CrashenX · May 6, 2023 00:20 · Sep 11, 2016 · Sep 11, 2016
diff --git a/popup.js b/popup.js
@@ -57,10 +57,10 @@ function getCurrentTabUrl(callback) {
 function getImageUrl(searchTerm, callback, errorCallback) {
   // Google image search - 100 searches per day.
   // https://developers.google.com/custom-search/json-api/v1/using_rest
-  var searchUrl = 'https://www.googleapis.com/customsearch/v1?searchType=image'
   var cx = 'insert-your-cx-from:https://cse.google.com'
   // WARNING: Hard-coding your api key in code is really insecure
   var key = 'insert-your-key-from:https://console.developers.google.com'
+  var searchUrl = 'https://www.googleapis.com/customsearch/v1?searchType=image'
     + '&cx=' + encodeURIComponent(cx)
     + '&key=' + encodeURIComponent(key)
     + '&q=' + encodeURIComponent(searchTerm);

diff --git a/popup.js b/popup.js
@@ -0,0 +1,122 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Get the current URL.
+ *
+ * @param {function(string)} callback - called when the URL of the current tab
+ *   is found.
+ */
+function getCurrentTabUrl(callback) {
+  // Query filter to be passed to chrome.tabs.query - see
+  // https://developer.chrome.com/extensions/tabs#method-query
+  var queryInfo = {
+    active: true,
+    currentWindow: true
+  };
+
+  chrome.tabs.query(queryInfo, function(tabs) {
+    // chrome.tabs.query invokes the callback with a list of tabs that match the
+    // query. When the popup is opened, there is certainly a window and at least
+    // one tab, so we can safely assume that |tabs| is a non-empty array.
+    // A window can only have one active tab at a time, so the array consists of
+    // exactly one tab.
+    var tab = tabs[0];
+
+    // A tab is a plain object that provides information about the tab.
+    // See https://developer.chrome.com/extensions/tabs#type-Tab
+    var url = tab.url;
+
+    // tab.url is only available if the "activeTab" permission is declared.
+    // If you want to see the URL of other tabs (e.g. after removing active:true
+    // from |queryInfo|), then the "tabs" permission is required to see their
+    // "url" properties.
+    console.assert(typeof url == 'string', 'tab.url should be a string');
+
+    callback(url);
+  });
+
+  // Most methods of the Chrome extension APIs are asynchronous. This means that
+  // you CANNOT do something like this:
+  //
+  // var url;
+  // chrome.tabs.query(queryInfo, function(tabs) {
+  //   url = tabs[0].url;
+  // });
+  // alert(url); // Shows "undefined", because chrome.tabs.query is async.
+}
+
+/**
+ * @param {string} searchTerm - Search term for Google Image search.
+ * @param {function(string,number,number)} callback - Called when an image has
+ *   been found. The callback gets the URL, width and height of the image.
+ * @param {function(string)} errorCallback - Called when the image is not found.
+ *   The callback gets a string that describes the failure reason.
+ */
+function getImageUrl(searchTerm, callback, errorCallback) {
+  // Google image search - 100 searches per day.
+  // https://developers.google.com/custom-search/json-api/v1/using_rest
+  var searchUrl = 'https://www.googleapis.com/customsearch/v1?searchType=image'
+  var cx = 'insert-your-cx-from:https://cse.google.com'
+  // WARNING: Hard-coding your api key in code is really insecure
+  var key = 'insert-your-key-from:https://console.developers.google.com'
+    + '&cx=' + encodeURIComponent(cx)
+    + '&key=' + encodeURIComponent(key)
+    + '&q=' + encodeURIComponent(searchTerm);
+  var x = new XMLHttpRequest();
+  x.open('GET', searchUrl);
+  // The Google image search API responds with JSON, so let Chrome parse it.
+  x.responseType = 'json';
+  x.onload = function() {
+    // Parse and process the response from Google Image Search.
+    var response = x.response;
+    if (!response || !response.items || !response.items.length) {
+        errorCallback('No response from Google Image search')
+        return;
+    }
+    var firstResult = response.items[0];
+    // Take the thumbnail instead of the full image to get an approximately
+    // consistent image size.
+    var imageUrl = firstResult.image.thumbnailLink;
+    var width = parseInt(firstResult.image.thumbnailWidth);
+    var height = parseInt(firstResult.image.thumbnailHeight);
+    console.assert(
+        typeof imageUrl == 'string' && !isNaN(width) && !isNaN(height),
+        'Unexpected respose from the Google Image Search API!');
+    callback(imageUrl, width, height);
+  };
+  x.onerror = function() {
+    errorCallback('Network error.');
+  };
+  x.send();
+}
+
+function renderStatus(statusText) {
+  document.getElementById('status').textContent = statusText;
+}
+
+document.addEventListener('DOMContentLoaded', function() {
+  getCurrentTabUrl(function(url) {
+    // Put the image URL in Google search.
+    renderStatus('Performing Google Image search for ' + url);
+
+    getImageUrl(url, function(imageUrl, width, height) {
+
+      renderStatus('Search term: ' + url + '\n' +
+          'Google image search result: ' + imageUrl);
+      var imageResult = document.getElementById('image-result');
+      // Explicitly set the width/height to minimize the number of reflows. For
+      // a single image, this does not matter, but if you're going to embed
+      // multiple external images in your page, then the absence of width/height
+      // attributes causes the popup to resize multiple times.
+      imageResult.width = width;
+      imageResult.height = height;
+      imageResult.src = imageUrl;
+      imageResult.hidden = false;
+
+    }, function(errorMessage) {
+      renderStatus('Cannot display image. ' + errorMessage);
+    });
+  });
+});