Chrome API - Check if Chrome has Focus - javascript

I'm creating an extension where I'd like to be able to figure out whether Chrome (as an application) has the user's focus, i.e. is it not minimized or in the background?
I believe there are javascript functions that check if a tab has focus, would injecting that code into every tab and seeing if any of the tabs return false work? That sounds like terrible peformance though, maybe just inject it into the "active" window using chrome.tabs.onUpdated?
Or would this be do-able relatively easily using NPAPI? Would it require different code for different OSes?
Thanks!

Related

Monitoring JavaScript stack trace [duplicate]

Is it possible to view JavaScript function calls in the browser's JavaScript console? I know you can view XHR, but can you view function calls?
For example, I hover my mouse over some element on a page and a div pops up. I know there was a JavaScript function that was called to show the popup so it would be nice to be able to view this call in the console so I can see what function was called.
Am I missing something or is this not possible?
So basically you want to view JS calls in real-time?
The Firebug extension on Firefox offers that (http://getfirebug.com/javascript).
Basically, what you want to do is find your function within your code, then set a breakpoint on it. You should then be able to step through execution on it, just like a normal debugger. It shouldn't be hard to find the JS function associated with a and a particular event (e.g. mouseover) on that - is this page in question using straight JS or a framework? And if so, which one?
Google Chrome's built-in developer tools offer a smaller subset - depending on what you want, the Profile tab on it might be useful?
What exactly do you need to trace this JS function for? We might be able to recommend a better tool for you based on your particular need.
Check into the Firebug Profiler you can use it to see a break down of what's going on without having to manually add in console.log statements.
To use the profiler, just go to the Console tab and click the "Profile" button. Then use your app for a bit or reload the page and then click the "Profile" button again. You'll then see a detailed report that shows what functions were called and how much time each one took.
http://michaelsync.net/2007/09/10/firebug-tutorial-logging-profiling-and-commandline-part-ii
Understanding Firebug profiler output
Not unless you explicitly attach that information to the DOM.
You can, however, set breakpoints in the developers tools for some browsers, such as Safari, Chrome and Firebug for Firefox.

preventing a browser from losing focus on external app call

I'm building a quick VOIP demo using Skype and when I press a call button, the Skype application takes the focus away from the browser. You can try here http://developer.skype.com/skype-uris/skype-uri-tutorial-webpages where you'll find several "Try it here" links. When I click those links, I would like the browser to maintain focus. Is there a way to do this?
Thanks.
What you would need to do is apparently called "focus stealing" from my web searches.
At least as far as Windows is concerned, there does not seem to be a reliable way to do this from the browser alone.
I just googled "focus stealing" (which is what the JavaScript only solution would need to do to get this done) and found many answers showing that, though theoretically possible, depending on the configuration of Windows stealing the focus away from Skype by the browser would probably not work in the majority of cases.
The complaints in the Google links are numerous and some answers conflict, but it looks like reliably "stealing the focus" back to the browser is not going to be supported.
This is a good thing though, if you think about it - I do not personally want just any old JavaScript program running in my browser to change my focus from what I am working on back to the browser willy nilly - this would be a very annoying behavior for a web page to be able to do at best, making my system useless at worst.
If you could do it in this case using some methodology allowed in a browser, so could anyone else - even malevolent websites.
The best answer is to never let the focus leave the browser, but I have no idea how to do that in your specific case. Perhaps whatever means you are using to launch Skype may have an option or something to launch it in the background or whatever, never changing the focus.
I did not hit on specific links pertaining to Apple OSes, Linux or mobile OSes, but I have a feeling the same concerns and limitations apply for those as well.
Here are some of the links on the Google search (and sorry about the bad news for your needs):
Microsoft Answers Forum Post
Focus stealing is evil
http://pcsupport.about.com/od/windowsxp/ht/stealingfocus02.htm
you can open it on new window, then close the new window and refocus on yours
somthing like:
a=window.open('skype:ohadcn?chat',10,10);
//i couldn't find a relevant event, onload() do not work for me here
//so i used setTimeOut, hoping that two seconds is enough to open skype but not enough to loose the user
setTimeout(function(){ a.close();window.focus();},2000)
I went to the skype tutorial page in Chrome, brought up the console and tried Ohad's answer, but it would not return the focus to the tutorial web page.
I even tried a script to perpetually put the focus in the Search textbox:
function ASDF() {
document.getElementsByName("q")[0].focus();
setTimeout(ASDF, 1000);
}
setTimeout(ASDF, 1000);
Still no luck.
I tried changing Ohad's script so that it would reopen the tutorial page in a new window after the skype app opened. It would work if the tutoral/console page was the only tab in the window:
a=window.open('skype:ohadcn?chat',10,10);
setTimeout(function(){
a.close();
a=window.open('http://developer.skype.com/skype-uris/skype-uri-tutorial-webpages', 10, 10);
window.close();},2000);
However, if the tutorial page/console script was in window with other tabs, it did not return focus to the reopened page. Not to mention, IE might warn the user that the original page is trying to close.
I do not think there is a way to consistently achieve your goal, but I reserve the right to be wrong.

Detect if browser has more then 1 tab/window open

So i am developing a quiz web application. And i wanted to add a setting that the administrator of the quiz could set that would make it so the user could only have 1 window/tab open while the quiz is being taken.
The reason for this is to make it so they cant goto like google and google the answer while the quiz window/tab is open. Of course they could always open a different browser and do it that way, but still thought it would be a nice feature to have for them to enable.
Now i dont know if this would fall under a security sandbox violation (and thus not be available at all) but since i only want to detect if another tab or window is open and not get actual information about the tab/window i am hoping that this is someway possible using javascript.
You can't, but a possible workaround would be to use the new HTML5 fullscreen API. You could use a setInterval function to regularly test that document.fullScreen == true to ensure that the user has not toggled off the full screen.
This only works in modern browsers, and it's trivial to work around if the user knows his way around the JS console, but it does seem to fit your requirements.
Note that all fullscreen API implementations are currently vendor-prefixed.
There seems to be viable alternative to the approach described below the line: using Page Visibility API, currently supported by all the modern browsers. This looks like far more reliable than listening for blur. There's one possible way to do it:
// on quiz start
document.addEventListener('visibilitychange', function() {
if (document.hidden) {
console.log('Y U hide?');
}
});
The problem is that visibilitychange event is fired only when page goes from visible to hidden (and vise versa). It still lets user open two browser instances - one with the quiz page, one with any favorite search engine, for example.
While you cannot detect the number of tabs open, you can try to check when the user goes away from the quiz page with this trick:
$(function(){
$(window).blur(function() {
console.log('I see what you did here!');
});
});
Sadly, it'll also give you plenty of false positives.
Can't, and shouldn't, be done.

Mozilla notification showing browser on click

I'm trying to make Mozilla FireFox plugin showing notification. Notifications are visible for Windows and even Mac I want the user to click the notification and open the web page, it sounds pretty simple.
But when adding observer and making window.open or gBroswer.addTab window is opened and tab is opened but in case FireFox is minimized when the notification is shown windows are opened in background and not visible to the user.
Tried to use Components.interfaces.nsIAlertsService and chrome://global/content/alerts/alert.xul they work the same from this perspective.
Is there a way to tell the browser to be top most and be visible to the user?
It doesn't look like this can be done. Firefox generally only supports switching focus between different browser windows when one of them is already focused (via window.focus()). To handle notifications the way you want it (and the way Thunderbird does it) one would need to call SetForegroundWindow() on Windows - there are only two occasions in the Firefox code where this function is called. One is when a new Firefox process is started, the other is when one Firefox window is being minimized. Unfortunately, in this case neither can really be used and Thunderbird indeed uses custom code rather than existing XPCOM APIs to bring itself into foreground.

Maximizing the current window in javascript

Is there a way I can maximize a currently minimized window from Javascript? Here's my situation:
I have a series of links that all target the same external window (e.g. "MyNewWindow"). When I click a link, a new window pops up. If I click another link, the page pops up in the same window as expected. If I minimize the "MyNewWindow" popup, I'd like to be able to click another link and have that window maximize.
My approach was to put something on the onLoad part of the body so that when the page is refreshed it will automatically "maximize" if it is minimized. Note: Using window.MoveTo() and window.resizeTo() doesnt seem to do the trick (the window stays minimized).
Thanks!
For all of you know-it-alls, there are perfectly good reasons to want to know how to do this. Here's the reason I needed this:
I'm deploying SCORM modules to a variety of Learning Management Systems (LMSs)
One LMS that a client is using launches the module in a small (600x400) window, with the user controls to maximize or resize said window DISABLED
The client doesn't know how to change this launch behavior
My only option is to try to maximize via javascript, because the idiots who made the LMS took away the user's ability to manage their own windows.
window.moveTo(0, 0);
window.resizeTo(screen.availWidth, screen.availHeight);
This may not work in IE depending on the security zone your page is falling under, and it may not work in Chrome at all. But for a corporate environment in an intranet, it has a good chance of working.
Don't do this, you are not allowed to do this by most modern browsers for a reason.
In a tabbed environment you're not messing with only the window you may have created, but all of my tabs, that's unacceptable. It's the user's computer, user's browser, it's the user who chose to go to your site...let them size the window the way they want it, doing anything else breaks their experience...and their trust in your site.
The behavior you're looking to emulate is what your run-of-the-mill malware does...re-think your approach, please. For example focusing that window is appropriate for what you want, let the default behavior of the browser take over from there, like this:
var thatWindow = window.open(url, "linkWindow");
thatWindow.focus();
try to use window.open(url,fullscreen=yes);
if you out fullscreen=yes than while clinking on link automatically

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