Arrange labels for all kind of density

index.js

function dpToPixel(dp) {
    return ( parseInt(dp) * (Titanium.Platform.displayCaps.dpi / 160));
}

// convert pixel to dp.
function pixelToDp(px,nounit) {
    return ( parseInt(px) / (Titanium.Platform.displayCaps.dpi / 160)) + (nounit?0:'dp');
}

var reArrangeLable = function(){
	var screenwidth = pixelToDp($.vw.toImage().width,true);
	var screenheight = pixelToDp($.vw.toImage().height,true);
	Ti.API.info([screenwidth,screenheight]);
	$.lefttop.top = 0;
	$.lefttop.left = 0;
	
	$.righttop.top = 0;
	$.righttop.left = (screenwidth -$.righttop.width - 20) + 'dp';
	
	$.center.top = (screenheight/2 - $.center.height/2) + 'dp';
	$.center.left = pixelToDp(Ti.Platform.displayCaps.platformWidth/2,true)-($.center.width/2) + 'dp'; 

	
	$.leftbottom.top = screenheight - $.leftbottom.height;
	$.leftbottom.left = 0;
	
	$.rightbottom.top = screenheight - $.rightbottom.height;
	$.rightbottom.left = (screenwidth -$.rightbottom.width) + 'dp';
};

Ti.Gesture.addEventListener('orientationchange',function(e) {
	setTimeout(reArrangeLable,1000);
});

$.index.open();
setTimeout(reArrangeLable,1000);

index.xml

<Alloy>
	<Window class="container">
		<View id="vw">
		<Label id="lefttop" onClick="doClick" backgroundColor="#12ef43">lefttop</Label>
		<Label id="righttop" onClick="doClick" backgroundColor="#ff1243">righttop</Label>
		<Label id="leftbottom" onClick="doClick" backgroundColor="#12ef43">leftbottom</Label>
		<Label id="rightbottom" onClick="doClick" backgroundColor="#ff1243">rightbottom</Label>
		<Label id="center" onClick="doClick" backgroundColor="#ff1243">center</Label>
		</View>
	</Window>
</Alloy>