Resizing transition using cache placholder

[leondeklerk]

Hi,
For my application I currently have the following logic:

I have a list with images that, when an element is clicked, opens a dialog with a new ImageView. First, the dialog ImageView is resized to match the location and size of the list item, then .load(..) is called on that view with the cache key of the list item as a placeholder. Upon loading the image in the new view, a listener creates a new Android TransitionSet, adds it to the TransitionManager, resizes the imageView to match its parent, and changes scaleType from CENTER_CROP to FIT_CENTER.

See the following code snippet which achieves the transition:

val imageView = binding.imageView
val rect = startData.rect
imageView.scaleType = ImageView.ScaleType.CENTER_CROP
imageView.requestNewSize(rect.width(), rect.height())
imageView.applyMargin(rect) // Extension function to set 4 margins based on rect
imageView.post {
    imageView.load(uri) {
        placeholderMemoryCacheKey(cacheKey) // cacheKey comes from the list imageView
        size(binding.layout.width, binding.layout.height)
        listener(onSuccess = { _, _ ->
            val transition = TransitionSet()
            transition
                .addTransition(ChangeClipBounds())
                .addTransition(ChangeTransform())
                .addTransition(ChangeBounds())
                .addTransition(ChangeImageTransform())
                .addListener(/**listeners**/)

             TransitionManager.beginDelayedTransition(binding.imageContainer, transition)

             imageView.scaleType = ImageView.ScaleType.FIT_CENTER
             imageView.layoutParams = (imageView.layoutParams as ViewGroup.MarginLayoutParams).apply {
                 marginStart = 0
                 marginEnd = 0
                 topMargin = 0
                 bottomMargin = 0
                 width = MATCH_PARENT
                 height = MATCH_PARENT
             }
         })
    }
}

Now I really want to achieve the following:

• Once the placeholder is loaded it is used for the transition without waiting for the full image to load.
• Whenever the full image is loaded, it replaces the placeholder in the transition (or is just set if the transition already ended)
• Achieve this with logic in the Coil loading chain/custom transition.

So basically the question is if this is possible within Coil and if it is, what the general elements are that I would need.
(I don't expect a full solution, just happy with any help I can get)