android.content.ComponentCallbacks

/*
 * copyright (c) 2006 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
 *
 *https://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;

import android.content.res.configuration;

/**
 * the set of callback apis that are common to all application components
 * ({@link android.app.activity}, {@link android.app.service},
 * {@link contentprovider}, and {@link android.app.application}).
 *
 * 

note: you should also implement the {@link * componentcallbacks2} interface, which provides the {@link * componentcallbacks2#ontrimmemory} callback to help your app manage its memory usage more * effectively.

*/ public interface componentcallbacks { /** * called by the system when the device configuration changes while your * component is running. note that, unlike activities, other components * are never restarted when a configuration changes: they must always deal * with the results of the change, such as by re-retrieving resources. * *

at the time that this function has been called, your resources * object will have been updated to return resource values matching the * new configuration. * *

for more information, read handling runtime changes. * * @param newconfig the new device configuration. */ void onconfigurationchanged(configuration newconfig); /** * this is called when the overall system is running low on memory, and * actively running processes should trim their memory usage. while * the exact point at which this will be called is not defined, generally * it will happen when all background process have been killed. * that is, before reaching the point of killing processes hosting * service and foreground ui that we would like to avoid killing. * *

you should implement this method to release * any caches or other unnecessary resources you may be holding on to. * the system will perform a garbage collection for you after returning from this method. *

preferably, you should implement {@link componentcallbacks2#ontrimmemory} from * {@link componentcallbacks2} to incrementally unload your resources based on various * levels of memory demands. that api is available for api level 14 and higher, so you should * only use this {@link #onlowmemory} method as a fallback for older versions, which can be * treated the same as {@link componentcallbacks2#ontrimmemory} with the {@link * componentcallbacks2#trim_memory_complete} level.

*/ void onlowmemory(); }