diff options
Diffstat (limited to 'core/java/android/content/pm/RegisteredServicesCache.java')
| -rw-r--r-- | core/java/android/content/pm/RegisteredServicesCache.java | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/core/java/android/content/pm/RegisteredServicesCache.java b/core/java/android/content/pm/RegisteredServicesCache.java new file mode 100644 index 0000000..d8f8478 --- /dev/null +++ b/core/java/android/content/pm/RegisteredServicesCache.java @@ -0,0 +1,233 @@ +/* + * Copyright (C) 2009 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 android.content.Context; +import android.content.BroadcastReceiver; +import android.content.Intent; +import android.content.IntentFilter; +import android.content.ComponentName; +import android.content.res.XmlResourceParser; +import android.util.Log; +import android.util.AttributeSet; +import android.util.Xml; + +import java.util.Map; +import java.util.Collection; +import java.util.Collections; +import java.util.List; +import java.io.FileDescriptor; +import java.io.PrintWriter; +import java.io.IOException; + +import com.google.android.collect.Maps; +import org.xmlpull.v1.XmlPullParserException; +import org.xmlpull.v1.XmlPullParser; + +/** + * A cache of registered services. This cache + * is built by interrogating the {@link PackageManager} and is updated as packages are added, + * removed and changed. The services are referred to by type V and + * are made available via the {@link #getServiceInfo} method. + * @hide + */ +public abstract class RegisteredServicesCache<V> { + private static final String TAG = "PackageManager"; + + public final Context mContext; + private final String mInterfaceName; + private final String mMetaDataName; + private final String mAttributesName; + + // no need to be synchronized since the map is never changed once mService is written + private volatile Map<V, ServiceInfo<V>> mServices; + + // synchronized on "this" + private BroadcastReceiver mReceiver = null; + + public RegisteredServicesCache(Context context, String interfaceName, String metaDataName, + String attributeName) { + mContext = context; + mInterfaceName = interfaceName; + mMetaDataName = metaDataName; + mAttributesName = attributeName; + } + + public void dump(FileDescriptor fd, PrintWriter fout, String[] args) { + getAllServices(); + Map<V, ServiceInfo<V>> services = mServices; + fout.println("RegisteredServicesCache: " + services.size() + " services"); + for (ServiceInfo info : services.values()) { + fout.println(" " + info); + } + } + + private boolean maybeRegisterForPackageChanges() { + synchronized (this) { + if (mReceiver == null) { + synchronized (this) { + mReceiver = new BroadcastReceiver() { + public void onReceive(Context context, Intent intent) { + mServices = generateServicesMap(); + } + }; + } + + IntentFilter intentFilter = new IntentFilter(); + intentFilter.addAction(Intent.ACTION_PACKAGE_ADDED); + intentFilter.addAction(Intent.ACTION_PACKAGE_CHANGED); + intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED); + mContext.registerReceiver(mReceiver, intentFilter); + return true; + } + return false; + } + } + + private void maybeUnregisterForPackageChanges() { + synchronized (this) { + if (mReceiver != null) { + mContext.unregisterReceiver(mReceiver); + mReceiver = null; + } + } + } + + /** + * Value type that describes a Service. The information within can be used + * to bind to the service. + */ + public static class ServiceInfo<V> { + public final V type; + public final ComponentName componentName; + + private ServiceInfo(V type, ComponentName componentName) { + this.type = type; + this.componentName = componentName; + } + + public String toString() { + return "ServiceInfo: " + type + ", " + componentName; + } + } + + /** + * Accessor for the registered authenticators. + * @param type the account type of the authenticator + * @return the AuthenticatorInfo that matches the account type or null if none is present + */ + public ServiceInfo getServiceInfo(V type) { + if (mServices == null) { + maybeRegisterForPackageChanges(); + mServices = generateServicesMap(); + } + return mServices.get(type); + } + + /** + * @return a collection of {@link RegisteredServicesCache.ServiceInfo} objects for all + * registered authenticators. + */ + public Collection<ServiceInfo<V>> getAllServices() { + if (mServices == null) { + maybeRegisterForPackageChanges(); + mServices = generateServicesMap(); + } + return Collections.unmodifiableCollection(mServices.values()); + } + + /** + * Stops the monitoring of package additions, removals and changes. + */ + public void close() { + maybeUnregisterForPackageChanges(); + } + + protected void finalize() throws Throwable { + synchronized (this) { + if (mReceiver != null) { + Log.e(TAG, "RegisteredServicesCache finalized without being closed"); + } + } + close(); + super.finalize(); + } + + private Map<V, ServiceInfo<V>> generateServicesMap() { + Map<V, ServiceInfo<V>> services = Maps.newHashMap(); + PackageManager pm = mContext.getPackageManager(); + + List<ResolveInfo> resolveInfos = + pm.queryIntentServices(new Intent(mInterfaceName), PackageManager.GET_META_DATA); + + for (ResolveInfo resolveInfo : resolveInfos) { + try { + ServiceInfo<V> info = parseServiceInfo(resolveInfo); + if (info != null) { + services.put(info.type, info); + } else { + Log.w(TAG, "Unable to load input method " + resolveInfo.toString()); + } + } catch (XmlPullParserException e) { + Log.w(TAG, "Unable to load input method " + resolveInfo.toString(), e); + } catch (IOException e) { + Log.w(TAG, "Unable to load input method " + resolveInfo.toString(), e); + } + } + + return services; + } + + private ServiceInfo<V> parseServiceInfo(ResolveInfo service) + throws XmlPullParserException, IOException { + android.content.pm.ServiceInfo si = service.serviceInfo; + ComponentName componentName = new ComponentName(si.packageName, si.name); + + PackageManager pm = mContext.getPackageManager(); + + XmlResourceParser parser = null; + try { + parser = si.loadXmlMetaData(pm, mMetaDataName); + if (parser == null) { + throw new XmlPullParserException("No " + mMetaDataName + " meta-data"); + } + + AttributeSet attrs = Xml.asAttributeSet(parser); + + int type; + while ((type=parser.next()) != XmlPullParser.END_DOCUMENT + && type != XmlPullParser.START_TAG) { + } + + String nodeName = parser.getName(); + if (!mAttributesName.equals(nodeName)) { + throw new XmlPullParserException( + "Meta-data does not start with " + mAttributesName + " tag"); + } + + V v = parseServiceAttributes(attrs); + if (v == null) { + return null; + } + return new ServiceInfo<V>(v, componentName); + } finally { + if (parser != null) parser.close(); + } + } + + public abstract V parseServiceAttributes(AttributeSet attrs); +} |