Implements the basic structure for providing localized documentation;

the site tabs are now in a separate file to ease the translation process,
the language selection menu has been added to the header,
scripts have been added to dynamically switch the language of the
site tabs and dev guide side navigation and save the language
preference in a browser cookie,
and some of the functions in macro.cs have moved into customization.cs.

patch 2:
revised the logic for changing tab and nav languages so that,
in the event that a SPAN node exists for the newly selected language
but the translation has not actually been put there, it will not be selected
and the previously selected language will remain for that node.

patch 3:
revised the logic introduced in patch 2, which, when loading a new page
would actually reveal all languages if the selected language had no
translation. Now, we must loop through each occurance and check whether
a translation is available. If not, then we hide it and show English.

patch 4:
small error fix

tools/droiddoc/templates/assets/android-developer-docs.js

@@ -4,7 +4,7 @@ var devdocNav;
 var sidenav;
 var content;
 var HEADER_HEIGHT = 117;
-var cookie_style = 'android_developer';
+var cookie_namespace = 'android_developer';
 var NAV_PREF_TREE = "tree";
 var NAV_PREF_PANELS = "panels";
 var nav_pref;
@@ -70,8 +70,8 @@ function restoreHeight(packageHeight) {
   $("#nav-tree").css({height:swapperHeight + "px"});
 }
 
-function getCookie(cookie) {
-  var myCookie = cookie_style+"_"+cookie+"=";
+function readCookie(cookie) {
+  var myCookie = cookie_namespace+"_"+cookie+"=";
   if (document.cookie) {
     var index = document.cookie.indexOf(myCookie);
     if (index != -1) {
@@ -87,16 +87,15 @@ function getCookie(cookie) {
   return 0;
 }
 
-function writeCookie(cookie, val, path, expiration) {
+function writeCookie(cookie, val, section, expiration) {
   if (!val) return;  
-  var date = new Date();
-  date.setTime(date.getTime()+(10*365*24*60*60*1000)); // default expiration is one week
-  expiration = expiration ? expiration : date.toGMTString();
-  if (location.href.indexOf("/reference/") != -1) {
-    document.cookie = cookie_style+'_reference_'+cookie+'='+val+'; expires='+expiration+'; path='+'/'+path;
-  } else if (location.href.indexOf("/guide/") != -1) {
-    document.cookie = cookie_style+'_guide_'+cookie+'='+val+'; expires='+expiration+'; path='+'/'+path;
+  section = section == null ? "_" : "_"+section+"_";
+  if (expiration == null) {
+    var date = new Date();
+    date.setTime(date.getTime()+(10*365*24*60*60*1000)); // default expiration is one week
+    expiration = date.toGMTString();
   }
+  document.cookie = cookie_namespace+section+cookie+"="+val+"; expires="+expiration+"; path=/";
 } 
 
 function init() {
@@ -116,8 +115,8 @@ function init() {
   if (!isMobile) {
     $("#resize-packages-nav").resizable({handles: "s", resize: function(e, ui) { resizeHeight(); } });
     $(".side-nav-resizable").resizable({handles: "e", resize: function(e, ui) { resizeWidth(); } });
-    var cookieWidth = getCookie(cookiePath+'width');
-    var cookieHeight = getCookie(cookiePath+'height');
+    var cookieWidth = readCookie(cookiePath+'width');
+    var cookieHeight = readCookie(cookiePath+'height');
     if (cookieWidth) {
       restoreWidth(cookieWidth);
     } else if ($(".side-nav-resizable").length) {
@@ -175,7 +174,9 @@ function resizeHeight() {
   $("#packages-nav").css({height:parseInt(resizePackagesNav.css("height")) - 6 + "px"}); //move 6px for handle
   devdocNav.css({height:sidenav.css("height")});
   $("#nav-tree").css({height:swapperHeight + "px"});
-  writeCookie("height", resizePackagesNav.css("height"), "", null);
+  
+  var section = location.pathname.substring(1,location.pathname.indexOf("/",1));
+  writeCookie("height", resizePackagesNav.css("height"), section, null);
 }
 
 function resizeWidth() {
@@ -190,7 +191,9 @@ function resizeWidth() {
   resizePackagesNav.css({width:sidenavWidth});
   classesNav.css({width:sidenavWidth});
   $("#packages-nav").css({width:sidenavWidth});
-  writeCookie("width", sidenavWidth, "", null);
+  
+  var section = location.pathname.substring(1,location.pathname.indexOf("/",1));
+  writeCookie("width", sidenavWidth, section, null);
 }
 
 function resizeAll() {
@@ -207,7 +210,7 @@ function loadLast(cookiePath) {
   if (location.indexOf("/"+cookiePath+"/") != -1) {
     return true;
   }
-  var lastPage = getCookie(cookiePath + "_lastpage");
+  var lastPage = readCookie(cookiePath + "_lastpage");
   if (lastPage) {
     window.location = lastPage;
     return false;
@@ -216,11 +219,11 @@ function loadLast(cookiePath) {
 }
 
 $(window).unload(function(){
-  var href = location.href;
-  if (href.indexOf("/reference/") != -1) {
-    writeCookie("lastpage", href, "", null);
-  } else if (href.indexOf("/guide/") != -1) {
-    writeCookie("lastpage", href, "", null);
+  var path = location.pathname;
+  if (path.indexOf("/reference/") != -1) {
+    writeCookie("lastpage", path, "reference", null);
+  } else if (path.indexOf("/guide/") != -1) {
+    writeCookie("lastpage", path, "guide", null);
   }
 });
 
@@ -257,7 +260,7 @@ function buildToggleLists() {
 }
 
 function getNavPref() {
-  var v = getCookie('reference_nav');
+  var v = readCookie('reference_nav');
   if (v != NAV_PREF_TREE) {
     v = NAV_PREF_PANELS;
   }
@@ -283,7 +286,7 @@ function swapNav() {
   }
   var date = new Date();
   date.setTime(date.getTime()+(10*365*24*60*60*1000)); // keep this for 10 years
-  writeCookie("nav", nav_pref, "", date.toGMTString());
+  writeCookie("nav", nav_pref, null, date.toGMTString());
 
   $("#nav-panels").toggle();
   $("#panel-link").toggle();
@@ -349,3 +352,57 @@ function toggleAllSummaryInherited(linkObj) {
   }
   return false;
 }
+
+
+function changeTabLang(lang) {
+  var nodes = $("#header-tabs").find("."+lang);
+  for (i=0; i < nodes.length; i++) { // for each node in this language 
+    var node = $(nodes[i]);
+    node.siblings().css("display","none"); // hide all siblings 
+    if (node.not(":empty").length != 0) { //if this languages node has a translation, show it 
+      node.css("display","inline");
+    } else { //otherwise, show English instead 
+      node.css("display","none");
+      node.siblings().filter(".en").css("display","inline");
+    }
+  }
+}
+
+function changeNavLang(lang) {
+  var nodes = $("#side-nav").find("."+lang);
+  for (i=0; i < nodes.length; i++) { // for each node in this language 
+    var node = $(nodes[i]);
+    node.siblings().css("display","none"); // hide all siblings 
+    if (node.not(":empty").length != 0) { // if this languages node has a translation, show it 
+      node.css("display","inline");
+    } else { // otherwise, show English instead 
+      node.css("display","none");
+      node.siblings().filter(".en").css("display","inline");
+    }
+  }
+}
+
+function changeDocLang(lang) {
+  changeTabLang(lang);
+  changeNavLang(lang);
+}
+
+function changeLangPref(lang) {
+  var date = new Date();
+  date.setTime(date.getTime()+(50*365*24*60*60*1000)); // keep this for 50 years
+  writeCookie("pref_lang", lang, null, date);
+  
+  changeDocLang(lang);
+}
+
+function loadLangPref() {
+  var lang = readCookie("pref_lang");
+  if (lang != 0) {
+    $("#language").find("option[value='"+lang+"']").attr("selected",true);
+  }
+}
+
+function getLangPref() {
+  return $("#language").find(":selected").attr("value");
+}
+