Ext Controller Button click event firing twice.

Search.js

/* Ext Controller Button click event firing twice.
 * 
 * In our custom routing we lookup the controller by name and fire the init() method.
 * We found in doing so when we had components with event listeners firing twice. 
 * To get around all the duplicate events, rather than say clearing all the event
 * listeners in init(), we moved the this.control() into the onLaunch() event. 
 * As init() is called when your application boots up, and the onLaunch() is
 * kind of like init(), but called after the viewport is created.
 */

Ext.define('App.controller.Search', {
    extend: 'Ext.app.Controller',
    
    views: [
        'transaction.Search'
    ],
    
    // Called when your application boots.
    init: function(app) {
        console.log('App.controller.Transaction.Search init');
    },
    
    // Like init, but called after the viewport is created.
    onLaunch: function(app){
	console.log('App.controller.Transaction.Search onLaunch');	
	
	this.control({
	    'transaction-search tool[action=help]': {
		click: this.onHelpClick
	    }
        });    
    },
    
    index: function(){
	console.log('App.controller.Transaction.Search index');
	this.render('transaction.Search');
    },
    
    onHelpClick: function(btn) {
	Ext.Msg.show({
	    title: 'Help Text',
	    msg: 'Lorem ipsum dolor set amet.',
	    buttons: Ext.Msg.OK,
	    icon: Ext.Msg.QUESTION
	});
    }
});