src/background.js

// To generate isoLangs, edit code at isolangs.json and use Closure to minimize it
var isoLangs={af:{name:"Afrikaans",nativeName:"Afrikaans"},sq:{name:"Albanian",nativeName:"Shqip"},am:{name:"Amharic",nativeName:"\u12a0\u121b\u122d\u129b"},ar:{name:"Arabic",nativeName:"\u0627\u0644\u0639\u0631\u0628\u064a\u0629"},hy:{name:"Armenian",nativeName:"\u0540\u0561\u0575\u0565\u0580\u0565\u0576"},az:{name:"Azerbaijani",nativeName:"az\u0259rbaycan dili"},eu:{name:"Basque",nativeName:"euskara"},be:{name:"Belarusian",nativeName:"\u0411\u0435\u043b\u0430\u0440\u0443\u0441\u043a\u0430\u044f"},
bn:{name:"Bengali",nativeName:"\u09ac\u09be\u0982\u09b2\u09be"},bs:{name:"Bosnian",nativeName:"bosanski jezik"},bg:{name:"Bulgarian",nativeName:"\u0431\u044a\u043b\u0433\u0430\u0440\u0441\u043a\u0438 \u0435\u0437\u0438\u043a"},ca:{name:"Catalan",nativeName:"Catal\u00e0"},ceb:{name:"Cebuano",nativeName:"Bisaya"},ny:{name:"Chichewa",nativeName:"chiChe\u0175a"},zh:{name:"Chinese",nativeName:"\u4e2d\u6587 (Zh\u014dngw\u00e9n)"},co:{name:"Corsican",nativeName:"corsu"},hr:{name:"Croatian",nativeName:"hrvatski"},
cs:{name:"Czech",nativeName:"\u010desky"},da:{name:"Danish",nativeName:"dansk"},nl:{name:"Dutch",nativeName:"Nederlands"},en:{name:"English",nativeName:"English"},eo:{name:"Esperanto",nativeName:"Esperanto"},et:{name:"Estonian",nativeName:"eesti"},tl:{name:"Filipino",nativeName:"Pilipino"},fi:{name:"Finnish",nativeName:"suomi"},fr:{name:"French",nativeName:"fran\u00e7ais"},fy:{name:"Frisian",nativeName:"Frysk"},gl:{name:"Galician",nativeName:"Galego"},ka:{name:"Georgian",nativeName:"\u10e5\u10d0\u10e0\u10d7\u10e3\u10da\u10d8"},
de:{name:"German",nativeName:"Deutsch"},el:{name:"Greek",nativeName:"\u0395\u03bb\u03bb\u03b7\u03bd\u03b9\u03ba\u03ac"},gu:{name:"Gujarati",nativeName:"\u0a97\u0ac1\u0a9c\u0ab0\u0abe\u0aa4\u0ac0"},ht:{name:"Haitian Creole",nativeName:"Krey\u00f2l ayisyen"},ha:{name:"Hausa",nativeName:"Hausa"},haw:{name:"Hawaiian",nativeName:"Hausa"},iw:{name:"Hebrew",nativeName:"\u05e2\u05d1\u05e8\u05d9\u05ea"},hi:{name:"Hindi",nativeName:"\u0939\u093f\u0928\u094d\u0926\u0940, \u0939\u093f\u0902\u0926\u0940"},hmn:{name:"Hmong",
nativeName:"lus Hmoob"},hu:{name:"Hungarian",nativeName:"Magyar"},is:{name:"Icelandic",nativeName:"\u00cdslenska"},ig:{name:"Igbo",nativeName:"As\u1ee5s\u1ee5 Igbo"},id:{name:"Indonesian",nativeName:"Bahasa Indonesia"},ga:{name:"Irish",nativeName:"Gaeilge"},it:{name:"Italian",nativeName:"Italiano"},ja:{name:"Japanese",nativeName:"\u65e5\u672c\u8a9e (\u306b\u307b\u3093\u3054\uff0f\u306b\u3063\u307d\u3093\u3054)"},jv:{name:"Javanese",nativeName:"basa Jawa"},kn:{name:"Kannada",nativeName:"\u0c95\u0ca8\u0ccd\u0ca8\u0ca1"},
kk:{name:"Kazakh",nativeName:"\u049a\u0430\u0437\u0430\u049b \u0442\u0456\u043b\u0456"},km:{name:"Khmer",nativeName:"\u1797\u17b6\u179f\u17b6\u1781\u17d2\u1798\u17c2\u179a"},ko:{name:"Korean",nativeName:"\ud55c\uad6d\uc5b4 (\u97d3\u570b\u8a9e)"},ku:{name:"Kurdish (Kurmanji)",nativeName:"Kurd\u00ee"},ky:{name:"Kyrgyz",nativeName:"\u043a\u044b\u0440\u0433\u044b\u0437 \u0442\u0438\u043b\u0438"},lo:{name:"Lao",nativeName:"\u0e9e\u0eb2\u0eaa\u0eb2\u0ea5\u0eb2\u0ea7"},la:{name:"Latin",nativeName:"latine"},
lv:{name:"Latvian",nativeName:"latvie\u0161u valoda"},lt:{name:"Lithuanian",nativeName:"lietuvi\u0173 kalba"},lb:{name:"Luxembourgish",nativeName:"L\u00ebtzebuergesch"},mk:{name:"Macedonian",nativeName:"\u043c\u0430\u043a\u0435\u0434\u043e\u043d\u0441\u043a\u0438 \u0458\u0430\u0437\u0438\u043a"},mg:{name:"Malagasy",nativeName:"Malagasy fiteny"},ms:{name:"Malay",nativeName:"bahasa Melayu"},ml:{name:"Malayalam",nativeName:"\u0d2e\u0d32\u0d2f\u0d3e\u0d33\u0d02"},mt:{name:"Maltese",nativeName:"Malti"},
mi:{name:"M\u0101ori",nativeName:"te reo M\u0101ori"},mr:{name:"Marathi",nativeName:"\u092e\u0930\u093e\u0920\u0940"},mn:{name:"Mongolian",nativeName:"\u043c\u043e\u043d\u0433\u043e\u043b"},my:{name:"Myanmar",nativeName:"\u1017\u1019\u102c\u1005\u102c"},ne:{name:"Nepali",nativeName:"\u0928\u0947\u092a\u093e\u0932\u0940"},no:{name:"Norwegian",nativeName:"Norsk"},ps:{name:"Pashto",nativeName:"\u067e\u069a\u062a\u0648"},fa:{name:"Persian",nativeName:"\u0641\u0627\u0631\u0633\u06cc"},pl:{name:"Polish",
nativeName:"polski"},pt:{name:"Portuguese",nativeName:"Portugu\u00eas"},pa:{name:"Punjabi",nativeName:"\u0a2a\u0a70\u0a1c\u0a3e\u0a2c"},ro:{name:"Romanian",nativeName:"rom\u00e2n\u0103"},ru:{name:"Russian",nativeName:"\u0440\u0443\u0441\u0441\u043a\u0438\u0439 \u044f\u0437\u044b\u043a"},sm:{name:"Samoan",nativeName:"gagana faa Samoa"},gd:{name:"Scots Gaelic",nativeName:"G\u00e0idhlig"},sr:{name:"Serbian",nativeName:"\u0441\u0440\u043f\u0441\u043a\u0438 \u0458\u0435\u0437\u0438\u043a"},st:{name:"Sesotho",
nativeName:"Sesotho"},sn:{name:"Shona",nativeName:"chiShona"},sd:{name:"Sindhi",nativeName:"\u0938\u093f\u0928\u094d\u0927\u0940"},si:{name:"Sinhala",nativeName:"\u0dc3\u0dd2\u0d82\u0dc4\u0dbd"},sk:{name:"Slovak",nativeName:"sloven\u010dina"},sl:{name:"Slovenian",nativeName:"sloven\u0161\u010dina"},so:{name:"Somali",nativeName:"Soomaaliga"},es:{name:"Spanish",nativeName:"espa\u00f1ol"},su:{name:"Sundanese",nativeName:"Basa Sunda"},sw:{name:"Swahili",nativeName:"Kiswahili"},sv:{name:"Swedish",nativeName:"svenska"},
tg:{name:"Tajik",nativeName:"\u0442\u043e\u04b7\u0438\u043a\u04e3"},ta:{name:"Tamil",nativeName:"\u0ba4\u0bae\u0bbf\u0bb4\u0bcd"},te:{name:"Telugu",nativeName:"\u0c24\u0c46\u0c32\u0c41\u0c17\u0c41"},th:{name:"Thai",nativeName:"\u0e44\u0e17\u0e22"},tr:{name:"Turkish",nativeName:"T\u00fcrk\u00e7e"},uk:{name:"Ukrainian",nativeName:"\u0443\u043a\u0440\u0430\u0457\u043d\u0441\u044c\u043a\u0430"},ur:{name:"Urdu",nativeName:"\u0627\u0631\u062f\u0648"},uz:{name:"Uzbek",nativeName:"zbek"},vi:{name:"Vietnamese",
nativeName:"Ti\u1ebfng Vi\u1ec7t"},cy:{name:"Welsh",nativeName:"Cymraeg"},xh:{name:"Xhosa",nativeName:"isiXhosa"},yi:{name:"Yiddish",nativeName:"\u05d9\u05d9\u05b4\u05d3\u05d9\u05e9"},yo:{name:"Yoruba",nativeName:"Yor\u00f9b\u00e1"},za:{name:"Zhuang, Chuang",nativeName:"Sa\u026f cue\u014b\u0185"},zu:{name:"Zulu",nativeName:"isiZulu"}};

var array_elements = new Array(), translator_tab = false, translator_window = false;

function isEmpty(obj) {
    return Object.keys(obj).length === 0;
}

function click(info, tab) {
	chrome.storage.sync.get("uniquetab", function(items) {
		var settings_tab = {'url': 'https://translate.google.com/#auto/'+array_elements[info.menuItemId]['langCode']+'/'+encodeURIComponent(info.selectionText)};
		if (translator_tab && items.uniquetab == "yep") {
			chrome.tabs.update(translator_tab, settings_tab, function(tab){
				chrome.tabs.highlight({'windowId': tab.windowId, 'tabs': tab.index}, function() {
					chrome.windows.update(tab.windowId, {focused: true}, function() {});
				});
			});
		} else if (items.uniquetab == "panel") {
			chrome.windows.create({
				type: 'panel', url: 'https://translate.google.com/#auto/'+array_elements[info.menuItemId]['langCode']+'/'+encodeURIComponent(info.selectionText), width: 1000, height: 382}, function(tab) {
					translator_window = tab.windowId;
					translator_tab = tab.id;
					chrome.windows.onRemoved.addListener(function (windowId) {
						if (windowId == translator_window) {
							translator_window = false;
							translator_tab = false;
						}
					});
				}
			);
		} else {
			chrome.tabs.create(settings_tab, function(tab) {
				translator_window = tab.windowId;
				translator_tab = tab.id;
				chrome.tabs.onRemoved.addListener(function (tabId, removeInfo) {
					if (tabId == translator_tab) {
						translator_window = false;
						translator_tab = false;
					}
				});
			});
		}
	});
}

function click2(info, tab) {
	if (chrome.runtime.openOptionsPage) {
		// New way to open options pages, if supported (Chrome 42+).
		chrome.runtime.openOptionsPage();
	} else {
		chrome.tabs.create({'url': 'chrome-extension://'+chrome.i18n.getMessage("@@extension_id")+'/options.html', 'active': true}, function(tab) {
			chrome.windows.update(tab.windowId, {'focused': true}, function() {});
		});
	}

}

function createmenus() {
	chrome.storage.sync.get("translateinto", function(items) {
		chrome.contextMenus.removeAll();

		var count = 0, singleone = true;

		for (var language in items.translateinto) {
			if (count == 0) {
				count++;
			} else {
				singleone = false;
				break;
			}
		}

		if (singleone) {
			for (var language_id in items.translateinto) {
				var language = items.translateinto[language_id];
				var languagem = isoLangs[language];
				var title = languagem.name + " ("+languagem.nativeName+")";
				var parent = chrome.contextMenus.create({"id": "tr_single_parent", "title": chrome.i18n.getMessage("contextmenu_title2", languagem.name), "contexts": ["selection"]});
				array_elements[parent] = new Array();
				array_elements[parent]["langCode"] = language;
				array_elements[parent]["langName"] = languagem.name;
				array_elements[parent]["langNativeName"] = language.nativeName;
			}
		} else {
			var parent = chrome.contextMenus.create({"id": "parent", "title": chrome.i18n.getMessage("contextmenu_title"), "contexts": ["selection"]});
			for (var language_id in items.translateinto) {
				var language = items.translateinto[language_id];
				var languagem = isoLangs[language];
				var title = languagem.name + " ("+languagem.nativeName+")";
				var id = chrome.contextMenus.create({"id": "tr_language_"+language, "title": title, "parentId": parent, "contexts":["selection"]});
				array_elements[id] = new Array();
				array_elements[id]["langCode"] = language;
				array_elements[id]["langName"] = languagem.name;
				array_elements[id]["langNativeName"] = language.nativeName;
			}
			var id = chrome.contextMenus.create({"id": "tr_separator", "type": "separator","parentId": parent, "contexts":["selection"]});
			var id = chrome.contextMenus.create({"id": "tr_options", "title": chrome.i18n.getMessage("contextmenu_edit"), "parentId": parent, "contexts":["selection"]});
		}
	});
}

chrome.runtime.onInstalled.addListener(function(details) {
	chrome.storage.sync.get(null, function(items) {
		if (details.reason == "install") {
			if (isEmpty(items)) {
				var settings = {'translateinto': {}, 'uniquetab': ''}, default_language = chrome.i18n.getMessage("@@ui_locale").split("_")[0];
				if (isoLangs[default_language] != "undefined") {
					settings.translateinto[default_language] = default_language;
				}
				chrome.storage.sync.set(settings, function() {
					chrome.notifications.create("install", {
						type: "basic",
						iconUrl: "icons/translate-128.png",
						title: chrome.i18n.getMessage("notification_install_title"),
						message: chrome.i18n.getMessage("notification_install_message"),
						isClickable: true
					}, function(id) {});
				});
			}
		}
		if (details.reason == "update") {
			var version = details.previousVersion.split(".");
			if (version[0] == "0" && version[1] < "6") {
				var settings = {'languages': {}, 'uniquetab': ''}, default_language = chrome.i18n.getMessage("@@ui_locale").split("_")[0];
				if (isoLangs[default_language] != "undefined") {
					settings.languages[default_language] = default_language;
				}
				chrome.storage.sync.set(settings, function() {
					chrome.notifications.create("upgradedtostorage", {
						type: "basic",
						iconUrl: "icons/translate-128.png",
						title: chrome.i18n.getMessage("notification_upgradedtostorage_title"),
						message: chrome.i18n.getMessage("notification_upgradedtostorage_message"),
						isClickable: true
					}, function(id) {});
				});
			}
			if (version[0] == "0" && version[1] < "7") {
				items.translateinto = {};
				var i = 0;
				for (var language in items.languages) {
					items.translateinto[i] = items.languages[language];
					i++;
				}
				delete(items.languages);
				chrome.storage.sync.set(items, function() {
					chrome.notifications.create("reorder", {
						type: "basic",
						iconUrl: "icons/translate-128.png",
						title: chrome.i18n.getMessage("notification_reorder_title"),
						message: chrome.i18n.getMessage("notification_reorder_message"),
						isClickable: true
					}, function(id) {});
				});
			}
		}
	});
});

chrome.storage.onChanged.addListener(function(changes, areaName) {
	if (areaName == "sync")
		createmenus();
});

chrome.storage.sync.get(null, function(items) {
	if (items.translateinto) {
		createmenus();
	} else {
		chrome.contextMenus.removeAll();
		var parent = chrome.contextMenus.create({"id": "tr_parent", "title": chrome.i18n.getMessage("contextmenu_title"), "contexts":["selection"]});
		var id = chrome.contextMenus.create({"id": "tr_options", "title": chrome.i18n.getMessage("contextmenu_edit"), "parentId": parent, "contexts":["selection"]});
	}
});

chrome.notifications.onClicked.addListener(function(notification_id) {
	switch(notification_id) {
		case "install":
		click2();
		break;

		case "upgradedtostorage":
		click2();
		break;

		case "reorder":
		click2();
		break;
	}
	chrome.notifications.clear(notification_id, function() {

	});
});

chrome.contextMenus.onClicked.addListener(function(info, tab) {
	if (info.menuItemId == "tr_options") {
		click2(info, tab);
	} else {
		click(info, tab);
	}
});