I am trying to get a preview of a composable which takes one data class as input and another one is the clickable listener. I am not sure how the @PreviewParameter annotation is supposed to be used.
Preview error:
Composable functions with non-default parameters are not supported in Preview unless they are annotated with @PreviewParameter.
Data class
data class MaterialData(
var title:String,
var description:String,
var image: Int = R.drawable.m3_red_banner_mini,
var textColor:String,
var ref:String)
Main activity sample calling fun:
CardViewWidget(
MaterialData(
"All buttons",
"When choosing the right button for an action, consider the level of emphasis inherent to a button type.",
R.drawable.m3_red_banner_mini,
"FFFFFF",
"https://m3.material.io/components/cards/implementation/android") ,
onClick = {
})
Called fun
package com.materialize.compose.util
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.Card
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.withStyle
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.materialize.compose.model.MaterialData
@Preview
@Composable
fun CardViewWidget( @PreviewParameter() mdcData: MaterialData, onClick:()-> Unit) {
// start card view
Card(
modifier = Modifier
.fillMaxWidth()
.padding(15.dp)
.clickable(onClick = onClick),
shape = RoundedCornerShape(10.dp),
elevation = 10.dp
) {
Column(
modifier = Modifier.padding(15.dp)
) {
Text(
buildAnnotatedString {
append("welcome to ")
withStyle(style = SpanStyle(fontWeight = FontWeight.W900, color = Color(0xFF4552B8))
) {
append("Jetpack Compose Playground")
}
}
)
Text(
buildAnnotatedString {
append("Now you are in the ")
withStyle(style = SpanStyle(fontWeight = FontWeight.W900)) {
append("Card")
}
append(" section")
}
)
}
}
// end card view
}
Tried the below answer: still, i got some error
package com.materialize.compose.util
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.Card
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.withStyle
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.tooling.preview.PreviewParameter
import androidx.compose.ui.tooling.preview.PreviewParameterProvider
import androidx.compose.ui.unit.dp
import com.materialize.compose.R
import com.materialize.compose.model.MaterialData
class SampleObjProvider: PreviewParameterProvider<MaterialData> {
override val values = sequenceOf(
MaterialData(
"All buttons 1",
"When choosing the right button for an action, consider the level of emphasis inherent to a button type.",
R.drawable.m3_red_banner_mini,
"FFFFFF",
"https://m3.material.io/components/cards/implementation/android"),
MaterialData(
"All buttons 2",
"When choosing the right button for an action, consider the level of emphasis inherent to a button type.",
R.drawable.m3_red_banner_mini,
"FFFFFF",
"https://m3.material.io/components/cards/implementation/android"))
override val count: Int = values.count()
}
@Preview(showBackground = true)
@Composable
fun CardViewWidget(@PreviewParameter(SampleObjProvider::class) mdcData: MaterialData,
onClick:()-> Unit) {
// start card view
Card(
modifier = Modifier
.fillMaxWidth()
.padding(15.dp)
.clickable(onClick = onClick),
shape = RoundedCornerShape(10.dp),
elevation = 10.dp
) {
Column(
modifier = Modifier.padding(15.dp)
) {
Text(
buildAnnotatedString {
append("welcome to ")
withStyle(style = SpanStyle(fontWeight = FontWeight.W900, color = Color(0xFF4552B8))
) {
append("Jetpack Compose Playground")
}
}
)
Text(
buildAnnotatedString {
append("Now you are in the ")
withStyle(style = SpanStyle(fontWeight = FontWeight.W900)) {
append("Card")
}
append(" section")
}
)
}
}
// end card view
}
Error is:
java.lang.NullPointerException: Parameter specified as non-null is null: method com.materialize.compose.util.CardViewKt.CardViewWidget, parameter onClick
at com.materialize.compose.util.CardViewKt.CardViewWidget(CardView.kt)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at androidx.compose.ui.tooling.CommonPreviewUtils.invokeComposableMethod(CommonPreviewUtils.kt:149)
at androidx.compose.ui.tooling.CommonPreviewUtils.invokeComposableViaReflection$ui_tooling_release(CommonPreviewUtils.kt:188)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3$1$composable$1.invoke(ComposeViewAdapter.kt:571)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3$1$composable$1.invoke(ComposeViewAdapter.kt:569)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3$1.invoke(ComposeViewAdapter.kt:608)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3$1.invoke(ComposeViewAdapter.kt:564)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:215)
at androidx.compose.ui.tooling.InspectableKt.Inspectable(Inspectable.kt:64)
at androidx.compose.ui.tooling.ComposeViewAdapter$WrapPreview$1.invoke(ComposeViewAdapter.kt:513)
at androidx.compose.ui.tooling.ComposeViewAdapter$WrapPreview$1.invoke(ComposeViewAdapter.kt:512)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:215)
at androidx.compose.ui.tooling.ComposeViewAdapter.WrapPreview(ComposeViewAdapter.kt:508)
at androidx.compose.ui.tooling.ComposeViewAdapter.access$WrapPreview(ComposeViewAdapter.kt:121)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3.invoke(ComposeViewAdapter.kt:564)
at androidx.compose.ui.tooling.ComposeViewAdapter$init$3.invoke(ComposeViewAdapter.kt:561)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.ui.platform.ComposeView.Content(ComposeView.android.kt:384)
at androidx.compose.ui.platform.AbstractComposeView$ensureCompositionCreated$1.invoke(ComposeView.android.kt:228)
at androidx.compose.ui.platform.AbstractComposeView$ensureCompositionCreated$1.invoke(ComposeView.android.kt:227)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:215)
at androidx.compose.ui.platform.CompositionLocalsKt.ProvideCommonCompositionLocals(CompositionLocals.kt:150)
at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt$ProvideAndroidCompositionLocals$3.invoke(AndroidCompositionLocals.android.kt:114)
at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt$ProvideAndroidCompositionLocals$3.invoke(AndroidCompositionLocals.android.kt:113)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:215)
at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt.ProvideAndroidCompositionLocals(AndroidCompositionLocals.android.kt:106)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$3.invoke(Wrapper.android.kt:162)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$3.invoke(Wrapper.android.kt:161)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:215)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Wrapper.android.kt:161)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Wrapper.android.kt:144)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
at androidx.compose.runtime.ComposerKt.invokeComposable(Composer.kt:3332)
at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:2577)
at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:2566)
at androidx.compose.runtime.SnapshotStateKt.observeDerivedStateRecalculations(SnapshotState.kt:540)
at androidx.compose.runtime.ComposerImpl.doCompose(Composer.kt:2566)
at androidx.compose.runtime.ComposerImpl.composeContent$runtime_release(Composer.kt:2517)
at androidx.compose.runtime.CompositionImpl.composeContent(Composition.kt:477)
at androidx.compose.runtime.Recomposer.composeInitial$runtime_release(Recomposer.kt:727)
at androidx.compose.runtime.CompositionImpl.setContent(Composition.kt:433)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:144)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:135)
at androidx.compose.ui.platform.AndroidComposeView.setOnViewTreeOwnersAvailable(AndroidComposeView.android.kt:727)
at androidx.compose.ui.platform.WrappedComposition.setContent(Wrapper.android.kt:135)
at androidx.compose.ui.platform.WrappedComposition.onStateChanged(Wrapper.android.kt:187)
at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:354)
at androidx.lifecycle.LifecycleRegistry.addObserver(LifecycleRegistry.java:196)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:142)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:135)
at androidx.compose.ui.platform.AndroidComposeView.onAttachedToWindow(AndroidComposeView.android.kt:814)
at android.view.View.dispatchAttachedToWindow(View.java:20479)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3489)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.AttachInfo_Accessor.setAttachInfo(AttachInfo_Accessor.java:44)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:360)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:431)
at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:141)
at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:714)
at com.android.tools.idea.rendering.RenderTask.lambda$inflate$7(RenderTask.java:870)
at com.android.tools.idea.rendering.RenderExecutor$runAsyncActionWithTimeout$2.run(RenderExecutor.kt:187)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
