[TIMOB-14290] iOS: ListView: scrollToItem lags with large lists

var myTemplate = {
    childTemplates: [
        {                     
            type: 'Ti.UI.Label',
            bindId: 'one',      
            properties: {       
                color: 'black',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '10dp'
            }
        },
        {                         
            type: 'Ti.UI.Label',  
            bindId: 'two',      
            properties: {        
                color: 'black',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '50dp'
            }
        },
        {                        
            type: 'Ti.UI.Label', 
            bindId: 'three',   
            properties: {        
                color: 'gray',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '90dp'
            }
        },
        {                        
            type: 'Ti.UI.Label', 
            bindId: 'four',   
            properties: {        
                color: 'gray',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '130dp'
            }
        },
        {                        
            type: 'Ti.UI.Label', 
            bindId: 'five',   
            properties: {        
                color: 'gray',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '170dp'
            }
        },
        {                        
            type: 'Ti.UI.Label', 
            bindId: 'six',   
            properties: {        
                color: 'gray',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '210dp'
            }
        },
        {                        
            type: 'Ti.UI.Label', 
            bindId: 'seven',   
            properties: {        
                color: 'gray',
                font: { fontFamily:'Arial', fontSize: '14dp' },
                left: '240dp'
            }
        }
    ]
};
 
var upa = function() {
    $.list.scrollToItem(0, 0, {position: Titanium.UI.iPhone.TableViewScrollPosition.TOP});  
}
 
var downa = function() {
    $.list.scrollToItem(3, 0, {position: Titanium.UI.iPhone.TableViewScrollPosition.TOP});  
}
 
var up = function() {
    $.list.scrollToItem(0, 0, {animated: false, position: Titanium.UI.iPhone.TableViewScrollPosition.TOP}); 
}
 
var down = function() {
    $.list.scrollToItem(3, 0, {animated: false, position: Titanium.UI.iPhone.TableViewScrollPosition.TOP}); 
}
 
 
var genData = function(section) {
    var data = [];
    for(i=0;i<20;i++) {
        data.push({one:{text:section + ' one'}, two:{text: 'two'}, three:{text: 'three'}, four:{text: 'four'}, five:{text: 'five'}, six:{text: 'six'}, seven:{text: 'seven'}, template: 'template'})
    }
 
    return data;
}
 
var genSections = function() {
    var sections = [];
    for(j=0;j<5;j++) {
        var section = Ti.UI.createListSection({headerTitle:'Section '+j});
        section.setItems(genData(j));
        sections.push(section);
    }
 
    return sections;
}
 
var listView = $.list;
listView.templates = { 'template': myTemplate };
listView.setSections(genSections());

$.index.open();

<Alloy>
	<Window>
        <View id="listView">
            <ListView id="list"/>
            <View id="buttons">
                <Button onClick="upa">Up (anim)</Button>
                <Button onClick="downa">Down (anim)</Button>
                <Button onClick="up">Up</Button>
                <Button onClick="down">Down</Button>
            </View>
        </View>
    </Window>
</Alloy>

"#listView": {
    backgroundColor: "white"
}
 
"#list" : {
    height: 420,
    top: 0
}
 
"#buttons": {
    backgroundColor: "gray",
    bottom:0,
    height:40,
    layout: 'horizontal'
}