pr sample 1

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/DevicePreviews.kt

@@ -22,8 +22,8 @@ import androidx.compose.ui.tooling.preview.Preview
  * Multipreview annotation that represents various device sizes. Add this annotation to a composable
  * to render various devices.
  */
-@Preview(name = "phone", device = "spec:shape=Normal,width=360,height=640,unit=dp,dpi=480")
-@Preview(name = "landscape", device = "spec:shape=Normal,width=640,height=360,unit=dp,dpi=480")
-@Preview(name = "foldable", device = "spec:shape=Normal,width=673,height=841,unit=dp,dpi=480")
-@Preview(name = "tablet", device = "spec:shape=Normal,width=1280,height=800,unit=dp,dpi=480")
+@Preview(name = "phone", device = "spec:shape=Normal,width=360,height=640,unit=dp,dpi=480", showBackground = true)
+@Preview(name = "landscape", device = "spec:shape=Normal,width=640,height=360,unit=dp,dpi=480", showBackground = true)
+@Preview(name = "foldable", device = "spec:shape=Normal,width=673,height=841,unit=dp,dpi=480", showBackground = true)
+@Preview(name = "tablet", device = "spec:shape=Normal,width=1280,height=800,unit=dp,dpi=480", showBackground = true)
 annotation class DevicePreviews

feature/foryou/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/foryou/VaidatorWithError.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.foryou
+
+abstract class ValidatorWithErrorType<ParamType : Any, ReturnType : Any, Error : Any> {
+    fun validate(data: ParamType): ValidatorResult<ReturnType, Error> {
+        return doValidation(data)
+    }
+
+    protected abstract fun doValidation(data: ParamType): ValidatorResult<ReturnType, Error>
+    sealed class ValidatorResult<out Success : Any, out Error : Any> {
+        data class Success<out ReturnType : Any>(val data: ReturnType) : ValidatorResult<ReturnType, Nothing>()
+        data class Failure<out Error : Any>(val error: Error) : ValidatorResult<Nothing, Error>()
+    }
+}

feature/foryou/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/foryou/VerifyMobileTopUpIdentifierValidator.kt

@@ -0,0 +1,67 @@
+package com.google.samples.apps.nowinandroid.feature.foryou
+
+import androidx.annotation.StringRes
+import java.io.Serializable
+import javax.inject.Inject
+
+abstract class AddMobileTopUpTemplateValidator : ValidatorWithErrorType<
+    AddMobileTopUpTemplateValidator.Params,
+    AddMobileTopUpTemplateValidator.Params,
+    AddMobileTopUpTemplateValidator.Error
+    >() {
+
+    data class Params(
+        val mobileNumber: String?,
+        val serviceProvider: MTUServiceProviderFace?,
+        val paymentService: MTUPaymentServiceFace?,
+        val isAllDataRequired: Boolean? = null
+    )
+
+    data class Error(
+        @StringRes var emptyMobileNumber: Int? = null,
+        @StringRes var emptyServiceProvider: Int? = null,
+        @StringRes var emptyPaymentService: Int? = null,
+    )
+}
+
+class AddMobileTopUpTemplateValidatorImpl @Inject constructor() : AddMobileTopUpTemplateValidator() {
+    override fun doValidation(data: Params): ValidatorResult<Params, Error> {
+        var isValid = true
+        val error = Error()
+        if (data.mobileNumber.isNullOrEmpty()) {
+            error.emptyMobileNumber = R.string.feature_foryou_done
+            isValid = false
+        }
+
+        if (data.serviceProvider == null && data.isAllDataRequired == true) {
+            error.emptyServiceProvider = R.string.feature_foryou_done
+            isValid = false
+        }
+
+        if (data.paymentService == null && data.isAllDataRequired == true) {
+            error.emptyPaymentService = R.string.feature_foryou_done
+            isValid = false
+        }
+
+        return if (isValid) {
+            ValidatorResult.Success(data)
+        } else {
+            ValidatorResult.Failure(error)
+        }
+    }
+}
+
+data class MTUServiceProviderFace(
+    val id: Long,
+    val name: String,
+    val shortName: String
+) : Serializable
+
+data class MTUPaymentServiceFace(
+    val id: Long,
+    val name: String,
+    val isMobilePackage: Boolean,
+    val allowedPaymentAmount: Long?,
+    val packageDescriptions: Map<String, String>?,
+    val serviceProvider: MTUServiceProviderFace? = null
+) : Serializable

feature/search/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/search/SearchScreen.kt

@@ -549,7 +549,7 @@ private fun SearchTextField(
     }
 }
 
-@Preview
+@Preview(showBackground = true)
 @Composable
 private fun SearchToolbarPreview() {
     NiaTheme {
@@ -562,7 +562,7 @@ private fun SearchToolbarPreview() {
     }
 }
 
-@Preview
+@Preview(showBackground = true)
 @Composable
 private fun EmptySearchResultColumnPreview() {
     NiaTheme {
@@ -573,7 +573,7 @@ private fun EmptySearchResultColumnPreview() {
     }
 }
 
-@Preview
+@Preview(showBackground = true)
 @Composable
 private fun RecentSearchesBodyPreview() {
     NiaTheme {
@@ -585,7 +585,7 @@ private fun RecentSearchesBodyPreview() {
     }
 }
 
-@Preview
+@Preview(showBackground = true)
 @Composable
 private fun SearchNotReadyBodyPreview() {
     NiaTheme {