Migration Guide

This page centrally records future breaking changes and recommended migration paths across BetterAndroid modules.

Migrate BackPressedController

When handling system back pressed events, if you previously used BackPressedController from ui-component → System Event, it is now recommended to migrate to the extension-based usage in ui-extension → BackPressed Extension, which is built on the official OnBackPressedDispatcher.

The new approach no longer requires an extra controller, interface access, or manual destroy handling, and directly reuses the lifecycle management already provided by androidx.

How to Migrate

The previous usage usually looked like this.

The following example

val backPressed by lazy { BackPressedController.from(this) }

val callback = backPressed.addCallback {
    // Your code here.
}

backPressed.trigger()
backPressed.destroy()

Now you can directly change it to the following.

The following example

val callback = OnBackPressedCallback {
    // Your code here.
}

onBackPressedDispatcher.addCallback(this, callback)

If you need to continue dispatching the current back event inside the current callback, you can directly use trigger(onBackPressedDispatcher).

The following example

onBackPressedDispatcher.addCallback(this, OnBackPressedCallback {
    trigger(onBackPressedDispatcher)
    trigger(onBackPressedDispatcher, removed = true)
})

For Fragment, you can directly use fragment.onBackPressedDispatcher, then bind it to viewLifecycleOwner or the Fragment itself as needed.

The following example

onBackPressedDispatcher.addCallback(viewLifecycleOwner, OnBackPressedCallback {
    // Your code here.
})

If you register a back pressed callback from a View, you can also migrate it directly like this.

The following example

binding.root.onBackPressedDispatcher.addCallback(
    binding.root.requireLifecycleOwner(),
    OnBackPressedCallback {
        // Your code here.
    }
)

Mapping

• BackPressedController.from(activity) → activity.onBackPressedDispatcher
• backPressed.addCallback { ... } → onBackPressedDispatcher.addCallback(this, OnBackPressedCallback { ... })
• backPressed.trigger() → call trigger(onBackPressedDispatcher) inside OnBackPressedCallback
• backPressed.destroy() → no longer needed, handled by the official lifecycle
• IBackPressedController → no longer needed

Migrate SystemColors

If you previously used SystemColors from ui-extension → System Colors, please note that this entire capability has now been removed.

ui-extension no longer introduces the material dependency, so the SystemColors related APIs are no longer retained.

How to Migrate

If you only used SystemColors.isAvailable to determine whether the current system supports dynamic colors, you can now migrate to the official DynamicColors.isDynamicColorAvailable().

The following example

// Before
val isAvailable = SystemColors.isAvailable

// After
val isAvailable = DynamicColors.isDynamicColorAvailable()

Other than that, SystemColors.from(context) and all color retrieval related usages are no longer supported, and ui-extension no longer provides a replacement wrapper for them.

If your business still depends on this capability, please switch to your own material dependency solution directly, or reevaluate whether you still need dynamic color retrieval logic.