Add a clone() API to create copies of builders.

checkstyle_suppressions.xml

@@ -7,5 +7,6 @@
 <suppressions>
     <suppress files=".*[/\\]library[/\\]src[/\\]androidTest[/\\].*" checks="Javadoc.*"/>
     <suppress files=".*[/\\]gif_encoder[/\\].*" checks=".*"/>
+    <suppress files=".*RequestBuilder.java|ChildLoadProvider.java" checks="NoClone" />
 </suppressions>
 

library/src/androidTest/java/com/bumptech/glide/GlideTest.java

@@ -30,6 +30,7 @@
 import com.bumptech.glide.load.resource.bytes.BytesResource;
 import com.bumptech.glide.load.resource.drawable.GlideDrawable;
 import com.bumptech.glide.load.resource.gif.GifDrawable;
+import com.bumptech.glide.load.resource.gifbitmap.GifBitmapWrapper;
 import com.bumptech.glide.load.resource.transcode.ResourceTranscoder;
 import com.bumptech.glide.manager.Lifecycle;
 import com.bumptech.glide.request.Request;
@@ -676,6 +677,38 @@ public void testByteData() {
         requestManager.load(data).into(target);
     }
 
+    @Test
+    public void testClone() throws IOException {
+        GlideDrawable firstResult = mock(GlideDrawable.class);
+        Resource<GlideDrawable> firstResource = mock(Resource.class);
+        when(firstResource.get()).thenReturn(firstResult);
+        ResourceTranscoder<GifBitmapWrapper, GlideDrawable> firstTranscoder = mock(ResourceTranscoder.class);
+        when(firstTranscoder.transcode(any(Resource.class))).thenReturn(firstResource);
+        when(firstTranscoder.getId()).thenReturn("transcoder1");
+
+        GlideDrawable secondResult = mock(GlideDrawable.class);
+        Resource<GlideDrawable> secondResource = mock(Resource.class);
+        when(secondResource.get()).thenReturn(secondResult);
+        ResourceTranscoder<GifBitmapWrapper, GlideDrawable> secondTranscoder = mock(ResourceTranscoder.class);
+        when(secondTranscoder.transcode(any(Resource.class))).thenReturn(secondResource);
+        when(secondTranscoder.getId()).thenReturn("transcoder2");
+
+        DrawableRequestBuilder<String> firstRequest = requestManager.from(String.class).transcoder(firstTranscoder)
+                .override(100, 100);
+        DrawableRequestBuilder<String> secondRequest = firstRequest.clone().transcoder(secondTranscoder);
+
+        Target firstTarget = mock(Target.class);
+        Target secondTarget = mock(Target.class);
+
+        String fakeUri = mockUri("content://fakeUri");
+
+        firstRequest.load(fakeUri).into(firstTarget);
+        verify(firstTarget).onResourceReady(eq(firstResult), any(GlideAnimation.class));
+
+        secondRequest.load(fakeUri).into(secondTarget);
+        verify(secondTarget).onResourceReady(eq(secondResult), any(GlideAnimation.class));
+    }
+
     @SuppressWarnings("unchecked")
     private <T, Z> void registerFailFactory(Class<T> failModel, Class<Z> failResource) throws Exception {
         DataFetcher<Z> failFetcher = mock(DataFetcher.class);

library/src/main/java/com/bumptech/glide/BitmapRequestBuilder.java

@@ -44,6 +44,7 @@
 public class BitmapRequestBuilder<ModelType, TranscodeType>
         extends GenericRequestBuilder<ModelType, ImageVideoWrapper, Bitmap, TranscodeType> implements BitmapOptions {
     private final BitmapPool bitmapPool;
+
     private Downsampler downsampler = Downsampler.AT_LEAST;
     private DecodeFormat decodeFormat = DecodeFormat.PREFER_RGB_565;
     private ResourceDecoder<InputStream, Bitmap> imageDecoder;
@@ -458,6 +459,11 @@ public BitmapRequestBuilder<ModelType, TranscodeType> load(ModelType model) {
         return this;
     }
 
+    @Override
+    public BitmapRequestBuilder<ModelType, TranscodeType> clone() {
+        return (BitmapRequestBuilder<ModelType, TranscodeType>) super.clone();
+    }
+
     /**
      * {@inheritDoc}
      *

library/src/main/java/com/bumptech/glide/DrawableRequestBuilder.java

@@ -412,6 +412,11 @@ public DrawableRequestBuilder<ModelType> load(ModelType model) {
         return this;
     }
 
+    @Override
+    public DrawableRequestBuilder<ModelType> clone() {
+        return (DrawableRequestBuilder<ModelType>) super.clone();
+    }
+
     /**
      * {@inheritDoc}
      *

library/src/main/java/com/bumptech/glide/GenericRequestBuilder.java

@@ -44,18 +44,17 @@
  * @param <ResourceType> The type of the resource that will be loaded.
  * @param <TranscodeType> The type of resource the decoded resource will be transcoded to.
  */
-public class GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType> {
+public class GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType> implements Cloneable {
     protected final Class<ModelType> modelClass;
     protected final Context context;
     protected final Glide glide;
     protected final Class<TranscodeType> transcodeClass;
     protected final RequestTracker requestTracker;
     protected final Lifecycle lifecycle;
-    private final ChildLoadProvider<ModelType, DataType, ResourceType, TranscodeType> loadProvider;
-
-    private Key signature = EmptySignature.obtain();
+    private ChildLoadProvider<ModelType, DataType, ResourceType, TranscodeType> loadProvider;
 
     private ModelType model;
+    private Key signature = EmptySignature.obtain();
     // model may occasionally be null, so to enforce that load() was called, set a boolean rather than relying on model
     // not to be null.
     private boolean isModelSet;
@@ -80,11 +79,11 @@ public class GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeT
             Class<TranscodeType> transcodeClass, GenericRequestBuilder<ModelType, ?, ?, ?> other) {
         this(other.context, other.modelClass, loadProvider, transcodeClass, other.glide, other.requestTracker,
                 other.lifecycle);
+        this.model = other.model;
+        this.isModelSet = other.isModelSet;
         this.signature = other.signature;
         this.diskCacheStrategy = other.diskCacheStrategy;
         this.isCacheable = other.isCacheable;
-        this.model = other.model;
-        this.isModelSet = other.isModelSet;
     }
 
     GenericRequestBuilder(Context context, Class<ModelType> modelClass,
@@ -559,6 +558,28 @@ public GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType> l
         return this;
     }
 
+    /**
+     * Returns a copy of this request builder with all of the options set so far on this builder.
+     *
+     * <p>
+     *     This method returns a "deep" copy in that all non-immutable arguments are copied such that changes to one
+     *     builder will not affect the other builder. However, in addition to immutable arguments, the current model
+     *     is not copied copied so changes to the model will affect both builders.
+     * </p>
+     */
+    @SuppressWarnings("unchecked")
+    @Override
+    public GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType> clone() {
+        try {
+            GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType> clone =
+                    (GenericRequestBuilder<ModelType, DataType, ResourceType, TranscodeType>) super.clone();
+            clone.loadProvider = loadProvider != null ? loadProvider.clone() : null;
+            return clone;
+        } catch (CloneNotSupportedException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     /**
      * Set the target the resource will be loaded into.
      *
@@ -729,7 +750,7 @@ private Request buildRequestRecursive(Target<TranscodeType> target, ThumbnailReq
         }
     }
 
-    private <Z> Request obtainRequest(Target<TranscodeType> target, float sizeMultiplier, Priority priority,
+    private Request obtainRequest(Target<TranscodeType> target, float sizeMultiplier, Priority priority,
             RequestCoordinator requestCoordinator) {
         return GenericRequest.obtain(
                 loadProvider,

library/src/main/java/com/bumptech/glide/GifRequestBuilder.java

@@ -403,6 +403,11 @@ public GifRequestBuilder<ModelType> load(ModelType model) {
         return this;
     }
 
+    @Override
+    public GifRequestBuilder<ModelType> clone() {
+        return (GifRequestBuilder<ModelType>) super.clone();
+    }
+
     @Override
     void applyFitCenter() {
         fitCenter();

library/src/main/java/com/bumptech/glide/provider/ChildLoadProvider.java

@@ -17,7 +17,7 @@
  * @param <Z> The type of the resource that will be decoded from the data.
  * @param <R> The type of the resource that will be transcoded from the decoded resource.
  */
-public class ChildLoadProvider<A, T, Z, R> implements LoadProvider<A, T, Z, R> {
+public class ChildLoadProvider<A, T, Z, R> implements LoadProvider<A, T, Z, R>, Cloneable {
     private final LoadProvider<A, T, Z, R> parent;
 
     private ResourceDecoder<File, Z> cacheDecoder;
@@ -141,4 +141,14 @@ public ResourceTranscoder<Z, R> getTranscoder() {
             return parent.getTranscoder();
         }
     }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public ChildLoadProvider<A, T, Z, R> clone() {
+        try {
+            return (ChildLoadProvider<A, T, Z, R>) super.clone();
+        } catch (CloneNotSupportedException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }

samples/flickr/src/main/java/com/bumptech/glide/samples/flickr/FlickrPhotoGrid.java

@@ -8,7 +8,6 @@
 import android.widget.BaseAdapter;
 import android.widget.GridView;
 import android.widget.ImageView;
-
 import com.bumptech.glide.DrawableRequestBuilder;
 import com.bumptech.glide.GenericRequestBuilder;
 import com.bumptech.glide.Glide;
@@ -64,14 +63,10 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
 
         thumbnailRequest = Glide.with(this)
                 .from(Photo.class)
-                .priority(Priority.HIGH)
                 .diskCacheStrategy(DiskCacheStrategy.SOURCE)
                 .override(Api.SQUARE_THUMB_SIZE, Api.SQUARE_THUMB_SIZE);
 
-        preloadRequest = thumbnail ? thumbnailRequest : Glide.with(this)
-                .from(Photo.class)
-                .priority(Priority.HIGH)
-                .centerCrop();
+        preloadRequest = thumbnail ? thumbnailRequest.clone().priority(Priority.HIGH) : fullRequest;
 
         final View result = inflater.inflate(R.layout.flickr_photo_grid, container, false);
         grid = (GridView) result.findViewById(R.id.images);

samples/flickr/src/main/java/com/bumptech/glide/samples/flickr/FlickrPhotoList.java

@@ -11,12 +11,10 @@
 import android.widget.ImageView;
 import android.widget.ListView;
 import android.widget.TextView;
-
 import com.bumptech.glide.DrawableRequestBuilder;
 import com.bumptech.glide.GenericRequestBuilder;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.ListPreloader;
-import com.bumptech.glide.Priority;
 import com.bumptech.glide.load.engine.DiskCacheStrategy;
 import com.bumptech.glide.samples.flickr.api.Api;
 import com.bumptech.glide.samples.flickr.api.Photo;
@@ -36,7 +34,6 @@ public class FlickrPhotoList extends Fragment implements PhotoViewer {
     private ListView list;
     private DrawableRequestBuilder<Photo> fullRequest;
     private DrawableRequestBuilder<Photo> thumbRequest;
-    private DrawableRequestBuilder<Photo> preloadRequest;
 
     public static FlickrPhotoList newInstance() {
         return new FlickrPhotoList();
@@ -67,18 +64,11 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
                 .placeholder(new ColorDrawable(Color.GRAY))
                 .centerCrop();
 
-        preloadRequest = Glide.with(FlickrPhotoList.this)
-                .from(Photo.class)
-                .placeholder(new ColorDrawable(Color.GRAY))
-                .centerCrop()
-                .priority(Priority.HIGH);
-
         thumbRequest = Glide.with(FlickrPhotoList.this)
                 .from(Photo.class)
                 .diskCacheStrategy(DiskCacheStrategy.SOURCE)
                 .override(Api.SQUARE_THUMB_SIZE, Api.SQUARE_THUMB_SIZE);
 
-
         if (savedInstanceState != null) {
             int index = savedInstanceState.getInt(STATE_POSITION_INDEX);
             int offset = savedInstanceState.getInt(STATE_POSITION_OFFSET);
@@ -139,7 +129,7 @@ protected List<Photo> getItems(int start, int end) {
 
         @Override
         protected GenericRequestBuilder getRequestBuilder(Photo item) {
-            return preloadRequest
+            return fullRequest
                     .thumbnail(thumbRequest.load(item))
                     .load(item);
         }

samples/giphy/src/main/java/com/bumptech/glide/samples/giphy/MainActivity.java

@@ -12,7 +12,6 @@
 import com.bumptech.glide.GenericRequestBuilder;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.ListPreloader;
-import com.bumptech.glide.Priority;
 
 import java.io.InputStream;
 import java.util.ArrayList;
@@ -25,7 +24,7 @@ public class MainActivity extends Activity implements Api.Monitor {
     private static final String TAG = "GiphyActivity";
 
     private GifAdapter adapter;
-    private DrawableRequestBuilder<Api.GifResult> preloadRequest;
+    private DrawableRequestBuilder<Api.GifResult> fullRequest;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -44,15 +43,10 @@ protected void onCreate(Bundle savedInstanceState) {
         ListView gifList = (ListView) findViewById(R.id.gif_list);
         GiphyPreloader preloader = new GiphyPreloader(2);
 
-        DrawableRequestBuilder<Api.GifResult> fullRequest = Glide.with(this)
+        fullRequest = Glide.with(this)
                 .from(Api.GifResult.class)
                 .fitCenter();
 
-        preloadRequest = Glide.with(this)
-                .from(Api.GifResult.class)
-                .fitCenter()
-                .priority(Priority.HIGH);
-
         adapter = new GifAdapter(this, preloader, fullRequest);
         gifList.setAdapter(adapter);
         gifList.setOnScrollListener(preloader);
@@ -99,7 +93,7 @@ protected List<Api.GifResult> getItems(int start, int end) {
 
         @Override
         protected GenericRequestBuilder getRequestBuilder(Api.GifResult item) {
-            return preloadRequest.load(item);
+            return fullRequest.load(item);
         }
     }