Seriously improved GalleryAdapter

android/src/main/java/com/wix/RNCameraKit/GalleryAdapter.java

@@ -1,10 +1,10 @@
 package com.wix.RNCameraKit;
 
+import android.app.Activity;
 import android.content.Context;
 import android.database.Cursor;
 import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
+import android.graphics.Color;
-import android.os.AsyncTask;
 import android.provider.MediaStore;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
@@ -12,6 +12,10 @@ import android.view.ViewGroup;
 import android.widget.ImageView;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Created by yedidyak on 30/06/2016.
@@ -20,25 +24,32 @@ public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.StupidHo
 
 
     public static final String[] PROJECTION = new String[]{
-            MediaStore.Images.Media.DATA
+            MediaStore.Images.Media.DATA,
+            MediaStore.Images.Media._ID
     };
 
-    private ArrayList<String> images = new ArrayList<>();
+    private ArrayList<String> uris = new ArrayList<>();
+    private ArrayList<Integer> ids = new ArrayList<>();
 
     public class StupidHolder extends RecyclerView.ViewHolder {
         public StupidHolder(View itemView) {
             super(itemView);
         }
+        int id;
+        String uri;
     }
 
     private Context context;
+    private ThreadPoolExecutor executor;
 
     public GalleryAdapter(Context context) {
         this.context = context;
+        int cores = Runtime.getRuntime().availableProcessors();
+        executor = new ThreadPoolExecutor(cores, cores, 1, TimeUnit.SECONDS, new LinkedBlockingDeque<Runnable>());
     }
 
     public void setAlbum(String albumName) {
-        images.clear();
+        ids.clear();
 
         String selection = null;
         if(albumName != null || !albumName.equals("All Photos")) {
@@ -55,11 +66,16 @@ public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.StupidHo
 
         if (cursor.moveToFirst()) {
             int dataIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
+            int idIndex = cursor.getColumnIndex(MediaStore.Images.Media._ID);
             do {
-                images.add(cursor.getString(dataIndex));
+                uris.add(cursor.getString(dataIndex));
+                ids.add(cursor.getInt(idIndex));
             } while(cursor.moveToNext());
         }
 
+        Collections.reverse(uris);
+        Collections.reverse(ids);
+
         cursor.close();
     }
 
@@ -72,29 +88,42 @@ public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.StupidHo
             }
         };
         v.setScaleType(ImageView.ScaleType.CENTER_CROP);
+        v.setBackgroundColor(Color.LTGRAY);
         return new StupidHolder(v);
     }
 
     @Override
     public void onBindViewHolder(final StupidHolder holder, final int position) {
 
-        new AsyncTask<Void, Void, Bitmap>() {
+        final ImageView imageView = (ImageView)holder.itemView;
-            @Override
+        imageView.setImageBitmap(null);
-            protected Bitmap doInBackground(Void... params) {
+        imageView.setBackgroundColor(Color.LTGRAY);
-                BitmapFactory.Options options = new BitmapFactory.Options();
+        holder.id = ids.get(position);
-                options.inSampleSize = 2;
+        holder.uri = uris.get(position);
-                return BitmapFactory.decodeFile(images.get(position), options);
-            }
 
+        executor.execute(new Runnable() {
             @Override
-            protected void onPostExecute(Bitmap bitmap) {
+            public void run() {
-                ((ImageView)holder.itemView).setImageBitmap(bitmap);
+                final Bitmap bmp = MediaStore.Images.Thumbnails.getThumbnail(
+                        context.getContentResolver(),
+                        ids.get(holder.getAdapterPosition()),
+                        MediaStore.Images.Thumbnails.MINI_KIND,
+                        null);
+
+                if (holder.id == ids.get(holder.getAdapterPosition())) {
+                    ((Activity) context).runOnUiThread(new Runnable() {
+                        @Override
+                        public void run() {
+                            imageView.setImageBitmap(bmp);
                         }
-        }.execute();
+                    });
+                }
+            }
+        });
     }
 
     @Override
     public int getItemCount() {
-        return images.size();
+        return ids.size();
     }
 }

android/src/main/java/com/wix/RNCameraKit/GalleryViewManager.java

@@ -24,8 +24,6 @@ public class GalleryViewManager extends SimpleViewManager<GalleryView> {
         view.setAlbumName(albumName);
     }
 
-
-
     @ReactProp(name = "minimumInteritemSpacing")
     public void setItemSpacing(GalleryView view, int itemSpacing) {
         view.setItemSpacing(itemSpacing/2);
@@ -40,5 +38,4 @@ public class GalleryViewManager extends SimpleViewManager<GalleryView> {
     public void setColumnCount(GalleryView view, int columnCount) {
         view.setColumnCount(columnCount);
     }
-
 }

android/src/main/java/com/wix/RNCameraKit/NativeGalleryModule.java

@@ -94,6 +94,7 @@ public class NativeGalleryModule extends ReactContextBaseJavaModule {
                 }
             } while (imagesCursor.moveToNext());
         }
+        imagesCursor.close();
         return albums;
     }