| /* |
| * 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 com.android.server.textclassifier; |
| |
| import android.annotation.Nullable; |
| import android.net.Uri; |
| import android.util.ArrayMap; |
| import android.util.Log; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.annotations.VisibleForTesting.Visibility; |
| |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.UUID; |
| import java.util.function.Supplier; |
| |
| /** |
| * A helper for mapping an icon resource to a content uri. |
| * |
| * <p>NOTE: Care must be taken to avoid passing resource uris to non-permitted apps via this helper. |
| */ |
| @VisibleForTesting(visibility = Visibility.PACKAGE) |
| public final class IconsUriHelper { |
| |
| public static final String AUTHORITY = "com.android.textclassifier.icons"; |
| |
| private static final String TAG = "IconsUriHelper"; |
| private static final Supplier<String> DEFAULT_ID_SUPPLIER = () -> UUID.randomUUID().toString(); |
| |
| // TODO: Consider using an LRU cache to limit resource usage. |
| // This may depend on the expected number of packages that a device typically has. |
| @GuardedBy("mPackageIds") |
| private final Map<String, String> mPackageIds = new ArrayMap<>(); |
| |
| private final Supplier<String> mIdSupplier; |
| |
| private static final IconsUriHelper sSingleton = new IconsUriHelper(null); |
| |
| private IconsUriHelper(@Nullable Supplier<String> idSupplier) { |
| mIdSupplier = (idSupplier != null) ? idSupplier : DEFAULT_ID_SUPPLIER; |
| |
| // Useful for testing: |
| // Magic id for the android package so it is the same across classloaders. |
| // This is okay as this package does not have access restrictions, and |
| // the TextClassifierService hardly returns icons from this package. |
| mPackageIds.put("android", "android"); |
| } |
| |
| /** |
| * Returns a new instance of this object for testing purposes. |
| */ |
| public static IconsUriHelper newInstanceForTesting(@Nullable Supplier<String> idSupplier) { |
| return new IconsUriHelper(idSupplier); |
| } |
| |
| static IconsUriHelper getInstance() { |
| return sSingleton; |
| } |
| |
| /** |
| * Returns a Uri for the specified icon resource. |
| * |
| * @param packageName the resource's package name |
| * @param resId the resource id |
| * @see #getResourceInfo(Uri) |
| */ |
| public Uri getContentUri(String packageName, int resId) { |
| Objects.requireNonNull(packageName); |
| synchronized (mPackageIds) { |
| if (!mPackageIds.containsKey(packageName)) { |
| // TODO: Ignore packages that don't actually exist on the device. |
| mPackageIds.put(packageName, mIdSupplier.get()); |
| } |
| return new Uri.Builder() |
| .scheme("content") |
| .authority(AUTHORITY) |
| .path(mPackageIds.get(packageName)) |
| .appendPath(Integer.toString(resId)) |
| .build(); |
| } |
| } |
| |
| /** |
| * Returns a valid {@link ResourceInfo} for the specified uri. Returns {@code null} if a valid |
| * {@link ResourceInfo} cannot be returned for the specified uri. |
| * |
| * @see #getContentUri(String, int); |
| */ |
| @Nullable |
| public ResourceInfo getResourceInfo(Uri uri) { |
| if (!"content".equals(uri.getScheme())) { |
| return null; |
| } |
| if (!AUTHORITY.equals(uri.getAuthority())) { |
| return null; |
| } |
| |
| final List<String> pathItems = uri.getPathSegments(); |
| try { |
| synchronized (mPackageIds) { |
| final String packageId = pathItems.get(0); |
| final int resId = Integer.parseInt(pathItems.get(1)); |
| for (String packageName : mPackageIds.keySet()) { |
| if (packageId.equals(mPackageIds.get(packageName))) { |
| return new ResourceInfo(packageName, resId); |
| } |
| } |
| } |
| } catch (Exception e) { |
| Log.v(TAG, "Could not get resource info. Reason: " + e.getMessage()); |
| } |
| return null; |
| } |
| |
| /** |
| * A holder for a resource's package name and id. |
| */ |
| public static final class ResourceInfo { |
| |
| public final String packageName; |
| public final int id; |
| |
| private ResourceInfo(String packageName, int id) { |
| this.packageName = Objects.requireNonNull(packageName); |
| this.id = id; |
| } |
| } |
| } |