I'm exploring Google Chrome extensions for the first time. I would like to create what appears as a toolbar along the top of the page when y开发者_开发百科ou click the extension icon, much like the StumbleUpon toolbar.

I can't see how to do this. The examples mainly show a popup.html, and not a fixed toolbar.

Although this answer shows two ways to create a toolbar in Chrome, I strongly recommend using page action or browser action badges. These do not take as much space as toolbars, and can also be used to show a panel on click, and even get temporary host permissions to interact with the page.

The `chrome.infobars` API

This section used to show a demo using the chrome.infobars API. This API has never been to the stable channel, and will be removed; do not use it.

The `chrome.sidebar` API

There was a proposal in 2015 for a sidebar API, as an alternative to the chrome.infobars (described above). But this idea was rejected in 2016 in order to prioritize "Chrome’s core value of simplicity" (source).

It seems that there is no way to make an "advanced" tool bar in Chrome without placing it in the document window.

Content scripts

Creation of toolbars using content scripts is tricky. You have to insert code in the page, and even modify the structure of the document, which could break some pages on the internet.

To create a toolbar using content scripts, the following steps have to be taken:

Execute a content script on the page which runs the next two steps.
Insert the toolbar (<iframe> - explained later).
Shift the content of the page.

Step 1 is easy, see my previous example or read the documentation of content scripts.

Step 2: Insert the toolbar

To minimize styling conflicts, and to prevent the page from using your toolbar, insert an iframe. Unlike the previous method, you do not directly have access to the extension API (because the embedded page is neither a content script, nor a page running in the extension's process).

Inserting the toolbar:

`add-toolbar.js` (content script)

var height = '40px';
var iframe = document.createElement('iframe');
iframe.src = chrome.runtime.getURL('toolbar.html');
iframe.style.height = height;
iframe.style.width = '100%';
iframe.style.position = 'fixed';
iframe.style.top = '0';
iframe.style.left = '0';
iframe.style.zIndex = '938089'; // Some high value
// Etc. Add your own styles if you want to
document.documentElement.appendChild(iframe);

Now create a file called toolbar.html and add it to the "web_accessible_resources" section of your manifest file. This file is going to used at the spot of the toolbar, feel free to do anything non-evil with it. Just keep in mind that it acts like a normal web page, it literally does not have access to any of the Chrome APIs.

Step 3: Shifting the content

So far, you've only added a frame to the page. There's one problem: The content on the page is partially hidden. That is not very nice. There are several ways to fix this, I choose to use CSS transforms, because it's relatively easy to use, and most pages don't use this property on the body element.

// continuing add-toolbar.js
var bodyStyle = document.body.style;
var cssTransform = 'transform' in bodyStyle ? 'transform' : 'webkitTransform';
bodyStyle[cssTransform] = 'translateY(' + height + ')';

translateY causes the body to shift down, including those child elements with position:fixed. Because we've appended the iframe to the root element, outside the <body> tag, the element is not affected.

I want to use extension APIs in the toolbar!

Unfortunately, Chrome treats the embedded html page as a non-privileged extension page. You can only use some of the extension APIs (similar to content scripts).

Another option is to load a page from your server, then execute a content script on that specific page. Set up a Cache manifest to ensure that your toolbar is still available if the user isn't on a network.

Chrome API doesn't have any toolbar widget to assist you. You would need to manually create and position a toolbar div on a page. You can do this by utilizing content scripts, which allow you to inject javascript and css to pages.

This gives you a stumble-upon-like browser extension for a variety of browsers, although you can limit the download to just chrome if you wish.

Installers

General install page (provides an executable that can be signed if you are on windows to ease the installation process):

http://crossrider.com/apps/35180/install_page

Specific installs:

Firefox: http://crossrider.com/download/ff/35180
IE: http://crossrider.com/download/ie/35180
Chrome: http://crossrider.com/download/chrome/35180
Safari: (will work, but need to go through process with Apple for that)

Crossrider also makes it easy to publish to chrome store as well and provides an easy way to sign your extension for executable downloads on windows.

Info

Here are the docs for the API, its quite extensive for a cross-browser solution:

http://docs.crossrider.com/

In the code below I'm not putting the html & css because there are limits to the number of characters for answers. However, if that looks good, you can either open it up (crx's are zips, just rename extension to .zip) to get the css and html inside or we can figure out a way for me to send it to you. Note that I'm injecting the HTML and CSS into the page.

I usually write the css and html, then minify both (http://cssminifier.com/ and http://www.willpeavy.com/minifier/), then I take the minified output and I use a string escape tool like http://www.htmlescape.net/stringescape_tool.html to escape it so that it can be put into the extension code, as you want that to be as fast as possible, given that its an extension, not a web page of course.

So, if this looks good, go to crossrider.com, set up an account (it is 100% free), and paste these files in the appropriate places and put in the minified/escaped HTML and CSS you need, replacing the stuff in the cssstr and htmlstr in the extension.js below.

Code

extension.js:

appAPI.ready(function($) {
    // Place your code here (you can also define new functions above this scope)
    // The $ object is the extension's jQuery object

    // Adds a listener that handle incoming messages
    var lid = appAPI.message.addListener(function(msg) {
        switch(msg.action) {
            case 'SHOWEXAMPLEBAR': 
            $('#examplebar-toolbar').show();
                break;
            case 'HIDEEXAMPLEBAR': 
                $('#examplebar-toolbar').hide();
                break;
            default: 
                break;
         }
    });

    // Add toolbar (not included here due to size - be sure it is escaped)
    var cssstr = '/* The CSS of your toolbar */';

    // Add toolbar HTML (not included here due to size - be sure it is escaped)
    var htmlstr = '\x3C!-- the html of your toolbar --\x3E';

    $('\x3Cstyle\x3E'+cssstr+'\x3C/style\x3E' + htmlstr).prependTo('body');
    $('#examplebar-close').click(function() {
        //Tell the background to change its buttonstate:
        $('#examplebar-toolbar').hide();
        appAPI.message.toBackground({action: "HIDEEXAMPLEBAR"});
    });
});

background.js:

// Note: the $ variable that represents the jQuery object is not available
//       in the background scope
appAPI.ready(function() {
    // Global variable to hold the toggle state of the button
    var buttonState = true;

    // Sets the initial browser icon
    appAPI.browserAction.setResourceIcon('button.png');

    // Sets the tooltip for the button
    appAPI.browserAction.setTitle('Bar');

    // Sets the text and background color for the button
    if (appAPI.browser.name !== 'safari') {
        appAPI.browserAction.setBadgeText('bar');
        appAPI.browserAction.setBadgeBackgroundColor([255,0,0,50]);
    }else{
        // Safari only supports numeric characters
        // and has a fixed background color
        appAPI.browserAction.setBadgeText('1234');
    }

    // Sets the initial onClick event handler for the button
    appAPI.browserAction.onClick(function(){
        if (buttonState) {
            //Hide the toolbar by notifying the extension code:
            appAPI.message.toAllTabs({action: "HIDEEXAMPLEBAR"});
            if (appAPI.browser.name !== 'safari') {
            // Sets the text and background color for the button
            // using the optional background parameter
                appAPI.browserAction.setBadgeText('helo', [0,0,255,255]);
                // Sets the icon to use for the button.
                appAPI.browserAction.setResourceIcon('button.png');
            } else {
                // Safari only supports numeric characters,
                // has a fixed background color,
                // and can only use the extension's icon
                appAPI.browserAction.setBadgeText('4321');
            }
        } else {
            appAPI.message.toAllTabs({action: "SHOWEXAMPLEBAR"});
            // Remove the badge from the button
            appAPI.browserAction.removeBadge();

            if (appAPI.browser.name !== 'safari'){
                // Reset the icon for the image
                appAPI.browserAction.setResourceIcon('button.png');
            }
        }

        // Toggle the state
        buttonState = !buttonState;
    });

    // Adds a listener that handle incoming messages
    var lid = appAPI.message.addListener(function(msg) {
        switch (msg.action) {
            case 'HIDEEXAMPLEBAR': 
            buttonState = !buttonState;
            break;
            default:
                break;
        }
    });    
});

Notes

Also note that jQuery is automatically available in the extension scope, so you get that for free along with the API's. And, if you want to inject into an iframe, be sure not to forget to enable iframes in the settings.

For the community support site: https://getsatisfaction.com/crossrider

They are very responsive and can help you out when you run into trouble.