| /* |
| * Copyright (C) 2018 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.internal.inputmethod; |
| |
| import android.annotation.AnyThread; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.os.IBinder; |
| |
| import com.android.internal.annotations.GuardedBy; |
| |
| import java.lang.ref.WeakReference; |
| import java.util.WeakHashMap; |
| |
| /** |
| * A weak-reference-based mapper from IME token to {@link InputMethodPrivilegedOperations} that is |
| * used only to support deprecated IME APIs in {@link android.view.inputmethod.InputMethodManager}. |
| * |
| * <p>This class is designed to be used as a per-process global registry.</p> |
| */ |
| public final class InputMethodPrivilegedOperationsRegistry { |
| private InputMethodPrivilegedOperationsRegistry() { |
| // Not intended to be instantiated. |
| } |
| |
| private static final Object sLock = new Object(); |
| |
| @Nullable |
| @GuardedBy("sLock") |
| private static WeakHashMap<IBinder, WeakReference<InputMethodPrivilegedOperations>> sRegistry; |
| |
| @Nullable |
| private static InputMethodPrivilegedOperations sNop; |
| |
| @NonNull |
| @AnyThread |
| private static InputMethodPrivilegedOperations getNopOps() { |
| // Strict thread-safety is not necessary because temporarily creating multiple nop instance |
| // is basically harmless |
| if (sNop == null) { |
| sNop = new InputMethodPrivilegedOperations(); |
| } |
| return sNop; |
| } |
| |
| /** |
| * Put a new entry to the registry. |
| * |
| * <p>Note: {@link InputMethodPrivilegedOperationsRegistry} does not hold strong reference to |
| * {@code token} and {@code ops}. The caller must be responsible for holding strong references |
| * to those objects, that is until {@link android.inputmethodservice.InputMethodService} is |
| * destroyed.</p> |
| * |
| * @param token IME token |
| * @param ops {@link InputMethodPrivilegedOperations} to be associated with the given IME token |
| */ |
| @AnyThread |
| public static void put(IBinder token, InputMethodPrivilegedOperations ops) { |
| synchronized (sLock) { |
| if (sRegistry == null) { |
| sRegistry = new WeakHashMap<>(); |
| } |
| final WeakReference<InputMethodPrivilegedOperations> previousOps = |
| sRegistry.put(token, new WeakReference<>(ops)); |
| if (previousOps != null) { |
| throw new IllegalStateException(previousOps.get() + " is already registered for " |
| + " this token=" + token + " newOps=" + ops); |
| } |
| } |
| } |
| |
| /** |
| * Get a {@link InputMethodPrivilegedOperations} from the given IME token. If it is not |
| * available, return a fake instance that does nothing except for showing warning messages. |
| * |
| * @param token IME token |
| * @return real {@link InputMethodPrivilegedOperations} object if {@code token} is still valid. |
| * Otherwise a fake instance of {@link InputMethodPrivilegedOperations} hat does nothing |
| * except for showing warning messages |
| */ |
| @NonNull |
| @AnyThread |
| public static InputMethodPrivilegedOperations get(IBinder token) { |
| synchronized (sLock) { |
| if (sRegistry == null) { |
| return getNopOps(); |
| } |
| final WeakReference<InputMethodPrivilegedOperations> wrapperRef = sRegistry.get(token); |
| if (wrapperRef == null) { |
| return getNopOps(); |
| } |
| final InputMethodPrivilegedOperations wrapper = wrapperRef.get(); |
| if (wrapper == null) { |
| return getNopOps(); |
| } |
| return wrapper; |
| } |
| } |
| |
| /** |
| * Explicitly removes the specified entry. |
| * |
| * <p>Note: Calling this method is optional. In general, {@link WeakHashMap} and |
| * {@link WeakReference} guarantee that the entry will be removed after specified binder proxies |
| * are garbage collected.</p> |
| * |
| * @param token IME token to be removed. |
| */ |
| @AnyThread |
| public static void remove(IBinder token) { |
| synchronized (sLock) { |
| if (sRegistry == null) { |
| return; |
| } |
| sRegistry.remove(token); |
| if (sRegistry.isEmpty()) { |
| sRegistry = null; |
| } |
| } |
| } |
| |
| /** |
| * Check the given IME token registration status. |
| * |
| * @param token IME token |
| * @return {@code true} when the IME token has already registered |
| * {@link InputMethodPrivilegedOperations}, {@code false} otherwise. |
| */ |
| @AnyThread |
| public static boolean isRegistered(IBinder token) { |
| synchronized (sLock) { |
| if (sRegistry == null) { |
| return false; |
| } |
| return sRegistry.containsKey(token); |
| } |
| } |
| } |