Add a 'translate selection' intent

extension/background/pageMetadata-contentScript.js

@@ -0,0 +1,8 @@
+/* globals communicate */
+
+this.pageMetadataContentScript = (function() {
+  communicate.register("getSelection", message => {
+    const selection = window.getSelection();
+    return { selection: { text: String(selection) } };
+  });
+})();

extension/background/pageMetadata.js

@@ -0,0 +1,18 @@
+/* globals content */
+
+this.pageMetadata = (function() {
+  const exports = {};
+
+  exports.getSelection = async function(tabId) {
+    await content.lazyInject(
+      tabId,
+      "/background/pageMetadata-contentScript.js"
+    );
+    const resp = await browser.tabs.sendMessage(tabId, {
+      type: "getSelection",
+    });
+    return resp.selection;
+  };
+
+  return exports;
+})();

extension/content/communicate.js

@@ -3,12 +3,14 @@
 this.communicate = (function() {
   const exports = {};
   const HANDLERS = {};
+
   exports.register = function(type, handler) {
     if (HANDLERS[type]) {
       throw new Error(`There is already a handler registerd for ${type}`);
     }
     HANDLERS[type] = handler;
   };
+
   exports.handle = async function(script, message, sender) {
     log.messaging(`${script}->`, JSON.stringify(message));
     if (!HANDLERS[message.type]) {

extension/intents/navigation/navigation.js

@@ -1,4 +1,4 @@
-/* globals searching, serviceList */
+/* globals searching, serviceList, pageMetadata */
 
 this.intents.navigation = (function() {
   this.intentRunner.registerIntent({
@@ -82,4 +82,25 @@ this.intents.navigation = (function() {
       browser.tabs.update(tab.id, { url: translation });
     },
   });
+
+  this.intentRunner.registerIntent({
+    name: "navigation.translateSelection",
+    match: `
+    translate (this |) selection (to english |)
+    `,
+    examples: ["Translate selection"],
+    async run(context) {
+      const tab = (await browser.tabs.query({ active: true }))[0];
+      const selection = await pageMetadata.getSelection(tab.id);
+      if (!selection || !selection.text) {
+        const e = new Error("No text selected");
+        e.displayMessage = "No text selected";
+        throw e;
+      }
+      const url = `https://translate.google.com/#view=home&op=translate&sl=auto&tl=en&text=${encodeURIComponent(
+        selection.text
+      )}`;
+      await browser.tabs.create({ url });
+    },
+  });
 })();

extension/manifest.json.ejs

@@ -30,6 +30,7 @@
       "catcher.js",
       "settings.js",
       "js/vendor/fuse.js",
+      "background/pageMetadata.js",
       "background/main.js",
       "background/voiceSchema.js",
       "background/telemetry.js",