Advanced shared elements with shape morphing | Jetpack Compose Tips

REBECCA FRANKS: Users love screens that feel fluid and show continuity between transitions.

In a previous video, we covered how to get started with the basics of shared elements in Jetpack Compose.

In this tip, we will cover a more advanced example application of shared elements and how you can also add moments of delight to your app.

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In Androidify, we are using the new material shapes that come as part of the Material 3 Expressive updates.

We have two screens, the Creation screen that shows the camera button and the Camera screen that shows the camera viewfinder and the related buttons.

Currently, we've transitioned between the two screens, but we don't have a nice animation between the two.

So what if we wanted to transform between the Take Photo button, which is this delicious cookie shape, to the full-screen square that the camera screen takes on as a shared element, slowly having the cookie reveal the camera screen as it grows in size and transforms to the screen's rectangle shape.

We need to do three things to achieve this animation-- use shared elements to grow from the Photo button to the camera screen; reveal the camera screen as the button grows in size; and clip the shared element to the morphing shape.

So for step 1, we use the same concept shown in the shared element video that's linked below.

Firstly, we need to make sure that the top level of our app we are using a SharedTransitionLayout.

We've placed our SharedTransitionLayout at our top level of the theme in order to use it all throughout the Androidify app.

We also set a composition local for the SharedTransitionScope so that we don't need to pass the scope around.

The next step is to ensure that we have an animated visibility scope, which drives the transition between the two screens.

We are using Navigation 3 in this sample, which provides a built-in composition local where you can access when needed.