fix(sample): Drop Nav3 Activity ui.load transactions when the toggle is off

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/navigation/nav3/Nav3Activity.kt

@@ -92,11 +92,10 @@ class Nav3Activity : ComponentActivity() {
     configuration.applyToCurrentOptions()
     showActivityUiLoadTransactionDelayMessage = configuration.hasOnlyActivityUiLoadTransactions
 
-    if (!configuration.enableActivityUiLoadTransaction) {
-      // Cancel the already-started Activity transaction before Compose installs SentryNavEffect,
-      // otherwise the initial /Landing route transaction gets preempted by the lingering ui.load.
-      cancelCurrentActivityUiLoadTransaction()
-    }
+    // When the toggle is off, cancel the already-started Activity transaction before Compose
+    // installs SentryNavEffect, otherwise the lingering ui.load preempts the initial /Landing route
+    // transaction.
+    applyActivityUiLoadTransactionSetting(this, configuration.enableActivityUiLoadTransaction)
 
     NavigationTransactionHistory.install()
 

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/navigation/nav3/Nav3MultiActivity.kt

@@ -89,9 +89,7 @@ class Nav3ProductsActivity : ComponentActivity() {
     super.onCreate(savedInstanceState)
     val configuration = (intent.extras ?: Bundle()).nav3SampleConfiguration()
     NavigationTransactionHistory.install()
-    if (!configuration.enableActivityUiLoadTransaction) {
-      cancelCurrentActivityUiLoadTransaction()
-    }
+    applyActivityUiLoadTransactionSetting(this, configuration.enableActivityUiLoadTransaction)
     setContent {
       val stack = rememberSaveableNav3BackStack(Nav3Route.ProductList)
       SideEffect {
@@ -174,9 +172,7 @@ open class Nav3CheckoutActivity : ComponentActivity() {
     val crashOnFirstComposition =
       savedInstanceState == null && intent.getBooleanExtra(EXTRA_CRASH_ON_FIRST_COMPOSITION, false)
     NavigationTransactionHistory.install()
-    if (!configuration.enableActivityUiLoadTransaction) {
-      cancelCurrentActivityUiLoadTransaction()
-    }
+    applyActivityUiLoadTransactionSetting(this, configuration.enableActivityUiLoadTransaction)
     setContent {
       Nav3SampleTheme {
         if (showAsSheet) {

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/navigation/nav3/Nav3MultiFragment.kt

@@ -76,9 +76,7 @@ class Nav3FragmentsActivity : FragmentActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     NavigationTransactionHistory.install()
-    if (!configuration.enableActivityUiLoadTransaction) {
-      cancelCurrentActivityUiLoadTransaction()
-    }
+    applyActivityUiLoadTransactionSetting(this, configuration.enableActivityUiLoadTransaction)
 
     val controls =
       ComposeView(this).apply {

sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/navigation/nav3/Nav3SampleTracing.kt

@@ -1,8 +1,12 @@
 package io.sentry.samples.android.navigation.nav3
 
+import android.app.Activity
+import io.sentry.EventProcessor
+import io.sentry.Hint
 import io.sentry.Sentry
 import io.sentry.SpanStatus
 import io.sentry.protocol.SentryTransaction
+import java.util.concurrent.ConcurrentHashMap
 import kotlin.coroutines.resume
 import kotlinx.coroutines.suspendCancellableCoroutine
 
@@ -21,6 +25,50 @@ internal fun SentryTransaction.navigationSampleScenarioLabel(): String =
     ?: getTag(NAV3_SCENARIO_TAG)
     ?: UNKNOWN_NAVIGATION_SCENARIO_LABEL
 
+/**
+ * Applies the sample's "Activity ui.load transaction" toggle to [activity].
+ *
+ * Call from `onCreate` after `super.onCreate`, once the SDK has started the Activity's ui.load
+ * transaction. When [enabled] is false, the transaction is cancelled if it's bound to the scope.
+ * It's also dropped before sending, because the SDK doesn't bind it when another transaction (such
+ * as the previous Activity's nav transaction) is already bound, and the sample can't reach an
+ * unbound ui.load transaction to cancel it.
+ */
+internal fun applyActivityUiLoadTransactionSetting(activity: Activity, enabled: Boolean) {
+  // Matches the transaction name ActivityLifecycleIntegration uses.
+  val activityName = activity.javaClass.simpleName
+  if (enabled) {
+    SuppressedActivityUiLoadTransactions.activityNames.remove(activityName)
+    return
+  }
+  SuppressedActivityUiLoadTransactions.install()
+  SuppressedActivityUiLoadTransactions.activityNames.add(activityName)
+  cancelCurrentActivityUiLoadTransaction()
+}
+
+/** Drops ui.load transactions for sample Activities created with the ui.load toggle off. */
+private object SuppressedActivityUiLoadTransactions : EventProcessor {
+  val activityNames: MutableSet<String> = ConcurrentHashMap.newKeySet()
+
+  @Volatile private var installed = false
+
+  fun install() {
+    if (installed) return
+    synchronized(this) {
+      if (installed) return
+      Sentry.getCurrentScopes().options.addEventProcessor(this)
+      installed = true
+    }
+  }
+
+  override fun process(transaction: SentryTransaction, hint: Hint): SentryTransaction? {
+    val isSuppressed =
+      transaction.contexts.trace?.operation == ACTIVITY_UI_LOAD_OP &&
+        transaction.transaction in activityNames
+    return if (isSuppressed) null else transaction
+  }
+}
+
 internal fun cancelCurrentActivityUiLoadTransaction() {
   Sentry.configureScope { scope ->
     scope.withTransaction { transaction ->