Ext.onReady(function(){
    //==== Progress bar 1 ====
    var pbar1 = new Ext.ProgressBar({
       text:'Initializing...'
    });
    var btn1 = Ext.get('btn1');
    btn1.on('click', function(){
        Ext.fly('p1text').update('Working');
        if (!pbar1.rendered){
            pbar1.render('p1');
        }else{
            pbar1.text = 'Initializing...';
            pbar1.show();
        }
        Runner.run(pbar1, Ext.get('btn1'), 10, function(){
            pbar1.reset(true);
            Ext.fly('p1text').update('Done.').show();
        });
    });

    //==== Progress bar 2 ====
    var pbar2 = new Ext.ProgressBar({
        text:'Ready',
        id:'pbar2',
        cls:'left-align',
        renderTo:'p2'
    });
    var btn2 = Ext.get('btn2');
    btn2.on('click', function(){
        Runner.run(pbar2, btn2, 12, function(){
            pbar2.reset();
            pbar2.updateText('Done.');
        });
    });

    //==== Progress bar 3 ====
    var pbar3 = new Ext.ProgressBar({
        id:'pbar3',
        width:300,
        renderTo:'p3'
    });
    pbar3.on('update', function(val){
        //You can handle this event at each progress interval if
        //needed to perform some other action
        Ext.fly('p3text').dom.innerHTML += '.';
    });
    var btn3 = Ext.get('btn3');
    btn3.on('click', function(){
        Ext.fly('p3text').update('Working');
        btn3.dom.disabled = true;
        pbar3.wait({
            interval:200,
            duration:5000,
            increment:15,
            fn:function(){
                btn3.dom.disabled = false;
                Ext.fly('p3text').update('Done');
            }
        });
    });

    //==== Progress bar 4 ====
    var pbar4 = new Ext.ProgressBar({
        text:'Waiting on you...',
        id:'pbar4',
        textEl:'p4text',
        cls:'custom',
        renderTo:'p4'
    });
    var btn4 = Ext.get('btn4');
    btn4.on('click', function(){
        Runner.run(pbar4, btn4, 19, function(){
            pbar4.updateText('All finished!');
        });
    });
});

//Please do not use the following code as a best practice! :)
var Runner = function(){
    var f = function(v, pbar, btn, count, cb){
        return function(){
            if(v > count){
                btn.dom.disabled = false;
                cb();
            }else{
                if(pbar.id=='pbar4'){
                    //give this one a different count style for fun
                    var i = v/count;
                    pbar.updateProgress(i, Math.round(100*i)+'% completed...');
                }else{
                    pbar.updateProgress(v/count, 'Loading item ' + v + ' of '+count+'...');
                }
            }
       };
    };
    return {
        run : function(pbar, btn, count, cb){
            btn.dom.disabled = true;
            var ms = 5000/count;
            for(var i = 1; i < (count+2); i++){
               setTimeout(f(i, pbar, btn, count, cb), i*ms);
            }
        }
    }
}();