IssueTracker

Is there remaining work for this feature request. Support for predictive back in Dialogs would allow Material3 to remove some Dialog forks and would be very helpful!

Yeah, we probably want to investigate new API shapes here to take advantage of predictive back. No work ongoing yet though, needs prioritization

(recapping my chat with Ian)

The tricky part is that the onDismissRequest is really the final signal and a chance for the app to just say 'nope, I don't want the dialog to dismiss' (since they own the state of 'should the dialog be shown or not' simply by either adding the Dialog to composition or leaving out of composition) - that's the just-in-time problem that the comment talks about. It would be very odd to have any kind of progress animation that doesn't actually lead to the dialog being dismissed when it is committed"

so really it needs to be a more holistic look at how to do dialogs and swap from a binary state (shown/not shown) to something that actually has something in between for cases like predictive back

Problem not fixed for Translations - suggest reopening.

My fix to allow enterTransition to act as if Hold() was working correctly. I don't enterTransition animate at all:

exitTransition = HoldBackground(resources).setDuration(duration)
enterTransition = Slide(Gravity.RIGHT).setDuration(duration)

With HoldBackground looking like this:

class HoldBackground(val resources : Resources) : Transition() {

    init {
        duration = resources.getInteger(android.R.integer.config_mediumAnimTime).toLong()
    }
    var inProgress = false

    @Synchronized
    override fun captureStartValues(transitionValues: TransitionValues) {
        if(inProgress) return
        transitionValues.view.also { exitingView ->
            exitingView.parent.also { fragmentContainer ->
                if(fragmentContainer is View && exitingView.width > 0 && exitingView.height > 0) {
                    inProgress = true
                    val previousBackground = fragmentContainer.background
                    val bitmap = Bitmap.createBitmap(
                        exitingView.width,
                        exitingView.height,
                        Bitmap.Config.ARGB_8888
                    )
                    exitingView.draw(Canvas(bitmap))
                    fragmentContainer.background = BitmapDrawable(resources, bitmap)
                    // Simple animator so timing matches developer animation scales
                    val animator = ValueAnimator.ofInt(0, 1).setDuration(duration)
                    animator.addListener(object : BlankAnimatorListener() {
                        override fun onAnimationEnd(animation: Animator?) {
                            fragmentContainer.background = previousBackground
                            inProgress = false
                        }
                    })
                    animator.start()
                }
            }
        }
    }

    override fun captureEndValues(transitionValues: TransitionValues) {}
}

It's very likely stupidly resource intensive given it's creating a screen size bitmap... but it does happen to work.