/*

� 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,

CSS, or JavaScript files) or binary form (for associated images), for the sole purpose of creating S60

Widgets.

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WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A

PARTICULAR PURPOSE, REGARDING THE EXAMPLES OR ITS USE AND OPERATION

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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;

// View switch animation

UIManager.prototype.viewSwitchAnimation = false;

UIManager.prototype.viewSwitchTimer = null;

UIManager.prototype.viewSwitchDivPos = 0;

UIManager.prototype.VIEW_SWITCH_TIMER_INTERVAL = 25;

// 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){

	// 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();

}