Google Chrome插件开发-Context Menus

本节主要介绍如何在Google Chrome浏览器web页面上点击右键弹出自定义菜单，即如何使用谷歌Context Menus API接口。上节已经把主要流程介绍了，这节就直接上代码，代码都是官方例子没有实际意义，但是可以起到抛砖引玉的作用，大家根据自己的需要开发出自己想要的功能才是王道。

manifest.json代码如下：

{
"name": "Context Menus Sample",
"description": "Shows some of the features of the Context Menus API",
"version": "0.6",
"permissions": ["contextMenus"],
"background": {
"scripts": ["sample.js"]
},
"manifest_version": 2
}

sample.js代码如下：

// Copyright (c) 2010 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.  

// A generic onclick callback function.
function genericOnClick(info, tab) {
  console.log("item " + info.menuItemId + " was clicked");
  console.log("info: " + JSON.stringify(info));
  console.log("tab: " + JSON.stringify(tab));
}  

// Create one test item for each context type.
var contexts = ["page","selection","link","editable","image","video",
                "audio"];
for (var i = 0; i < contexts.length; i++) {
  var context = contexts[i];
  var title = "Test '" + context + "' menu item";
  var id = chrome.contextMenus.create({"title": title, "contexts":[context],
                                       "onclick": genericOnClick});
  console.log("'" + context + "' item:" + id);
}  

// Create a parent item and two children.
var parent = chrome.contextMenus.create({"title": "Test parent item"});
var child1 = chrome.contextMenus.create(
{"title": "Child 1", "parentId": parent, "onclick": genericOnClick});
var child2 = chrome.contextMenus.create(
  {"title": "Child 2", "parentId": parent, "onclick": genericOnClick});
console.log("parent:" + parent + " child1:" + child1 + " child2:" + child2);  

// Create some radio items.
function radioOnClick(info, tab) {
  console.log("radio item " + info.menuItemId +
              " was clicked (previous checked state was "  +
              info.wasChecked + ")");
}
var radio1 = chrome.contextMenus.create({"title": "Radio 1", "type": "radio",
                                         "onclick":radioOnClick});
var radio2 = chrome.contextMenus.create({"title": "Radio 2", "type": "radio",
                                         "onclick":radioOnClick});
console.log("radio1:" + radio1 + " radio2:" + radio2);  

// Create some checkbox items.
function checkboxOnClick(info, tab) {
  console.log(JSON.stringify(info));
  console.log("checkbox item " + info.menuItemId +
              " was clicked, state is now: " + info.checked +
              "(previous state was " + info.wasChecked + ")");  

}
var checkbox1 = chrome.contextMenus.create(
  {"title": "Checkbox1", "type": "checkbox", "onclick":checkboxOnClick});
var checkbox2 = chrome.contextMenus.create(
  {"title": "Checkbox2", "type": "checkbox", "onclick":checkboxOnClick});
console.log("checkbox1:" + checkbox1 + " checkbox2:" + checkbox2);  

// Intentionally create an invalid item, to show off error checking in the
// create callback.
console.log("About to try creating an invalid item - an error about " +
            "item 999 should show up");
chrome.contextMenus.create({"title": "Oops", "parentId":999}, function() {
  if (chrome.extension.lastError) {
    console.log("Got expected error: " + chrome.extension.lastError.message);
  }
});  

插件加载流程参考：http://blog.csdn.net/anda0109/article/details/50325849