/*

© Copyright 2008 Nokia Corporation. All rights reserved.

IMPORTANT:  The Nokia software ("WRTKit and Example Widget files") is supplied to you by Nokia

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Widget files, to use, reproduce, and redistribute the WRTKit and Example files, in text form (for HTML,

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Widgets.

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WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

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*/

///////////////////////////////////////////////////////////////////////////////

// The UI manager manages a set of views and other user interface elements.

// Constructor.

function UIManager(viewParentElement, scrollbarParentElement, enableScrollBar, delayInit) {    

    uiLogger.debug("UIManager(" + viewParentElement + ", " + scrollbarParentElement + ")");

    if (delayInit == null) {

        this.init(viewParentElement, enableScrollBar, scrollbarParentElement);

    }

}

// Parent element for views.

UIManager.prototype.viewParentElement = null;

// Parent element for scrollbar.

UIManager.prototype.scrollbarParentElement = null;

// The currently displayed view.

UIManager.prototype.currentView = null;

// Reference to the scrollbar.

UIManager.prototype.scrollbar = null;

// Current scroll Y position.

UIManager.prototype.scrollY = -1;

// Current viewport height.

UIManager.prototype.viewportHeight = -1;

// Current document height.

UIManager.prototype.documentHeight = -1;

// Timer identifier or null if no active timer.

UIManager.prototype.timerId = null;

// Interval for timer ticks for the UI manager timer (in milliseconds)

UIManager.prototype.TIMER_INTERVAL = 250;

// Reference to the notification popup used to displays notifications.

UIManager.prototype.notificationPopup = null;

// is scrollbar enabled

UIManager.prototype.enableScrollBar = null;

// init function

UIManager.prototype.init = function(viewParentElement, enableScrollBar, scrollbarParentElement) {

    this.enableScrollBar = enableScrollBar;

    // parent element for views

    if (viewParentElement == null) {

        // create a parent for views

        this.viewParentElement = document.createElement("div");

        this.viewParentElement.className = "ViewContainer";

        document.body.appendChild(this.viewParentElement);

    }

    else {

        this.viewParentElement = viewParentElement;

    }

    // parent element for scrollbar

    if (enableScrollBar) {

        if (scrollbarParentElement == null) {

            // create a parent for the scrollbar

            this.scrollbarParentElement = document.createElement("div");

            this.scrollbarParentElement.className = "DocumentScrollbarContainer";

            document.body.appendChild(this.scrollbarParentElement);

        }

        else {

            this.scrollbarParentElement = scrollbarParentElement;

        }

    }

    // currently selected view

    this.currentView = null;

    // create the notification popup

    // the notification popup adds itself as a child element to the document body

    this.notificationPopup = new NotificationPopup();

    // create scrollbar

    if (enableScrollBar) {

        this.scrollbar = new Scrollbar(this.scrollbarParentElement);

    }

    // setup scrollbar tracking

    var self = this;

    this.startTimer();

    if (enableScrollBar) {

        window.addEventListener("resize", function(){

            self.updateScrollbar();

        }, false);

        window.addEventListener("scroll", function(){

            self.updateScrollbar();

        }, false);

    }

};

// Returns the current view.

UIManager.prototype.getView = function() {

    return this.currentView;

};

// Switches to the specified view.

UIManager.prototype.setView = function(view) {

    uiLogger.debug("View set to " + view.id);

    // remove the current view from the parent element

    if (this.currentView != null) {

        this.viewParentElement.removeChild(this.currentView.rootElement);

    }

    // reset scroll

    window.scrollTo(0, 0);

    // add the new view to the parent element

    if (view != null) {

        this.currentView = view;

        this.currentView.resetControlFocusStates();

        this.viewParentElement.appendChild(this.currentView.rootElement);

    }

    // update scrollbar

    if (this.enableScrollBar) {

        this.updateScrollbar();

    }

    // focus the first focusable control

    // a timer is used to prevent unwanted focus shift

    setTimeout(function() { view.focusFirstControl(); }, 1);

};

// Updates the scrollbar.

UIManager.prototype.updateScrollbar = function() {

    if (this.enableScrollBar) {

        // get current viewport and document position and dimensions

        var scrollY = window.scrollY;

        var viewportHeight = window.innerHeight;

        var documentHeight = Math.max(document.documentElement.scrollHeight, document.height);

        // check if the scroll position or view has changed

        if (this.scrollY != scrollY ||

                this.viewportHeight != viewportHeight ||

                this.documentHeight != documentHeight) {

            // scroll position or view has changed

            this.scrollY = scrollY;

            this.viewportHeight = viewportHeight;

            this.documentHeight = documentHeight;

            // update the scrollbar

            this.scrollbar.update(scrollY, viewportHeight, documentHeight);

            uiLogger.debug("Scrollbar updated");

        }

    }

};

// Starts the view manager timer.

UIManager.prototype.startTimer = function() {

    if (this.timerId == null) {

        uiLogger.debug("UIManager timer started");

        var self = this;

        // setup the timer

        this.timerId = setInterval(function() { self.onTimer(); }, this.TIMER_INTERVAL);

    } else {

        uiLogger.warn("UIManager timer already running");

    }

};

// Stops the view manager timer.

UIManager.prototype.stopTimer = function() {

    if (this.timerId != null) {

        // stop the timer

        clearTimeout(this.timerId);

        this.timerId = null;

    } else {

        uiLogger.warn("UIManager timer already stopped");

    }

};

// Timer callback function.

UIManager.prototype.onTimer = function() {

    if (this.enableScrollBar) {

        // make sure the scrollbar is up to date

        this.updateScrollbar();

    }

};

// Displays a notification.

UIManager.prototype.showNotification = function(displayTime, type, text, progress) {

    uiLogger.debug("UIManager.showNotification(" + displayTime + ", " + type + ", " + text + ", " + progress + ")");

    // use the notification popup to show the notification

    this.notificationPopup.showNotification(displayTime, type, text, progress);

};

// Hides the currently displayed notification.

UIManager.prototype.hideNotification = function() {

    uiLogger.debug("UIManager.hideNotification()");

    // hide the notification popup

    this.notificationPopup.hideNotification();

};