Fix elements styling to follow the Proton Design System more closely

This includes fixes for the hover, active and focus states of all the
elements that didn't have one.

src/js/options.js

@@ -53,11 +53,20 @@ async function enableDisableReplaceTab() {
   await browser.storage.local.set({replaceTabEnabled: !!checkbox.checked});
 }
 
+async function changeTheme(event) {
+  const theme = event.currentTarget;
+  await browser.storage.local.set({currentTheme: theme.value});
+  await browser.storage.local.set({currentThemeId: theme.selectedIndex});
+}
+
 async function setupOptions() {
   const { syncEnabled } = await browser.storage.local.get("syncEnabled");
   const { replaceTabEnabled } = await browser.storage.local.get("replaceTabEnabled");
+  const { currentThemeId } = await browser.storage.local.get("currentThemeId");
+
   document.querySelector("#syncCheck").checked = !!syncEnabled;
   document.querySelector("#replaceTabCheck").checked = !!replaceTabEnabled;
+  document.querySelector("#changeTheme").selectedIndex = currentThemeId;
   setupContainerShortcutSelects();
 }
 
@@ -114,6 +123,8 @@ browser.permissions.onRemoved.addListener(resetPermissionsUi);
 document.addEventListener("DOMContentLoaded", setupOptions);
 document.querySelector("#syncCheck").addEventListener( "change", enableDisableSync);
 document.querySelector("#replaceTabCheck").addEventListener( "change", enableDisableReplaceTab);
+document.querySelector("#changeTheme").addEventListener( "change", changeTheme);
+
 maybeShowPermissionsWarningIcon();
 for (let i=0; i < NUMBER_OF_KEYBOARD_SHORTCUTS; i++) {
   document.querySelector("#open_container_"+i)

src/js/pageAction.js

@@ -32,6 +32,9 @@ async function init() {
   list.appendChild(fragment);
 
   MozillaVPN.handleContainerList(identities);
+
+  // Set the theme
+  Utils.applyTheme();
 }
 
 init();

src/js/popup.js

@@ -51,6 +51,7 @@ async function getExtensionInfo() {
   return extensionInfo;
 }
 
+
 // This object controls all the panels, identities and many other things.
 const Logic = {
   _identities: [],
@@ -65,6 +66,9 @@ const Logic = {
       method: "MozillaVPN_attemptPort"
     }),
 
+    // Set the theme
+    Utils.applyTheme();
+
     // Remove browserAction "upgraded" badge when opening panel
     this.clearBrowserActionBadge();
 
@@ -1492,7 +1496,7 @@ Logic.registerPanel(P_CONTAINER_EDIT, {
             } else {
               MozillaVPN.handleMozillaCtaClick("mac-edit-container-panel-btn");
             }
-           
+
           });
 
           this.switch.addEventListener("click", async() => {

src/js/utils.js

@@ -169,6 +169,26 @@ const Utils = {
       false
     );
   },
+  /* Theme helper
+   *
+   * First, we look if there's a theme already set in the local storage. If
+   * there isn't one, we set the theme based on `prefers-color-scheme`.
+   * */
+  getTheme(currentTheme, window) {
+    if (typeof currentTheme !== "undefined" && currentTheme !== "auto") {
+      return currentTheme;
+    }
+    if (window.matchMedia("(prefers-color-scheme: dark)").matches) {
+      return "dark";
+    }
+    return "light";
+  },
+  async applyTheme() {
+    const { currentTheme } = await browser.storage.local.get("currentTheme");
+    const popup = document.getElementsByTagName("html")[0];
+    const theme = Utils.getTheme(currentTheme, window);
+    popup.setAttribute("data-theme", theme);
+  }
 };
 
 window.Utils = Utils;