Harbs,
I posted a 3 MXML tag example. Will it work like it does in Flex with your
changes? If so, how/why?
If not, then we need the old code. It is unfortunate that it causes extra
reflows, but setting x,y should be rare. And if you can propose a different
solution that is PAYG, even better. I keep wondering if we should go back to
setting position!=static on the parentNode when x,y is set.
The scenario where offsetParent changes also needs to be understood to know how
rare it is or if it is a result of some other bug. We have to be careful about
spending lots of time on these cases if they are corner cases or a side-effect.
All I'm trying to do is make sure your analysis and proposed changes are
correct. There have been scenarios cited (RoyaleStore) and solutions proposed
(Application * selector0 that weren't valid so I'm just trying to help make
sure this is right. It just isn't making sense to me that offsetParent doesn't
matter in the x,y calculation or that there is framework code that changes
offsetParent. I don't want to worry about the performance of x,y being set if
most UI really shouldn't be setting it. But for sure, it has to produce the
right values.
Thanks,
-Alex
On 6/7/18, 3:26 PM, "Harbs" <harbs.li...@gmail.com> wrote:
> On Jun 8, 2018, at 1:11 AM, Alex Harui <aha...@adobe.com.INVALID> wrote:
>
> In your animation code example, having the offsetParent code in the
setter makes the animation *way* less efficient. There is a an extra forced
reflow for every assignment of the new value.
>
> I don't understand this point. Can you provide more detail? I would
imagine animations are going to cause reflows. If there is a way to do
animations without resulting in a reflow that would be great.
The point is that there is a forced reflow. There will definitely be a
reflow when the browser draws the animation change, but the offsetParent code
forces the browser to calculate an extra reflow during the code execution prior
to setting the x value.
This has two problems:
1. There is two reflows per cycle instead of one. If the animation sets
both x and y values, there will be three reflows (the first two forced) instead
of one.
2. The first reflow is forced to happen during javascript execution rather
than when the browser decides it’s the optimum time to do so.
>
>> I think you are saying there is a bug in the current code, but it
somehow involves offsetParent changing. Can you explain what causes
offsetParent to change?
>
> If/when the parent (or grandparent or great-grandparent, etc.) element
position changes from static to some other value, the offsetParent will change.
>
> Again, how important/prevalent is such a scenario?
It’s hard to say, but one such scenario sparked this discussion. I think
that avoiding lifecycle issues is pretty important.
