Saving playground code state (#1917)

The embedded Playground's code reset when you navigate between slides.
This has caused problems: if people navigate away from a slide to look
something up, they've suddenly lost their work.

book.toml

@@ -46,7 +46,12 @@ urlcolor = "red"
 
 [output.html]
 curly-quotes = true
-additional-js = ["theme/speaker-notes.js", "theme/redbox.js"]
+additional-js = [
+  "theme/speaker-notes.js",
+  "theme/redbox.js",
+  "theme/save-playgrounds.js",
+  "theme/instructor-menu.js",
+]
 additional-css = [
   "theme/css/svgbob.css",
   "theme/css/redbox.css",

theme/css/redbox.css

@@ -18,3 +18,7 @@ div#aspect-ratio-helper div {
        of vertical space to borders. */
   aspect-ratio: 16/8.5;
 }
+
+#instructor-menu-list {
+  margin-left: 55px;
+}

theme/instructor-menu.js

@@ -0,0 +1,71 @@
+(function handleInstructor() {
+  function handleInstructorMenu() {
+    let leftButtons = document.getElementsByClassName("left-buttons")[0];
+    let instructorMenu = document.createElement("button");
+    let instructorMenuList = document.createElement("ul");
+    let redBoxItem = document.createElement("li");
+    let redBoxButton = document.createElement("button");
+    let playgroundStateItem = document.createElement("li");
+    let playgroundStateButton = document.createElement("button");
+
+    leftButtons.insertBefore(instructorMenu, leftButtons.lastChild);
+    leftButtons.insertBefore(instructorMenuList, leftButtons.lastChild);
+    instructorMenuList.insertBefore(redBoxItem, instructorMenuList.lastChild);
+    instructorMenuList.insertBefore(
+      playgroundStateItem,
+      instructorMenuList.lastChild
+    );
+    redBoxItem.insertBefore(redBoxButton, redBoxItem.lastChild);
+    playgroundStateItem.insertBefore(
+      playgroundStateButton,
+      playgroundStateItem.lastChild
+    );
+
+    instructorMenu.title = "Utilities for course instructors";
+    instructorMenu.innerHTML =
+      '<i class="fa fa-ellipsis-v" aria-hidden="true"></i>';
+    redBoxButton.innerHTML = "aspect-ratio box";
+    redBoxButton.title =
+      "Outline the area that fits on one screen while teaching the course.";
+    playgroundStateButton.innerHTML = "reset all playgrounds";
+    playgroundStateButton.title =
+      "Reset code in all playgrounds to its original value.";
+
+    instructorMenu.className = "icon-button";
+    instructorMenuList.className = "theme-popup";
+    redBoxButton.className = "theme";
+    playgroundStateButton.className = "theme";
+    instructorMenuList.style.display = "none";
+
+    instructorMenuList.role = "menu";
+    redBoxItem.role = "none";
+    playgroundStateItem.role = "none";
+    redBoxButton.role = "menuitem";
+    playgroundStateButton.role = "menuitem";
+
+    redBoxButton.id = "redbox";
+    instructorMenuList.id = "instructor-menu-list";
+    playgroundStateButton.id = "playground-state";
+
+    instructorMenu.addEventListener("click", () => {
+      if (instructorMenuList.style.display === "none") {
+        instructorMenuList.style.display = "block";
+      } else {
+        instructorMenuList.style.display = "none";
+      }
+    });
+
+    document.addEventListener("click", (e) => {
+      if (!instructorMenu.contains(e.target)) {
+        instructorMenuList.style.display = "none";
+      }
+    });
+  }
+  handleInstructorMenu();
+  var redBoxButton = document.getElementById("redbox");
+  var playgroundStateButton = document.getElementById("playground-state");
+  redBoxButton.addEventListener("click", () => window.redboxButtonClicked());
+  playgroundStateButton.addEventListener("click", () =>
+    window.resetPlaygroundsClicked()
+  );
+})();

theme/redbox.js

@@ -11,28 +11,19 @@
   var parentElement = document.body; // Change this to your desired parent element
   // Append the new div to the parent element
   parentElement.insertBefore(newDiv, parentElement.firstChild);
-  // Create the button element
-  var hideShowButton = document.createElement("button");
-  hideShowButton.innerHTML = '<i class="fa fa-square-o"></i>';
-  hideShowButton.className = "icon-button";
-  hideShowButton.type = "button";
-  hideShowButton.title =
-    "Outline the area that fits on one screen while teaching the course.";
-  hideShowButton.id = "Dev";
-  var navbarButtons = document.getElementsByClassName("left-buttons");
-  navbarButtons[0].insertBefore(hideShowButton, navbarButtons.firstChild);
   //Default hiding the redbox
   document.getElementById("aspect-ratio-helper").style.display = "none";
-  //Add Event listener to button to perform on click action.
-  hideShowButton.addEventListener("click", function () {
-    if (
-      document.getElementById("aspect-ratio-helper").style.display === "none"
-    ) {
-      document.getElementById("aspect-ratio-helper").style.display = "block";
-      hideShowButton.innerHTML = '<i class="fa fa-square"></i>';
-    } else {
-      document.getElementById("aspect-ratio-helper").style.display = "none";
-      hideShowButton.innerHTML = '<i class="fa fa-square-o"></i>';
-    }
-  });
 })();
+
+//Create a function to button to perform on click action.
+function redboxButtonClicked() {
+  var hideShowButton = document.getElementById("redbox");
+  if (document.getElementById("aspect-ratio-helper").style.display === "none") {
+    document.getElementById("aspect-ratio-helper").style.display = "block";
+    hideShowButton.innerHTML = "aspect-ratio box";
+  } else {
+    document.getElementById("aspect-ratio-helper").style.display = "none";
+    hideShowButton.innerHTML = "aspect-ratio box";
+  }
+}
+window.redboxButtonClicked = redboxButtonClicked;

theme/save-playgrounds.js

@@ -0,0 +1,46 @@
+(function savePlaygrounds() {
+  function setCodeToPlayground() {
+    var codes = JSON.parse(
+      localStorage.getItem(`${window.location.href}₹code`)
+    );
+    if (codes) {
+      var i = 0;
+      Array.from(document.querySelectorAll(".playground")).forEach(function (
+        pre_block
+      ) {
+        let code_block = pre_block.querySelector("code");
+        let editor = window.ace.edit(code_block);
+        editor.setValue(codes[i]);
+        editor.clearSelection();
+        i += 1;
+      });
+    }
+  }
+  function getCodeFromPlayground() {
+    var codes = [];
+    Array.from(document.querySelectorAll(".playground")).forEach(function (
+      pre_block
+    ) {
+      let code_block = pre_block.querySelector("code");
+      let editor = window.ace.edit(code_block);
+      let code = editor.getValue();
+      codes.push(code);
+    });
+    localStorage.setItem(`${window.location.href}₹code`, JSON.stringify(codes));
+  }
+  setCodeToPlayground();
+  addEventListener("pagehide", getCodeFromPlayground);
+})();
+
+function resetPlaygroundsClicked() {
+  let keys = [];
+  for (var i = 0, len = localStorage.length; i < len; i++) {
+    if (localStorage.key(i).includes("₹code")) {
+      keys.push(localStorage.key(i));
+    }
+  }
+  for (let j = 0; j < keys.length; j++) {
+    localStorage.removeItem(keys[j]);
+  }
+}
+window.resetPlaygroundsClicked = resetPlaygroundsClicked;