feat: 添加剪裁背景相关组件及版本更新

- 新增BackgroundRadioButton自定义单选按钮组件
- 新增CustomApplicationBackground应用背景管理类
- 更新build.properties版本构建号(0->19)
- 完善封面剪裁背景修改功能相关基础设施

gallery/build.properties

@@ -1,8 +1,8 @@
 #Created by .winboll/winboll_app_build.gradle
-#Fri May 01 08:34:01 HKT 2026
-stageCount=13
+#Sat May 02 10:32:03 CST 2026
+stageCount=16
 libraryProject=
 baseVersion=15.0
-publishVersion=15.0.12
-buildCount=0
-baseBetaVersion=15.0.13
+publishVersion=15.0.15
+buildCount=19
+baseBetaVersion=15.0.16

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

@@ -3,7 +3,6 @@ package cc.winboll.studio.gallery;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.RectF;
-import android.graphics.drawable.GradientDrawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.content.DialogInterface;
@@ -19,6 +18,7 @@ import android.widget.ImageView;
 import android.widget.ScrollView;
 import android.widget.SeekBar;
 import android.widget.TextView;
+import android.widget.LinearLayout;
 import android.widget.Toast;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
@@ -26,6 +26,7 @@ import cc.winboll.studio.libappbase.LogUtils;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.util.Random;
 
 public class CropActivity extends AppCompatActivity {
     public static final String TAG = "CropActivity";
@@ -43,6 +44,7 @@ public class CropActivity extends AppCompatActivity {
     private int cropWidth = 240;
     private int cropHeight = 120;
     private float cropRatio = 2.0f;
+    private Preferences prefs;
     
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -54,7 +56,8 @@ public class CropActivity extends AppCompatActivity {
         cropWidth = getIntent().getIntExtra(EXTRA_CROP_WIDTH, 240);
         cropHeight = getIntent().getIntExtra(EXTRA_CROP_HEIGHT, 120);
         
-        Preferences prefs = new Preferences(this);
+        prefs = new Preferences(this);
+        int bgType = prefs.getBgType();
         if (cropWidth > 0 && cropHeight > 0) {
             cropRatio = (float) cropWidth / cropHeight;
         } else {
@@ -70,16 +73,6 @@ public class CropActivity extends AppCompatActivity {
             }
         });
         
-        final ImageView btnColorPick = findViewById(R.id.btn_color_pick);
-        btnColorPick.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                boolean pickMode = !cropCanvasView.isColorPickMode();
-                cropCanvasView.setColorPickMode(pickMode);
-                btnColorPick.setAlpha(pickMode ? 0.5f : 1.0f);
-            }
-        });
-        
         findViewById(R.id.btn_done).setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -94,6 +87,13 @@ public class CropActivity extends AppCompatActivity {
             }
         });
         
+        findViewById(R.id.btn_change_bg).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Toast.makeText(CropActivity.this, "修改剪裁背景颜色", Toast.LENGTH_SHORT).show();
+            }
+        });
+        
         zoomContainer = findViewById(R.id.zoom_container);
         
         SeekBar seekBarZoom = findViewById(R.id.seekbar_zoom);
@@ -115,38 +115,14 @@ public class CropActivity extends AppCompatActivity {
         
         cropCanvasView = findViewById(R.id.crop_canvas_view);
         
-        final View colorView = findViewById(R.id.color_view);
-        final GradientDrawable colorDrawable = (GradientDrawable) colorView.getBackground();
+        cropCanvasView.setBackgroundType(bgType);
+        
         cropCanvasView.setOnBackgroundColorChangedListener(new CropCanvasView.OnBackgroundColorChangedListener() {
             @Override
             public void onBackgroundColorChanged(int color) {
-                colorDrawable.setColor(color);
             }
         });
         
-        cropCanvasView.setOnColorPickedListener(new CropCanvasView.OnColorPickedListener() {
-            @Override
-            public void onColorPicked(int color) {
-                int pickX = cropCanvasView.getLastPickImageX();
-                int pickY = cropCanvasView.getLastPickImageY();
-                colorDrawable.setColor(color);
-                Toast.makeText(CropActivity.this, 
-                    "颜色已拾取: #" + String.format("%06X", color & 0xFFFFFF) + 
-                    " (" + pickX + "," + pickY + ")", 
-                    Toast.LENGTH_SHORT).show();
-            }
-        });
-        
-        cropCanvasView.setOnColorPickEndListener(new CropCanvasView.OnColorPickEndListener() {
-            @Override
-            public void onColorPickEnd() {
-                cropCanvasView.setColorPickMode(false);
-                btnColorPick.setAlpha(1.0f);
-            }
-        });
-        
-        colorDrawable.setColor(cropCanvasView.getBackgroundColor());
-        
         loadImage();
     }
     
@@ -261,7 +237,9 @@ public class CropActivity extends AppCompatActivity {
         info.append("画布宽度: ").append(cropCanvasView.getCanvasWidth()).append("px\n");
         info.append("画布高度: ").append(cropCanvasView.getCanvasHeight()).append("px\n");
         
-        info.append("\n=== 拾取颜色 ===\n");
+        info.append("\n=== 背景类型 ===\n");
+        String[] bgNames = {"灰白相间", "全白", "全黑"};
+        info.append("背景: ").append(bgNames[cropCanvasView.getBackgroundType()]).append("\n");
         int bgColor = cropCanvasView.getBackgroundColor();
         info.append("背景颜色: #").append(String.format("%06X", bgColor & 0xFFFFFF)).append("\n");
         info.append("拾取坐标: ").append(cropCanvasView.getLastPickImageX()).append(",")
@@ -295,10 +273,18 @@ public class CropActivity extends AppCompatActivity {
         View dialogView = getLayoutInflater().inflate(R.layout.dialog_crop_info, null);
         TextView infoText = dialogView.findViewById(R.id.info_text);
         ImageView previewImage = dialogView.findViewById(R.id.preview_image);
+        final LinearLayout previewImageContainer = dialogView.findViewById(R.id.preview_image_container);
         infoText.setText(info.toString());
         if (previewBitmap != null) {
             previewImage.setImageBitmap(previewBitmap);
         }
+        previewImage.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                int randomColor = 0xFF000000 | new Random().nextInt(0x00FFFFFF);
+                previewImageContainer.setBackgroundColor(randomColor);
+            }
+        });
         
         AlertDialog dialog = new AlertDialog.Builder(this)
             .setTitle("裁剪信息")
@@ -324,4 +310,4 @@ public class CropActivity extends AppCompatActivity {
             originalBitmap = null;
         }
     }
-}
+}

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

@@ -2,11 +2,14 @@ package cc.winboll.studio.gallery;
 
 import android.content.Context;
 import android.graphics.Bitmap;
+import android.graphics.BitmapShader;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.RectF;
+import android.graphics.Shader;
+import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
@@ -71,6 +74,10 @@ public class CropCanvasView extends View {
     private Bitmap displayBitmap;
     private RectF initialSpanRect;
     private float initialSpan;
+    private int bgType = 2;
+    private Bitmap tileBitmap;
+    private BitmapShader tileShader;
+    private Paint bgPaint;
     private int backgroundColor = Color.BLUE;
     private boolean colorPickMode = false;
     private int previewColor = 0;
@@ -111,6 +118,60 @@ public class CropCanvasView extends View {
         cornerPaint = new Paint();
         cornerPaint.setColor(Color.WHITE);
         cornerPaint.setStyle(Paint.Style.FILL);
+        
+        bgType = 2;
+        bgPaint = new Paint();
+        initTileBitmap();
+    }
+    
+    private void initTileBitmap() {
+        if (tileBitmap != null && !tileBitmap.isRecycled()) {
+            tileBitmap.recycle();
+            tileBitmap = null;
+        }
+        tileShader = null;
+        
+        if (bgType == 0) {
+            Drawable drawable = getContext().getDrawable(R.drawable.bg_checkerboard);
+            if (drawable != null) {
+                int w = drawable.getIntrinsicWidth();
+                int h = drawable.getIntrinsicHeight();
+                if (w <= 0) w = 10;
+                if (h <= 0) h = 10;
+                tileBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
+                Canvas c = new Canvas(tileBitmap);
+                drawable.setBounds(0, 0, w, h);
+                drawable.draw(c);
+                tileShader = new BitmapShader(tileBitmap, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
+            }
+        }
+    }
+    
+    public void setBackgroundType(int type) {
+        if (bgType != type) {
+            bgType = type;
+            initTileBitmap();
+            invalidate();
+        }
+    }
+    
+    public int getBackgroundType() {
+        return bgType;
+    }
+    
+    private void drawBackground(Canvas canvas) {
+        if (bgType == 0 && tileShader != null) {
+            bgPaint.setShader(tileShader);
+            canvas.drawRect(canvasBounds, bgPaint);
+        } else if (bgType == 1) {
+            bgPaint.setShader(null);
+            bgPaint.setColor(Color.WHITE);
+            canvas.drawRect(canvasBounds, bgPaint);
+        } else {
+            bgPaint.setShader(null);
+            bgPaint.setColor(Color.BLACK);
+            canvas.drawRect(canvasBounds, bgPaint);
+        }
     }
     
     public void setImageBitmap(Bitmap bitmap) {
@@ -175,7 +236,7 @@ public class CropCanvasView extends View {
         }
         Bitmap canvasBmp = Bitmap.createBitmap(canvasWidth, canvasHeight, Bitmap.Config.ARGB_8888);
         Canvas canvas = new Canvas(canvasBmp);
-        canvas.drawColor(backgroundColor);
+        drawBackground(canvas);
         if (displayBitmap != null && !displayBitmap.isRecycled()) {
             if (displayBitmap == originalBitmap) {
                 canvas.drawBitmap(displayBitmap, imageBounds.left, imageBounds.top, imagePaint);
@@ -409,7 +470,7 @@ public class CropCanvasView extends View {
             getDisplayMatrix(matrix);
             canvas.concat(matrix);
             
-            canvas.drawColor(backgroundColor);
+            drawBackground(canvas);
             
             if (displayBitmap == originalBitmap) {
                 canvas.drawBitmap(displayBitmap, imageBounds.left, imageBounds.top, imagePaint);
@@ -523,7 +584,7 @@ public class CropCanvasView extends View {
                     if (imageBounds.contains(imgX, imgY)) {
                         previewColor = getImageColorAt(x, y);
                     } else if (canvasBounds.contains(x, y)) {
-                        previewColor = backgroundColor;
+                        previewColor = (bgType == 1) ? Color.WHITE : Color.BLACK;
                     } else {
                         previewColor = Color.TRANSPARENT;
                     }
@@ -545,7 +606,7 @@ public class CropCanvasView extends View {
                         pickedColor = colorAtPoint;
                         backgroundColor = colorAtPoint;
                     } else {
-                        pickedColor = backgroundColor;
+                        pickedColor = (bgType == 1) ? Color.WHITE : Color.BLACK;
                     }
                     if (colorPickedListener != null) {
                         colorPickedListener.onColorPicked(pickedColor);

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

@@ -4,6 +4,7 @@ import cc.winboll.studio.libaes.utils.WinBoLLActivityManager;
 import cc.winboll.studio.libappbase.GlobalApplication;
 import cc.winboll.studio.libappbase.LogUtils;
 import cc.winboll.studio.libappbase.ToastUtils;
+import cc.winboll.studio.gallery.utils.BackgroundUtils;
 
 /**
  * @Author 豆包&ZhanGSKen<zhangsken@qq.com>
@@ -23,6 +24,8 @@ public class GlobalWinBoLLApplication extends GlobalApplication {
 
         WinBoLLActivityManager.init(this);
 
+        BackgroundUtils.initFromPreferences(this);
+
         // 初始化 Toast 框架
         ToastUtils.init(this);
         // 设置 Toast 布局样式

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

@@ -16,25 +16,10 @@ 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, int bgType) {
+    public ImagePagerAdapter(ArrayList<Uri> imageUrls) {
         this.imageUrls = imageUrls;
-        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;
-        }
+        LogUtils.d(TAG, "ImagePagerAdapter created with " + imageUrls.size() + " images");
     }
 
     @Override
@@ -47,7 +32,7 @@ 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());
+        view.setBackgroundResource(R.color.black);
         ImageView imageView = view.findViewById(R.id.image);
         
         Glide.with(imageView.getContext())

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

@@ -34,9 +34,7 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
     private ImageButton btnDelete;
     private ImageButton btnShare;
     private ImageButton btnInfo;
-    private ImageButton btnBg;
     private ImageButton btnGallery;
-    private int bgType = 0;
     private GestureDetector gestureDetector;
     private TrashManager trashManager;
     private Preferences prefs;
@@ -55,7 +53,6 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
         
         trashManager = new TrashManager(this);
         prefs = new Preferences(this);
-        bgType = prefs.getBgType();
         
         viewPager = findViewById(R.id.view_pager);
         toolbar = findViewById(R.id.toolbar);
@@ -63,13 +60,10 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
         btnDelete = findViewById(R.id.btn_delete);
         btnShare = findViewById(R.id.btn_share);
         btnInfo = findViewById(R.id.btn_info);
-        btnBg = findViewById(R.id.btn_bg);
         
         btnGallery = findViewById(R.id.btn_gallery);
         
-        applyBg();
-        
-        ImagePagerAdapter adapter = new ImagePagerAdapter(imageUrls, bgType);
+        ImagePagerAdapter adapter = new ImagePagerAdapter(imageUrls);
         viewPager.setAdapter(adapter);
         viewPager.setCurrentItem(currentPosition);
         viewPager.addOnPageChangeListener(this);
@@ -117,13 +111,6 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
             }
         });
         
-        btnBg.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                switchBg();
-            }
-        });
-        
         btnGallery.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -147,52 +134,6 @@ 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?")
@@ -257,7 +198,7 @@ public class ImageViewerActivity extends Activity implements ViewPager.OnPageCha
             if (currentPosition >= imageUrls.size()) {
                 currentPosition = imageUrls.size() - 1;
             }
-            viewPager.setAdapter(new ImagePagerAdapter(imageUrls, bgType));
+            viewPager.setAdapter(new ImagePagerAdapter(imageUrls));
             viewPager.setCurrentItem(currentPosition);
         }
     }

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

@@ -26,10 +26,12 @@ 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.gallery.utils.BackgroundUtils;
 import cc.winboll.studio.libappbase.LogActivity;
+import cc.winboll.studio.libappbase.LogUtils;
+import com.a4455jkjh.colorpicker.ColorPickerDialog;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import java.io.File;
 import java.io.FileFilter;
 import java.io.FilenameFilter;
@@ -49,55 +51,60 @@ public class MainActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         LogUtils.d(TAG, "onCreate");
-        
+
+        View content = findViewById(android.R.id.content);
+        if (content != null) {
+            content.setBackground(BackgroundUtils.getInstance().getDrawable());
+        }
+
         Toolbar toolbar = findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);
-        
+
         prefs = new Preferences(this);
-        
+
         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);
-            }
-        });
-        
+				@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);
-                    }
-                }
-            }
-        });
-        
+				@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) {
-                Intent intent = new Intent(MainActivity.this, AlbumActivity.class);
-                intent.putExtra(AlbumActivity.EXTRA_ALBUM_PATH, album.getPath());
-                intent.putExtra(AlbumActivity.EXTRA_ALBUM_NAME, album.getName());
-                startActivity(intent);
-            }
-        });
-        
+				@Override
+				public void onAlbumClick(Album album) {
+					Intent intent = new Intent(MainActivity.this, AlbumActivity.class);
+					intent.putExtra(AlbumActivity.EXTRA_ALBUM_PATH, album.getPath());
+					intent.putExtra(AlbumActivity.EXTRA_ALBUM_NAME, album.getName());
+					startActivity(intent);
+				}
+			});
+
         checkAndRequestPermissions();
     }
-    
+
     private void checkAndRequestPermissions() {
         LogUtils.i(TAG, "checkAndRequestPermissions");
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
@@ -113,14 +120,14 @@ public class MainActivity extends AppCompatActivity {
                 return;
             }
         }
-        
+
         if (checkPermission()) {
             loadAlbums();
         } else {
             requestPermission();
         }
     }
-    
+
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
@@ -134,7 +141,7 @@ public class MainActivity extends AppCompatActivity {
             }
         }
     }
-    
+
     private boolean checkPermission() {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
             return Environment.isExternalStorageManager();
@@ -145,13 +152,13 @@ public class MainActivity extends AppCompatActivity {
 
     private void requestPermission() {
         ActivityCompat.requestPermissions(this, 
-            new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
-            PERMISSION_REQUEST_CODE);
+										  new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
+										  PERMISSION_REQUEST_CODE);
     }
 
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, 
-            @NonNull int[] grantResults) {
+										   @NonNull int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
         if (requestCode == PERMISSION_REQUEST_CODE) {
             if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
@@ -162,12 +169,12 @@ 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 = Preferences.getDefaultPath();
             baseFolder = new File(folderPath);
@@ -178,10 +185,10 @@ private void loadAlbums() {
                 LogUtils.d(TAG, "try Pictures: " + baseFolder.getAbsolutePath() + ", exists=" + baseFolder.exists());
             }
         }
-        
+
         AlbumCoverDbHelper coverDbHelper = AlbumCoverDbHelper.getInstance(this);
         ArrayList<Album> albums = new ArrayList<>();
-        
+
         FileFilter directoryFilter = new FileFilter() {
             @Override
             public boolean accept(File file) {
@@ -224,7 +231,7 @@ private void loadAlbums() {
                 }
             }
         }
-        
+
         if (albums.isEmpty()) {
             Toast.makeText(this, R.string.no_images_found, Toast.LENGTH_SHORT).show();
             LogUtils.i(TAG, "No albums found");
@@ -232,14 +239,14 @@ private void loadAlbums() {
         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)) {
+			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));
@@ -249,18 +256,18 @@ private void loadAlbums() {
         }
         return null;
     }
-    
+
     private ArrayList<Uri> getImagesInFolder(String folderPath) {
         ArrayList<Uri> imageUrls = new ArrayList<>();
         ContentResolver contentResolver = getContentResolver();
         Uri collection = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
-        
+
         String selection = MediaStore.Images.Media.DATA + " LIKE ?";
         String[] selectionArgs = new String[]{folderPath + "/%"};
         String sortOrder = MediaStore.Images.Media.DATE_ADDED + " DESC";
-        
+
         LogUtils.d(TAG, "getImagesInFolder: " + folderPath);
-        
+
         try (Cursor cursor = contentResolver.query(collection, null, selection, selectionArgs, sortOrder)) {
             if (cursor != null) {
                 LogUtils.d(TAG, "cursor count: " + cursor.getCount());
@@ -295,6 +302,33 @@ private void loadAlbums() {
             intent.addCategory(Intent.CATEGORY_APP_GALLERY);
             startActivity(intent);
             return true;
+        } else if (id == R.id.action_change_bg_color) {
+            //Toast.makeText(this, "修改背景颜色", Toast.LENGTH_SHORT).show();
+			if (BackgroundUtils.DrawableType.COLOR == BackgroundUtils.getInstance().getDrawableType()) {
+
+				ColorPickerDialog dlg = new ColorPickerDialog(this, BackgroundUtils.getInstance().getColor());
+				dlg.setOnColorChangedListener(new com.a4455jkjh.colorpicker.view.OnColorChangedListener() {
+
+						@Override
+						public void beforeColorChanged() {
+						}
+
+						@Override
+						public void onColorChanged(int color) {
+							BackgroundUtils.getInstance().initFromColor(MainActivity.this, color);
+							View content = findViewById(android.R.id.content);
+							if (content != null) {
+								content.setBackground(BackgroundUtils.getInstance().getDrawable());
+							}
+						}
+
+						@Override
+						public void afterColorChanged() {
+						}
+					});
+				dlg.show();
+			}
+            return true;
         } else if (id == R.id.action_settings) {
             startActivity(new Intent(this, SettingsActivity.class));
             return true;
@@ -310,7 +344,7 @@ private void loadAlbums() {
         }
         return super.onOptionsItemSelected(item);
     }
-    
+
     private BroadcastReceiver coverUpdatedReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
@@ -319,7 +353,7 @@ private void loadAlbums() {
             }
         }
     };
-    
+
     @Override
     protected void onResume() {
         super.onResume();
@@ -334,35 +368,35 @@ private void loadAlbums() {
             adapter.refreshCover();
         }
     }
-    
+
     @Override
     protected void onPause() {
         super.onPause();
         unregisterReceiver(coverUpdatedReceiver);
     }
-    
+
     private void scanMediaStore() {
         String folderPath = prefs.getFolderPath();
         File baseFolder = new File(folderPath);
         if (baseFolder.exists() && baseFolder.isDirectory()) {
             File[] subfolders = baseFolder.listFiles(new FileFilter() {
-                @Override
-                public boolean accept(File file) {
-                    return file.isDirectory();
-                }
-            });
+					@Override
+					public boolean accept(File file) {
+						return file.isDirectory();
+					}
+				});
             if (subfolders != null) {
                 ArrayList<String> paths = new ArrayList<>();
                 for (File subfolder : subfolders) {
                     File[] images = subfolder.listFiles(new FilenameFilter() {
-                        @Override
-                        public boolean accept(File dir, String name) {
-                            String lower = name.toLowerCase();
-                            return lower.endsWith(".jpg") || lower.endsWith(".jpeg") 
-                                || lower.endsWith(".png") || lower.endsWith(".gif")
-                                || lower.endsWith(".webp") || lower.endsWith(".bmp");
-                        }
-                    });
+							@Override
+							public boolean accept(File dir, String name) {
+								String lower = name.toLowerCase();
+								return lower.endsWith(".jpg") || lower.endsWith(".jpeg") 
+									|| lower.endsWith(".png") || lower.endsWith(".gif")
+									|| lower.endsWith(".webp") || lower.endsWith(".bmp");
+							}
+						});
                     if (images != null) {
                         for (File img : images) {
                             paths.add(img.getAbsolutePath());
@@ -373,11 +407,11 @@ private void loadAlbums() {
                     LogUtils.d(TAG, "scanning " + paths.size() + " files to MediaStore");
                     String[] pathArray = paths.toArray(new String[0]);
                     MediaScannerConnection.scanFile(this, pathArray, null, new MediaScannerConnection.OnScanCompletedListener() {
-                        @Override
-                        public void onScanCompleted(String path, Uri uri) {
-                            LogUtils.d(TAG, "scanCompleted: " + path + " -> " + uri);
-                        }
-                    });
+							@Override
+							public void onScanCompleted(String path, Uri uri) {
+								LogUtils.d(TAG, "scanCompleted: " + path + " -> " + uri);
+							}
+						});
                 }
             }
         }

gallery/src/main/java/cc/winboll/studio/gallery/utils/BackgroundUtils.java

@@ -0,0 +1,129 @@
+package cc.winboll.studio.gallery.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import androidx.annotation.ColorInt;
+import androidx.annotation.DrawableRes;
+import androidx.core.content.ContextCompat;
+
+public class BackgroundUtils {
+
+    public enum DrawableType {
+        RESOURCE_ID,
+        COLOR
+    }
+
+    private static volatile BackgroundUtils instance;
+
+    private static final String PREF_NAME = "background_prefs";
+    private static final String KEY_TYPE = "bg_type";
+    private static final String KEY_RES_ID = "bg_res_id";
+    private static final String KEY_COLOR = "bg_color";
+
+    private Context context;
+    private Drawable drawable;
+    private DrawableType drawableType;
+    private int resId;
+    private int color;
+
+    private BackgroundUtils() {
+    }
+
+    public static BackgroundUtils getInstance() {
+        if (instance == null) {
+            synchronized (BackgroundUtils.class) {
+                if (instance == null) {
+                    instance = new BackgroundUtils();
+                }
+            }
+        }
+        return instance;
+    }
+
+    public static BackgroundUtils initFromResource(Context context, @DrawableRes int resId) {
+        synchronized (BackgroundUtils.class) {
+            BackgroundUtils utils = getInstance();
+            utils.context = context.getApplicationContext();
+            utils.drawableType = DrawableType.RESOURCE_ID;
+            utils.resId = resId;
+            utils.drawable = ContextCompat.getDrawable(utils.context, resId);
+            utils.saveToPreferences();
+            return utils;
+        }
+    }
+
+    public static BackgroundUtils initFromColor(Context context, @ColorInt int color) {
+        synchronized (BackgroundUtils.class) {
+            BackgroundUtils utils = getInstance();
+            utils.context = context.getApplicationContext();
+            utils.drawableType = DrawableType.COLOR;
+            utils.color = color;
+            utils.drawable = new ColorDrawable(color);
+            utils.saveToPreferences();
+            return utils;
+        }
+    }
+
+    public static BackgroundUtils initFromPreferences(Context context) {
+        synchronized (BackgroundUtils.class) {
+            Context appContext = context.getApplicationContext();
+            SharedPreferences prefs = appContext.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+            int type = prefs.getInt(KEY_TYPE, -1);
+            if (type == 0) {
+                int resId = prefs.getInt(KEY_RES_ID, 0);
+                if (resId != 0) {
+                    return initFromResource(appContext, resId);
+                }
+            } else if (type == 1) {
+                int color = prefs.getInt(KEY_COLOR, Color.BLACK);
+                return initFromColor(appContext, color);
+            }
+            // 默认情况，initFromColor 内部已经调用了 saveToPreferences()
+            return initFromColor(appContext, 0xFF00FF00);
+        }
+    }
+
+    public Drawable getDrawable() {
+        return drawable;
+    }
+
+    public DrawableType getDrawableType() {
+        return drawableType;
+    }
+
+    public DrawableType getAttributeValueType() {
+        return drawableType;
+    }
+
+    public int getResId() {
+        return resId;
+    }
+
+    public int getColor() {
+        return color;
+    }
+
+    public void saveToPreferences() {
+        if (context == null) return;
+        SharedPreferences prefs = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = prefs.edit();
+        if (drawableType == DrawableType.RESOURCE_ID) {
+            editor.putInt(KEY_TYPE, 0);
+            editor.putInt(KEY_RES_ID, resId);
+            editor.remove(KEY_COLOR);
+        } else {
+            editor.putInt(KEY_TYPE, 1);
+            editor.putInt(KEY_COLOR, color);
+            editor.remove(KEY_RES_ID);
+        }
+        editor.apply();
+    }
+
+    public static void clearPreferences(Context context) {
+        SharedPreferences prefs = context.getApplicationContext().getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        prefs.edit().clear().apply();
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/utils/CropBackgroundUtils.java

@@ -0,0 +1,124 @@
+package cc.winboll.studio.gallery.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import androidx.annotation.ColorInt;
+import androidx.annotation.DrawableRes;
+import androidx.core.content.ContextCompat;
+
+public class CropBackgroundUtils {
+
+    public enum DrawableType {
+        RESOURCE_ID,
+        COLOR
+    }
+
+    private static volatile CropBackgroundUtils instance;
+
+    private static final String PREF_NAME = "crop_background_prefs";
+    private static final String KEY_TYPE = "crop_bg_type";
+    private static final String KEY_RES_ID = "crop_bg_res_id";
+    private static final String KEY_COLOR = "crop_bg_color";
+
+    private Context context;
+    private Drawable drawable;
+    private DrawableType drawableType;
+    private int resId;
+    private int color;
+
+    private CropBackgroundUtils() {
+    }
+
+    public static CropBackgroundUtils getInstance() {
+        if (instance == null) {
+            synchronized (CropBackgroundUtils.class) {
+                if (instance == null) {
+                    instance = new CropBackgroundUtils();
+                }
+            }
+        }
+        return instance;
+    }
+
+    public static CropBackgroundUtils initFromResource(Context context, @DrawableRes int resId) {
+        synchronized (CropBackgroundUtils.class) {
+            CropBackgroundUtils utils = getInstance();
+            utils.context = context.getApplicationContext();
+            utils.drawableType = DrawableType.RESOURCE_ID;
+            utils.resId = resId;
+            utils.drawable = ContextCompat.getDrawable(utils.context, resId);
+            utils.saveToPreferences();
+            return utils;
+        }
+    }
+
+    public static CropBackgroundUtils initFromColor(Context context, @ColorInt int color) {
+        synchronized (CropBackgroundUtils.class) {
+            CropBackgroundUtils utils = getInstance();
+            utils.context = context.getApplicationContext();
+            utils.drawableType = DrawableType.COLOR;
+            utils.color = color;
+            utils.drawable = new ColorDrawable(color);
+            utils.saveToPreferences();
+            return utils;
+        }
+    }
+
+    public static CropBackgroundUtils initFromPreferences(Context context) {
+        synchronized (CropBackgroundUtils.class) {
+            Context appContext = context.getApplicationContext();
+            SharedPreferences prefs = appContext.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+            int type = prefs.getInt(KEY_TYPE, -1);
+            if (type == 0) {
+                int resId = prefs.getInt(KEY_RES_ID, 0);
+                if (resId != 0) {
+                    return initFromResource(appContext, resId);
+                }
+            } else if (type == 1) {
+                int color = prefs.getInt(KEY_COLOR, Color.BLACK);
+                return initFromColor(appContext, color);
+            }
+            return initFromColor(appContext, 0xFF00FF00);
+        }
+    }
+
+    public Drawable getDrawable() {
+        return drawable;
+    }
+
+    public DrawableType getDrawableType() {
+        return drawableType;
+    }
+
+    public int getResId() {
+        return resId;
+    }
+
+    public int getColor() {
+        return color;
+    }
+
+    public void saveToPreferences() {
+        if (context == null) return;
+        SharedPreferences prefs = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = prefs.edit();
+        if (drawableType == DrawableType.RESOURCE_ID) {
+            editor.putInt(KEY_TYPE, 0);
+            editor.putInt(KEY_RES_ID, resId);
+            editor.remove(KEY_COLOR);
+        } else {
+            editor.putInt(KEY_TYPE, 1);
+            editor.putInt(KEY_COLOR, color);
+            editor.remove(KEY_RES_ID);
+        }
+        editor.apply();
+    }
+
+    public static void clearPreferences(Context context) {
+        SharedPreferences prefs = context.getApplicationContext().getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        prefs.edit().clear().apply();
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/views/BackgroundRadioButton.java

@@ -0,0 +1,34 @@
+package cc.winboll.studio.gallery.views;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.RadioButton;
+
+public class BackgroundRadioButton extends RadioButton {
+
+    CustomApplicationBackground mCustomApplicationBackground;
+
+    public BackgroundRadioButton(Context context) {
+        super(context);
+    }
+
+    public BackgroundRadioButton(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public BackgroundRadioButton(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public void setupCustomApplicationBackground(Context context, int resId) {
+        mCustomApplicationBackground = new CustomApplicationBackground(context, resId);
+    }
+
+    public void setCustomApplicationBackground(CustomApplicationBackground customApplicationBackground) {
+        mCustomApplicationBackground = customApplicationBackground;
+    }
+
+    public CustomApplicationBackground getCustomApplicationBackground() {
+        return mCustomApplicationBackground;
+    }
+}

gallery/src/main/java/cc/winboll/studio/gallery/views/CustomApplicationBackground.java

@@ -0,0 +1,29 @@
+package cc.winboll.studio.gallery.views;
+
+import android.content.Context;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+
+public class CustomApplicationBackground {
+    Drawable mDrawable;
+
+    public CustomApplicationBackground(Drawable drawable) {
+        mDrawable = drawable;
+    }
+
+    public CustomApplicationBackground(int color) {
+        mDrawable = new ColorDrawable(color);
+    }
+
+    public CustomApplicationBackground(Context context, int resId) {
+        mDrawable = context.getDrawable(resId);
+    }
+
+    public Drawable getDrawable() {
+        return mDrawable;
+    }
+
+    public void setDrawable(Drawable drawable) {
+        mDrawable = drawable;
+    }
+}

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

@@ -33,30 +33,6 @@
             android:gravity="center"
             android:layout_marginEnd="8dp"/>
 
-        <FrameLayout
-            android:id="@+id/color_icon_container"
-            android:layout_width="40dp"
-            android:layout_height="40dp"
-            android:layout_marginStart="8dp"
-            android:background="@android:color/transparent">
-
-            <View
-                android:id="@+id/color_view"
-                android:layout_width="32dp"
-                android:layout_height="32dp"
-                android:layout_gravity="center"
-                android:background="@drawable/bg_color_circle"/>
-
-        </FrameLayout>
-
-        <ImageView
-            android:id="@+id/btn_color_pick"
-            android:layout_width="40dp"
-            android:layout_height="40dp"
-            android:padding="5dp"
-            android:src="@drawable/ic_color_pick"
-            android:background="?attr/selectableItemBackgroundBorderless"/>
-
         <View
             android:layout_width="0dp"
             android:layout_height="0dp"
@@ -70,6 +46,15 @@
             android:src="@drawable/ic_info"
             android:background="?attr/selectableItemBackgroundBorderless"/>
 
+        <ImageView
+            android:id="@+id/btn_change_bg"
+            android:layout_width="40dp"
+            android:layout_height="40dp"
+            android:padding="5dp"
+            android:src="@drawable/ic_color_pick"
+            android:background="?attr/selectableItemBackgroundBorderless"
+            android:contentDescription="修改剪裁背景颜色"/>
+
         <ImageView
             android:id="@+id/btn_done"
             android:layout_width="40dp"

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

@@ -60,14 +60,6 @@
             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

@@ -27,7 +27,7 @@
             android:id="@+id/recycler_view"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
-            android:background="@color/black"/>
+            android:background="@android:color/transparent"/>
 
     </LinearLayout>
 

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

@@ -1,26 +1,36 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:orientation="vertical"
-    android:padding="16dp"
-    android:background="@drawable/bg_dialog">
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	android:layout_width="match_parent"
+	android:layout_height="wrap_content"
+	android:orientation="vertical"
+	android:padding="16dp"
+	android:background="@drawable/bg_dialog"
+	android:gravity="center_horizontal">
 
-    <TextView
-        android:id="@+id/info_text"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:textSize="14sp"
-        android:fontFamily="monospace"
-        android:textColor="@android:color/white"/>
+	<TextView
+		android:id="@+id/info_text"
+		android:layout_width="match_parent"
+		android:layout_height="wrap_content"
+		android:textSize="14sp"
+		android:fontFamily="monospace"
+		android:textColor="@android:color/white"/>
 
-    <ImageView
-        android:id="@+id/preview_image"
-        android:layout_width="match_parent"
-        android:layout_height="200dp"
-        android:layout_marginTop="16dp"
-        android:scaleType="fitCenter"
-        android:background="@android:color/black"/>
+	<LinearLayout
+		android:id="@+id/preview_image_container"
+		android:orientation="horizontal"
+		android:layout_width="match_parent"
+		android:layout_height="wrap_content"
+		android:padding="2dp"
+		android:background="#FFBBD505">
+
+		<ImageView
+			android:id="@+id/preview_image"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			android:scaleType="fitCenter"/>
+
+	</LinearLayout>
+
+</LinearLayout>
 
-</LinearLayout>

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

@@ -8,6 +8,11 @@
         android:icon="@drawable/ic_mi_gallery"
         app:showAsAction="ifRoom"/>
     
+    <item
+        android:id="@+id/action_change_bg_color"
+        android:title="修改背景颜色"
+        app:showAsAction="never"/>
+    
     <item
         android:id="@+id/action_trash"
         android:title="@string/trash"