1 files changed, 93 insertions, 14 deletions

diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/picker/GalleryAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/picker/GalleryAdapter.java
index faad73e8a..d123cee74 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/picker/GalleryAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/picker/GalleryAdapter.java
@@ -1,35 +1,75 @@
 package it.niedermann.nextcloud.deck.ui.card.attachments.picker;
 
+import android.annotation.SuppressLint;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.Context;
+import android.database.Cursor;
+import android.graphics.Bitmap;
+import android.os.Handler;
+import android.os.Looper;
+import android.provider.MediaStore;
+import android.util.Pair;
+import android.util.Size;
 import android.view.LayoutInflater;
 import android.view.ViewGroup;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.RecyclerView;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.FutureTask;
 
+import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.databinding.ItemAttachmentImageBinding;
 
+import static android.os.Build.VERSION.SDK_INT;
+import static android.os.Build.VERSION_CODES.Q;
+import static androidx.recyclerview.widget.RecyclerView.NO_ID;
+
 public class GalleryAdapter extends RecyclerView.Adapter<GalleryItemViewHolder> {
 
     @NonNull
-    List<Long> imageIds = new ArrayList<>();
+    private final Context context;
+    private final int columnIndex;
+    private final int count;
+    @Nullable
+    private final Cursor cursor;
+    @NonNull
+    private final ContentResolver contentResolver;
+    @NonNull
+    private final Map<Integer, Pair<Long, FutureTask<Bitmap>>> itemCache = new HashMap<>();
+    private final ExecutorService bitmapFetcherExecutor = Executors.newCachedThreadPool();
+    private final ExecutorService bitmapWaiterExecutor = Executors.newCachedThreadPool();
 
-    public GalleryAdapter() {
-        setHasStableIds(true);
-    }
+    public GalleryAdapter(@NonNull Context context) {
+        this.context = context;
+        this.contentResolver = context.getContentResolver();
+        log("Start Query");
+        @SuppressLint("InlinedApi") final String sortOrder = (SDK_INT >= Q)
+                ? MediaStore.Images.Media.DATE_TAKEN
+                : MediaStore.Images.Media.DATE_ADDED;
+        cursor = Objects.requireNonNull(contentResolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[]{MediaStore.Images.Media._ID}, null, null, sortOrder + " DESC"));
+        this.columnIndex = cursor.getColumnIndex(MediaStore.Images.Media._ID);
+        this.count = cursor.getCount();
 
-    public void setImageIds(@NonNull Collection<Long> imageIds) {
-        this.imageIds.clear();
-        this.imageIds.addAll(imageIds);
-        notifyDataSetChanged();
+        log("Cursor count = " + this.count);
+        notifyItemRangeInserted(0, this.count);
+        setHasStableIds(true);
     }
 
     @Override
     public long getItemId(int position) {
-        return super.getItemId(position);
+        Pair<Long, ?> itemAtPosition = getImageId(position);
+        return itemAtPosition == null ? NO_ID : itemAtPosition.first;
     }
 
     @NonNull
@@ -40,11 +80,50 @@ public class GalleryAdapter extends RecyclerView.Adapter<GalleryItemViewHolder>
 
     @Override
     public void onBindViewHolder(@NonNull GalleryItemViewHolder holder, int position) {
-        holder.bind(imageIds.get(position));
+        FutureTask<Bitmap> imageFuture = getImageId(position).second;
+        bitmapFetcherExecutor.execute(imageFuture);
+        bitmapWaiterExecutor.execute(() -> {
+            try {
+                final Bitmap image = imageFuture.get();
+                new Handler(Looper.getMainLooper()).post(() -> holder.bind(image));
+            } catch (ExecutionException | InterruptedException ignored) {
+                new Handler(Looper.getMainLooper()).post(() -> holder.bind(null));
+            }
+        });
     }
 
     @Override
     public int getItemCount() {
-        return this.imageIds.size();
+        return count;
+    }
+
+    private Pair<Long, FutureTask<Bitmap>> getImageId(int position) {
+        if (itemCache.containsKey(position)) {
+            return itemCache.get(position);
+        } else {
+            if (cursor == null) {
+                return new Pair<>(NO_ID, null);
+            }
+            if (cursor.moveToPosition(position)) {
+                long id = cursor.getLong(columnIndex);
+                return itemCache.put(position, new Pair<>(id, new FutureTask<>(() -> {
+                    if (SDK_INT >= Q) {
+                        return contentResolver.loadThumbnail(ContentUris.withAppendedId(
+                                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, id), new Size(512, 384), null);
+                    } else {
+                        return MediaStore.Images.Thumbnails.getThumbnail(
+                                contentResolver, id,
+                                MediaStore.Images.Thumbnails.MINI_KIND, null);
+                    }
+                })));
+            } else {
+                throw new NoSuchElementException("Could not find ID for position " + position);
+            }
+        }
+    }
+
+    private void log(String msg) {
+        DeckLog.log(msg);
+        Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
     }
 }