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      1 /*
      2  * Copyright (C) 2017 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 package com.android.car.media.drawer;
     17 
     18 import android.content.Context;
     19 import android.graphics.Bitmap;
     20 import android.media.MediaDescription;
     21 import android.text.TextUtils;
     22 import android.view.View;
     23 
     24 import com.android.car.apps.common.BitmapDownloader;
     25 import com.android.car.apps.common.BitmapWorkerOptions;
     26 import com.android.car.apps.common.UriUtils;
     27 import com.android.car.media.R;
     28 
     29 import androidx.car.drawer.CarDrawerAdapter;
     30 import androidx.car.drawer.DrawerItemViewHolder;
     31 
     32 /**
     33  * Component that handles fetching of items for {@link MediaDrawerAdapter}.
     34  * <p>
     35  * It also handles ViewHolder population and item clicks.
     36  */
     37 interface MediaItemsFetcher {
     38     int DONT_SCROLL = -1;
     39 
     40     /**
     41      * Used to inform owning {@link MediaDrawerAdapter} that items have changed.
     42      */
     43     interface ItemsUpdatedCallback {
     44         void onItemsUpdated();
     45     }
     46 
     47     /**
     48      * Kick-off fetching/monitoring of items.
     49      *
     50      * @param callback Callback that is invoked when items are first loaded ar if they change
     51      *                 subsequently.
     52      */
     53     void start(ItemsUpdatedCallback callback);
     54 
     55     /**
     56      * @return Number of items currently fetched.
     57      */
     58     int getItemCount();
     59 
     60     /**
     61      * Used to indicate the kind of layout (small or normal) to use for the views that will display
     62      * this item in a {@link CarDrawerAdapter}. See {@link CarDrawerAdapter#usesSmallLayout}
     63      *
     64      * @param position Adapter position of item
     65      * @return Whether to use small (true) or normal layout (false).
     66      */
     67     boolean usesSmallLayout(int position);
     68 
     69     /**
     70      * Used by owning {@link MediaDrawerAdapter} to populate views.
     71      *
     72      * @param holder View-holder to populate.
     73      * @param position Item position.
     74      */
     75     void populateViewHolder(DrawerItemViewHolder holder, int position);
     76 
     77     /**
     78      * Used by owning {@link MediaDrawerAdapter} to handle clicks.
     79      *
     80      * @param position Item position.
     81      */
     82     void onItemClick(int position);
     83 
     84     /**
     85      * Used when this instance is going to be released. Subclasses should release resources.
     86      */
     87     void cleanup();
     88 
     89 
     90     /**
     91      * Get the position to scroll to if any.
     92      * @return An integer greater than or equal to 0 if there is a position to scroll to, the
     93      *         constant {@link DONT_SCROLL} otherwise.
     94      */
     95     int getScrollPosition();
     96 
     97     /**
     98      * Utility method to determine if description can be displayed in a small layout.
     99      */
    100     static boolean usesSmallLayout(MediaDescription description) {
    101         // Small layout is sufficient if there's no sub-title to display for the item.
    102         return TextUtils.isEmpty(description.getSubtitle());
    103     }
    104 
    105     /**
    106      * Utility method to populate {@code holder} with details from {@code description}. It populates
    107      * title, text and icon at most.
    108      */
    109     static void populateViewHolderFrom(DrawerItemViewHolder holder, MediaDescription description) {
    110         Context context = holder.itemView.getContext();
    111         holder.getTitle().setText(description.getTitle());
    112         // If normal layout, populate subtitle.
    113         if (!usesSmallLayout(description)) {
    114             holder.getText().setText(description.getSubtitle());
    115         }
    116         Bitmap iconBitmap = description.getIconBitmap();
    117         holder.getIcon().setImageBitmap(iconBitmap);    // Ok to set null here for clearing.
    118         if (iconBitmap == null) {
    119             if (description.getIconUri() != null) {
    120                 holder.getIcon().setVisibility(View.VISIBLE);
    121                 int bitmapSize =
    122                         context.getResources().getDimensionPixelSize(R.dimen.car_primary_icon_size);
    123                 // We don't want to cache android resources as they are needed to be refreshed after
    124                 // configuration changes.
    125                 int cacheFlag = UriUtils.isAndroidResourceUri(description.getIconUri())
    126                         ? (BitmapWorkerOptions.CACHE_FLAG_DISK_DISABLED
    127                         | BitmapWorkerOptions.CACHE_FLAG_MEM_DISABLED)
    128                         : 0;
    129                 BitmapWorkerOptions options = new BitmapWorkerOptions.Builder(context)
    130                         .resource(description.getIconUri())
    131                         .height(bitmapSize)
    132                         .width(bitmapSize)
    133                         .cacheFlag(cacheFlag)
    134                         .build();
    135                 BitmapDownloader.getInstance(context).loadBitmap(options, holder.getIcon());
    136             } else {
    137                 holder.getIcon().setVisibility(View.GONE);
    138             }
    139         }
    140     }
    141 }
    142