famo.us Firefox设置z-index不起作用

Question

I am trying to control the layering of surfaces using zIndex property. It works just fine in Chrome whereas it doesn't in Firefox. After examining the DOM, I observed that the z-index is marked as 0 no matter what we set.

I reproduced the problem in famo.us tutorial code @ http://famo.us/university/famous-101/displaying/5/ . Replace the tutorial code with the following code. Notice the difference between Chrome and Firefox with the same code.

var Engine = require('famous/core/Engine');
var Surface = require('famous/core/Surface');

var mainContext = Engine.createContext();

var firstSurface = new Surface({
  size: [200, 400],
  content: 'top',
  properties: {
    color: 'white',
    textAlign: 'center',
    backgroundColor: '#FA5C4F',
    zIndex: 10
  }
});

var secondSurface = new Surface({
  size: [300, 200],
  content: 'bottom',
  properties: {
    color: 'white',
    textAlign: 'center',
    backgroundColor: 'green',
    zIndex: 8
  }
});

mainContext.add(firstSurface);
mainContext.add(secondSurface);

Answer 1

You should try to avoid using the zIndex property, because Famo.us does Z indexing for you with their 3D render Engine. To achieve what you wish, use a StateModifier and translate your surfaces in the Z direction.

This now works in FireFox as well. Hope it helps!

var Engine = require('famous/core/Engine');
var Surface = require('famous/core/Surface');
var Transform  = require('famous/core/Transform');
var StateModifier = require('famous/modifiers/StateModifier');

var mainContext = Engine.createContext();

var firstSurface = new Surface({
  size: [200, 400],
  content: 'top',
  properties: {
    color: 'white',
    textAlign: 'center',
    backgroundColor: '#FA5C4F'
  }
});

firstSurface.state = new StateModifier({
    transform: Transform.translate(0,0,10)
});

var secondSurface = new Surface({
  size: [300, 200],
  content: 'bottom',
  properties: {
    color: 'white',
    textAlign: 'center',
    backgroundColor: 'green',
    }
});

secondSurface.state = new StateModifier({
    transform:Transform.translate(0,0,8)
});

mainContext.add(firstSurface.state).add(firstSurface);
mainContext.add(secondSurface.state).add(secondSurface);