[TIMOB-17923] iOS: Complex non-composite layouts show before lay-out since 3.3.0

A few weeks ago I started noticing that a lot of apps where I used complex horizontal and vertical layouts were showing their children before they were layed out. I made a simple test case that showed this has been the case since 3.3.0 and is not related to iOS 8 which I first assumed. *NOTE:* In some occasions I've (as well as Jason) have seen the children not being layed out at all!

Test case

Run the following test case again Titanium 3.3.0.GA or later:

var win = Ti.UI.createWindow({
  backgroundColor: 'white'
});

win.add(Ti.UI.createLabel({
  text: 'Click'
}));

win.addEventListener('click', function(e) {

  var win = Ti.UI.createWindow({
    backgroundColor: 'red',
    layout: 'vertical',
  });

  win.addEventListener('click', function(e) {
    win.close();
  });

  for (var i = 0; i < 500; i++) {
    win.add(Ti.UI.createLabel({
      top: (i === 0) ? 20 : 0,
      color: 'white',
      text: 'Line #' + (i + 1)
    }));
  }

  win.open();

});

win.open();

Attached videos

The movies I recorded show clearly that the children show center-top (except the first label which has top:20 before being layed out at their proper place. Before Titanium 3.3.x the children views didn't show up until they were layed out, which of course looks better. - 323-710.mov Titanium 3.2.3 & iOS 7.1 (vertical) (/) - 330-710.mov Titanium 3.3.0 & iOS 7.1 (vertical) (x) - 330-710-horizontal.mov Titanium 3.3.0 & iOS 7.1 (horizontal) (x) - 340-810.mov Titanium 3.4.0 & iOS 8.1 (vertical) (x)