MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

var nav = WinJS.Navigation;
WinJS.Namespace.define("Application", {
PageControlNavigator: WinJS.Class.define(
// Define the constructor function for the PageControlNavigator.
function PageControlNavigator (element, options) {
this.element = element || document.createElement("div");
this.element.appendChild(this._createPageElement());
this.home = options.home;
nav.onnavigated = this._navigated.bind(this);
window.onresize = this._resized.bind(this);
//...
document.body.onkeyup = this._keyupHandler.bind(this);
document.body.onkeypress = this._keypressHandler.bind(this);
document.body.onmspointerup = this._mspointerupHandler.bind(this);
}, {
First we see the definition of the Application namespace as a container for the PageControl-
Navigator class. Its constructor receives the element that contains it (the contenthost div in
default.html), or it creates a new one if none is given. The constructor also receives the options declared
in the data-win-options attribute of that element. The page control then appends its contents to this
root element, adds a listener for the WinJS.Navigation.onnavigated event, and sets up listeners for
keyboard, mouse, and resizing events. It then waits for someone to call WinJS.Navigation.navigate,
which happens in the activated handler of js/default.js, to navigate to either the home page or the last
page viewed if previous session state was reloaded:
if (app.sessionState.history) {
nav.history = app.sessionState.history;
}
args.setPromise(WinJS.UI.processAll().then(function () {
if (nav.location) {
nav.history.current.initialPlaceholder = true;
return nav.navigate(nav.location, nav.state);
} else {
return nav.navigate(Application.navigator.home);
}
}));
When that happens, the PageControlNavigator’s _navigated handler is invoked, which in turn calls
WinJS.UI.Pages.render to do the loading, the contents of which are then appended as child elements
to the navigator control:
_navigated: function (args) {
var that = this;
var newElement = that._createPageElement();
var parentedComplete;
var parented = new WinJS.Promise(function (c) { parentedComplete = c; });
args.detail.setPromise(
WinJS.Promise.timeout().then(function () {
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