installation module

index.css

@@ -2273,8 +2273,9 @@ svg.button {
 
 
 .dontAsk {
-  display: inline-block;
   margin: 0.9em 0 0 0.6em;
+  display: inline-flex;
+  align-items: center;
 }
 
 #errorBox {

index.html

@@ -6297,7 +6297,7 @@
 
     <script src="modules/ui/general.js"></script>
     <script src="modules/ui/options.js"></script>
-    <script src="main.js"></script>
+    <script src="main.js?v=13052022"></script>
 
     <script defer src="modules/relief-icons.js"></script>
     <script defer src="modules/ui/style.js"></script>

main.js

@@ -10,13 +10,22 @@ const TIME = DEBUG || !PRODUCTION;
 const WARN = true;
 const ERROR = true;
 
-// register service worker responsible for caching
 if ("serviceWorker" in navigator) {
   window.addEventListener("load", () => {
     navigator.serviceWorker.register("./sw.js").catch(err => {
       console.error("ServiceWorker registration failed: ", err);
     });
   });
+
+  window.addEventListener(
+    "beforeinstallprompt",
+    async event => {
+      event.preventDefault();
+      const Installation = await import("/modules/dynamic/installation.js");
+      Installation.init(event);
+    },
+    {once: true}
+  );
 }
 
 // append svg layers (in default order)

modules/dynamic/installation.js

@@ -0,0 +1,70 @@
+// module to prompt PWA installation
+let installButton = null;
+let deferredPrompt = null;
+
+export function init(event) {
+  const dontAskforInstallation = localStorage.getItem("installationDontAsk");
+  if (dontAskforInstallation) return;
+
+  installButton = createButton();
+  deferredPrompt = event;
+
+  window.addEventListener("appinstalled", () => {
+    tip("Application is installed", false, "success", 8000);
+    cleanup();
+  });
+}
+
+function createButton() {
+  const button = document.createElement("button");
+  button.style = `
+      position: fixed;
+      top: 1em;
+      right: 1em;
+      padding: 0.6em 0.8em;
+      width: auto;
+    `;
+  button.className = "options glow";
+  button.innerHTML = "Install";
+  button.onclick = openDialog;
+  button.onmouseenter = () => tip("Install the Application");
+  document.querySelector("body").appendChild(button);
+  return button;
+}
+
+function openDialog() {
+  alertMessage.innerHTML = /* html */ `You can install the tool so that it will look and feel like desktop application`;
+  $("#alert").dialog({
+    resizable: false,
+    title: "Install the Application",
+    buttons: {
+      Install: function () {
+        $(this).dialog("close");
+        deferredPrompt.prompt();
+      },
+      Cancel: function () {
+        $(this).dialog("close");
+      }
+    },
+    open: function () {
+      const checkbox =
+        '<span><input id="dontAsk" class="checkbox" type="checkbox"><label for="dontAsk" class="checkbox-label dontAsk"><i>do not ask again</i></label><span>';
+      const pane = this.parentElement.querySelector(".ui-dialog-buttonpane");
+      pane.insertAdjacentHTML("afterbegin", checkbox);
+    },
+    close: function () {
+      const box = this.parentElement.querySelector(".checkbox");
+      if (box?.checked) {
+        localStorage.setItem("installationDontAsk", true);
+        cleanup();
+      }
+      $(this).dialog("destroy");
+    }
+  });
+
+  function cleanup() {
+    installButton.remove();
+    installButton = null;
+    deferredPrompt = null;
+  }
+}

modules/ui/tools.js

@@ -2,10 +2,7 @@
 // module to control the Tools options (click to edit, to re-geenerate, tp add)
 
 toolsContent.addEventListener("click", function (event) {
-  if (customization) {
-    tip("Please exit the customization mode first", false, "warning");
-    return;
-  }
+  if (customization) return tip("Please exit the customization mode first", false, "warning");
   if (!["BUTTON", "I"].includes(event.target.tagName)) return;
   const button = event.target.id;