Added StackId object for checking what features a stack supports

Helps make the code easier to follow since we are no longer checking
multiple stack ids at various decision points.

Bug: 25282299
Change-Id: Ifa6864a1ef56ce2eca4c94f87a4e0b993de987cd

24 files changed, 208 insertions, 191 deletions

diff --git a/cmds/am/src/com/android/commands/am/Am.java b/cmds/am/src/com/android/commands/am/Am.java
index 12780a8742b9..7f33cb5df1a3 100644
--- a/cmds/am/src/com/android/commands/am/Am.java
+++ b/cmds/am/src/com/android/commands/am/Am.java
@@ -18,7 +18,7 @@
 
 package com.android.commands.am;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
 import static android.app.ActivityManager.RESIZE_MODE_SYSTEM;
 import static android.app.ActivityManager.RESIZE_MODE_USER;
 
diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index 2f0849f39aa2..472d97fdb9ed 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -2728,8 +2728,8 @@ public class Activity extends ContextThemeWrapper
     /**
      * Called to move the window and its activity/task to a different stack container.
      * For example, a window can move between
-     * {@link android.app.ActivityManager#FULLSCREEN_WORKSPACE_STACK_ID} stack and
-     * {@link android.app.ActivityManager#FREEFORM_WORKSPACE_STACK_ID} stack.
+     * {@link android.app.ActivityManager.StackId#FULLSCREEN_WORKSPACE_STACK_ID} stack and
+     * {@link android.app.ActivityManager.StackId#FREEFORM_WORKSPACE_STACK_ID} stack.
      *
      * @param stackId stack Id to change to.
      * @hide
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index fce1b2e7241a..30a43f578dea 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -73,7 +73,6 @@ import java.util.List;
  */
 public class ActivityManager {
     private static String TAG = "ActivityManager";
-    private static boolean localLOGV = false;
 
     private static int gMaxRecentTasks = -1;
 
@@ -397,60 +396,112 @@ public class ActivityManager {
      */
     public static final int COMPAT_MODE_TOGGLE = 2;
 
-    /**
-     * Invalid stack ID.
-     * @hide
-     */
-    public static final int INVALID_STACK_ID = -1;
+    /** @hide */
+    public static class StackId {
+        /** Invalid stack ID. */
+        public static final int INVALID_STACK_ID = -1;
 
-    /**
-     * First static stack ID.
-     * @hide
-     */
-    public static final int FIRST_STATIC_STACK_ID = 0;
+        /** First static stack ID. */
+        public static final int FIRST_STATIC_STACK_ID = 0;
 
-    /**
-     * Home activity stack ID.
-     * @hide
-     */
-    public static final int HOME_STACK_ID = FIRST_STATIC_STACK_ID;
+        /** Home activity stack ID. */
+        public static final int HOME_STACK_ID = FIRST_STATIC_STACK_ID;
 
-    /**
-     * ID of stack where fullscreen activities are normally launched into.
-     * @hide
-     */
-    public static final int FULLSCREEN_WORKSPACE_STACK_ID = 1;
+        /** ID of stack where fullscreen activities are normally launched into. */
+        public static final int FULLSCREEN_WORKSPACE_STACK_ID = 1;
 
-    /**
-     * ID of stack where freeform/resized activities are normally launched into.
-     * @hide
-     */
-    public static final int FREEFORM_WORKSPACE_STACK_ID = FULLSCREEN_WORKSPACE_STACK_ID + 1;
+        /** ID of stack where freeform/resized activities are normally launched into. */
+        public static final int FREEFORM_WORKSPACE_STACK_ID = FULLSCREEN_WORKSPACE_STACK_ID + 1;
 
-    /**
-     * ID of stack that occupies a dedicated region of the screen.
-     * @hide
-     */
-    public static final int DOCKED_STACK_ID = FREEFORM_WORKSPACE_STACK_ID + 1;
+        /** ID of stack that occupies a dedicated region of the screen. */
+        public static final int DOCKED_STACK_ID = FREEFORM_WORKSPACE_STACK_ID + 1;
 
-    /**
-     * ID of stack that always on top (always visible) when it exist.
-     * Mainly used for this in Picture-in-Picture mode.
-     * @hide
-     */
-    public static final int PINNED_STACK_ID = DOCKED_STACK_ID + 1;
+        /** ID of stack that always on top (always visible) when it exist. */
+        public static final int PINNED_STACK_ID = DOCKED_STACK_ID + 1;
 
-    /**
-     * Last static stack stack ID.
-     * @hide
-     */
-    public static final int LAST_STATIC_STACK_ID = PINNED_STACK_ID;
+        /** Last static stack stack ID. */
+        public static final int LAST_STATIC_STACK_ID = PINNED_STACK_ID;
 
-    /**
-     * Start of ID range used by stacks that are created dynamically.
-     * @hide
-     */
-    public static final int FIRST_DYNAMIC_STACK_ID = LAST_STATIC_STACK_ID + 1;
+        /** Start of ID range used by stacks that are created dynamically. */
+        public static final int FIRST_DYNAMIC_STACK_ID = LAST_STATIC_STACK_ID + 1;
+
+        public static boolean isStaticStack(int stackId) {
+            return stackId >= FIRST_STATIC_STACK_ID && stackId <= LAST_STATIC_STACK_ID;
+        }
+
+        /**
+         * Returns true if the activities contained in the input stack display a shadow around
+         * their border.
+         */
+        public static boolean hasWindowShadow(int stackId) {
+            return stackId == FREEFORM_WORKSPACE_STACK_ID || stackId == PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if the activities contained in the input stack display a decor view.
+         */
+        public static boolean hasWindowDecor(int stackId) {
+            return stackId == FREEFORM_WORKSPACE_STACK_ID;
+        }
+
+        /**
+         * Returns true if the tasks contained in the stack can be resized independently of the
+         * stack.
+         */
+        public static boolean isTaskResizeAllowed(int stackId) {
+            return stackId == FREEFORM_WORKSPACE_STACK_ID;
+        }
+
+        /**
+         * Returns true if the task bounds should persist across power cycles.
+         */
+        public static boolean persistTaskBounds(int stackId) {
+            return isStaticStack(stackId) &&
+                    stackId != DOCKED_STACK_ID && stackId != PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if dynamic stacks are allowed to be visible behind the input stack.
+         */
+        public static boolean isDynamicStacksVisibleBehindAllowed(int stackId) {
+            return stackId == PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if we try to maintain focus in the current stack when the top activity
+         * finishes.
+         */
+        public static boolean keepFocusInStackIfPossible(int stackId) {
+            return stackId == FREEFORM_WORKSPACE_STACK_ID
+                    || stackId == DOCKED_STACK_ID || stackId == PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if Stack size is affected by the docked stack changing size.
+         */
+        public static boolean isResizeableByDockedStack(int stackId) {
+            return isStaticStack(stackId) &&
+                    stackId != DOCKED_STACK_ID && stackId != PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if the size of tasks in the input stack are affected by the docked stack
+         * changing size.
+         */
+        public static boolean isTaskResizeableByDockedStack(int stackId) {
+            return isStaticStack(stackId) && stackId != FREEFORM_WORKSPACE_STACK_ID
+                    && stackId != DOCKED_STACK_ID && stackId != PINNED_STACK_ID;
+        }
+
+        /**
+         * Returns true if the windows of tasks being moved to this stack should be preserved so
+         * there isn't a display gap.
+         */
+        public static boolean preserveWindowOnTaskMove(int stackId) {
+            return stackId == FULLSCREEN_WORKSPACE_STACK_ID
+                    || stackId == DOCKED_STACK_ID || stackId == PINNED_STACK_ID;
+        }
+    }
 
     /**
      * Input parameter to {@link android.app.IActivityManager#moveTaskToDockedStack} which
diff --git a/core/java/android/view/Window.java b/core/java/android/view/Window.java
index d9ec866ffbab..61497a769167 100644
--- a/core/java/android/view/Window.java
+++ b/core/java/android/view/Window.java
@@ -552,8 +552,8 @@ public abstract class Window {
         /**
          * Called to move the window and its activity/task to a different stack container.
          * For example, a window can move between
-         * {@link android.app.ActivityManager#FULLSCREEN_WORKSPACE_STACK_ID} stack and
-         * {@link android.app.ActivityManager#FREEFORM_WORKSPACE_STACK_ID} stack.
+         * {@link android.app.ActivityManager.StackId#FULLSCREEN_WORKSPACE_STACK_ID} stack and
+         * {@link android.app.ActivityManager.StackId#FREEFORM_WORKSPACE_STACK_ID} stack.
          *
          * @param stackId stack Id to change to.
          */
diff --git a/core/java/com/android/internal/policy/PhoneWindow.java b/core/java/com/android/internal/policy/PhoneWindow.java
index 7fab31f6f9ea..ad230618cc60 100644
--- a/core/java/com/android/internal/policy/PhoneWindow.java
+++ b/core/java/com/android/internal/policy/PhoneWindow.java
@@ -16,11 +16,8 @@
 
 package com.android.internal.policy;
 
-import static android.app.ActivityManager.FIRST_DYNAMIC_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.INVALID_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 import static android.view.View.MeasureSpec.AT_MOST;
 import static android.view.View.MeasureSpec.EXACTLY;
 import static android.view.View.MeasureSpec.getMode;
@@ -30,6 +27,7 @@ import static android.view.WindowManager.LayoutParams.*;
 
 import android.animation.Animator;
 import android.animation.ObjectAnimator;
+import android.app.ActivityManager.StackId;
 import android.app.ActivityManagerNative;
 import android.app.SearchManager;
 import android.os.Build;
@@ -712,9 +710,9 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
             if (mWorkspaceId != workspaceId) {
                 mWorkspaceId = workspaceId;
                 // We might have to change the kind of surface before we do anything else.
-                mNonClientDecorView.phoneWindowUpdated(hasNonClientDecor(mWorkspaceId),
-                        nonClientDecorHasShadow(mWorkspaceId));
-                mDecor.enableNonClientDecor(hasNonClientDecor(workspaceId));
+                mNonClientDecorView.phoneWindowUpdated(StackId.hasWindowDecor(mWorkspaceId),
+                        StackId.hasWindowShadow(mWorkspaceId));
+                mDecor.enableNonClientDecor(StackId.hasWindowDecor(workspaceId));
             }
         }
     }
@@ -3710,7 +3708,7 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
          * @return Returns true when the window has a shadow created by the non client decor.
          **/
         private boolean windowHasShadow() {
-            return windowHasNonClientDecor() && nonClientDecorHasShadow(mWindow.mWorkspaceId);
+            return windowHasNonClientDecor() && StackId.hasWindowShadow(mWindow.mWorkspaceId);
         }
 
         void setWindow(PhoneWindow phoneWindow) {
@@ -4209,7 +4207,7 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
         mWorkspaceId = getWorkspaceId();
         // Only a non floating application window on one of the allowed workspaces can get a non
         // client decor.
-        if (!isFloating() && isApplication && mWorkspaceId < FIRST_DYNAMIC_STACK_ID) {
+        if (!isFloating() && isApplication && StackId.isStaticStack(mWorkspaceId)) {
             // Dependent on the brightness of the used title we either use the
             // dark or the light button frame.
             if (nonClientDecorView == null) {
@@ -4225,12 +4223,13 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
                             R.layout.non_client_decor_light, null);
                 }
             }
-            nonClientDecorView.setPhoneWindow(this, hasNonClientDecor(mWorkspaceId),
-                    nonClientDecorHasShadow(mWorkspaceId), getResizingBackgroundDrawable(),
+            nonClientDecorView.setPhoneWindow(this, StackId.hasWindowDecor(mWorkspaceId),
+                    StackId.hasWindowShadow(mWorkspaceId), getResizingBackgroundDrawable(),
                     mDecor.getContext().getDrawable(R.drawable.non_client_decor_title_focused));
         }
         // Tell the decor if it has a visible non client decor.
-        mDecor.enableNonClientDecor(nonClientDecorView != null && hasNonClientDecor(mWorkspaceId));
+        mDecor.enableNonClientDecor(
+                nonClientDecorView != null&& StackId.hasWindowDecor(mWorkspaceId));
 
         return nonClientDecorView;
     }
@@ -5403,24 +5402,6 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
         return workspaceId;
     }
 
-    /**
-     * Determines if the window should show a non client decor for the workspace it is in.
-     * @param workspaceId The Id of the workspace which contains this window.
-     * @Return Returns true if the window should show a non client decor.
-     **/
-    private static boolean hasNonClientDecor(int workspaceId) {
-        return workspaceId == FREEFORM_WORKSPACE_STACK_ID;
-    }
-
-    /**
-     * Determines if the window should show a shadow or not, dependent on the workspace.
-     * @param workspaceId The Id of the workspace which contains this window.
-     * @Return Returns true if the window should show a shadow.
-     **/
-    private static boolean nonClientDecorHasShadow(int workspaceId) {
-        return workspaceId == FREEFORM_WORKSPACE_STACK_ID || workspaceId == PINNED_STACK_ID;
-    }
-
     @Override
     public void setTheme(int resid) {
         mTheme = resid;
diff --git a/core/java/com/android/internal/widget/NonClientDecorView.java b/core/java/com/android/internal/widget/NonClientDecorView.java
index 5d502c9dcca0..59783ed88565 100644
--- a/core/java/com/android/internal/widget/NonClientDecorView.java
+++ b/core/java/com/android/internal/widget/NonClientDecorView.java
@@ -16,8 +16,9 @@
 
 package com.android.internal.widget;
 
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+
 import android.content.Context;
-import android.graphics.Color;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.os.Looper;
@@ -332,8 +333,7 @@ public class NonClientDecorView extends LinearLayout
         Window.WindowControllerCallback callback = mOwner.getWindowControllerCallback();
         if (callback != null) {
             try {
-                callback.changeWindowStack(
-                        android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID);
+                callback.changeWindowStack(FULLSCREEN_WORKSPACE_STACK_ID);
             } catch (RemoteException ex) {
                 Log.e(TAG, "Cannot change task workspace.");
             }
diff --git a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
index d02e2affaaa7..d5bbad2f5335 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
@@ -16,7 +16,7 @@
 
 package com.android.systemui.recents;
 
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 
 import android.app.ActivityManager;
 import android.app.ActivityOptions;
diff --git a/packages/SystemUI/src/com/android/systemui/recents/RecentsResizeTaskDialog.java b/packages/SystemUI/src/com/android/systemui/recents/RecentsResizeTaskDialog.java
index 28299d3217fb..d4158451b54b 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/RecentsResizeTaskDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/RecentsResizeTaskDialog.java
@@ -33,8 +33,8 @@ import com.android.systemui.recents.misc.SystemServicesProxy;
 import com.android.systemui.recents.model.Task;
 import com.android.systemui.recents.views.RecentsView;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 
 /**
  * A helper for the dialogs that show when task debugging is on.
diff --git a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
index 141562c86b90..d8d9f076e174 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
@@ -71,8 +71,10 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Random;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.INVALID_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 
 /**
  * Acts as a shim around the real system services that we need to access data from, and provides
@@ -310,14 +312,14 @@ public class SystemServicesProxy {
      * Returns whether the given stack id is the home stack id.
      */
     public static boolean isHomeStack(int stackId) {
-        return stackId == ActivityManager.HOME_STACK_ID;
+        return stackId == HOME_STACK_ID;
     }
 
     /**
      * Returns whether the given stack id is the freeform workspace stack id.
      */
     public static boolean isFreeformStack(int stackId) {
-        return stackId == ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+        return stackId == FREEFORM_WORKSPACE_STACK_ID;
     }
 
     /**
@@ -714,7 +716,7 @@ public class SystemServicesProxy {
 
         try {
             // Use the home stack bounds
-            ActivityManager.StackInfo stackInfo = mIam.getStackInfo(ActivityManager.HOME_STACK_ID);
+            ActivityManager.StackInfo stackInfo = mIam.getStackInfo(HOME_STACK_ID);
             if (stackInfo != null) {
                 windowRect.set(stackInfo.bounds);
             }
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
index a8a8259e79e5..32f7e20df94a 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
@@ -60,7 +60,9 @@ import com.android.systemui.recents.model.TaskStack;
 import java.util.ArrayList;
 import java.util.List;
 
-import static android.app.ActivityManager.INVALID_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 
 /**
  * This view is the the top level layout that contains TaskStacks (which are laid out according
@@ -488,14 +490,14 @@ public class RecentsView extends FrameLayout implements TaskStackView.TaskStackV
             int destinationStack) {
         final int targetStackId = destinationStack != INVALID_STACK_ID ?
                 destinationStack : clickedTask.getTask().key.stackId;
-        if (targetStackId != ActivityManager.FREEFORM_WORKSPACE_STACK_ID
-                && targetStackId != ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID) {
+        if (targetStackId != FREEFORM_WORKSPACE_STACK_ID
+                && targetStackId != FULLSCREEN_WORKSPACE_STACK_ID) {
             return null;
         }
         // If this is a full screen stack, the transition will be towards the single, full screen
         // task. We only need the transition spec for this task.
         List<AppTransitionAnimationSpec> specs = new ArrayList<>();
-        if (targetStackId == ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID) {
+        if (targetStackId == FULLSCREEN_WORKSPACE_STACK_ID) {
             specs.add(createThumbnailHeaderAnimationSpec(
                     stackView, offsetX, offsetY, stackScroll, clickedTask,
                     clickedTask.getTask().key.id, ADD_HEADER_BITMAP));
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
index dfa36d81affb..f9cd3133eee5 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
@@ -58,7 +58,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 
-import static android.app.ActivityManager.INVALID_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 
 
 /* The visual representation of a task stack view */
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarApps.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarApps.java
index 4ac2c3185b6d..a51f62ad0b69 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarApps.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarApps.java
@@ -16,7 +16,7 @@
 
 package com.android.systemui.statusbar.phone;
 
-import static android.app.ActivityManager.INVALID_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 
 import android.animation.LayoutTransition;
 import android.annotation.Nullable;
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index d5ee5e846277..18337658f801 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -19,12 +19,11 @@ package com.android.server.am;
 import static android.Manifest.permission.INTERACT_ACROSS_USERS;
 import static android.Manifest.permission.INTERACT_ACROSS_USERS_FULL;
 import static android.Manifest.permission.START_TASKS_FROM_RECENTS;
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.HOME_STACK_ID;
-import static android.app.ActivityManager.INVALID_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 import static android.app.ActivityManager.RESIZE_MODE_PRESERVE_WINDOW;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static com.android.internal.util.XmlUtils.readBooleanAttribute;
@@ -47,6 +46,7 @@ import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
 import static org.xmlpull.v1.XmlPullParser.START_TAG;
 
 import android.Manifest;
+import android.app.ActivityManager.StackId;
 import android.app.AppOpsManager;
 import android.app.ApplicationThreadNative;
 import android.app.BroadcastOptions;
@@ -8651,12 +8651,9 @@ public final class ActivityManagerService extends ActivityManagerNative
                 // - a non-null bounds on a non-freeform (fullscreen OR docked) task moves
                 //   that task to freeform
                 // - otherwise the task is not moved
-                // Note it's not allowed to resize a home, docked, or pinned stack task.
                 int stackId = task.stack.mStackId;
-                if (stackId == HOME_STACK_ID || stackId == DOCKED_STACK_ID
-                        || stackId == PINNED_STACK_ID) {
-                    throw new IllegalArgumentException("trying to resizeTask on a "
-                            + "home or docked task");
+                if (!StackId.isTaskResizeAllowed(stackId)) {
+                    throw new IllegalArgumentException("resizeTask not allowed on task=" + task);
                 }
                 if (bounds == null && stackId == FREEFORM_WORKSPACE_STACK_ID) {
                     stackId = FULLSCREEN_WORKSPACE_STACK_ID;
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 2104830c6666..0f5927d38716 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -16,14 +16,11 @@
 
 package com.android.server.am;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FIRST_STATIC_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.HOME_STACK_ID;
-import static android.app.ActivityManager.INVALID_STACK_ID;
-import static android.app.ActivityManager.LAST_STATIC_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
 import static android.content.pm.ActivityInfo.FLAG_SHOW_FOR_ALL_USERS;
 
 import static com.android.server.am.ActivityManagerDebugConfig.*;
@@ -49,6 +46,7 @@ import com.android.server.wm.WindowManagerService;
 
 import android.app.Activity;
 import android.app.ActivityManager;
+import android.app.ActivityManager.StackId;
 import android.app.ActivityOptions;
 import android.app.AppGlobals;
 import android.app.IActivityController;
@@ -255,9 +253,6 @@ final class ActivityStack {
 
     private final LaunchingTaskPositioner mTaskPositioner;
 
-    // If the bounds of task contained in this stack should be persisted across power cycles.
-    final boolean mPersistTaskBounds;
-
     static final int PAUSE_TIMEOUT_MSG = ActivityManagerService.FIRST_ACTIVITY_STACK_MSG + 1;
     static final int DESTROY_TIMEOUT_MSG = ActivityManagerService.FIRST_ACTIVITY_STACK_MSG + 2;
     static final int LAUNCH_TICK_MSG = ActivityManagerService.FIRST_ACTIVITY_STACK_MSG + 3;
@@ -371,7 +366,6 @@ final class ActivityStack {
         mRecentTasks = recentTasks;
         mTaskPositioner = mStackId == FREEFORM_WORKSPACE_STACK_ID
                 ? new LaunchingTaskPositioner() : null;
-        mPersistTaskBounds = mStackId != DOCKED_STACK_ID && mStackId != PINNED_STACK_ID;
     }
 
     void attachDisplay(ActivityStackSupervisor.ActivityDisplay activityDisplay, boolean onTop) {
@@ -1365,7 +1359,7 @@ final class ActivityStack {
             }
         }
 
-        if (mStackId >= FIRST_STATIC_STACK_ID && mStackId <= LAST_STATIC_STACK_ID) {
+        if (StackId.isStaticStack(mStackId)) {
             // Visibility of any static stack should have been determined by the conditions above.
             return false;
         }
@@ -1377,9 +1371,7 @@ final class ActivityStack {
                 continue;
             }
 
-            if (stack.mStackId == FREEFORM_WORKSPACE_STACK_ID
-                    || stack.mStackId == HOME_STACK_ID
-                    || stack.mStackId == FULLSCREEN_WORKSPACE_STACK_ID) {
+            if (!StackId.isDynamicStacksVisibleBehindAllowed(stack.mStackId)) {
                 // These stacks can't have any dynamic stacks visible behind them.
                 return false;
             }
@@ -2797,8 +2789,7 @@ final class ActivityStack {
             ActivityRecord next = topRunningActivityLocked();
             final String myReason = reason + " adjustFocus";
             if (next != r) {
-                if (next != null && (mStackId == FREEFORM_WORKSPACE_STACK_ID
-                        || mStackId == DOCKED_STACK_ID || mStackId == PINNED_STACK_ID)) {
+                if (next != null && StackId.keepFocusInStackIfPossible(mStackId)) {
                     // For freeform, docked, and pinned stacks we always keep the focus within the
                     // stack as long as there is a running activity in the stack that we can adjust
                     // focus to.
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 1cd71a1cb61a..7e42dce74fea 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -18,6 +18,15 @@ package com.android.server.am;
 
 import static android.Manifest.permission.START_ANY_ACTIVITY;
 import static android.app.ActivityManager.*;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FIRST_DYNAMIC_STACK_ID;
+import static android.app.ActivityManager.StackId.FIRST_STATIC_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
+import static android.app.ActivityManager.StackId.LAST_STATIC_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
@@ -40,6 +49,7 @@ import static com.android.server.am.TaskRecord.LOCK_TASK_AUTH_WHITELISTED;
 import android.Manifest;
 import android.app.Activity;
 import android.app.ActivityManager;
+import android.app.ActivityManager.StackId;
 import android.app.ActivityManager.StackInfo;
 import android.app.ActivityOptions;
 import android.app.AppGlobals;
@@ -554,8 +564,8 @@ public final class ActivityStackSupervisor implements DisplayListener {
      * @param id Id of the task we would like returned.
      * @param restoreFromRecents If the id was not in the active list, but was found in recents,
      *                           restore the task from recents to the active list.
-     * @param stackId The stack to restore the task to (default launch stack will be used
-     *                if stackId is {@link android.app.ActivityManager#INVALID_STACK_ID}).
+     * @param stackId The stack to restore the task to (default launch stack will be used if
+     *                stackId is {@link android.app.ActivityManager.StackId#INVALID_STACK_ID}).
      */
     TaskRecord anyTaskForIdLocked(int id, boolean restoreFromRecents, int stackId) {
         int numDisplays = mActivityDisplays.size();
@@ -1820,8 +1830,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
         final ArrayList<ActivityStack> homeDisplayStacks = mHomeStack.mStacks;
         for (int stackNdx = homeDisplayStacks.size() - 1; stackNdx >= 0; --stackNdx) {
             stack = homeDisplayStacks.get(stackNdx);
-            final boolean isDynamicStack = stack.mStackId >= FIRST_DYNAMIC_STACK_ID;
-            if (isDynamicStack) {
+            if (!StackId.isStaticStack(stack.mStackId)) {
                 if (DEBUG_FOCUS || DEBUG_STACK) Slog.d(TAG_FOCUS,
                         "computeStackFocus: Setting focused stack=" + stack);
                 return stack;
@@ -2899,15 +2908,14 @@ public final class ActivityStackSupervisor implements DisplayListener {
         if (activityContainer != null) {
             return activityContainer.mStack;
         }
-        if (!createStaticStackIfNeeded
-                || (stackId < FIRST_STATIC_STACK_ID || stackId > LAST_STATIC_STACK_ID)) {
+        if (!createStaticStackIfNeeded || !StackId.isStaticStack(stackId)) {
             return null;
         }
         return createStackOnDisplay(stackId, Display.DEFAULT_DISPLAY, createOnTop);
     }
 
     ArrayList<ActivityStack> getStacks() {
-        ArrayList<ActivityStack> allStacks = new ArrayList<ActivityStack>();
+        ArrayList<ActivityStack> allStacks = new ArrayList<>();
         for (int displayNdx = mActivityDisplays.size() - 1; displayNdx >= 0; --displayNdx) {
             allStacks.addAll(mActivityDisplays.valueAt(displayNdx).mStacks);
         }
@@ -3025,7 +3033,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
                     // In this case we make all other static stacks fullscreen and move all
                     // docked stack tasks to the fullscreen stack.
                     for (int i = FIRST_STATIC_STACK_ID; i <= LAST_STATIC_STACK_ID; i++) {
-                        if (i != DOCKED_STACK_ID && getStack(i) != null) {
+                        if (StackId.isResizeableByDockedStack(i) && getStack(i) != null) {
                             resizeStackLocked(i, null, preserveWindows, true);
                         }
                     }
@@ -3046,7 +3054,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
                     mWindowManager.getStackDockedModeBounds(HOME_STACK_ID, tempRect);
 
                     for (int i = FIRST_STATIC_STACK_ID; i <= LAST_STATIC_STACK_ID; i++) {
-                        if (i != DOCKED_STACK_ID) {
+                        if (StackId.isResizeableByDockedStack(i)) {
                             ActivityStack otherStack = getStack(i);
                             if (otherStack != null) {
                                 resizeStackLocked(i, tempRect, PRESERVE_WINDOWS, true);
@@ -3190,7 +3198,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
      * Restores a recent task to a stack
      * @param task The recent task to be restored.
      * @param stackId The stack to restore the task to (default launch stack will be used
-     *                if stackId is {@link android.app.ActivityManager#INVALID_STACK_ID}).
+     *                if stackId is {@link android.app.ActivityManager.StackId#INVALID_STACK_ID}).
      * @return true if the task has been restored successfully.
      */
     private boolean restoreRecentTaskLocked(TaskRecord task, int stackId) {
@@ -3275,8 +3283,7 @@ public final class ActivityStackSupervisor implements DisplayListener {
             Slog.w(TAG, "moveTaskToStack: no task for id=" + taskId);
             return;
         }
-        if (stackId == DOCKED_STACK_ID || stackId == PINNED_STACK_ID
-                || stackId == FULLSCREEN_WORKSPACE_STACK_ID) {
+        if (StackId.preserveWindowOnTaskMove(stackId)) {
             // We are about to relaunch the activity because its configuration changed due to
             // being maximized, i.e. size change. The activity will first remove the old window
             // and then add a new one. This call will tell window manager about this, so it can
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 120b40c73c13..5fd213f96c66 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -16,11 +16,9 @@
 
 package com.android.server.am;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.HOME_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_DOCUMENT;
 import static android.content.Intent.FLAG_ACTIVITY_RETAIN_IN_RECENTS;
 import static android.content.pm.ActivityInfo.LOCK_TASK_LAUNCH_MODE_ALWAYS;
@@ -35,6 +33,7 @@ import static com.android.server.am.ActivityRecord.RECENTS_ACTIVITY_TYPE;
 
 import android.app.Activity;
 import android.app.ActivityManager;
+import android.app.ActivityManager.StackId;
 import android.app.ActivityManager.TaskThumbnail;
 import android.app.ActivityManager.TaskDescription;
 import android.app.ActivityOptions;
@@ -1193,14 +1192,14 @@ final class TaskRecord {
 
         mFullscreen = bounds == null;
         if (mFullscreen) {
-            if (mBounds != null && stack.mPersistTaskBounds) {
+            if (mBounds != null && StackId.persistTaskBounds(stack.mStackId)) {
                 mLastNonFullscreenBounds = mBounds;
             }
             mBounds = null;
             mOverrideConfig = Configuration.EMPTY;
         } else {
             mBounds = new Rect(bounds);
-            if (stack == null || stack.mPersistTaskBounds) {
+            if (stack == null || StackId.persistTaskBounds(stack.mStackId)) {
                 mLastNonFullscreenBounds = mBounds;
             }
 
@@ -1244,7 +1243,7 @@ final class TaskRecord {
                 || stackId == HOME_STACK_ID
                 || stackId == FULLSCREEN_WORKSPACE_STACK_ID) {
             return (mResizeable && stack != null) ? stack.mBounds : null;
-        } else if (!stack.mPersistTaskBounds) {
+        } else if (!StackId.persistTaskBounds(stackId)) {
             return stack.mBounds;
         }
         return mLastNonFullscreenBounds;
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index b38b9ceb0712..209751ee4bcd 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -16,8 +16,8 @@
 
 package com.android.server.policy;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 import static android.view.WindowManager.LayoutParams.*;
 import static android.view.WindowManagerPolicy.WindowManagerFuncs.LID_ABSENT;
 import static android.view.WindowManagerPolicy.WindowManagerFuncs.LID_OPEN;
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index fab8ee55b22c..d6f807eb0ab8 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -16,14 +16,15 @@
 
 package com.android.server.wm;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.HOME_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
 import static com.android.server.wm.WindowManagerService.DEBUG_VISIBILITY;
 import static com.android.server.wm.WindowManagerService.TAG;
 import static com.android.server.wm.WindowState.RESIZE_HANDLE_WIDTH_IN_DP;
 import static com.android.server.wm.WindowState.BOUNDS_FOR_TOUCH;
 
+import android.app.ActivityManager.StackId;
 import android.graphics.Rect;
 import android.graphics.Region;
 import android.util.DisplayMetrics;
@@ -311,7 +312,7 @@ class DisplayContent {
         final int delta = mService.dipToPixel(RESIZE_HANDLE_WIDTH_IN_DP, mDisplayMetrics);
         for (int stackNdx = mStacks.size() - 1; stackNdx >= 0; --stackNdx) {
             TaskStack stack = mStacks.get(stackNdx);
-            if (!stack.allowTaskResize()) {
+            if (!StackId.isTaskResizeAllowed(stack.mStackId)) {
                 break;
             }
             final ArrayList<Task> tasks = stack.getTasks();
diff --git a/services/core/java/com/android/server/wm/DockedStackDividerController.java b/services/core/java/com/android/server/wm/DockedStackDividerController.java
index 04cba81726ec..eafc3c6beccf 100644
--- a/services/core/java/com/android/server/wm/DockedStackDividerController.java
+++ b/services/core/java/com/android/server/wm/DockedStackDividerController.java
@@ -16,7 +16,7 @@
 
 package com.android.server.wm;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
 import static android.content.res.Configuration.ORIENTATION_LANDSCAPE;
 import static android.view.PointerIcon.STYLE_HORIZONTAL_DOUBLE_ARROW;
 import static android.view.PointerIcon.STYLE_VERTICAL_DOUBLE_ARROW;
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index ad4419604896..0a313c3ac549 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -16,22 +16,21 @@
 
 package com.android.server.wm;
 
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.HOME_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.HOME_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
 import static android.app.ActivityManager.RESIZE_MODE_SYSTEM_SCREEN_ROTATION;
 import static com.android.server.wm.WindowManagerService.TAG;
 import static com.android.server.wm.WindowManagerService.DEBUG_RESIZE;
 import static com.android.server.wm.WindowManagerService.DEBUG_STACK;
 import static com.android.server.wm.WindowManagerService.H.RESIZE_TASK;
 
-
+import android.app.ActivityManager.StackId;
 import android.content.res.Configuration;
 import android.graphics.Rect;
 import android.util.EventLog;
 import android.util.Slog;
-import android.util.SparseArray;
 import android.view.DisplayInfo;
 import android.view.Surface;
 
@@ -245,7 +244,7 @@ class Task implements DimLayer.DimLayerUser {
     private boolean useCurrentBounds() {
         final DisplayContent displayContent = mStack.getDisplayContent();
         if (mFullscreen
-                || mStack.allowTaskResize()
+                || !StackId.isTaskResizeableByDockedStack(mStack.mStackId)
                 || displayContent == null
                 || displayContent.getDockedStackLocked() != null) {
             return true;
diff --git a/services/core/java/com/android/server/wm/TaskPositioner.java b/services/core/java/com/android/server/wm/TaskPositioner.java
index 227b3f01fac2..aae3bd24439f 100644
--- a/services/core/java/com/android/server/wm/TaskPositioner.java
+++ b/services/core/java/com/android/server/wm/TaskPositioner.java
@@ -18,7 +18,7 @@ package com.android.server.wm;
 
 import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_BOTTOM_OR_RIGHT;
 import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_TOP_OR_LEFT;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 import static android.app.ActivityManager.RESIZE_MODE_USER;
 import static android.app.ActivityManager.RESIZE_MODE_USER_FORCED;
 import static android.content.res.Configuration.ORIENTATION_LANDSCAPE;
diff --git a/services/core/java/com/android/server/wm/TaskStack.java b/services/core/java/com/android/server/wm/TaskStack.java
index df664bd271bd..95e23917b7e3 100644
--- a/services/core/java/com/android/server/wm/TaskStack.java
+++ b/services/core/java/com/android/server/wm/TaskStack.java
@@ -17,17 +17,16 @@
 package com.android.server.wm;
 
 import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_TOP_OR_LEFT;
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FIRST_STATIC_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.FULLSCREEN_WORKSPACE_STACK_ID;
-import static android.app.ActivityManager.LAST_STATIC_STACK_ID;
-import static android.app.ActivityManager.PINNED_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
 import static com.android.server.wm.WindowManagerService.DEBUG_TASK_MOVEMENT;
 import static com.android.server.wm.WindowManagerService.H.RESIZE_STACK;
 import static com.android.server.wm.WindowManagerService.TAG;
 
 import android.annotation.IntDef;
+import android.app.ActivityManager.StackId;
 import android.content.res.Configuration;
 import android.graphics.Rect;
 import android.os.Debug;
@@ -122,12 +121,6 @@ public class TaskStack implements DimLayer.DimLayerUser {
         }
     }
 
-    boolean allowTaskResize() {
-        return mStackId == FREEFORM_WORKSPACE_STACK_ID
-                || mStackId == DOCKED_STACK_ID
-                || mStackId == PINNED_STACK_ID;
-    }
-
     /**
      * Set the bounds of the stack and its containing tasks.
      * @param stackBounds New stack bounds. Passing in null sets the bounds to fullscreen.
@@ -203,8 +196,7 @@ public class TaskStack implements DimLayer.DimLayerUser {
     /** Return true if the current bound can get outputted to the rest of the system as-is. */
     private boolean useCurrentBounds() {
         if (mFullscreen
-                || mStackId == DOCKED_STACK_ID
-                || mStackId == PINNED_STACK_ID
+                || !StackId.isResizeableByDockedStack(mStackId)
                 || mDisplayContent == null
                 || mDisplayContent.getDockedStackLocked() != null) {
             return true;
@@ -396,9 +388,9 @@ public class TaskStack implements DimLayer.DimLayerUser {
 
         Rect bounds = null;
         final TaskStack dockedStack = mService.mStackIdToStack.get(DOCKED_STACK_ID);
-        if (mStackId == DOCKED_STACK_ID || (dockedStack != null && mStackId != PINNED_STACK_ID
-                && mStackId >= FIRST_STATIC_STACK_ID && mStackId <= LAST_STATIC_STACK_ID)) {
-            // The existence of a docked stack affects the size of any static stack created since
+        if (mStackId == DOCKED_STACK_ID
+                || (dockedStack != null && StackId.isResizeableByDockedStack(mStackId))) {
+            // The existence of a docked stack affects the size of other static stack created since
             // the docked stack occupies a dedicated region on screen.
             bounds = new Rect();
             displayContent.getLogicalDisplayRect(mTmpRect);
@@ -424,10 +416,7 @@ public class TaskStack implements DimLayer.DimLayerUser {
     }
 
     void getStackDockedModeBoundsLocked(Rect outBounds) {
-        if (mStackId == DOCKED_STACK_ID
-                || mStackId == PINNED_STACK_ID
-                || mStackId > LAST_STATIC_STACK_ID
-                || mDisplayContent == null) {
+        if (!StackId.isResizeableByDockedStack(mStackId) || mDisplayContent == null) {
             outBounds.set(mBounds);
             return;
         }
@@ -537,9 +526,7 @@ public class TaskStack implements DimLayer.DimLayerUser {
         for (int i = 0; i < count; i++) {
             final TaskStack otherStack = mService.mStackIdToStack.valueAt(i);
             final int otherStackId = otherStack.mStackId;
-            if (otherStackId != DOCKED_STACK_ID && mStackId != PINNED_STACK_ID
-                    && otherStackId >= FIRST_STATIC_STACK_ID
-                    && otherStackId <= LAST_STATIC_STACK_ID) {
+            if (StackId.isResizeableByDockedStack(otherStackId)) {
                 mService.mH.sendMessage(
                         mService.mH.obtainMessage(RESIZE_STACK, otherStackId,
                                 1 /*allowResizeInDockedMode*/, bounds));
diff --git a/services/core/java/com/android/server/wm/WallpaperController.java b/services/core/java/com/android/server/wm/WallpaperController.java
index 7f2f2cda8128..4a9d8cbdf006 100644
--- a/services/core/java/com/android/server/wm/WallpaperController.java
+++ b/services/core/java/com/android/server/wm/WallpaperController.java
@@ -16,7 +16,7 @@
 
 package com.android.server.wm;
 
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 import static android.view.WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER;
 import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_KEYGUARD;
 import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION_STARTING;
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 140fbaf01f58..fe4eb5117293 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -17,8 +17,8 @@
 package com.android.server.wm;
 
 import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_TOP_OR_LEFT;
-import static android.app.ActivityManager.DOCKED_STACK_ID;
-import static android.app.ActivityManager.FREEFORM_WORKSPACE_STACK_ID;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_BEHIND;
 import static android.view.WindowManager.LayoutParams.FIRST_APPLICATION_WINDOW;