Have dijit layout method fire after CSS transitions

[Wouter Hager]

It might be rather obtrusive, but when the layout/resize method on dijits fires, it doesn't take in account any CSS transitions that may still be in progress. Instead of hacking together listeners for each widget, it may be convenient to have _WidgetBase check for CSS transitions attached to its DOM and handle the layout method accordingly.

[bill]

Dijit doesn't have any transition effects on its layout widgets. Can you attach a test case of what you mean?

[Wouter Hager]

Say the widget gets a transition effect that will adjust its width and height over the course of a second. Any children of the widget will get resized immediately, not when the scaling is done. Layout gets out of sync.

I'm not suggesting dijit has any relation to CSS transitions, but in the specific case of a timed resize event, the layout mixin could take this into account, just as it does border and padding.

[bill]

OK, but I still need you to attach a test case.

[Wouter Hager]

It turns out the problem is a bit more complicated. Since layout widgets depend on JS to calculate their children's new positions, it would be best to calculate the new size ahead of transitions, instead of when transitions end.

However, new positions and dimensions are currently calculated from the parent DOM node only. The parent's new dimensions aren't handed down to layoutChildren. So when the transition starts, the children are repositioned immediately, based on a parent that is not yet ready.

It may be possible to hand down what the actual dimensions of the parent will be (as calculated in the resize method) to layoutChildren, and calculate children's positions from that, instead of the parent's DOM node. This may be quite a radical change, but in that way, CSS transitions won't affect the LayoutWidget? resize/layout events.

[Wouter Hager]

Nevermind that last comment. It seems resize is actually called twice, the second time with the correct calculation before the transition. I must have some point in my code where this second call gets lost.

[bill]

OK. If this is still an issue, then I'm still waiting for a test case. I realize this is an ER rather than a bug report but I still want to see an actual example of the thing you want to support.

[Wouter Hager]

My bad, usually layout widgets do this correctly. I have some code where resize doesn't set the right dimensions. Apologies.

[bill]

Ok, no worries, I'll close this then.