<gallery>APK 15.0.5 release Publish.

- 新增 AlbumCoverDbHelper 数据库类，存储相册集封面路径
- 相册集浏览窗口长按菜单添加"设置为封面"选项
- 封面图片右下角显示封面图标标识
- 主窗口加载时优先使用设置的封面图片
- 修复 Cursor 在 try-with-resources 中的处理问题

gallery/build.properties

@@ -1,8 +1,8 @@
 #Created by .winboll/winboll_app_build.gradle
-#Sat Apr 25 05:49:42 HKT 2026
+#Sun Apr 26 11:32:37 HKT 2026
-stageCount=1
+stageCount=6
 libraryProject=
 baseVersion=15.0
-publishVersion=15.0.0
+publishVersion=15.0.5
 buildCount=0
-baseBetaVersion=15.0.1
+baseBetaVersion=15.0.6

gallery/src/main/java/cc/winboll/studio/gallery/AlbumActivity.java

@@ -8,6 +8,7 @@ import android.net.Uri;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.View;
 import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
@@ -16,6 +17,7 @@ import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import java.util.ArrayList;
 
 import cc.winboll.studio.libappbase.LogUtils;
@@ -30,6 +32,8 @@ public class AlbumActivity extends AppCompatActivity {
     private ImageAdapter adapter;
     private String albumPath;
     private String albumName;
+    private FloatingActionButton fabScrollTop;
+    private Preferences prefs;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -45,11 +49,39 @@ public class AlbumActivity extends AppCompatActivity {
         
         getSupportActionBar().setTitle(albumName);
         
+        prefs = new Preferences(this);
+        
         recyclerView = findViewById(R.id.recycler_view);
         recyclerView.setLayoutManager(new GridLayoutManager(this, 3));
         adapter = new ImageAdapter();
+        adapter.setContext(this);
+        adapter.setAlbumPath(albumPath);
         recyclerView.setAdapter(adapter);
         
+        fabScrollTop = findViewById(R.id.fab_scroll_top);
+        fabScrollTop.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                recyclerView.scrollToPosition(0);
+            }
+        });
+        
+        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+            @Override
+            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
+                super.onScrolled(recyclerView, dx, dy);
+                GridLayoutManager layoutManager = (GridLayoutManager) recyclerView.getLayoutManager();
+                if (layoutManager != null) {
+                    int firstVisible = layoutManager.findFirstVisibleItemPosition();
+                    if (firstVisible > 0) {
+                        fabScrollTop.setVisibility(View.VISIBLE);
+                    } else {
+                        fabScrollTop.setVisibility(View.GONE);
+                    }
+                }
+            }
+        });
+        
         adapter.setOnImageClickListener(new OnImageClickListener() {
             @Override
             public void onImageClick(int position, ArrayList<Uri> urls, ArrayList<String> paths) {
@@ -92,6 +124,20 @@ public class AlbumActivity extends AppCompatActivity {
         }
     }
 
+private String getSortOrder(int sortMode) {
+        switch (sortMode) {
+            case Preferences.SORT_TIME_ASC:
+                return android.provider.MediaStore.Images.Media.DATE_ADDED + " ASC";
+            case Preferences.SORT_NAME_DESC:
+                return android.provider.MediaStore.Images.Media.DISPLAY_NAME + " DESC";
+            case Preferences.SORT_NAME_ASC:
+                return android.provider.MediaStore.Images.Media.DISPLAY_NAME + " ASC";
+            case Preferences.SORT_TIME_DESC:
+            default:
+                return android.provider.MediaStore.Images.Media.DATE_ADDED + " DESC";
+        }
+    }
+    
     private void loadImages() {
         LogUtils.d(TAG, "loadImages");
         ArrayList<Uri> imageUrls = new ArrayList<>();
@@ -101,7 +147,8 @@ public class AlbumActivity extends AppCompatActivity {
         
         String selection = android.provider.MediaStore.Images.Media.DATA + " LIKE ?";
         String[] selectionArgs = new String[]{albumPath + "%"};
-        String sortOrder = android.provider.MediaStore.Images.Media.DATE_ADDED + " DESC";
+        int sortMode = prefs.getAlbumSortMode();
+        String sortOrder = getSortOrder(sortMode);
         
         try (Cursor cursor = contentResolver.query(collection, null, selection, selectionArgs, sortOrder)) {
             if (cursor != null) {
@@ -125,19 +172,59 @@ public class AlbumActivity extends AppCompatActivity {
         adapter.setData(imageUrls, imagePaths);
         LogUtils.d(TAG, "Loaded " + imageUrls.size() + " images");
     }
-
+    
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.menu_main, menu);
+        getMenuInflater().inflate(R.menu.menu_album, menu);
+        int sortMode = prefs.getAlbumSortMode();
+        int menuId = getSortMenuId(sortMode);
+        MenuItem item = menu.findItem(menuId);
+        if (item != null) {
+            item.setChecked(true);
+        }
+        MenuItem sortItem = menu.findItem(R.id.action_sort);
+        if (sortItem != null && sortItem.getSubMenu() != null) {
+            sortItem.getSubMenu().setGroupCheckable(0, true, true);
+        }
         return true;
     }
-
+    
+    private int getSortMenuId(int sortMode) {
+        switch (sortMode) {
+            case Preferences.SORT_TIME_ASC:
+                return R.id.sort_time_asc;
+            case Preferences.SORT_NAME_DESC:
+                return R.id.sort_name_desc;
+            case Preferences.SORT_NAME_ASC:
+                return R.id.sort_name_asc;
+            case Preferences.SORT_TIME_DESC:
+            default:
+                return R.id.sort_time_desc;
+        }
+    }
+    
     @Override
     public boolean onOptionsItemSelected(@NonNull MenuItem item) {
-        if (item.getItemId() == R.id.action_refresh) {
+        int itemId = item.getItemId();
-            if (checkPermission()) {
+        if (itemId == R.id.sort_time_desc) {
-                loadImages();
+            prefs.setAlbumSortMode(Preferences.SORT_TIME_DESC);
-            }
+            item.setChecked(true);
+            loadImages();
+            return true;
+        } else if (itemId == R.id.sort_time_asc) {
+            prefs.setAlbumSortMode(Preferences.SORT_TIME_ASC);
+            item.setChecked(true);
+            loadImages();
+            return true;
+        } else if (itemId == R.id.sort_name_desc) {
+            prefs.setAlbumSortMode(Preferences.SORT_NAME_DESC);
+            item.setChecked(true);
+            loadImages();
+            return true;
+        } else if (itemId == R.id.sort_name_asc) {
+            prefs.setAlbumSortMode(Preferences.SORT_NAME_ASC);
+            item.setChecked(true);
+            loadImages();
             return true;
         }
         return super.onOptionsItemSelected(item);
@@ -149,5 +236,8 @@ public class AlbumActivity extends AppCompatActivity {
         if (checkPermission()) {
             loadImages();
         }
+        if (adapter != null) {
+            adapter.refreshBg();
+        }
     }
 }

gallery/src/main/java/cc/winboll/studio/gallery/AlbumAdapter.java

@@ -5,6 +5,7 @@ import android.provider.MediaStore;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
+import android.view.View.OnLongClickListener;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.TextView;
@@ -13,6 +14,8 @@ import androidx.recyclerview.widget.RecyclerView;
 import com.bumptech.glide.Glide;
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 
 import cc.winboll.studio.libappbase.LogUtils;
 
@@ -20,6 +23,22 @@ public class AlbumAdapter extends RecyclerView.Adapter<AlbumAdapter.ViewHolder>
     public static final String TAG = "AlbumAdapter";
     private ArrayList<Album> albums = new ArrayList<>();
     private OnAlbumClickListener listener;
+    private Preferences prefs;
+    private int bgType = 0;
+    private PinnedAlbumDbHelper pinnedDbHelper;
+    
+    private int getBgRes() {
+        switch (bgType) {
+            case 0:
+                return R.drawable.bg_checkerboard;
+            case 1:
+                return R.drawable.bg_white;
+            case 2:
+                return R.drawable.bg_black;
+            default:
+                return R.drawable.bg_checkerboard;
+        }
+    }
 
     public interface OnAlbumClickListener {
         void onAlbumClick(Album album);
@@ -30,10 +49,89 @@ public class AlbumAdapter extends RecyclerView.Adapter<AlbumAdapter.ViewHolder>
     }
 
     public void setData(ArrayList<Album> albums) {
-        this.albums = albums;
+        this.albums = sortAlbums(albums);
         LogUtils.d(TAG, "setData: " + albums.size() + " albums");
         notifyDataSetChanged();
     }
+    
+    private ArrayList<Album> sortAlbums(ArrayList<Album> list) {
+        if (pinnedDbHelper == null || list == null || list.isEmpty()) {
+            return list;
+        }
+        ArrayList<Album> pinned = new ArrayList<>();
+        ArrayList<Album> unpinned = new ArrayList<>();
+        for (Album album : list) {
+            if (pinnedDbHelper.isPinned(album.getPath())) {
+                pinned.add(album);
+            } else {
+                unpinned.add(album);
+            }
+        }
+        pinned.addAll(unpinned);
+        return pinned;
+    }
+    
+    public void setContext(android.content.Context context) {
+        prefs = new Preferences(context);
+        bgType = prefs.getBgType();
+        pinnedDbHelper = PinnedAlbumDbHelper.getInstance(context);
+    }
+    
+    public void refreshBg() {
+        if (prefs != null) {
+            bgType = prefs.getBgType();
+        }
+        notifyDataSetChanged();
+    }
+    
+    public void refreshPinned() {
+        if (pinnedDbHelper != null && albums != null && !albums.isEmpty()) {
+            ArrayList<Album> pinned = new ArrayList<>();
+            ArrayList<Album> unpinned = new ArrayList<>();
+            for (Album album : albums) {
+                if (pinnedDbHelper.isPinned(album.getPath())) {
+                    pinned.add(album);
+                } else {
+                    unpinned.add(album);
+                }
+            }
+            Comparator<Album> nameComparator = new Comparator<Album>() {
+                @Override
+                public int compare(Album a1, Album a2) {
+                    return a1.getName().compareToIgnoreCase(a2.getName());
+                }
+            };
+            Collections.sort(pinned, nameComparator);
+            Collections.sort(unpinned, nameComparator);
+            albums.clear();
+            albums.addAll(pinned);
+            albums.addAll(unpinned);
+            notifyDataSetChanged();
+        }
+    }
+    
+private void showContextMenu(View view, final Album album) {
+        android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(view.getContext());
+        builder.setTitle(album.getName());
+        boolean isPinned = pinnedDbHelper != null && pinnedDbHelper.isPinned(album.getPath());
+        String[] items = isPinned ? new String[]{"取消置顶"} : new String[]{"置顶"};
+        builder.setItems(items, new android.content.DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(android.content.DialogInterface dialog, int which) {
+                if (pinnedDbHelper != null) {
+                    if (which == 0) {
+                        if (isPinned) {
+                            pinnedDbHelper.unpinAlbum(album.getPath());
+                        } else {
+                            pinnedDbHelper.pinAlbum(album.getPath());
+                        }
+                        refreshPinned();
+                    }
+                }
+            }
+        });
+        builder.show();
+    }
 
     @NonNull
     @Override
@@ -48,6 +146,19 @@ public class AlbumAdapter extends RecyclerView.Adapter<AlbumAdapter.ViewHolder>
         final Album album = albums.get(position);
         LogUtils.d(TAG, "bind: " + album.getName() + ", cover=" + album.getCoverUri());
         
+        holder.coverImage.setBackgroundResource(getBgRes());
+        
+        boolean isPinned = pinnedDbHelper != null && pinnedDbHelper.isPinned(album.getPath());
+        holder.pinIcon.setVisibility(isPinned ? View.VISIBLE : View.GONE);
+        
+        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
+            @Override
+            public boolean onLongClick(View v) {
+                showContextMenu(holder.itemView, album);
+                return true;
+            }
+        });
+        
         holder.albumName.setText(album.getName());
         holder.imageCount.setText(album.getImageCount() + " photos");
         
@@ -105,11 +216,13 @@ public class AlbumAdapter extends RecyclerView.Adapter<AlbumAdapter.ViewHolder>
 
     static class ViewHolder extends RecyclerView.ViewHolder {
         ImageView coverImage;
+        ImageView pinIcon;
         TextView albumName;
         TextView imageCount;
         ViewHolder(View itemView) {
             super(itemView);
             coverImage = itemView.findViewById(R.id.album_cover);
+            pinIcon = itemView.findViewById(R.id.pin_icon);
             albumName = itemView.findViewById(R.id.album_name);
             imageCount = itemView.findViewById(R.id.image_count);
         }

gallery/src/main/java/cc/winboll/studio/gallery/AlbumCoverDbHelper.java

@@ -0,0 +1,74 @@
+package cc.winboll.studio.gallery;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import cc.winboll.studio.libappbase.LogUtils;
+
+public class AlbumCoverDbHelper extends SQLiteOpenHelper {
+    public static final String TAG = "AlbumCoverDbHelper";
+    private static final String DB_NAME = "album_cover.db";
+    private static final int DB_VERSION = 1;
+    private static final String TABLE_NAME = "album_covers";
+    private static final String COLUMN_ALBUM_PATH = "album_path";
+    private static final String COLUMN_IMAGE_PATH = "image_path";
+    
+    private static final String SQL_CREATE = "CREATE TABLE " + TABLE_NAME + " (" 
+        + COLUMN_ALBUM_PATH + " TEXT PRIMARY KEY, "
+        + COLUMN_IMAGE_PATH + " TEXT)";
+    
+    private static AlbumCoverDbHelper dbHelper;
+    
+    public static AlbumCoverDbHelper getInstance(Context context) {
+        if (dbHelper == null) {
+            dbHelper = new AlbumCoverDbHelper(context.getApplicationContext());
+        }
+        return dbHelper;
+    }
+    
+    public AlbumCoverDbHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+    
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        db.execSQL(SQL_CREATE);
+    }
+    
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
+        onCreate(db);
+    }
+    
+    public void setCover(String albumPath, String imagePath) {
+        SQLiteDatabase db = getWritableDatabase();
+        ContentValues values = new ContentValues();
+        values.put(COLUMN_ALBUM_PATH, albumPath);
+        values.put(COLUMN_IMAGE_PATH, imagePath);
+        db.insertWithOnConflict(TABLE_NAME, null, values, SQLiteDatabase.CONFLICT_REPLACE);
+        LogUtils.d(TAG, "setCover: album=" + albumPath + ", image=" + imagePath);
+    }
+    
+    public String getCover(String albumPath) {
+        SQLiteDatabase db = getReadableDatabase();
+        Cursor cursor = db.query(TABLE_NAME, new String[]{COLUMN_IMAGE_PATH}, 
+            COLUMN_ALBUM_PATH + " = ?", new String[]{albumPath}, null, null, null);
+        String coverPath = null;
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                coverPath = cursor.getString(0);
+            }
+            cursor.close();
+        }
+        return coverPath;
+    }
+    
+    public void clearCover(String albumPath) {
+        SQLiteDatabase db = getWritableDatabase();
+        db.delete(TABLE_NAME, COLUMN_ALBUM_PATH + " = ?", new String[]{albumPath});
+        LogUtils.d(TAG, "clearCover: " + albumPath);
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/ImageAdapter.java

@@ -1,5 +1,6 @@
 package cc.winboll.studio.gallery;
 
+import android.content.DialogInterface;
 import android.net.Uri;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -10,6 +11,8 @@ import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
 import com.bumptech.glide.Glide;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 
 import cc.winboll.studio.libappbase.LogUtils;
 
@@ -18,6 +21,24 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
     private ArrayList<Uri> imageUrls = new ArrayList<>();
     private ArrayList<String> imagePaths = new ArrayList<>();
     private OnImageClickListener listener;
+    private int bgType = 0;
+    private Preferences prefs;
+    private PinnedImageDbHelper pinnedDbHelper;
+    private AlbumCoverDbHelper coverDbHelper;
+    private String albumPath;
+    
+    private int getBgRes() {
+        switch (bgType) {
+            case 0:
+                return R.drawable.bg_checkerboard;
+            case 1:
+                return R.drawable.bg_white;
+            case 2:
+                return R.drawable.bg_black;
+            default:
+                return R.drawable.bg_checkerboard;
+        }
+    }
 
     public interface OnImageClickListener {
         void onImageClick(int position, ArrayList<Uri> urls, ArrayList<String> paths);
@@ -30,10 +51,93 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
     public void setData(ArrayList<Uri> urls, ArrayList<String> paths) {
         this.imageUrls = urls;
         this.imagePaths = paths;
+        sortPinnedFirst();
         LogUtils.d(TAG, "setData: " + urls.size() + " images");
         notifyDataSetChanged();
     }
-
+    
+    private void sortPinnedFirst() {
+        if (pinnedDbHelper == null || imagePaths.isEmpty()) {
+            return;
+        }
+        ArrayList<Uri> pinnedUrls = new ArrayList<>();
+        ArrayList<String> pinnedPaths = new ArrayList<>();
+        ArrayList<Uri> unpinnedUrls = new ArrayList<>();
+        ArrayList<String> unpinnedPaths = new ArrayList<>();
+        for (int i = 0; i < imagePaths.size(); i++) {
+            String path = imagePaths.get(i);
+            if (pinnedDbHelper.isPinned(path)) {
+                pinnedUrls.add(imageUrls.get(i));
+                pinnedPaths.add(path);
+            } else {
+                unpinnedUrls.add(imageUrls.get(i));
+                unpinnedPaths.add(path);
+            }
+        }
+        
+        imageUrls.clear();
+        imagePaths.clear();
+        imageUrls.addAll(pinnedUrls);
+        imageUrls.addAll(unpinnedUrls);
+        imagePaths.addAll(pinnedPaths);
+        imagePaths.addAll(unpinnedPaths);
+    }
+    
+    public void setContext(android.content.Context context) {
+        prefs = new Preferences(context);
+        bgType = prefs.getBgType();
+        pinnedDbHelper = PinnedImageDbHelper.getInstance(context);
+        coverDbHelper = AlbumCoverDbHelper.getInstance(context);
+    }
+    
+    public void setAlbumPath(String albumPath) {
+        this.albumPath = albumPath;
+    }
+    
+    public void refreshBg() {
+        if (prefs != null) {
+            bgType = prefs.getBgType();
+            notifyDataSetChanged();
+        }
+    }
+    
+    public void refreshPinned() {
+        if (pinnedDbHelper == null || imagePaths.isEmpty()) {
+            return;
+        }
+        sortPinnedFirst();
+        notifyDataSetChanged();
+    }
+    
+    private void showContextMenu(View view, final int position) {
+        final String imagePath = imagePaths.get(position);
+        android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(view.getContext());
+        builder.setTitle("Image");
+        boolean isPinned = pinnedDbHelper != null && pinnedDbHelper.isPinned(imagePath);
+        String[] items = isPinned ? new String[]{"取消置顶", "设置为封面"} : new String[]{"置顶", "设置为封面"};
+        builder.setItems(items, new android.content.DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(android.content.DialogInterface dialog, int which) {
+                if (which == 0) {
+                    if (pinnedDbHelper != null) {
+                        if (isPinned) {
+                            pinnedDbHelper.unpinImage(imagePath);
+                        } else {
+                            pinnedDbHelper.pinImage(imagePath);
+                        }
+                        refreshPinned();
+                    }
+                } else if (which == 1) {
+                    if (coverDbHelper != null && albumPath != null) {
+                        coverDbHelper.setCover(albumPath, imagePath);
+                        notifyDataSetChanged();
+                    }
+                }
+            }
+        });
+        builder.show();
+    }
+    
     @NonNull
     @Override
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
@@ -44,6 +148,8 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
 
     @Override
     public void onBindViewHolder(@NonNull ViewHolder holder, final int position) {
+        holder.imageView.setBackgroundResource(getBgRes());
+        
         Glide.with(holder.imageView.getContext())
             .load(imageUrls.get(position))
             .centerCrop()
@@ -51,7 +157,15 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
         
         final ArrayList<Uri> urls = imageUrls;
         final ArrayList<String> paths = imagePaths;
-        holder.imageView.setOnClickListener(new OnClickListener() {
+        final String imagePath = imagePaths.get(position);
+        
+        boolean isPinned = pinnedDbHelper != null && pinnedDbHelper.isPinned(imagePath);
+        holder.pinIcon.setVisibility(isPinned ? View.VISIBLE : View.GONE);
+        
+        boolean isCover = coverDbHelper != null && albumPath != null && imagePath.equals(coverDbHelper.getCover(albumPath));
+        holder.coverIcon.setVisibility(isCover ? View.VISIBLE : View.GONE);
+        
+        holder.itemView.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (listener != null) {
@@ -59,6 +173,14 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
                 }
             }
         });
+        
+        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
+            @Override
+            public boolean onLongClick(View v) {
+                showContextMenu(holder.itemView, position);
+                return true;
+            }
+        });
     }
 
     @Override
@@ -68,9 +190,13 @@ public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder>
 
     static class ViewHolder extends RecyclerView.ViewHolder {
         ImageView imageView;
+        ImageView pinIcon;
+        ImageView coverIcon;
         ViewHolder(View itemView) {
             super(itemView);
             imageView = itemView.findViewById(R.id.image);
+            pinIcon = itemView.findViewById(R.id.pin_icon);
+            coverIcon = itemView.findViewById(R.id.cover_icon);
         }
     }
 }

gallery/src/main/java/cc/winboll/studio/gallery/ImagePagerAdapter.java

@@ -16,10 +16,25 @@ import cc.winboll.studio.libappbase.LogUtils;
 public class ImagePagerAdapter extends PagerAdapter {
     public static final String TAG = "ImagePagerAdapter";
     private ArrayList<Uri> imageUrls;
+    private int bgType;
 
-    public ImagePagerAdapter(ArrayList<Uri> imageUrls) {
+    public ImagePagerAdapter(ArrayList<Uri> imageUrls, int bgType) {
         this.imageUrls = imageUrls;
-        LogUtils.d(TAG, "ImagePagerAdapter created with " + imageUrls.size() + " images");
+        this.bgType = bgType;
+        LogUtils.d(TAG, "ImagePagerAdapter created with " + imageUrls.size() + " images, bgType=" + bgType);
+    }
+    
+    private int getBgRes() {
+        switch (bgType) {
+            case 0:
+                return R.drawable.bg_checkerboard;
+            case 1:
+                return R.drawable.bg_white;
+            case 2:
+                return R.drawable.bg_black;
+            default:
+                return R.drawable.bg_checkerboard;
+        }
     }
 
     @Override
@@ -32,6 +47,7 @@ public class ImagePagerAdapter extends PagerAdapter {
     public Object instantiateItem(@NonNull ViewGroup container, int position) {
         View view = LayoutInflater.from(container.getContext())
             .inflate(R.layout.item_image_pager, container, false);
+        view.setBackgroundResource(getBgRes());
         ImageView imageView = view.findViewById(R.id.image);
         
         Glide.with(imageView.getContext())

gallery/src/main/java/cc/winboll/studio/gallery/ImageViewerActivity.java

@@ -32,8 +32,12 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
     private ImageButton btnBack;
     private ImageButton btnDelete;
     private ImageButton btnShare;
+    private ImageButton btnInfo;
+    private ImageButton btnBg;
+    private int bgType = 0;
     private GestureDetector gestureDetector;
     private TrashManager trashManager;
+    private Preferences prefs;
     
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -48,14 +52,20 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
         currentPosition = getIntent().getIntExtra(EXTRA_POSITION, 0);
         
         trashManager = new TrashManager(this);
+        prefs = new Preferences(this);
+        bgType = prefs.getBgType();
         
         viewPager = findViewById(R.id.view_pager);
         toolbar = findViewById(R.id.toolbar);
         btnBack = findViewById(R.id.btn_back);
         btnDelete = findViewById(R.id.btn_delete);
         btnShare = findViewById(R.id.btn_share);
+        btnInfo = findViewById(R.id.btn_info);
+        btnBg = findViewById(R.id.btn_bg);
         
-        ImagePagerAdapter adapter = new ImagePagerAdapter(imageUrls);
+        applyBg();
+        
+        ImagePagerAdapter adapter = new ImagePagerAdapter(imageUrls, bgType);
         viewPager.setAdapter(adapter);
         viewPager.setCurrentItem(currentPosition);
         viewPager.addOnPageChangeListener(this);
@@ -95,6 +105,20 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
                 shareCurrentImage();
             }
         });
+        
+        btnInfo.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                showImageInfo();
+            }
+        });
+        
+        btnBg.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                switchBg();
+            }
+        });
     }
     
     private void toggleToolbar() {
@@ -105,6 +129,52 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
         }
     }
     
+    private void applyBg() {
+        int bgRes;
+        switch (bgType) {
+            case 0:
+                bgRes = R.drawable.bg_checkerboard;
+                break;
+            case 1:
+                bgRes = R.drawable.bg_white;
+                break;
+            case 2:
+                bgRes = R.drawable.bg_black;
+                break;
+            default:
+                bgRes = R.drawable.bg_checkerboard;
+        }
+        View container = findViewById(R.id.container);
+        if (container != null) {
+            container.setBackgroundResource(bgRes);
+        }
+    }
+    
+    private void switchBg() {
+        final String[] bgNames = {"灰白相间", "全白", "全黑"};
+        final int[] bgResources = {R.drawable.bg_checkerboard, R.drawable.bg_white, R.drawable.bg_black};
+        
+        new AlertDialog.Builder(this)
+            .setTitle("选择背景")
+            .setSingleChoiceItems(bgNames, bgType, new android.content.DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(android.content.DialogInterface dialog, int which) {
+                    bgType = which;
+                    prefs.setBgType(which);
+                    int currentItem = viewPager.getCurrentItem();
+                    View container = findViewById(R.id.container);
+                    if (container != null) {
+                        container.setBackgroundResource(bgResources[which]);
+                    }
+                    viewPager.setAdapter(new ImagePagerAdapter(imageUrls, bgType));
+                    viewPager.setCurrentItem(currentItem);
+                    dialog.dismiss();
+                }
+            })
+            .setNegativeButton("取消", null)
+            .show();
+    }
+    
     private void showDeleteDialog() {
         new AlertDialog.Builder(this)
             .setMessage("Delete to trash?")
@@ -169,7 +239,7 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
             if (currentPosition >= imageUrls.size()) {
                 currentPosition = imageUrls.size() - 1;
             }
-            viewPager.setAdapter(new ImagePagerAdapter(imageUrls));
+            viewPager.setAdapter(new ImagePagerAdapter(imageUrls, bgType));
             viewPager.setCurrentItem(currentPosition);
         }
     }
@@ -201,6 +271,155 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
         }
     }
     
+    private void showImageInfo() {
+        if (currentPosition < 0 || currentPosition >= imageUrls.size()) {
+            return;
+        }
+        
+        String imagePath = "";
+        if (imagePaths != null && currentPosition < imagePaths.size()) {
+            imagePath = imagePaths.get(currentPosition);
+        } else {
+            imagePath = getPathFromUri(imageUrls.get(currentPosition));
+        }
+        
+        File imageFile = new File(imagePath);
+        if (!imageFile.exists()) {
+            imageFile = new File(imagePath);
+        }
+        
+        android.widget.LinearLayout layout = new android.widget.LinearLayout(this);
+        layout.setOrientation(android.widget.LinearLayout.VERTICAL);
+        layout.setPadding(48, 32, 48, 32);
+        
+        android.widget.TextView labelPath = new android.widget.TextView(this);
+        labelPath.setText("Path:");
+        labelPath.setTextColor(getColor(android.R.color.darker_gray));
+        labelPath.setTextSize(14);
+        labelPath.setTypeface(null, android.graphics.Typeface.BOLD);
+        layout.addView(labelPath);
+        
+        android.widget.TextView valuePath = new android.widget.TextView(this);
+        valuePath.setText(imagePath);
+        valuePath.setTextColor(getColor(android.R.color.black));
+        valuePath.setTextSize(14);
+        valuePath.setTextIsSelectable(true);
+        layout.addView(valuePath);
+        
+        if (imageFile.exists()) {
+            long sizeBytes = imageFile.length();
+            String size;
+            if (sizeBytes < 1024) {
+                size = sizeBytes + " B";
+            } else if (sizeBytes < 1024 * 1024) {
+                size = String.format("%.2f KB", sizeBytes / 1024.0);
+            } else {
+                size = String.format("%.2f MB", sizeBytes / (1024.0 * 1024.0));
+            }
+            
+            android.widget.TextView labelSize = new android.widget.TextView(this);
+            labelSize.setText("Size:");
+            labelSize.setTextColor(getColor(android.R.color.darker_gray));
+            labelSize.setTextSize(14);
+            labelSize.setTypeface(null, android.graphics.Typeface.BOLD);
+            layout.addView(labelSize);
+            
+            android.widget.TextView valueSize = new android.widget.TextView(this);
+            valueSize.setText(size);
+            valueSize.setTextColor(getColor(android.R.color.black));
+            valueSize.setTextSize(14);
+            valueSize.setTextIsSelectable(true);
+            layout.addView(valueSize);
+        }
+        
+        try {
+            android.graphics.BitmapFactory.Options options = new android.graphics.BitmapFactory.Options();
+            options.inJustDecodeBounds = true;
+            android.graphics.BitmapFactory.decodeFile(imagePath, options);
+            if (options.outWidth > 0 && options.outHeight > 0) {
+                android.widget.TextView labelPixels = new android.widget.TextView(this);
+                labelPixels.setText("Pixels:");
+                labelPixels.setTextColor(getColor(android.R.color.darker_gray));
+                labelPixels.setTextSize(14);
+                labelPixels.setTypeface(null, android.graphics.Typeface.BOLD);
+                layout.addView(labelPixels);
+                
+                android.widget.TextView valuePixels = new android.widget.TextView(this);
+                valuePixels.setText(options.outWidth + " x " + options.outHeight);
+                valuePixels.setTextColor(getColor(android.R.color.black));
+                valuePixels.setTextSize(14);
+                valuePixels.setTextIsSelectable(true);
+                layout.addView(valuePixels);
+            }
+        } catch (Exception e) {
+            LogUtils.e(TAG, "get pixels error: " + e.getMessage());
+        }
+        
+        try {
+            String[] projection = {
+                MediaStore.Images.Media.DATE_ADDED,
+                MediaStore.Images.Media.DATE_MODIFIED,
+                MediaStore.Images.Media.DATE_TAKEN
+            };
+            android.database.Cursor cursor = getContentResolver().query(
+                imageUrls.get(currentPosition), projection, null, null, null);
+            if (cursor != null) {
+                if (cursor.moveToFirst()) {
+                    int dateAddedCol = cursor.getColumnIndex(MediaStore.Images.Media.DATE_ADDED);
+                    int dateTakenCol = cursor.getColumnIndex(MediaStore.Images.Media.DATE_TAKEN);
+                    
+                    java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+                    
+                    if (dateTakenCol >= 0) {
+                        long dateTaken = cursor.getLong(dateTakenCol);
+                        if (dateTaken > 0) {
+                            android.widget.TextView labelTaken = new android.widget.TextView(this);
+                            labelTaken.setText("Date Taken:");
+                            labelTaken.setTextColor(getColor(android.R.color.darker_gray));
+                            labelTaken.setTextSize(14);
+                            labelTaken.setTypeface(null, android.graphics.Typeface.BOLD);
+                            layout.addView(labelTaken);
+                            
+                            android.widget.TextView valueTaken = new android.widget.TextView(this);
+                            valueTaken.setText(sdf.format(new java.util.Date(dateTaken)));
+                            valueTaken.setTextColor(getColor(android.R.color.black));
+                            valueTaken.setTextSize(14);
+                            valueTaken.setTextIsSelectable(true);
+                            layout.addView(valueTaken);
+                        }
+                    }
+                    if (dateAddedCol >= 0) {
+                        long dateAdded = cursor.getLong(dateAddedCol);
+                        if (dateAdded > 0) {
+                            android.widget.TextView labelAdded = new android.widget.TextView(this);
+                            labelAdded.setText("Date Added:");
+                            labelAdded.setTextColor(getColor(android.R.color.darker_gray));
+                            labelAdded.setTextSize(14);
+                            labelAdded.setTypeface(null, android.graphics.Typeface.BOLD);
+                            layout.addView(labelAdded);
+                            
+                            android.widget.TextView valueAdded = new android.widget.TextView(this);
+                            valueAdded.setText(sdf.format(new java.util.Date(dateAdded * 1000)));
+                            valueAdded.setTextColor(getColor(android.R.color.black));
+                            valueAdded.setTextSize(14);
+                            valueAdded.setTextIsSelectable(true);
+                            layout.addView(valueAdded);
+                        }
+                    }
+                }
+                cursor.close();
+            }
+        } catch (Exception e) {
+            LogUtils.e(TAG, "get date error: " + e.getMessage());
+        }
+        
+        new AlertDialog.Builder(this)
+            .setTitle("Image Info")
+            .setView(layout)
+            .setPositiveButton("OK", null)
+            .show();
+    }
+    
     @Override
     public void onPageSelected(int position) {
         currentPosition = position;

gallery/src/main/java/cc/winboll/studio/gallery/MainActivity.java

@@ -14,6 +14,7 @@ import android.provider.MediaStore;
 import android.provider.Settings;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.View;
 import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
@@ -22,6 +23,7 @@ import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import cc.winboll.studio.gallery.AlbumAdapter.OnAlbumClickListener;
 import cc.winboll.studio.libappbase.LogUtils;
 import cc.winboll.studio.libappbase.LogActivity;
@@ -37,6 +39,7 @@ public class MainActivity extends AppCompatActivity {
     private RecyclerView recyclerView;
     private AlbumAdapter adapter;
     private Preferences prefs;
+    private FloatingActionButton fabScrollTop;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -52,8 +55,33 @@ public class MainActivity extends AppCompatActivity {
         recyclerView = findViewById(R.id.recycler_view);
         recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
         adapter = new AlbumAdapter();
+        adapter.setContext(this);
         recyclerView.setAdapter(adapter);
         
+        fabScrollTop = findViewById(R.id.fab_scroll_top);
+        fabScrollTop.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                recyclerView.scrollToPosition(0);
+            }
+        });
+        
+        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+            @Override
+            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
+                super.onScrolled(recyclerView, dx, dy);
+                GridLayoutManager layoutManager = (GridLayoutManager) recyclerView.getLayoutManager();
+                if (layoutManager != null) {
+                    int firstVisible = layoutManager.findFirstVisibleItemPosition();
+                    if (firstVisible > 0) {
+                        fabScrollTop.setVisibility(View.VISIBLE);
+                    } else {
+                        fabScrollTop.setVisibility(View.GONE);
+                    }
+                }
+            }
+        });
+        
         adapter.setOnAlbumClickListener(new OnAlbumClickListener() {
             @Override
             public void onAlbumClick(Album album) {
@@ -131,16 +159,16 @@ public class MainActivity extends AppCompatActivity {
         }
     }
 
-    private void loadAlbums() {
+private void loadAlbums() {
         LogUtils.d(TAG, "loadAlbums");
         String folderPath = prefs.getFolderPath();
         File baseFolder = new File(folderPath);
         LogUtils.d(TAG, "baseFolder: " + baseFolder.getAbsolutePath() + ", exists=" + baseFolder.exists());
         
         if (!baseFolder.exists() || !baseFolder.isDirectory()) {
-            folderPath = Environment.getExternalStorageDirectory() + "/DCIM";
+            folderPath = Preferences.getDefaultPath();
             baseFolder = new File(folderPath);
-            LogUtils.d(TAG, "try DCIM: " + baseFolder.getAbsolutePath() + ", exists=" + baseFolder.exists());
+            LogUtils.d(TAG, "try default: " + baseFolder.getAbsolutePath() + ", exists=" + baseFolder.exists());
             if (!baseFolder.exists()) {
                 folderPath = Environment.getExternalStorageDirectory() + "/Pictures";
                 baseFolder = new File(folderPath);
@@ -148,6 +176,7 @@ public class MainActivity extends AppCompatActivity {
             }
         }
         
+        AlbumCoverDbHelper coverDbHelper = AlbumCoverDbHelper.getInstance(this);
         ArrayList<Album> albums = new ArrayList<>();
         
         FileFilter directoryFilter = new FileFilter() {
@@ -161,11 +190,26 @@ public class MainActivity extends AppCompatActivity {
         if (subfolders != null) {
             for (File subfolder : subfolders) {
                 LogUtils.d(TAG, "scanning folder: " + subfolder.getName());
-                ArrayList<Uri> images = getImagesInFolder(subfolder.getAbsolutePath());
+                String albumPath = subfolder.getAbsolutePath();
-                if (!images.isEmpty()) {
+                String coverPath = coverDbHelper.getCover(albumPath);
-                    Uri latestImage = images.get(0);
+                Uri coverUri = null;
-                    albums.add(new Album(subfolder.getName(), subfolder.getAbsolutePath(), latestImage, images.size()));
+                if (coverPath != null) {
-                    LogUtils.d(TAG, "album added: " + subfolder.getName() + ", " + images.size() + " images");
+                    coverUri = getUriFromPath(coverPath);
+                }
+                if (coverUri == null) {
+                    ArrayList<Uri> images = getImagesInFolder(albumPath);
+                    if (!images.isEmpty()) {
+                        coverUri = images.get(0);
+                    }
+                }
+                ArrayList<Uri> allImages = getImagesInFolder(albumPath);
+                if (coverUri != null || !allImages.isEmpty()) {
+                    if (coverUri == null && !allImages.isEmpty()) {
+                        coverUri = allImages.get(0);
+                    }
+                    int imageCount = allImages.size();
+                    albums.add(new Album(subfolder.getName(), albumPath, coverUri, imageCount));
+                    LogUtils.d(TAG, "album added: " + subfolder.getName() + ", " + imageCount + " images");
                 }
             }
         }
@@ -177,7 +221,24 @@ public class MainActivity extends AppCompatActivity {
         adapter.setData(albums);
         LogUtils.d(TAG, "Loaded " + albums.size() + " albums");
     }
-
+    
+    private Uri getUriFromPath(String path) {
+        String[] projection = { MediaStore.Images.Media._ID };
+        String selection = MediaStore.Images.Media.DATA + " = ?";
+        String[] selectionArgs = { path };
+        try (Cursor cursor = getContentResolver().query(
+                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+                projection, selection, selectionArgs, null)) {
+            if (cursor != null) {
+                if (cursor.moveToFirst()) {
+                    long id = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID));
+                    return Uri.withAppendedPath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, String.valueOf(id));
+                }
+            }
+        }
+        return null;
+    }
+    
     private ArrayList<Uri> getImagesInFolder(String folderPath) {
         ArrayList<Uri> imageUrls = new ArrayList<>();
         ContentResolver contentResolver = getContentResolver();
@@ -244,6 +305,10 @@ public class MainActivity extends AppCompatActivity {
             scanMediaStore();
             loadAlbums();
         }
+        if (adapter != null) {
+            adapter.refreshBg();
+            adapter.refreshPinned();
+        }
     }
     
     private void scanMediaStore() {

gallery/src/main/java/cc/winboll/studio/gallery/PinnedAlbumDbHelper.java

@@ -0,0 +1,78 @@
+package cc.winboll.studio.gallery;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import cc.winboll.studio.libappbase.LogUtils;
+
+public class PinnedAlbumDbHelper extends SQLiteOpenHelper {
+    public static final String TAG = "PinnedAlbumDbHelper";
+    private static final String DB_NAME = "pinned_album.db";
+    private static final int DB_VERSION = 1;
+    private static final String TABLE_NAME = "pinned_albums";
+    private static final String COLUMN_PATH = "album_path";
+    
+    private static final String SQL_CREATE = "CREATE TABLE " + TABLE_NAME + " (" 
+        + COLUMN_PATH + " TEXT PRIMARY KEY)";
+    
+    private static PinnedAlbumDbHelper dbHelper;
+    
+    public static PinnedAlbumDbHelper getInstance(Context context) {
+        if (dbHelper == null) {
+            dbHelper = new PinnedAlbumDbHelper(context.getApplicationContext());
+        }
+        return dbHelper;
+    }
+    
+    public PinnedAlbumDbHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+    
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        db.execSQL(SQL_CREATE);
+    }
+    
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
+        onCreate(db);
+    }
+    
+    public void pinAlbum(String albumPath) {
+        SQLiteDatabase db = getWritableDatabase();
+        ContentValues values = new ContentValues();
+        values.put(COLUMN_PATH, albumPath);
+        db.insertWithOnConflict(TABLE_NAME, null, values, SQLiteDatabase.CONFLICT_IGNORE);
+        LogUtils.d(TAG, "pinAlbum: " + albumPath);
+    }
+    
+    public void unpinAlbum(String albumPath) {
+        SQLiteDatabase db = getWritableDatabase();
+        db.delete(TABLE_NAME, COLUMN_PATH + " = ?", new String[]{albumPath});
+        LogUtils.d(TAG, "unpinAlbum: " + albumPath);
+    }
+    
+    public boolean isPinned(String albumPath) {
+        SQLiteDatabase db = getReadableDatabase();
+        Cursor cursor = db.query(TABLE_NAME, null, COLUMN_PATH + " = ?", 
+            new String[]{albumPath}, null, null, null);
+        boolean pinned = cursor.getCount() > 0;
+        cursor.close();
+        return pinned;
+    }
+    
+    public String[] getPinnedPaths() {
+        SQLiteDatabase db = getReadableDatabase();
+        Cursor cursor = db.query(TABLE_NAME, new String[]{COLUMN_PATH}, null, null, null, null, null);
+        String[] paths = new String[cursor.getCount()];
+        int i = 0;
+        while (cursor.moveToNext()) {
+            paths[i++] = cursor.getString(0);
+        }
+        cursor.close();
+        return paths;
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/PinnedImageDbHelper.java

@@ -0,0 +1,78 @@
+package cc.winboll.studio.gallery;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import cc.winboll.studio.libappbase.LogUtils;
+
+public class PinnedImageDbHelper extends SQLiteOpenHelper {
+    public static final String TAG = "PinnedImageDbHelper";
+    private static final String DB_NAME = "pinned_image.db";
+    private static final int DB_VERSION = 1;
+    private static final String TABLE_NAME = "pinned_images";
+    private static final String COLUMN_PATH = "image_path";
+    
+    private static final String SQL_CREATE = "CREATE TABLE " + TABLE_NAME + " (" 
+        + COLUMN_PATH + " TEXT PRIMARY KEY)";
+    
+    private static PinnedImageDbHelper dbHelper;
+    
+    public static PinnedImageDbHelper getInstance(Context context) {
+        if (dbHelper == null) {
+            dbHelper = new PinnedImageDbHelper(context.getApplicationContext());
+        }
+        return dbHelper;
+    }
+    
+    public PinnedImageDbHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+    
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        db.execSQL(SQL_CREATE);
+    }
+    
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
+        onCreate(db);
+    }
+    
+    public void pinImage(String imagePath) {
+        SQLiteDatabase db = getWritableDatabase();
+        ContentValues values = new ContentValues();
+        values.put(COLUMN_PATH, imagePath);
+        db.insertWithOnConflict(TABLE_NAME, null, values, SQLiteDatabase.CONFLICT_IGNORE);
+        LogUtils.d(TAG, "pinImage: " + imagePath);
+    }
+    
+    public void unpinImage(String imagePath) {
+        SQLiteDatabase db = getWritableDatabase();
+        db.delete(TABLE_NAME, COLUMN_PATH + " = ?", new String[]{imagePath});
+        LogUtils.d(TAG, "unpinImage: " + imagePath);
+    }
+    
+    public boolean isPinned(String imagePath) {
+        SQLiteDatabase db = getReadableDatabase();
+        Cursor cursor = db.query(TABLE_NAME, null, COLUMN_PATH + " = ?", 
+            new String[]{imagePath}, null, null, null);
+        boolean pinned = cursor.getCount() > 0;
+        cursor.close();
+        return pinned;
+    }
+    
+    public String[] getPinnedPaths() {
+        SQLiteDatabase db = getReadableDatabase();
+        Cursor cursor = db.query(TABLE_NAME, new String[]{COLUMN_PATH}, null, null, null, null, null);
+        String[] paths = new String[cursor.getCount()];
+        int i = 0;
+        while (cursor.moveToNext()) {
+            paths[i++] = cursor.getString(0);
+        }
+        cursor.close();
+        return paths;
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/Preferences.java

@@ -8,7 +8,16 @@ public class Preferences {
     public static final String TAG = "Preferences";
     private static final String PREF_NAME = "gallery_prefs";
     private static final String KEY_FOLDER_PATH = "folder_path";
-    private static final String DEFAULT_PATH = "/storage/emulated/0/DCIM";
+    private static final String KEY_BG_TYPE = "bg_type";
+    private static final String KEY_ALBUM_SORT_MODE = "album_sort_mode";
+    private static final int DEFAULT_BG_TYPE = 0;
+    private static final int DEFAULT_SORT_MODE = 0;
+    private static final String DEFAULT_PATH = "/storage/emulated/0/Pictures/Gallery/owner";
+    
+    public static final int SORT_TIME_DESC = 0;
+    public static final int SORT_TIME_ASC = 1;
+    public static final int SORT_NAME_DESC = 2;
+    public static final int SORT_NAME_ASC = 3;
     
     public static String getDefaultPath() {
         return DEFAULT_PATH;
@@ -30,4 +39,22 @@ public class Preferences {
         LogUtils.d(TAG, "setFolderPath: " + path);
         prefs.edit().putString(KEY_FOLDER_PATH, path).apply();
     }
+    
+    public int getBgType() {
+        return prefs.getInt(KEY_BG_TYPE, DEFAULT_BG_TYPE);
+    }
+    
+    public void setBgType(int type) {
+        LogUtils.d(TAG, "setBgType: " + type);
+        prefs.edit().putInt(KEY_BG_TYPE, type).apply();
+    }
+    
+    public int getAlbumSortMode() {
+        return prefs.getInt(KEY_ALBUM_SORT_MODE, DEFAULT_SORT_MODE);
+    }
+    
+    public void setAlbumSortMode(int mode) {
+        LogUtils.d(TAG, "setAlbumSortMode: " + mode);
+        prefs.edit().putInt(KEY_ALBUM_SORT_MODE, mode).apply();
+    }
 }

gallery/src/main/res/drawable/bg_black.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="#000000"/>
+</shape>

gallery/src/main/res/drawable/bg_checkerboard.xml

@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="10dp"
+    android:height="10dp"
+    android:viewportWidth="10"
+    android:viewportHeight="10">
+    <path
+        android:fillColor="#808080"
+        android:pathData="M0,0h1v1h-1z M2,0h1v1h-1z M4,0h1v1h-1z M6,0h1v1h-1z M8,0h1v1h-1z
+                             M1,1h1v1h-1z M3,1h1v1h-1z M5,1h1v1h-1z M7,1h1v1h-1z M9,1h1v1h-1z
+                             M0,2h1v1h-1z M2,2h1v1h-1z M4,2h1v1h-1z M6,2h1v1h-1z M8,2h1v1h-1z
+                             M1,3h1v1h-1z M3,3h1v1h-1z M5,3h1v1h-1z M7,3h1v1h-1z M9,3h1v1h-1z
+                             M0,4h1v1h-1z M2,4h1v1h-1z M4,4h1v1h-1z M6,4h1v1h-1z M8,4h1v1h-1z
+                             M1,5h1v1h-1z M3,5h1v1h-1z M5,5h1v1h-1z M7,5h1v1h-1z M9,5h1v1h-1z
+                             M0,6h1v1h-1z M2,6h1v1h-1z M4,6h1v1h-1z M6,6h1v1h-1z M8,6h1v1h-1z
+                             M1,7h1v1h-1z M3,7h1v1h-1z M5,7h1v1h-1z M7,7h1v1h-1z M9,7h1v1h-1z
+                             M0,8h1v1h-1z M2,8h1v1h-1z M4,8h1v1h-1z M6,8h1v1h-1z M8,8h1v1h-1z
+                             M1,9h1v1h-1z M3,9h1v1h-1z M5,9h1v1h-1z M7,9h1v1h-1z M9,9h1v1h-1z"/>
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M1,0h1v1h-1z M3,0h1v1h-1z M5,0h1v1h-1z M7,0h1v1h-1z M9,0h1v1h-1z
+                             M0,1h1v1h-1z M2,1h1v1h-1z M4,1h1v1h-1z M6,1h1v1h-1z M8,1h1v1h-1z
+                             M1,2h1v1h-1z M3,2h1v1h-1z M5,2h1v1h-1z M7,2h1v1h-1z M9,2h1v1h-1z
+                             M0,3h1v1h-1z M2,3h1v1h-1z M4,3h1v1h-1z M6,3h1v1h-1z M8,3h1v1h-1z
+                             M1,4h1v1h-1z M3,4h1v1h-1z M5,4h1v1h-1z M7,4h1v1h-1z M9,4h1v1h-1z
+                             M0,5h1v1h-1z M2,5h1v1h-1z M4,5h1v1h-1z M6,5h1v1h-1z M8,5h1v1h-1z
+                             M1,6h1v1h-1z M3,6h1v1h-1z M5,6h1v1h-1z M7,6h1v1h-1z M9,6h1v1h-1z
+                             M0,7h1v1h-1z M2,7h1v1h-1z M4,7h1v1h-1z M6,7h1v1h-1z M8,7h1v1h-1z
+                             M1,8h1v1h-1z M3,8h1v1h-1z M5,8h1v1h-1z M7,8h1v1h-1z M9,8h1v1h-1z
+                             M0,9h1v1h-1z M2,9h1v1h-1z M4,9h1v1h-1z M6,9h1v1h-1z M8,9h1v1h-1z"/>
+</vector>

gallery/src/main/res/drawable/bg_circle_white.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="oval">
+    <solid android:color="#CCFFFFFF"/>
+    <stroke
+        android:width="1dp"
+        android:color="#000000"/>
+</shape>

gallery/src/main/res/drawable/bg_white.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="#FFFFFF"/>
+</shape>

gallery/src/main/res/drawable/ic_arrow_up.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M7.41,15.41L12,10.83l4.59,4.58L18,14l-6,-6 -6,6z"/>
+</vector>

gallery/src/main/res/drawable/ic_bg.xml

@@ -0,0 +1,12 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M4,4h7v7h-7z M13,4h7v7h-7z M4,13h7v7h-7z M13,13h7v7h-7z"/>
+    <path
+        android:fillColor="#808080"
+        android:pathData="M11,4h2v7h-2z M4,11h7v2h-7z M13,11h7v2h-7z M11,13h2v7h-2z M13,4h2v7h-2z M4,13h7v2h-7z"/>
+</vector>

gallery/src/main/res/drawable/ic_cover.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#000000"
+        android:pathData="M21,3H3C1.9,3 1,3.9 1,5v14c0,1.1 0.9,2 2,2h18c1.1,0 2,-0.9 2,-2V5C23,3.9 22.1,3 21,3zM21,19H3V5h18V19z"/>
+    <path
+        android:fillColor="#000000"
+        android:pathData="M9,12l2,2l4,-4l1.5,1.5L11,17l-3,-3z"/>
+</vector>

gallery/src/main/res/drawable/ic_info.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM13,17h-2v-6h2v6zM13,9h-2L11,7h2v2z"/>
+</vector>

gallery/src/main/res/drawable/ic_pin.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M16,12V4H17V2H7V4H8V12L6,14V16H11.5V22H12.5V16H18V14L16,12Z"/>
+</vector>

gallery/src/main/res/drawable/ic_sort.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M3,18h6v-2H3v2zM3,6v2h18V6H3zM3,13h12v-2H3v2z"/>
+</vector>

gallery/src/main/res/layout/activity_image_viewer.xml

@@ -44,6 +44,22 @@
             android:src="@drawable/ic_share"
             android:contentDescription="Share"/>
 
+        <ImageButton
+            android:id="@+id/btn_info"
+            android:layout_width="48dp"
+            android:layout_height="48dp"
+            android:background="?attr/selectableItemBackgroundBorderless"
+            android:src="@drawable/ic_info"
+            android:contentDescription="Info"/>
+
+        <ImageButton
+            android:id="@+id/btn_bg"
+            android:layout_width="48dp"
+            android:layout_height="48dp"
+            android:background="?attr/selectableItemBackgroundBorderless"
+            android:src="@drawable/ic_bg"
+            android:contentDescription="Background"/>
+
         <ImageButton
             android:id="@+id/btn_delete"
             android:layout_width="48dp"

gallery/src/main/res/layout/activity_main.xml

@@ -1,28 +1,45 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout
+<FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="match_parent">
-    android:orientation="vertical">
 
-    <com.google.android.material.appbar.AppBarLayout
+    <LinearLayout
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
-        
-        <androidx.appcompat.widget.Toolbar
-            android:id="@+id/toolbar"
-            android:layout_width="match_parent"
-            android:layout_height="?attr/actionBarSize"
-            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
-
-    </com.google.android.material.appbar.AppBarLayout>
-
-    <androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/recycler_view"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:background="@color/black"/>
+        android:orientation="vertical">
 
-</LinearLayout>
+        <com.google.android.material.appbar.AppBarLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
+        
+            <androidx.appcompat.widget.Toolbar
+                android:id="@+id/toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
+
+        </com.google.android.material.appbar.AppBarLayout>
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/recycler_view"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:background="@color/black"/>
+
+    </LinearLayout>
+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fab_scroll_top"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="16dp"
+        android:src="@drawable/ic_arrow_up"
+        android:visibility="gone"
+        app:backgroundTint="@color/colorAccent"
+        app:tint="@color/white"/>
+
+</FrameLayout>

gallery/src/main/res/layout/item_album.xml

@@ -9,8 +9,8 @@
         android:id="@+id/album_cover"
         android:layout_width="match_parent"
         android:layout_height="120dp"
-        android:scaleType="centerCrop"
+        android:layout_margin="2dp"
-        android:background="@color/black"/>
+        android:scaleType="centerCrop"/>
 
     <TextView
         android:id="@+id/album_name"
@@ -24,6 +24,17 @@
         android:maxLines="1"
         android:ellipsize="end"/>
 
+    <ImageView
+        android:id="@+id/pin_icon"
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="6dp"
+        android:background="@android:color/transparent"
+        android:padding="3dp"
+        android:src="@drawable/ic_pin"
+        android:visibility="gone"/>
+
     <TextView
         android:id="@+id/image_count"
         android:layout_width="wrap_content"

gallery/src/main/res/layout/item_gallery.xml

@@ -12,4 +12,30 @@
         android:scaleType="centerCrop"
         android:background="@color/black"/>
 
+<ImageView
+        android:id="@+id/pin_icon"
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:layout_gravity="top|end"
+        android:layout_margin="4dp"
+        android:background="@drawable/bg_circle_white"
+        android:padding="4dp"
+        android:src="@drawable/ic_pin"
+        android:visibility="gone"
+        app:tint="@color/black"
+        xmlns:app="http://schemas.android.com/apk/res-auto"/>
+
+    <ImageView
+        android:id="@+id/cover_icon"
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="4dp"
+        android:background="@drawable/bg_circle_white"
+        android:padding="4dp"
+        android:src="@drawable/ic_cover"
+        android:visibility="gone"
+        app:tint="@color/black"
+        xmlns:app="http://schemas.android.com/apk/res-auto"/>
+
 </FrameLayout>

gallery/src/main/res/layout/item_image_pager.xml

@@ -2,8 +2,7 @@
 <FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="match_parent">
-    android:background="@color/black">
 
     <ImageView
         android:id="@+id/image"

gallery/src/main/res/menu/menu_album.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/action_sort"
+        android:icon="@drawable/ic_sort"
+        android:title="排序"
+        app:showAsAction="ifRoom">
+        <menu>
+            <group android:checkableBehavior="single">
+                <item
+                    android:id="@+id/sort_time_desc"
+                    android:title="时间倒序"/>
+                <item
+                    android:id="@+id/sort_time_asc"
+                    android:title="时间正序"/>
+                <item
+                    android:id="@+id/sort_name_desc"
+                    android:title="名称倒序"/>
+                <item
+                    android:id="@+id/sort_name_asc"
+                    android:title="名称正序"/>
+            </group>
+        </menu>
+    </item>
+</menu>