How to handle back button in sencha touch application without NavigationView?

Question

I have googled, but all the useful articles are all describing how to handle the back button in NavigationView, but I just use the common view like below.

Ext.define('emall.view.MyPage', {
    extend: 'Ext.Container',
    alias: 'widget.mypage',

    requires: [
        'emall.view.topplus',
        'Ext.TitleBar',
        'Ext.Button',
        'Ext.Toolbar'
    ],

I am do changes on the existing app, so I can not change the base architecture. So I am wondering how to handle the back button?

I know below way can capture the back button event.(I added the below method to app.js)

if (Ext.os.is('Android')) {
    document.addEventListener("backbutton", Ext.bind(onBackKeyDown, this), false);

    function onBackKeyDown(eve) {

        eve.preventDefault();
        //do something
        alert('back button pressed');
        history.back();  

    }
}

But what can I do in the method onBackKeyDown ? Since this event will be fired when I click the back button no matter which page I am staying. So I can not go to the previous page like Ext.Viewport.animateActiveItem('xxxx') since I do not know the current page I am staying.

If I can get the current page name, I can handle it like below.

if(currentpage=='xxx')
            Ext.Viewport.animateActiveItem('profile', {
                type : 'slide',
                direction:'left'
            });

Answer 1

Use this code:

document.addEventListener("deviceready", onDeviceReady, false);
function onDeviceReady() {if (navigator.userAgent.match("Android"))
{       document.addEventListener("backbutton", onBackKeyDown, true);  }  

}

function onBackKeyDown(e) {
    if (window.location.hash === "#splashviewRoute") {      
        navigator.app.exitApp();
    }   
    else  {
        window.history.back();
    }
}