New PermissionsChangedFlow

Also also clean up LiveDataTestUtil.

Bug: 321163306
Test: unit test
Change-Id: Id2d77f53569619654036e782285cab8931fd5bfc

packages/SettingsLib/Spa/testutils/src/com/android/settingslib/spa/testutils/LiveDataTestUtil.kt → packages/SettingsLib/SpaPrivileged/src/com/android/settingslib/spaprivileged/model/app/PermissionsChangedFlow.kt

 /*
- * Copyright (C) 2022 The Android Open Source Project
+ * Copyright (C) 2024 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.
@@ -14,37 +14,33 @@
  * limitations under the License.
  */
 
-package com.android.settingslib.spa.testutils
+package com.android.settingslib.spaprivileged.model.app
 
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.Observer
-import java.util.concurrent.CountDownLatch
-import java.util.concurrent.TimeUnit
-import java.util.concurrent.TimeoutException
+import android.content.Context
+import android.content.pm.ApplicationInfo
+import android.content.pm.PackageManager
+import com.android.settingslib.spaprivileged.framework.common.asUser
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.conflate
+import kotlinx.coroutines.flow.flowOn
 
-fun <T> LiveData<T>.getOrAwaitValue(
-    timeout: Long = 1,
-    timeUnit: TimeUnit = TimeUnit.SECONDS,
-    afterObserve: () -> Unit = {},
-): T? {
-    var data: T? = null
-    val latch = CountDownLatch(1)
-    val observer = Observer<T> { newData ->
-        data = newData
-        latch.countDown()
-    }
-    this.observeForever(observer)
-
-    afterObserve()
+/**
+ * Creates an instance of a cold Flow for permissions changed callback of given [app].
+ *
+ * An initial element will be always sent.
+ */
+fun Context.permissionsChangedFlow(app: ApplicationInfo) = callbackFlow {
+    val userPackageManager = asUser(app.userHandle).packageManager
 
-    try {
-        // Don't wait indefinitely if the LiveData is not set.
-        if (!latch.await(timeout, timeUnit)) {
-            throw TimeoutException("LiveData value was never set.")
-        }
-    } finally {
-        this.removeObserver(observer)
+    val onPermissionsChangedListener = PackageManager.OnPermissionsChangedListener { uid ->
+        if (uid == app.uid) trySend(Unit)
     }
+    userPackageManager.addOnPermissionsChangeListener(onPermissionsChangedListener)
+    trySend(Unit)
 
-    return data
-}
+    awaitClose {
+        userPackageManager.removeOnPermissionsChangeListener(onPermissionsChangedListener)
+    }
+}.conflate().flowOn(Dispatchers.Default)

packages/SettingsLib/SpaPrivileged/tests/src/com/android/settingslib/spaprivileged/model/app/PermissionsChangedFlowTest.kt

+/*
+ * Copyright (C) 2024 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
+ *
+ *      http://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.android.settingslib.spaprivileged.model.app
+
+import android.content.Context
+import android.content.pm.ApplicationInfo
+import android.content.pm.PackageManager
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.settingslib.spa.testutils.firstWithTimeoutOrNull
+import com.android.settingslib.spa.testutils.toListWithTimeout
+import com.android.settingslib.spaprivileged.framework.common.asUser
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.async
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.runBlocking
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.kotlin.any
+import org.mockito.kotlin.doAnswer
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.spy
+
+@RunWith(AndroidJUnit4::class)
+class PermissionsChangedFlowTest {
+
+    private var onPermissionsChangedListener: PackageManager.OnPermissionsChangedListener? = null
+
+    private val mockPackageManager = mock<PackageManager> {
+        on { addOnPermissionsChangeListener(any()) } doAnswer {
+            onPermissionsChangedListener =
+                it.arguments[0] as PackageManager.OnPermissionsChangedListener
+        }
+    }
+
+    private val context: Context = spy(ApplicationProvider.getApplicationContext()) {
+        on { asUser(APP.userHandle) } doReturn mock
+        on { packageManager } doReturn mockPackageManager
+    }
+
+    @Test
+    fun permissionsChangedFlow_sendInitialValueTrue() = runBlocking {
+        val flow = context.permissionsChangedFlow(APP)
+
+        assertThat(flow.firstWithTimeoutOrNull()).isNotNull()
+    }
+
+    @Test
+    fun permissionsChangedFlow_collectChanged_getTwo() = runBlocking {
+        val listDeferred = async {
+            context.permissionsChangedFlow(APP).toListWithTimeout()
+        }
+        delay(100)
+
+        onPermissionsChangedListener?.onPermissionsChanged(APP.uid)
+
+        assertThat(listDeferred.await()).hasSize(2)
+    }
+
+    private companion object {
+        val APP = ApplicationInfo().apply {
+            packageName = "package.name"
+            uid = 10000
+        }
+    }
+}