Add shortcuts (toggle & open on alt+click)

addon/background.js

@@ -37,6 +37,12 @@ browser.contextMenus.create({
   documentUrlPatterns: ["<all_urls>"],
 });
 
+browser.commands.onCommand.addListener(async command => {
+  if (command === "toggle-sidebar") {
+    await browser.sidebarAction.toggle();
+  }
+});
+
 browser.contextMenus.onClicked.addListener(async (info, tab) => {
   let url;
   let favIconUrl;

addon/content-script.js

@@ -0,0 +1,16 @@
+function getLinkNode(e) {
+    let target = e.target;
+    while ((target.tagName !== "A" || !target.href) && target.parentNode) {
+        target = target.parentNode;
+    }
+    return target;
+}
+
+function openUrl(e) {
+    let target = getLinkNode(e);
+    if (target.tagName !== "A" || !e.altKey) return;
+
+    browser.runtime.sendMessage({type: "openUrl", url: target.href});
+}
+
+window.addEventListener("click", openUrl);

addon/manifest.json.tmpl

@@ -15,12 +15,26 @@
         "strict_min_version": "57.0a1"
       }
     },
+    "commands": {
+      "toggle-sidebar": {
+        "suggested_key": {
+          "default": "Alt+1"
+        },
+        "description": "Toggle the sidebar"
+      }
+    },
     "background": {
       "scripts": [
         "build/buildSettings.js",
         "background.js"
       ]
     },
+    "content_scripts": [
+      {
+        "matches": ["<all_urls>"],
+        "js": ["content-script.js"]
+      }
+    ],
     "browser_action": {
       "default_icon": "side-view.svg",
       "default_popup": "popup.html",