Anr snippets

misc/src/main/java/com/example/snippets/anr/ViewThreadingViolationSnippet.kt

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+/*
+ * Copyright 2026 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.example.snippets.anr
+
+import android.view.View
+import android.widget.TextView
+import androidx.annotation.RequiresApi
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+// Mock/stub classes so the documentation snippets compile cleanly.
+interface MyData {
+    val title: String
+}
+
+interface MyRepository {
+    suspend fun getData(): MyData
+}
+
+@Suppress("unused")
+object ViewThreadingViolationSnippet {
+
+    fun switchContext(
+        lifecycleOwner: LifecycleOwner,
+        myRepository: MyRepository,
+        myTextView: TextView
+    ) {
+        // [START android_view_threading_violation_coroutine_kotlin]
+        lifecycleOwner.lifecycleScope.launch(Dispatchers.IO) {
+            val data = myRepository.getData()
+            withContext(Dispatchers.Main) { // Switch context to Main
+                myTextView.text = data.title
+            }
+        }
+        // [END android_view_threading_violation_coroutine_kotlin]
+    }
+
+    @RequiresApi(37)
+    fun checkViewThreadingViolation() {
+        // [START android_view_threading_violation_listener_kotlin]
+        val listener = object : View.CalledFromWrongThreadListener {
+            override fun onCalledFromWrongThread() {
+                // Handle the issue, e.g. crash if this is a dev build, or log an event
+                // e.g. Log.d(TAG, "CalledFromWrongThread: ${Exception().stackTraceToString()}")
+                // Unregister the listener to avoid redundant notifications for the same issue
+                View.unregisterCalledFromWrongThreadListener(this)
+            }
+        }
+        View.registerCalledFromWrongThreadListener(listener)
+        // [END android_view_threading_violation_listener_kotlin]
+    }
+}