Notify exception listener rather than crash when no available handlers.

Author: JakeWharton

picasso/src/main/java/com/squareup/picasso/BitmapHunter.java

@@ -54,6 +54,16 @@ class BitmapHunter implements Runnable {
 
   private static final AtomicInteger SEQUENCE_GENERATOR = new AtomicInteger();
 
+  private static final RequestHandler ERRORING_HANDLER = new RequestHandler() {
+    @Override public boolean canHandleRequest(Request data) {
+      return true;
+    }
+
+    @Override public Result load(Request data) throws IOException {
+      throw new IllegalStateException("Unrecognized type of request: " + data);
+    }
+  };
+
   final int sequence;
   final Picasso picasso;
   final Dispatcher dispatcher;
@@ -331,17 +341,18 @@ static void updateThreadName(Request data) {
   static BitmapHunter forRequest(Picasso picasso, Dispatcher dispatcher,
       Cache cache, Stats stats, Action action) {
     Request request = action.getRequest();
-
     List<RequestHandler> requestHandlers = picasso.getRequestHandlers();
-    final int count = requestHandlers.size();
-    for (int i = 0; i < count; i++) {
+
+    // Index-based loop to avoid allocating an iterator.
+    //noinspection ForLoopReplaceableByForEach
+    for (int i = 0, count = requestHandlers.size(); i < count; i++) {
       RequestHandler requestHandler = requestHandlers.get(i);
       if (requestHandler.canHandleRequest(request)) {
         return new BitmapHunter(picasso, dispatcher, cache, stats, action, requestHandler);
       }
     }
 
-    throw new IllegalStateException("Unrecognized type of request: " + request);
+    return new BitmapHunter(picasso, dispatcher, cache, stats, action, ERRORING_HANDLER);
   }
 
   static Bitmap applyCustomTransformations(List<Transformation> transformations, Bitmap result) {

picasso/src/main/java/com/squareup/picasso/Picasso.java

@@ -162,8 +162,11 @@ public enum Priority {
     this.listener = listener;
     this.requestTransformer = requestTransformer;
 
-    final int extraCount = (extraRequestHandlers != null ? extraRequestHandlers.size() : 0);
-    final List<RequestHandler> allRequestHandlers = new ArrayList<RequestHandler>(7 + extraCount);
+    int builtInHandlers = 7; // Adjust this as internal handlers are added or removed.
+    int extraCount = (extraRequestHandlers != null ? extraRequestHandlers.size() : 0);
+    List<RequestHandler> allRequestHandlers =
+        new ArrayList<RequestHandler>(builtInHandlers + extraCount);
+
     // ResourceRequestHandler needs to be the first in the list to avoid
     // forcing other RequestHandlers to perform null checks on request.uri
     // to cover the (request.resourceId != 0) case.

picasso/src/test/java/com/squareup/picasso/BitmapHunterTest.java

@@ -37,8 +37,8 @@
 import static com.squareup.picasso.BitmapHunter.forRequest;
 import static com.squareup.picasso.BitmapHunter.transformResult;
 import static com.squareup.picasso.Picasso.LoadedFrom.MEMORY;
-import static com.squareup.picasso.Picasso.Priority.LOW;
 import static com.squareup.picasso.Picasso.Priority.HIGH;
+import static com.squareup.picasso.Picasso.Priority.LOW;
 import static com.squareup.picasso.Picasso.Priority.NORMAL;
 import static com.squareup.picasso.TestUtils.ASSET_KEY_1;
 import static com.squareup.picasso.TestUtils.ASSET_URI_1;
@@ -47,6 +47,8 @@
 import static com.squareup.picasso.TestUtils.CONTACT_URI_1;
 import static com.squareup.picasso.TestUtils.CONTENT_1_URL;
 import static com.squareup.picasso.TestUtils.CONTENT_KEY_1;
+import static com.squareup.picasso.TestUtils.CUSTOM_URI;
+import static com.squareup.picasso.TestUtils.CUSTOM_URI_KEY;
 import static com.squareup.picasso.TestUtils.FILE_1_URL;
 import static com.squareup.picasso.TestUtils.FILE_KEY_1;
 import static com.squareup.picasso.TestUtils.MEDIA_STORE_CONTENT_1_URL;
@@ -59,10 +61,7 @@
 import static com.squareup.picasso.TestUtils.RESOURCE_TYPE_URI_KEY;
 import static com.squareup.picasso.TestUtils.URI_1;
 import static com.squareup.picasso.TestUtils.URI_KEY_1;
-import static com.squareup.picasso.TestUtils.CUSTOM_URI;
-import static com.squareup.picasso.TestUtils.CUSTOM_URI_KEY;
 import static com.squareup.picasso.TestUtils.mockAction;
-import static com.squareup.picasso.TestUtils.mockHunter;
 import static com.squareup.picasso.TestUtils.mockImageViewTarget;
 import static com.squareup.picasso.TestUtils.mockPicasso;
 import static org.fest.assertions.api.ANDROID.assertThat;
@@ -171,8 +170,9 @@ public class BitmapHunterTest {
 
   @Test public void huntUnrecognizedUri() throws Exception {
     Action action = mockAction(CUSTOM_URI_KEY, CUSTOM_URI);
+    BitmapHunter hunder = forRequest(picasso, dispatcher, cache, stats, action);
     try {
-      forRequest(picasso, dispatcher, cache, stats, action);
+      hunder.hunt();
       fail("Unrecognized URI should throw exception.");
     } catch (IllegalStateException expected) {
     }