Jetpack compose can't preview after updating to 1.0.0-rc01

this happened to me only when I updated to 1.0.0-rc01. it says:

> The following classes could not be found: > - androidx.compose.ui.tooling.preview.ComposeViewAdapter (Fix Build Path, Edit XML, Create Class)

my code:

@Composable
@Preview
fun CenterProgress(){
    Box(
        modifier= Modifier.fillMaxSize(),
        contentAlignment = Alignment.Center
    ){
        CircularProgressIndicator(strokeWidth = 3.dp)
    }
}

Update 07/20/2021: Just download and use the latest AS to fix the problem

---

They splitted some packages in rc01 but per @CommonsWare comment (all credits to him) it seems there is a problem with Android Studio version itself. You have 2 options:

1. Downgrade to beta09 until AS ArcticFox RC1 is out
2. Try the suggested workaround, use AS Arctic Fox Beta 5 leaving all compose dependencies to 1.0.0-rc01 version and downgrade only ui-tooling to 1.0.0-beta09 (confirmed by comments).

---

Extra details

Here you can find all the classes they moved in 1.0.0-rc01 https://android-review.googlesource.com/c/platform/frameworks/support/+/1739498 and the explanation on why this has been decided.

In short, you can now do this for some particular optimized scenarios (which should not be the default case):

debugImplementation "androidx.compose.ui:ui-tooling:1.0.0-rc01"
implementation "androidx.compose.ui:ui-tooling-preview:1.0.0-rc01"

Update: This is no longer needed with Android Studio Bumblebee | 2021.1.1 Canary 6 and Android Gradle Plugin 7.1.0-alpha06. Note: Canary 4 already fixed this issue but required a broken version of AGP. This is now also resolved.

In addition to the above answers: here is how to force the ui-tooling version in gradle:

implementation("androidx.compose.ui:ui-tooling:$compose_version") {
    version {
        // TODO: Remove this when Android Studio has become compatible again
        // Android Studio Bumblebee | 2021.1.1 Canary 3 is not compatible with module ui-tooling 1.0.0-rc01 or higher.
        // The Run Configuration for Composable Previews that Android Studio makes expects a PreviewActivity class
        // in the `androidx.compose.ui.tooling.preview` package, but it was moved in 1.0.0-rc01, and thus causes error:
        // "androidx.compose.ui.tooling.preview.PreviewActivity is not an Activity subclass or alias".
        // For more, see: https://stackoverflow.com/questions/68224361/jetpack-compose-cant-preview-after-updating-to-1-0-0-rc01
        strictly("1.0.0-beta09")
    }
}

For my case, it's because I left my build variant at "release". Changing it back to "debug" fixes the missing class bug.

the preview functionality is probably from the following line in build.gradle

debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"

I tried it like the comment above me and it actually helped me only that i had to delete the implementation of :

Link to Artic Fox Beta 5:
https://developer.android.com/studio/preview

androidx.compose.ui:ui-tooling-preview.
My compose config looks like the following:

android {

def compose_version = '1.0.0-rc01'


composeOptions {
  kotlinCompilerExtensionVersion "$compose_version"
}

dependencies {
  def compose_version = '1.0.0-rc01'
/**Compose Related*/

    implementation "androidx.compose.compiler:compiler:$compose_version"
    implementation "androidx.compose.ui:ui:$compose_version"
    implementation "androidx.activity:activity-compose:1.3.0-rc01"
    implementation "androidx.compose.material:material:$compose_version"

    implementation "androidx.compose.ui:ui-tooling:1.0.0-beta09"
//    Need to comment this two lines to work on artic fox
//    implementation "androidx.compose.ui:ui-tooling:$compose_version"
//    implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
    /**Accompanist*/
    // Coil
    implementation 'dev.chrisbanes.accompanist:accompanist-insets:0.6.2'
    implementation "com.google.accompanist:accompanist-coil:0.13.0"
    implementation "androidx.compose.runtime:runtime:$compose_version"
    implementation "androidx.compose.runtime:runtime-livedata:$compose_version"

    /** Material Icons */
    implementation "androidx.compose.material:material-icons-extended:$compose_version"


    // Jetpack Compose Integration
    implementation "androidx.navigation:navigation-compose:2.4.0-alpha04"
}

}

To people still get the error when downgrade the ui-tooling library:

Make sure you don't have library that have dependency on ui-tooling:1.0.0-rc01 You can find that out by using ./gradlew app:dependencies in your android studio terminal

In my case, I'm using com.google.accompanist:accompanist-swiperefresh:13.0.0 which depend on ui-tooling:1.0.0-rc01. Preview is working when I downgrade to accompanist-swiperefresh:12.0.0

On my case, where I have a "design system" module providing all compose-related dependencies, I had to add the following dependency:

implementation("androidx.activity:activity-compose:1.4.0")