I have a compile-time error with the samples provided in the code-labs.
This is the ViewModel
class VM : ViewModel() {
val isVisible = MutableStateFlow(true).asStateFlow()
}
This is what I'd like to write:
@Composable
fun Whatever(vm: VM = viewModel()) {
val isVisible by vm.isVisible.collectAsState(true)
// Use is visible here
}
But it yields to the following error:
Type 'State<TypeVariable(R)>' has no method 'getValue(Nothing?, KProperty<*>)' and thus it cannot serve as a delegate
Which is really strange because I can use it like so:
@Composable
fun Whatever(vm: VM = viewModel()) {
val isVisible = vm.isVisible.collectAsState(true)
if(isVisible.value) { … }
}
What dependency do I need to bring in to make the delegate work?
Here are my dependencies: and compose_version = 1.0.0-beta01
dependencies {
// LiveData
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.0"
implementation 'androidx.core:core-ktx:1.3.2'
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'com.google.android.material:material:1.3.0'
implementation "androidx.activity:activity-compose:1.3.0-alpha03"
implementation "androidx.compose.runtime:runtime:$compose_version"
implementation "androidx.compose.ui:ui:$compose_version"
implementation "androidx.compose.foundation:foundation-layout:$compose_version"
implementation "androidx.compose.material:material:$compose_version"
implementation "androidx.compose.material:material-icons-extended:$compose_version"
implementation "androidx.compose.foundation:foundation:$compose_version"
implementation "androidx.compose.animation:animation:$compose_version"
implementation "androidx.compose.ui:ui-tooling:$compose_version"
implementation "androidx.compose.runtime:runtime-livedata:$compose_version"
implementation "androidx.compose.runtime:runtime:$compose_version"
implementation "androidx.compose.ui:ui:$compose_version"
implementation "androidx.compose.ui:ui-tooling:$compose_version"
implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.0'
// Kotlin coroutines
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
implementation 'androidx.appcompat:appcompat:1.3.0-beta01'
implementation 'androidx.activity:activity-ktx:1.2.0'
implementation 'androidx.core:core-ktx:1.5.0-beta02'
implementation "androidx.activity:activity-compose:1.3.0-alpha03"
implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:2.3.0"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.0"
implementation "androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha02"
androidTestImplementation 'androidx.test:rules:1.3.0'
androidTestImplementation 'androidx.test:runner:1.3.0'
androidTestImplementation "androidx.compose.ui:ui-test:$compose_version"
androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
}
As described in the doc , try to add the following imports:
import androidx.compose.runtime.getValue
import androidx.compose.runtime.livedata.observeAsState
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