Home | History | Annotate | Download | only in recommendation
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.printservice.recommendation;
     18 
     19 import android.annotation.IntRange;
     20 import android.annotation.NonNull;
     21 import android.annotation.StringRes;
     22 
     23 /**
     24  * Interface to be implemented by each print service plugin.
     25  * <p/>
     26  * A print service plugin is a minimal version of a real {@link android.printservice.PrintService
     27  * print service}. You cannot print using the plugin. The only functionality in the plugin is to
     28  * report the number of printers that the real service would discover.
     29  */
     30 public interface PrintServicePlugin {
     31     /**
     32      * Call back used by the print service plugins.
     33      */
     34     interface PrinterDiscoveryCallback {
     35         /**
     36          * Announce that something changed and the UI for this plugin should be updated.
     37          *
     38          * @param numDiscoveredPrinters The number of printers discovered.
     39          */
     40         void onChanged(@IntRange(from = 0) int numDiscoveredPrinters);
     41     }
     42 
     43     /**
     44      * Get the name (a string reference) of the {@link android.printservice.PrintService print
     45      * service} with the {@link #getPackageName specified package name}. This is read once, hence
     46      * returning different data at different times is not allowed.
     47      *
     48      * @return The name of the print service as a string reference. The localization is handled
     49      *         outside of the plugin.
     50      */
     51     @StringRes int getName();
     52 
     53     /**
     54      * The package name of the full print service.
     55      *
     56      * @return The package name
     57      */
     58     @NonNull CharSequence getPackageName();
     59 
     60     /**
     61      * Start the discovery plugin.
     62      *
     63      * @param callback Callbacks used by this plugin.
     64      *
     65      * @throws Exception If anything went wrong when starting the plugin
     66      */
     67     void start(@NonNull PrinterDiscoveryCallback callback) throws Exception;
     68 
     69     /**
     70      * Stop the plugin. This can only return once the plugin is completely finished and cleaned up.
     71      *
     72      * @throws Exception If anything went wrong while stopping plugin
     73      */
     74     void stop() throws Exception;
     75 }
     76