rename variable and fix spotless errors

app-nia-catalog/src/main/java/com/google/samples/apps/niacatalog/ui/Catalog.kt

@@ -518,14 +518,14 @@ fun NiaCatalog() {
                 item { Text("Tags", Modifier.padding(top = 16.dp)) }
                 item {
                     FlowRow(mainAxisSpacing = 16.dp) {
-                        var expandedTopic by remember { mutableStateOf<String?>(null) }
+                        var expandedTopicId by remember { mutableStateOf<String?>(null) }
 
                         var firstFollowed by remember { mutableStateOf(false) }
                         NiaTopicTag(
-                            expanded = expandedTopic == "Topic 1",
+                            expanded = expandedTopicId == "Topic 1",
                             followed = firstFollowed,
                             onDropMenuToggle = { show ->
-                                expandedTopic = if (show) "Topic 1" else null
+                                expandedTopicId = if (show) "Topic 1" else null
                             },
                             onFollowClick = { firstFollowed = true },
                             onUnfollowClick = { firstFollowed = false },
@@ -537,10 +537,10 @@ fun NiaCatalog() {
                         )
                         var secondFollowed by remember { mutableStateOf(true) }
                         NiaTopicTag(
-                            expanded = expandedTopic == "Topic 2",
+                            expanded = expandedTopicId == "Topic 2",
                             followed = secondFollowed,
                             onDropMenuToggle = { show ->
-                                expandedTopic = if (show) "Topic 2" else null
+                                expandedTopicId = if (show) "Topic 2" else null
                             },
                             onFollowClick = { secondFollowed = true },
                             onUnfollowClick = { secondFollowed = false },

core-designsystem/src/main/java/com/google/samples/apps/nowinandroid/core/designsystem/component/Tag.kt

@@ -21,10 +21,6 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.contentColorFor
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
@@ -32,9 +28,9 @@ import com.google.samples.apps.nowinandroid.core.designsystem.R
 
 @Composable
 fun NiaTopicTag(
-    expanded : Boolean = false,
+    expanded: Boolean = false,
     followed: Boolean,
-    onDropMenuToggle : (show: Boolean) -> Unit = {},
+    onDropMenuToggle: (show: Boolean) -> Unit = {},
     onFollowClick: () -> Unit,
     onUnfollowClick: () -> Unit,
     onBrowseClick: () -> Unit,

core-ui/src/main/java/com/google/samples/apps/nowinandroid/core/ui/NewsResourceCard.kt

@@ -268,7 +268,9 @@ fun NewsResourceTopics(
     topics: List<Topic>,
     modifier: Modifier = Modifier
 ) {
-    var expandedTopic by remember { mutableStateOf<String?>(null) }
+    // Store the ID of the Topic which has its "following" menu expanded, if any.
+    // To avoid UI confusion, only one topic can have an expanded menu at a time.
+    var expandedTopicId by remember { mutableStateOf<String?>(null) }
 
     Row(
         modifier = modifier.horizontalScroll(rememberScrollState()), // causes narrow chips
@@ -276,10 +278,10 @@ fun NewsResourceTopics(
     ) {
         for (topic in topics) {
             NiaTopicTag(
-                expanded = expandedTopic == topic.id,
+                expanded = expandedTopicId == topic.id,
                 followed = true, // ToDo: Check if topic is followed
                 onDropMenuToggle = { show ->
-                    expandedTopic = if (show) topic.id else null
+                    expandedTopicId = if (show) topic.id else null
                 },
                 onFollowClick = { }, // ToDo
                 onUnfollowClick = { }, // ToDo