add hotkeys to move between tabs

src/002-config/mousetrapConfig.js

@@ -294,6 +294,16 @@ App.UI.Hotkeys.add("next-child", {
 		$("#next-child a.macro-link").trigger("click");
 	}, combinations: ["right", "e"], uiName: "Next Child"
 });
+App.UI.Hotkeys.add("Previous Tab", {
+	callback: function() {
+		App.UI.tabBar.openLeftTab();
+	}, combinations: []
+});
+App.UI.Hotkeys.add("Next Tab", {
+	callback: function() {
+		App.UI.tabBar.openRightTab();
+	}, combinations: []
+});
 App.UI.Hotkeys.add("walkpast", {
 	callback: function() {
 		$("#walkpast a.macro-link").trigger("click");

src/js/utilsSC.js

@@ -14,7 +14,8 @@ globalThis.html5passage = function(passageFunction) {
 };
 
 /**
- * If you want to include a SugarCube passage in a JS function use this. The result must be printed using the <<print>> macro.
+ * If you want to include a SugarCube passage in a JS function use this. The result must be printed using the <<print>>
+ * macro.
  * @param {string} passageTitle
  * @returns {string}
  */
@@ -120,7 +121,9 @@ App.UI.tabBar = function() {
 		tabButton: tabButton,
 		makeTab: makeTab,
 		handlePreSelectedTab: handlePreSelectedTab,
-		tabChoiceVarName: tabChoiceVarName
+		tabChoiceVarName: tabChoiceVarName,
+		openLeftTab: openLeft,
+		openRightTab: openRight
 	};
 
 	function openTab(evt, tabName) {
@@ -209,11 +212,29 @@ App.UI.tabBar = function() {
 	}
 
 	function openLeft() {
-
+		const tabLinks = /** @type {HTMLCollection<HTMLButtonElement>} */ document.getElementsByClassName("tab-links");
+		const index = currentIndex(tabLinks);
+		if (index - 1 >= 0) {
+			tabLinks[index - 1].click();
+		}
 	}
 
 	function openRight() {
+		const tabLinks = /** @type {HTMLCollection<HTMLButtonElement>} */ document.getElementsByClassName("tab-links");
+		const index = currentIndex(tabLinks);
+		if (index > -1 && index + 1 < tabLinks.length) {
+			tabLinks[index + 1].click();
+		}
+	}
 
+	function currentIndex(collection) {
+		// get current tab button
+		for (let i = 0; i < collection.length; i++) {
+			if (collection[i].classList.contains("active")) {
+				return i;
+			}
+		}
+		return -1;
 	}
 }();