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      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.car.radio;
     18 
     19 import android.support.annotation.Nullable;
     20 import android.util.Log;
     21 import android.view.LayoutInflater;
     22 import android.view.View;
     23 import android.view.ViewGroup;
     24 import android.widget.TextView;
     25 import com.android.car.radio.service.RadioStation;
     26 
     27 import java.util.List;
     28 
     29 /**
     30  * A {@link com.android.car.radio.CarouselView.Adapter} that supplies the views to be displayed
     31  * from a list of {@link RadioStation}s.
     32  */
     33 public class PrescannedRadioStationAdapter extends CarouselView.Adapter {
     34     private static final String TAG = "PreScanAdapter";
     35 
     36     private List<RadioStation> mStations;
     37     private int mCurrentPosition;
     38 
     39     /**
     40      * Sets the {@link RadioStation}s that will be used to bind to the views to be displayed.
     41      */
     42     public void setStations(List<RadioStation> stations) {
     43         mStations = stations;
     44         notifyDataSetChanged();
     45     }
     46 
     47     /**
     48      * Sets the the station within the list passed to {@link #setStations(List)} that should be
     49      * the first station displayed. A station is identified by the channel number and band.
     50      *
     51      * @return The index within the list of stations passed to {@link #setStations(List)} that the
     52      * starting station can be found at.
     53      */
     54     public int setStartingStation(int channelNumber, int band) {
     55         getIndexOrInsertForStation(channelNumber, band);
     56         return mCurrentPosition;
     57     }
     58 
     59     /**
     60      * Returns the station that is currently the first station to be displayed. This value can be
     61      * different from the value returned by {@link #setStartingStation(int, int)} if either
     62      * {@link #getPrevStation()} or {@link #getNextStation()} have been called.
     63      */
     64     public int getCurrentPosition() {
     65         return mCurrentPosition;
     66     }
     67 
     68     /**
     69      * Returns the previous station in the list based off the value returned by
     70      * {@link #getCurrentPosition()}. After calling this method, the current position returned by
     71      * that method will be the index of the {@link RadioStation} returned by this method.
     72      */
     73     @Nullable
     74     public RadioStation getPrevStation() {
     75         if (mStations == null) {
     76             return null;
     77         }
     78 
     79         if (--mCurrentPosition < 0) {
     80             mCurrentPosition = mStations.size() - 1;
     81         }
     82 
     83         return mStations.get(mCurrentPosition);
     84     }
     85 
     86     /**
     87      * Returns the next station in the list based off the value returned by
     88      * {@link #getCurrentPosition()}. After calling this method, the current position returned by
     89      * that method will be the index of the {@link RadioStation} returned by this method.
     90      */
     91     @Nullable
     92     public RadioStation getNextStation() {
     93         if (mStations == null) {
     94             return null;
     95         }
     96 
     97         if (++mCurrentPosition >= mStations.size()) {
     98             mCurrentPosition = 0;
     99         }
    100 
    101         return mStations.get(mCurrentPosition);
    102     }
    103 
    104     /**
    105      * Returns the index in the list set in {@link #setStations(List)} that corresponds to the
    106      * given channel number and band. If the given combination does not exist within the list, then
    107      * it will be inserted in ascending order.
    108      *
    109      * @return An index into the list or -1 if no list of stations has been set.
    110      */
    111     public int getIndexOrInsertForStation(int channelNumber, int band) {
    112         if (mStations == null) {
    113             mCurrentPosition = -1;
    114             return -1;
    115         }
    116 
    117         int indexToInsert = 0;
    118 
    119         for (int i = 0, size = mStations.size(); i < size; i++) {
    120             RadioStation station = mStations.get(i);
    121 
    122             if (channelNumber >= station.getChannelNumber()) {
    123                 // Need to add 1 to the index because the channel should be inserted after it.
    124                 indexToInsert = i + 1;
    125             }
    126 
    127             if (station.getChannelNumber() == channelNumber && station.getRadioBand() == band) {
    128                 mCurrentPosition = i;
    129                 return i;
    130             }
    131         }
    132 
    133         // If this path is reached, that means an exact match for the station was not found in
    134         // the given list. Instead, insert the station into the list and return that index.
    135         RadioStation stationToInsert = new RadioStation(channelNumber, 0 /* subChannel */,
    136                 band, null /* rds */);
    137         mStations.add(indexToInsert, stationToInsert);
    138         notifyDataSetChanged();
    139 
    140         mCurrentPosition = indexToInsert;
    141         return indexToInsert;
    142     }
    143 
    144     @Override
    145     public View createView(ViewGroup parent) {
    146         return LayoutInflater.from(parent.getContext()).inflate(R.layout.radio_channel, parent,
    147                 false);
    148     }
    149 
    150     @Override
    151     public void bindView(View view, int position, boolean isFirstView) {
    152         if (Log.isLoggable(TAG, Log.DEBUG)) {
    153             Log.d(TAG, "bindView(); position: " + position + "; isFirstView: " + isFirstView);
    154         }
    155 
    156         if (mStations == null || position >= mStations.size()) {
    157             return;
    158         }
    159 
    160         TextView radioChannel = (TextView) view.findViewById(R.id.radio_list_station_channel);
    161         TextView radioBandView = (TextView) view.findViewById(R.id.radio_list_station_band);
    162 
    163         RadioStation station = mStations.get(position);
    164 
    165         if (Log.isLoggable(TAG, Log.DEBUG)) {
    166             Log.d(TAG, "binding station: " + station);
    167         }
    168 
    169         int radioBand = station.getRadioBand();
    170 
    171         radioChannel.setText(RadioChannelFormatter.formatRadioChannel(radioBand,
    172                 station.getChannelNumber()));
    173 
    174         if (isFirstView) {
    175             radioBandView.setText(RadioChannelFormatter.formatRadioBand(view.getContext(),
    176                     radioBand));
    177         } else {
    178             radioBandView.setText(null);
    179         }
    180     }
    181 
    182     @Override
    183     public int getItemCount() {
    184         return mStations == null ? 0 : mStations.size();
    185     }
    186 }
    187