[flexiglass] Container config - UI layer.

The container configuration portion of the Flexiglass framework allows
OEMs to configure one or more Flexiglass containers with scenes. Each scene is a distinct bit of UI content that the
user can navigate to (for example by swiping in a direction) or that can
be navigated to automatically through the SceneInteractor methods.

Bug: 279501596
Test: Included unit tests. Manually tested through a testbed app that
uses Jetpack Compose to implement a simple UI to traverse all scenes.

Change-Id: I2c925707b0709e4aaf26bca8f94e5e2b3cf6bbcc

packages/SystemUI/src/com/android/systemui/scene/ui/viewmodel/SceneContainerViewModel.kt

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2023 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.scene.ui.viewmodel
+
+import com.android.systemui.scene.domain.interactor.SceneInteractor
+import com.android.systemui.scene.shared.model.SceneKey
+import com.android.systemui.scene.shared.model.SceneModel
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
+import kotlinx.coroutines.flow.StateFlow
+
+/** Models UI state for a single scene container. */
+class SceneContainerViewModel
+@AssistedInject
+constructor(
+    private val interactor: SceneInteractor,
+    @Assisted private val containerName: String,
+) {
+    /**
+     * Keys of all scenes in the container.
+     *
+     * The scenes will be sorted in z-order such that the last one is the one that should be
+     * rendered on top of all previous ones.
+     */
+    val allSceneKeys: List<SceneKey> = interactor.allSceneKeys(containerName)
+
+    /** The current scene. */
+    val currentScene: StateFlow<SceneModel> = interactor.currentScene(containerName)
+
+    /** Whether the container is visible. */
+    val isVisible: StateFlow<Boolean> = interactor.isVisible(containerName)
+
+    /** Requests a transition to the scene with the given key. */
+    fun setCurrentScene(scene: SceneModel) {
+        interactor.setCurrentScene(containerName, scene)
+    }
+
+    /** Notifies of the progress of a scene transition. */
+    fun setSceneTransitionProgress(progress: Float) {
+        interactor.setSceneTransitionProgress(containerName, progress)
+    }
+
+    @AssistedFactory
+    interface Factory {
+        fun create(
+            containerName: String,
+        ): SceneContainerViewModel
+    }
+}

packages/SystemUI/tests/src/com/android/systemui/scene/ui/viewmodel/SceneContainerViewModelTest.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+@file:OptIn(ExperimentalCoroutinesApi::class)
+
+package com.android.systemui.scene.ui.viewmodel
+
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.coroutines.collectLastValue
+import com.android.systemui.scene.data.repository.fakeSceneContainerRepository
+import com.android.systemui.scene.data.repository.fakeSceneKeys
+import com.android.systemui.scene.domain.interactor.SceneInteractor
+import com.android.systemui.scene.shared.model.SceneKey
+import com.android.systemui.scene.shared.model.SceneModel
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@SmallTest
+@RunWith(JUnit4::class)
+class SceneContainerViewModelTest : SysuiTestCase() {
+    private val interactor =
+        SceneInteractor(
+            repository = fakeSceneContainerRepository(),
+        )
+    private val underTest =
+        SceneContainerViewModel(
+            interactor = interactor,
+            containerName = "container1",
+        )
+
+    @Test
+    fun isVisible() = runTest {
+        val isVisible by collectLastValue(underTest.isVisible)
+        assertThat(isVisible).isTrue()
+
+        interactor.setVisible("container1", false)
+        assertThat(isVisible).isFalse()
+
+        interactor.setVisible("container1", true)
+        assertThat(isVisible).isTrue()
+    }
+
+    @Test
+    fun allSceneKeys() {
+        assertThat(underTest.allSceneKeys).isEqualTo(fakeSceneKeys())
+    }
+
+    @Test
+    fun sceneTransition() = runTest {
+        val currentScene by collectLastValue(underTest.currentScene)
+        assertThat(currentScene).isEqualTo(SceneModel(SceneKey.LockScreen))
+
+        underTest.setCurrentScene(SceneModel(SceneKey.Shade))
+        assertThat(currentScene).isEqualTo(SceneModel(SceneKey.Shade))
+    }
+}