Can't create a Kotlin Fragment in Android Studio

Question

When I create a new fragment in Android Studio by clicking:

and then choosing Kotlin as language for the new fragment, I get following warning that I have to implement two members or make the class abstract. When I make it abstract the program doesn't start, because it can't instanciate the abstract class. When I implement the methods I don't know what I have to put into them and the program doesn't start with the error that they don't override anything:

When I create the Fragment in Java it works, I don't understand it. Here is how I call the fragment from the activity:

class MovieListActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_movie_list)

        supportFragmentManager.beginTransaction()
                .replace(R.id.main_container, MovieListFragment())
                .commit()
    }
}

I'm using Java and Kotlin files in this project, so maybe that's causing a conflict? Until now it worked using Kotlin and Java in this project, for example with Kotlin and Java Activities. I just had this problem now when I created the first Kotlin fragment. This is my build.gradle file:

plugins {
    id 'com.android.application'
    id 'kotlin-android'
}

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.3"

    defaultConfig {
        applicationId "...myProjectName"
        minSdkVersion 23
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        // Support for Java 8 features
        coreLibraryDesugaringEnabled true
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    //kotlin & compose 
    kotlinOptions {
        useIR = true
        jvmTarget = JavaVersion.VERSION_1_8.toString()
    }
    composeOptions {
        def kotlin_compiler_version = "1.4.0"
        kotlinCompilerVersion kotlin_compiler_version

        def kotlin_compiler_extension_version = "1.0.0-alpha05"
        kotlinCompilerExtensionVersion kotlin_compiler_extension_version
    }
    buildFeatures {
        compose true
        viewBinding true
    }
}

dependencies {
  implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation 'androidx.annotation:annotation:1.1.0'
    implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.2.0'
    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0'
    def retrofitVersion = "2.9.0"
    def lifecycle_version = "1.1.1"
    def cardview_version = "1.0.0"
    def recyclerView_version = "1.0.0"
    def glideVersion = "4.11.0"
    def supportVersion = "28.0.0"
    def aws_version = "2.13.+"

    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.2'

    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'com.google.android.material:material:1.2.1'

    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    //retrofit
    implementation "com.squareup.retrofit2:retrofit:$retrofitVersion"
    // Retrofit gson converter
    implementation "com.squareup.retrofit2:converter-gson:$retrofitVersion"

    // ViewModel and LiveData
    implementation "android.arch.lifecycle:extensions:$lifecycle_version"

    // CardViews
    implementation "androidx.cardview:cardview:$cardview_version"

    // RecyclerView
    implementation "androidx.recyclerview:recyclerview:$recyclerView_version"

    //Design library
   implementation "com.android.support:design:$supportVersion"

    // Glide
    implementation 'com.github.bumptech.glide:glide:4.8.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.8.0'

    // Circular ImageView
    implementation 'de.hdodenhof:circleimageview:3.1.0'

    // Google Tabs
    implementation "androidx.browser:browser:1.2.0"

    // SwipeCards
    implementation 'com.lorentzos.swipecards:library:1.0.9'

    // Amplify core dependency (for AWS Cognito)
    implementation 'com.amplifyframework:core:1.6.4'
    implementation 'com.amplifyframework:aws-auth-cognito:1.6.4'

    // AWS Dependencies
    implementation "com.amazonaws:aws-android-sdk-core:$aws_version"
    implementation "com.amazonaws:aws-android-sdk-auth-core:$aws_version"
    implementation("com.amazonaws:aws-android-sdk-auth-userpools:$aws_version@aar") { transitive = true }
    implementation("com.amazonaws:aws-android-sdk-auth-ui:$aws_version") { transitive = true }

    // Support for Java 8 features
    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.10'

    implementation 'com.pddstudio:encrypted-preferences:1.3.0'

    // Required -- JUnit 4 framework
    testImplementation 'junit:junit:4.12'
    // Optional -- Robolectric environment
    testImplementation 'androidx.test:core:1.0.0'
    // Optional -- Mockito framework
    testImplementation 'org.mockito:mockito-core:1.10.19'

    def fragment_version = "1.2.5"

    // Java language implementation
    implementation "androidx.fragment:fragment:$fragment_version"

    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation fileTree(include: ['*.jar'], dir: 'app/libs')

    //HTTP Requests https://developer.android.com/training/volley
    implementation 'com.android.volley:volley:1.1.1'

    //compose 
    def compose = "1.0.0-alpha08"
    implementation "androidx.compose.ui:ui:$compose"
    implementation "androidx.compose.foundation:foundation:$compose"
    implementation "androidx.compose.runtime:runtime-livedata:$compose"
    implementation "androidx.compose.runtime:runtime-rxjava2:$compose"
    implementation "androidx.compose.material:material:$compose"
    implementation "androidx.compose.material:material-icons-core:$compose"
    implementation "androidx.compose.material:material-icons-extended:$compose"
}

Answer 1

I had same issue, that's only with Android Studio Canary, after doing couple experiments i ended up solving this issue by using fragment-ktx library:

implementation "androidx.fragment:fragment-ktx:1.3.0-beta01"