gistfile1.js

function FullTask()
{
    this._downloadTask = new DownloadTask();
    this._processTask = new ProcessTask();
    this._renderTask = new RenderTask();

    this._progress = new ProgressModel();
    this._progress.setTotal(this._downloadTask.progress().total() * 8 + 
        this._processTask.progress().total() +
        this._renderTask.progress().total());
    
    this._downloadTask.progress().addEventListener(WorkChanged, this._onWorkChanged.bind(this));
    this._processTask.progress().addEventListener(WorkChanged, this._onWorkChanged.bind(this));
    this._renderTask.progress().addEventListener(WorkChanged, this._onWorkChanged.bind(this));

    this._progress.addEventListener(Cancelled, this._onCancelled.bind(this));
    this._renderTask.progress().addEventListener(WorkDone, this._onDone.bind(this));
}

FullTask.prototype = {
    /**
     * @return {!ProgressInterface}
     */
    progress: function()
    {
        return this._progress;
    },

    _onWorkChanged: function(event)
    {
        this._progress.setWorked(this._downloadTask.progress().worked() * 8 + 
            this._processTask.progress().worked() +
            this._renderTask.progress().worked());
    },

    _onCancelled: function(event)
    {
        this._downloadTask.progress().cancel();
        this._processTask.progress().cancel();
        this._renderTask.progress().cancel();
    },

    _onDone: function(event)
    {
        this._progress.done();
    },
}