHide ? 0 : 100;
    });

    const hAB = document.querySelector("#hide-answer-button");

    if (hAB) {
      hAB.firstChild.innerText = shouldHide
        ? showAnswerButtonText
        : hideAnswerButtonText;
    }

    answersHidden = shouldHide;
  };

  const documentChanged = () => {
    const buttons = [...document.querySelectorAll("button")];

    const resetButtons = buttons.filter((btn) => {
      if (btn.firstChild.innerText === "Reset") {
        return true;
      }
    });

    if (resetButtons.length !== 0) {
      // Question popup is opened

      const resetButton = resetButtons[0];
      const hAB = document.querySelector("#hide-answer-button");
      if (hAB) {
        return;
      } else {
        const hideAnswerButton = buildElement(
          "button",
          {
            class:
              "px-3 py-0.5 text-sm border border-gray-600 rounded-full flex flex-row items-center space-x-2",
            id: "hide-answer-button",
          },
          buildElement("span", {}, hideAnswerButtonText)
        );
        hideAnswerButton.onclick = () => showHideAnswerChoices(!answersHidden);

        const buttonRow = resetButton.parentElement;
        buttonRow.prepend(hideAnswerButton);

        // Observe for question change
        const questionChangeObserver = new MutationObserver(() =>
          showHideAnswerChoices(answersHidden)
        );

        questionChangeObserver.observe(buttonRow.nextSibling, {
          subtree: true,
          childList: true,
        });
      }
    }
  };

  // Observe for question modal popping up
  const questionModalObserver = new MutationObserver(documentChanged);
  questionModalObserver.observe(document.body, {
    subtree: true,
    childList: true,
  });
})();