region.js

define(['component'], function (component) {

    /**
     * Region is activity container that has only one running activity at a time
     */
    var region = Object.create(component);


    /**
     * Adds activity to region
     *
     * @param {String} uid UID for the activity
     * @param {Activity} activity
     */
    region.addActivity = function(uid, activity) {
        var region = this;

        // var elId = 'activity' +  uid.substr(0, 1).toUpperCase() + uid.substr(1);
        var elId = uid;
        var el = this.el.find('#' + elId);
        if (el.length == 0) {
            // Create element for the activity
            el = $('<div>').attr('id', elId).appendTo(this.el);
        }

        // Init activity list, if not inited
        if (!this.activities) this.activities = {};

        // Add activity to the list
        this.activities[activity.uid] = activity;

        // Auto-initialize activity
        activity.init(uid, {el: el});


        // Proxy start method
        var activityStart = activity.start;
        activity.start = function(intent) {
            // console.info('REG start');
            // Stop running activity
            if (region.currentActivity && region.currentActivity.running 
                && region.currentActivity !== this) {
                region.currentActivity.stop();
            }

            // Store this as current activity
            region.currentActivity = this;
            activityStart.call(activity, intent);
        }

        // Proxy setState method
        var activitySetState = activity.setState;
    };

    return region;
});