Merge "Add z-order regions for task child layers" into tm-qpr-dev
diff --git a/core/java/android/window/TaskConstants.java b/core/java/android/window/TaskConstants.java
new file mode 100644
index 0000000..c403840
--- /dev/null
+++ b/core/java/android/window/TaskConstants.java
@@ -0,0 +1,106 @@
+/*
+ * 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 android.window;
+
+import android.annotation.IntDef;
+
+/**
+ * Holds constants related to task managements but not suitable in {@code TaskOrganizer}.
+ * @hide
+ */
+public class TaskConstants {
+
+    /**
+     * Sizes of a z-order region assigned to child layers of task layers. Components are allowed to
+     * use all values in [assigned value, assigned value + region size).
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_REGION_SIZE = 10000;
+
+    /**
+     * Indicates system responding to task drag resizing while app content isn't updated.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_TASK_BACKGROUND = -3 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Provides solid color letterbox background or blur effect and dimming for the wallpaper
+     * letterbox background. It also listens to touches for double tap gesture for repositioning
+     * letterbox.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_LETTERBOX_BACKGROUND =
+            -2 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * When a unresizable app is moved in the different configuration, a restart button appears
+     * allowing to adapt (~resize) app to the new configuration mocks.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_SIZE_COMPAT_RESTART_BUTTON =
+            TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Shown the first time an app is opened in size compat mode in landscape.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_LETTERBOX_EDUCATION = 2 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Captions, window frames and resize handlers around task windows.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_WINDOW_DECORATIONS = 3 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Overlays the task when going into PIP w/ gesture navigation.
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_RECENTS_ANIMATION_PIP_OVERLAY =
+            4 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Allows other apps to add overlays on the task (i.e. game dashboard)
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_TASK_OVERLAY = 5 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Legacy machanism to force an activity to the top of the task (i.e. for work profile
+     * comfirmation).
+     * @hide
+     */
+    public static final int TASK_CHILD_LAYER_TASK_OVERLAY_ACTIVITIES =
+            6 * TASK_CHILD_LAYER_REGION_SIZE;
+
+    /**
+     * Z-orders of task child layers other than activities, task fragments and layers interleaved
+     * with them, e.g. IME windows. [-10000, 10000) is reserved for these layers.
+     * @hide
+     */
+    @IntDef({
+            TASK_CHILD_LAYER_TASK_BACKGROUND,
+            TASK_CHILD_LAYER_LETTERBOX_BACKGROUND,
+            TASK_CHILD_LAYER_SIZE_COMPAT_RESTART_BUTTON,
+            TASK_CHILD_LAYER_LETTERBOX_EDUCATION,
+            TASK_CHILD_LAYER_WINDOW_DECORATIONS,
+            TASK_CHILD_LAYER_RECENTS_ANIMATION_PIP_OVERLAY,
+            TASK_CHILD_LAYER_TASK_OVERLAY,
+            TASK_CHILD_LAYER_TASK_OVERLAY_ACTIVITIES
+    })
+    public @interface TaskChildLayer {}
+}