1 files changed, 108 insertions, 0 deletions
diff --git a/core/java/android/app/compat/CompatChanges.java b/core/java/android/app/compat/CompatChanges.java
new file mode 100644
index 000000000000..5b367894ce69
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+++ b/core/java/android/app/compat/CompatChanges.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2020 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.app.compat;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.compat.Compatibility;
+import android.content.Context;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.UserHandle;
+
+import com.android.internal.compat.IPlatformCompat;
+
+/**
+ * CompatChanges APIs - to be used by platform code only (including mainline
+ * modules).
+ *
+ * @hide
+ */
+@SystemApi
+public final class CompatChanges {
+    private CompatChanges() {}
+
+    /**
+     * Query if a given compatibility change is enabled for the current process. This method is
+     * intended to be called by code running inside a process of the affected app only.
+     *
+     * <p>If this method returns {@code true}, the calling code should implement the compatibility
+     * change, resulting in differing behaviour compared to earlier releases. If this method returns
+     * {@code false}, the calling code should behave as it did in earlier releases.
+     *
+     * @param changeId The ID of the compatibility change in question.
+     * @return {@code true} if the change is enabled for the current app.
+     */
+    public static boolean isChangeEnabled(long changeId) {
+        return Compatibility.isChangeEnabled(changeId);
+    }
+
+    /**
+     * Same as {@code #isChangeEnabled(long)}, except this version should be called on behalf of an
+     * app from a different process that's performing work for the app.
+     *
+     * <p> Note that this involves a binder call to the system server (unless running in the system
+     * server). If the binder call fails, a {@code RuntimeException} will be thrown.
+     *
+     * <p> Caller must have android.permission.READ_COMPAT_CHANGE_CONFIG permission. If it
+     * doesn't, a {@code RuntimeException} will be thrown.
+     *
+     * @param changeId    The ID of the compatibility change in question.
+     * @param packageName The package name of the app in question.
+     * @param user        The user that the operation is done for.
+     * @return {@code true} if the change is enabled for the current app.
+     */
+    public static boolean isChangeEnabled(long changeId, @NonNull String packageName,
+            @NonNull UserHandle user) {
+        IPlatformCompat platformCompat = IPlatformCompat.Stub.asInterface(
+                ServiceManager.getService(Context.PLATFORM_COMPAT_SERVICE));
+        try {
+            return platformCompat.isChangeEnabledByPackageName(changeId, packageName,
+                    user.getIdentifier());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Same as {@code #isChangeEnabled(long)}, except this version should be called on behalf of an
+     * app from a different process that's performing work for the app.
+     *
+     * <p> Note that this involves a binder call to the system server (unless running in the system
+     * server). If the binder call fails, {@code RuntimeException}  will be thrown.
+     *
+     * <p> Caller must have android.permission.READ_COMPAT_CHANGE_CONFIG permission. If it
+     * doesn't, a {@code RuntimeException} will be thrown.
+     *
+     * <p> Returns {@code true} if there are no installed packages for the required UID, or if the
+     * change is enabled for ALL of the installed packages associated with the provided UID. Please
+     * use a more specific API if you want a different behaviour for multi-package UIDs.
+     *
+     * @param changeId The ID of the compatibility change in question.
+     * @param uid      The UID of the app in question.
+     * @return {@code true} if the change is enabled for the current app.
+     */
+    public static boolean isChangeEnabled(long changeId, int uid) {
+        IPlatformCompat platformCompat = IPlatformCompat.Stub.asInterface(
+                ServiceManager.getService(Context.PLATFORM_COMPAT_SERVICE));
+        try {
+            return platformCompat.isChangeEnabledByUid(changeId, uid);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+}