background.js

/* Capture image from tab */
function captureSelection(start, end, imageUrl) {

}
/* browser action */
chrome.browserAction.onClicked.addListener(function(tab) {
        chrome.tabs.executeScript(tab.id, {file: "capture.js"});
        chrome.tabs.insertCSS(tab.id, {file: "style.css"});
        if (HTMLCanvasElement && !HTMLCanvasElement.prototype.toBlob) {
            chrome.tabs.executeScript(null, {file: "canvas-toBlob.js"}); 
        }
    });

chrome.extension.onRequest.addListener(function(request, sender, sendResponse) {
    //var startPoint = request.start;
    //var endPoint = request.end;
    //var x = startPoint.x;
    //var y = startPoint.y;
    //var width = endPoint.x - startPoint.x;
    //var height = endPoint.y - startPoint.y;
    //capture whole window of selected tab
    console.log(sendResponse);
    if (request.action === 'capture') {
        chrome.tabs.captureVisibleTab(null, function(imageUrl) {
                sendResponse({image: imageUrl}); 
            });
    }
    else if (request.action === 'activate') {
        //loop through open window to find access token redirected url 
        var redirectedUrl = null;
        console.log('here here is run');
        /*
        chrome.windows.onCreated.addListener(function(popup) {
                //record the window id. 
                var popupId = popup.id;
                console.log(popupId);
                console.log(popup);
                var popupWindow = chrome.windows.get(popupId, {populate: true}, function(windowWithTabs) {
                        var currentTab =  
                    
                    });
                while (true) { 
                    for (var i = 0; i < popup.tabs.length; i++) {
                        console.log(popup.tabs[i]);
                        if (popup.tabs[i].url.match('www.facebook.com/connect/login_success.html')) {
                            redirectedUrl = popup.tabs[i].url; 
                            break;
                        } 
                    }
                    //if successfully retrieve the url
                    if (redirectedUrl) {
                        
                        sendResponse({accessToken: redirectedUrl});
                        break;
                    }
                }
            }); 
         */   
        getSuccessLoginUrl(sendResponse);
    }
});


function getSuccessLoginUrl(sendBackData) {
     chrome.windows.getAll({populate: true}, function (windows) {
            var successUrl = null;
            var loginWindowId = null;
            for (var i = 0; i < windows.length; i++) {
                var w = windows[i]; 
                if (w.type === 'popup') {
                    //if it is facebook popup
                    var url = w.tabs[0].url;
                    if (url.indexOf('https://www.facebook.com/connect/login_success.html') != -1) {
                        successUrl = url; 
                        loginWindowId = w.id;
                        break;
                    }
                }
            } 
            console.log(loginWindowId);
            if (successUrl != null) {
                console.log(successUrl);
                var accessToken = successUrl.match('access_token=(.*?)&')[1];
                var expireIn = successUrl.match('expires_in=([0-9]*)')[1];
                //chrome.windows.remove(w.id, function() {console.log('closed the logged in popup');});
                //sendResponse({'accessToken': accessToken, 'expireIn': expireIn});
                var authorizationData = {'accessToken': accessToken, 'expireIn': expireIn};
                sendBackData(authorizationData);
                //return authorizationData;
                chrome.windows.remove(loginWindowId, function() {console.log('closed the logged in popup');});
            }
            else {
                getSuccessLoginUrl(sendBackData); 
            }

        });
}