2 files changed, 120 insertions, 1 deletions
diff --git a/core/java/android/content/pm/ActivityInfo.java b/core/java/android/content/pm/ActivityInfo.java
index 03f6380e279f..af5f9ceb14d8 100644
--- a/core/java/android/content/pm/ActivityInfo.java
+++ b/core/java/android/content/pm/ActivityInfo.java
@@ -1348,7 +1348,8 @@ public class ActivityInfo extends ComponentInfo implements Parcelable {
     public boolean neverSandboxDisplayApis() {
         return CompatChanges.isChangeEnabled(NEVER_SANDBOX_DISPLAY_APIS,
                 applicationInfo.packageName,
-                UserHandle.getUserHandleForUid(applicationInfo.uid));
+                UserHandle.getUserHandleForUid(applicationInfo.uid))
+                || ConstrainDisplayApisConfig.neverConstrainDisplayApis(applicationInfo);
     }
 
     /**
diff --git a/core/java/android/content/pm/ConstrainDisplayApisConfig.java b/core/java/android/content/pm/ConstrainDisplayApisConfig.java
new file mode 100644
index 000000000000..1337347cdaf0
--- /dev/null
+++ b/core/java/android/content/pm/ConstrainDisplayApisConfig.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2021 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.content.pm;
+
+import static android.provider.DeviceConfig.NAMESPACE_CONSTRAIN_DISPLAY_APIS;
+
+import android.provider.DeviceConfig;
+import android.util.Slog;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Class for processing flags in the Device Config namespace 'constrain_display_apis'.
+ *
+ * @hide
+ */
+public final class ConstrainDisplayApisConfig {
+    private static final String TAG = ConstrainDisplayApisConfig.class.getSimpleName();
+
+    /**
+     * A string flag whose value holds a comma separated list of package entries in the format
+     * '<package-name>:<min-version-code>?:<max-version-code>?' for which Display APIs should never
+     * be constrained.
+     */
+    private static final String FLAG_NEVER_CONSTRAIN_DISPLAY_APIS = "never_constrain_display_apis";
+
+    /**
+     * A boolean flag indicating whether Display APIs should never be constrained for all
+     * packages. If true, {@link #FLAG_NEVER_CONSTRAIN_DISPLAY_APIS} is ignored.
+     */
+    private static final String FLAG_NEVER_CONSTRAIN_DISPLAY_APIS_ALL_PACKAGES =
+            "never_constrain_display_apis_all_packages";
+
+    /**
+     * Returns true if either the flag 'never_constrain_display_apis_all_packages' is true or the
+     * flag 'never_constrain_display_apis' contains a package entry that matches the given {@code
+     * applicationInfo}.
+     *
+     * @param applicationInfo Information about the application/package.
+     */
+    public static boolean neverConstrainDisplayApis(ApplicationInfo applicationInfo) {
+        if (DeviceConfig.getBoolean(NAMESPACE_CONSTRAIN_DISPLAY_APIS,
+                FLAG_NEVER_CONSTRAIN_DISPLAY_APIS_ALL_PACKAGES, /* defaultValue= */ false)) {
+            return true;
+        }
+        String configStr = DeviceConfig.getString(NAMESPACE_CONSTRAIN_DISPLAY_APIS,
+                FLAG_NEVER_CONSTRAIN_DISPLAY_APIS, /* defaultValue= */ "");
+
+        // String#split returns a non-empty array given an empty string.
+        if (configStr.isEmpty()) {
+            return false;
+        }
+
+        for (String packageEntryString : configStr.split(",")) {
+            if (matchesApplicationInfo(packageEntryString, applicationInfo)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Parses the given {@code packageEntryString} and returns true if {@code
+     * applicationInfo.packageName} matches the package name in the config and {@code
+     * applicationInfo.longVersionCode} is within the version range in the config.
+     *
+     * <p>Logs a warning and returns false in case the given {@code packageEntryString} is invalid.
+     *
+     * @param packageEntryStr A package entry expected to be in the format
+     *                        '<package-name>:<min-version-code>?:<max-version-code>?'.
+     * @param applicationInfo Information about the application/package.
+     */
+    private static boolean matchesApplicationInfo(String packageEntryStr,
+            ApplicationInfo applicationInfo) {
+        List<String> packageAndVersions = Arrays.asList(packageEntryStr.split(":", 3));
+        if (packageAndVersions.size() != 3) {
+            Slog.w(TAG, "Invalid package entry in flag 'never_constrain_display_apis': "
+                    + packageEntryStr);
+            return false;
+        }
+        String packageName = packageAndVersions.get(0);
+        String minVersionCodeStr = packageAndVersions.get(1);
+        String maxVersionCodeStr = packageAndVersions.get(2);
+
+        if (!packageName.equals(applicationInfo.packageName)) {
+            return false;
+        }
+        long version = applicationInfo.longVersionCode;
+        try {
+            if (!minVersionCodeStr.isEmpty() && version < Long.parseLong(minVersionCodeStr)) {
+                return false;
+            }
+            if (!maxVersionCodeStr.isEmpty() && version > Long.parseLong(maxVersionCodeStr)) {
+                return false;
+            }
+        } catch (NumberFormatException e) {
+            Slog.w(TAG, "Invalid APK version code in package entry: " + packageEntryStr);
+            return false;
+        }
+        return true;
+    }
+}