RefreshScheduler.

A piece of business logic used by interactors (in next CLs) that can
pause, unpause, and schedule "refresh users" logic to happen.

Bug: 246631653
Test: Included in CL
Change-Id: I18d51923bfaad7a06fc6cb372f5139f0fff65411

packages/SystemUI/src/com/android/systemui/user/domain/interactor/RefreshUsersScheduler.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2022 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.systemui.user.domain.interactor
+
+import com.android.systemui.dagger.SysUISingleton
+import com.android.systemui.dagger.qualifiers.Application
+import com.android.systemui.dagger.qualifiers.Main
+import com.android.systemui.user.data.repository.UserRepository
+import javax.inject.Inject
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+/** Encapsulates logic for pausing, unpausing, and scheduling a delayed job. */
+@SysUISingleton
+class RefreshUsersScheduler
+@Inject
+constructor(
+    @Application private val applicationScope: CoroutineScope,
+    @Main private val mainDispatcher: CoroutineDispatcher,
+    private val repository: UserRepository,
+) {
+    private var scheduledUnpauseJob: Job? = null
+    private var isPaused = false
+
+    fun pause() {
+        applicationScope.launch(mainDispatcher) {
+            isPaused = true
+            scheduledUnpauseJob?.cancel()
+            scheduledUnpauseJob =
+                applicationScope.launch {
+                    delay(PAUSE_REFRESH_USERS_TIMEOUT_MS)
+                    unpauseAndRefresh()
+                }
+        }
+    }
+
+    fun unpauseAndRefresh() {
+        applicationScope.launch(mainDispatcher) {
+            isPaused = false
+            refreshIfNotPaused()
+        }
+    }
+
+    fun refreshIfNotPaused() {
+        applicationScope.launch(mainDispatcher) {
+            if (isPaused) {
+                return@launch
+            }
+
+            repository.refreshUsers()
+        }
+    }
+
+    companion object {
+        private const val PAUSE_REFRESH_USERS_TIMEOUT_MS = 3000L
+    }
+}

packages/SystemUI/tests/src/com/android/systemui/user/domain/interactor/RefreshUsersSchedulerTest.kt

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2022 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.systemui.user.domain.interactor
+
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.user.data.repository.FakeUserRepository
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runBlocking
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import org.mockito.MockitoAnnotations
+
+@SmallTest
+@RunWith(JUnit4::class)
+class RefreshUsersSchedulerTest : SysuiTestCase() {
+
+    private lateinit var underTest: RefreshUsersScheduler
+
+    private lateinit var repository: FakeUserRepository
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+
+        repository = FakeUserRepository()
+    }
+
+    @Test
+    fun `pause - prevents the next refresh from happening`() =
+        runBlocking(IMMEDIATE) {
+            underTest =
+                RefreshUsersScheduler(
+                    applicationScope = this,
+                    mainDispatcher = IMMEDIATE,
+                    repository = repository,
+                )
+            underTest.pause()
+
+            underTest.refreshIfNotPaused()
+            assertThat(repository.refreshUsersCallCount).isEqualTo(0)
+        }
+
+    @Test
+    fun `unpauseAndRefresh - forces the refresh even when paused`() =
+        runBlocking(IMMEDIATE) {
+            underTest =
+                RefreshUsersScheduler(
+                    applicationScope = this,
+                    mainDispatcher = IMMEDIATE,
+                    repository = repository,
+                )
+            underTest.pause()
+
+            underTest.unpauseAndRefresh()
+
+            assertThat(repository.refreshUsersCallCount).isEqualTo(1)
+        }
+
+    @Test
+    fun `refreshIfNotPaused - refreshes when not paused`() =
+        runBlocking(IMMEDIATE) {
+            underTest =
+                RefreshUsersScheduler(
+                    applicationScope = this,
+                    mainDispatcher = IMMEDIATE,
+                    repository = repository,
+                )
+            underTest.refreshIfNotPaused()
+
+            assertThat(repository.refreshUsersCallCount).isEqualTo(1)
+        }
+
+    companion object {
+        private val IMMEDIATE = Dispatchers.Main.immediate
+    }
+}