background.js

var myTabs = (function () {

    // Instance stores a reference to the Singleton
    var instance;

    function init() {
        var GlobaltabList = [];
        return {
            getGlobalTabList: function () {
                return GlobaltabList;
            }
        };
    }

    return {

        // Get the Singleton instance if one exists
        // or create one if it doesn't
        getInstance: function () {

            if (!instance) {
                // console.log("new instance created");
                instance = init();
            }

            return instance;
        }
    };
})();


function getTabList() {
    return myTabs.getInstance().getGlobalTabList();
}

function printTabList() {
    // console.log("Ids.....");
    var tabList = getTabList();
    for (var i = 0; i < tabList.length; i++) {
        // console.log(tabList[i].id + "-->" + tabList[i].title + ":::" + i);
    }
}


function switchToNextTab() {
    var tabList = getTabList();
    if (tabList.length > 1) {
        switchTabs(tabList[1].id);
    }
}

function indexOfTab(tabId) {

    var tabList = getTabList();
    for (var j = 0; j < tabList.length; j++) {
        if (tabList[j].id === tabId) {
            return j;
        }
    }
    return -1;
}

function switchTabs(tabId) {
    var index = indexOfTab(parseInt(tabId, 10));
    var windowId = getTabList()[index].windowId;
    chrome.windows.update(windowId, {focused: true}, function () {
        chrome.tabs.update(parseInt(tabId, 10), {active: true});
    });
}


function recordTabsRemoved(tabId) {
    var tabList = getTabList();
    var idx = indexOfTab(tabId);
    if (idx >= 0) {
        tabList.splice(idx, 1);
    }
}

function recordTabsAdded(tab) {
    var tabList = getTabList();
    tabList.push(tab);
}

function recordTabsActivated(tabId) {
    var idx = indexOfTab(tabId);
    var tabList = getTabList();
    // console.log(idx);
    if (idx >= 0) {
        var tabs = tabList.splice(idx, 1);
        tabList.unshift(tabs[0]);
    }
}

function init() {

    // count and record all the open tabs for all the windows
    chrome.windows.getAll({populate: true}, function (windows) {

        for (var i = 0; i < windows.length; i++) {
            var t = windows[i].tabs;
            // console.log("new window");
            for (var j = 0; j < t.length; j++) {
                // console.log("new tab");
                recordTabsAdded(t[j]);
            }

        }

        // set the current tab as the first item in the tab list
        chrome.tabs.query({currentWindow: true, active: true}, function (tabArray) {
            // log('initial selected tab', tabArray);
            recordTabsActivated(tabArray[0].id);
        });
    });


    // attach an event handler to capture tabs as they are closed
    chrome.tabs.onRemoved.addListener(function (tabId) {
        // console.log("------------------------------------------------------");
        // console.log("TabId Removed:");
        // console.log(tabId);
        recordTabsRemoved(tabId);
        printTabList();
        // console.log("------------------------------------------------------");

    });

    // attach an event handler to capture tabs as they are opened
    chrome.tabs.onCreated.addListener(function (tab) {

        if (tab.id !== chrome.tabs.TAB_ID_NONE) {
            // console.log("------------------------------------------------------");
            // console.log("TabId created:");
            // console.log(tab.id);
            recordTabsAdded(tab);
            printTabList();
            // console.log("------------------------------------------------------");
        } else {
            // console.log("Null tab id created");
            // console.log(tab.id);
        }

    });

    chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
        if (changeInfo.status == 'complete' && tab.status == 'complete') {
            // console.log("------------------------------------------------------");
            // console.log("TabId Updated:");
            // console.log(tabId);
            var tabList = getTabList();
            var idx = indexOfTab(tabId);
            if (idx >= 0) {
                tabList[idx] = tab;
            } else {
                // console.log("Tab not found");
            }
            printTabList();
            // console.log("------------------------------------------------------");
        } else {
            // console.log("Incomplete request:" + "Old tab id:" + tabId + " new tab Id:" + tab.id);

        }
    });

    chrome.tabs.onReplaced.addListener(function (addedTabId, removedTabId) {
        var idx = indexOfTab(removedTabId);
        var tabList = getTabList();
        if (idx >= 0) {
            tabList[idx].id = addedTabId;
        }
        // console.log("Tab Replaced ^..^" + addedTabId + "Removed Tab Id:" + removedTabId);
    });

    chrome.tabs.onActivated.addListener(function (info) {
        // console.log("------------------------------------------------------");
        // console.log("TabId Activated:");
        // console.log(info.tabId);
        recordTabsActivated(info.tabId);
        printTabList();
        // console.log("------------------------------------------------------");

    });

    chrome.windows.onFocusChanged.addListener(function (windowId) {
        if (windowId != chrome.windows.WINDOW_ID_NONE) {
            chrome.tabs.query({windowId: windowId, active: true}, function (tabArray) {
                if (tabArray.length === 1) {
                    // console.log("------------------------------------------------------");
                    // console.log("TabId Activated(Window Changed):");
                    // console.log(tabArray[0].id);
                    recordTabsActivated(tabArray[0].id);
                    printTabList();
                    // console.log("------------------------------------------------------");
                }

            });
        }
    });

    chrome.commands.onCommand.addListener(function (command) {
        //log('Command:', command);

        if (command === "quick-next-tab") {
            switchToNextTab();
        }


    });

}

init();