Handle asset manager Uris.

Fixes #155.

library/src/androidTest/java/com/bumptech/glide/load/model/stream/UriLoaderTest.java

@@ -33,17 +33,25 @@ public class UriLoaderTest {
     private UriLoader loader;
     private DataFetcher<InputStream> localUriFetcher;
     private ModelLoader<GlideUrl, InputStream> urlLoader;
+    private DataFetcher<InputStream> assetUriFetcher;
 
+    @SuppressWarnings("uncecked")
     @Before
     public void setUp() throws Exception {
         urlLoader = mock(ModelLoader.class);
         localUriFetcher = mock(DataFetcher.class);
+        assetUriFetcher = mock(DataFetcher.class);
 
         loader = new UriLoader<InputStream>(Robolectric.application, urlLoader) {
             @Override
             protected DataFetcher<InputStream> getLocalUriFetcher(Context context, Uri uri) {
                 return localUriFetcher;
             }
+
+            @Override
+            protected DataFetcher<InputStream> getAssetPathFetcher(Context context, String path) {
+                return assetUriFetcher;
+            }
         };
     }
 
@@ -68,6 +76,13 @@ public class UriLoaderTest {
         assertEquals(localUriFetcher, dataFetcher);
     }
 
+    @Test
+    public void testHandlesAssetUris() {
+        Uri assetUri = Uri.parse("file:///android_asset/assetName");
+        DataFetcher fetcher = loader.getResourceFetcher(assetUri, IMAGE_SIDE, IMAGE_SIDE);
+        assertEquals(assetUriFetcher, fetcher);
+    }
+
     @Test
     public void testHandlesHttpUris() throws MalformedURLException {
         Uri httpUri = Uri.parse("http://www.google.com");

library/src/main/java/com/bumptech/glide/load/data/AssetPathFetcher.java

+package com.bumptech.glide.load.data;
+
+import android.content.res.AssetManager;
+import android.util.Log;
+import com.bumptech.glide.Priority;
+
+import java.io.IOException;
+
+/**
+ * An abstract class for obtaining data for an asset path using an {@link android.content.res.AssetManager}.
+ *
+ * @param <T> The type of data obtained from the asset path (InputStream, FileDescriptor etc).
+ */
+public abstract class AssetPathFetcher<T> implements DataFetcher<T> {
+    private static final String TAG = "AssetUriFetcher";
+    private final String assetPath;
+    private final AssetManager assetManager;
+    private T data;
+
+    public AssetPathFetcher(AssetManager assetManager, String assetPath) {
+        this.assetManager = assetManager;
+        this.assetPath = assetPath;
+    }
+
+    @Override
+    public T loadData(Priority priority) throws Exception {
+        data = loadResource(assetManager, assetPath);
+        return data;
+    }
+
+    @Override
+    public void cleanup() {
+        if (data == null) {
+            return;
+        }
+        try {
+            close(data);
+        } catch (IOException e) {
+            if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                Log.v(TAG, "Failed to close data", e);
+            }
+        }
+
+    }
+
+    @Override
+    public String getId() {
+        return assetPath;
+    }
+
+    @Override
+    public void cancel() {
+        // Do nothing.
+    }
+
+    /**
+     * Opens the given asset path with the given {@link android.content.res.AssetManager} and returns the conrete data
+     * type returned by the AssetManager.
+     *
+     * @param assetManager An AssetManager to use to open the given path.
+     * @param path A string path pointing to a resource in assets to open.
+     */
+    protected abstract T loadResource(AssetManager assetManager, String path) throws IOException;
+
+    /**
+     * Closes the concrete data type if necessary.
+     *
+     * @param data The data to close.
+     * @throws IOException
+     */
+    protected abstract void close(T data) throws IOException;
+}

library/src/main/java/com/bumptech/glide/load/data/FileDescriptorAssetPathFetcher.java

+package com.bumptech.glide.load.data;
+
+import android.content.res.AssetManager;
+import android.os.ParcelFileDescriptor;
+
+import java.io.IOException;
+
+/**
+ * Fetches an {@link android.os.ParcelFileDescriptor} for an asset path.
+ */
+public class FileDescriptorAssetPathFetcher extends AssetPathFetcher<ParcelFileDescriptor> {
+    public FileDescriptorAssetPathFetcher(AssetManager assetManager, String assetPath) {
+        super(assetManager, assetPath);
+    }
+
+    @Override
+    protected ParcelFileDescriptor loadResource(AssetManager assetManager, String path) throws IOException {
+        return assetManager.openFd(path).getParcelFileDescriptor();
+    }
+
+    @Override
+    protected void close(ParcelFileDescriptor data) throws IOException {
+        data.close();
+    }
+}

library/src/main/java/com/bumptech/glide/load/data/StreamAssetPathFetcher.java

+package com.bumptech.glide.load.data;
+
+import android.content.res.AssetManager;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Fetches an {@link java.io.InputStream} for an asset path.
+ */
+public class StreamAssetPathFetcher extends AssetPathFetcher<InputStream> {
+    public StreamAssetPathFetcher(AssetManager assetManager, String assetPath) {
+        super(assetManager, assetPath);
+    }
+
+    @Override
+    protected InputStream loadResource(AssetManager assetManager, String path) throws IOException {
+        return assetManager.open(path);
+    }
+
+    @Override
+    protected void close(InputStream data) throws IOException {
+        data.close();
+    }
+}

library/src/main/java/com/bumptech/glide/load/model/AssetUriParser.java

+package com.bumptech.glide.load.model;
+
+import android.content.ContentResolver;
+import android.net.Uri;
+
+/**
+ * A utility class for parsing Asset uris that look like: file:///android_asset/some/path/in/assets/folder.
+ */
+class AssetUriParser {
+    private static final String ASSET_PATH_SEGMENT = "android_asset";
+    private static final String ASSET_PREFIX = ContentResolver.SCHEME_FILE + ":///" + ASSET_PATH_SEGMENT + "/";
+    private static final int ASSET_PREFIX_LENGTH = ASSET_PREFIX.length();
+
+    /**
+     * Returns true if the given {@link android.net.Uri} matches the asset uri pattern.
+     */
+    public static boolean isAssetUri(Uri uri) {
+        return ContentResolver.SCHEME_FILE.equals(uri.getScheme()) && !uri.getPathSegments().isEmpty()
+                && ASSET_PATH_SEGMENT.equals(uri.getPathSegments().get(0));
+    }
+
+    /**
+     * Returns the string path for the given asset uri.
+     *
+     * <p>
+     *     Assumes the given {@link android.net.Uri} is in fact an asset uri.
+     * </p>
+     */
+    public static String toAssetPath(Uri uri) {
+        return uri.toString().substring(ASSET_PREFIX_LENGTH);
+    }
+}

library/src/main/java/com/bumptech/glide/load/model/UriLoader.java

@@ -13,6 +13,10 @@ import com.bumptech.glide.load.data.DataFetcher;
  * @param <T> The type of data that will be retrieved for {@link android.net.Uri}s.
  */
 public abstract class UriLoader<T> implements ModelLoader<Uri, T> {
+    private static final String ASSET_PATH_SEGMENT = "android_asset";
+    private static final String ASSET_PREFIX = ContentResolver.SCHEME_FILE + ":///" + ASSET_PATH_SEGMENT + "/";
+    private static final int ASSET_PREFIX_LENGTH = ASSET_PREFIX.length();
+
     private final Context context;
     private final ModelLoader<GlideUrl, T> urlLoader;
 
@@ -27,7 +31,12 @@ public abstract class UriLoader<T> implements ModelLoader<Uri, T> {
 
         DataFetcher<T> result = null;
         if (isLocalUri(scheme)) {
-            result = getLocalUriFetcher(context, model);
+            if (AssetUriParser.isAssetUri(model)) {
+                String path = AssetUriParser.toAssetPath(model);
+                result = getAssetPathFetcher(context, path);
+            } else {
+                result = getLocalUriFetcher(context, model);
+            }
         } else if (urlLoader != null && ("http".equals(scheme) || "https".equals(scheme))) {
             result = urlLoader.getResourceFetcher(new GlideUrl(model.toString()), width, height);
         }
@@ -37,6 +46,8 @@ public abstract class UriLoader<T> implements ModelLoader<Uri, T> {
 
     protected abstract DataFetcher<T> getLocalUriFetcher(Context context, Uri uri);
 
+    protected abstract DataFetcher<T> getAssetPathFetcher(Context context, String path);
+
     private static boolean isLocalUri(String scheme) {
         return ContentResolver.SCHEME_FILE.equals(scheme)
                 || ContentResolver.SCHEME_CONTENT.equals(scheme)

library/src/main/java/com/bumptech/glide/load/model/file_descriptor/FileDescriptorUriLoader.java

@@ -4,13 +4,14 @@ import android.content.Context;
 import android.net.Uri;
 import android.os.ParcelFileDescriptor;
 import com.bumptech.glide.Glide;
+import com.bumptech.glide.load.data.DataFetcher;
+import com.bumptech.glide.load.data.FileDescriptorAssetPathFetcher;
+import com.bumptech.glide.load.data.FileDescriptorLocalUriFetcher;
 import com.bumptech.glide.load.model.GenericLoaderFactory;
 import com.bumptech.glide.load.model.GlideUrl;
 import com.bumptech.glide.load.model.ModelLoader;
 import com.bumptech.glide.load.model.ModelLoaderFactory;
 import com.bumptech.glide.load.model.UriLoader;
-import com.bumptech.glide.load.data.DataFetcher;
-import com.bumptech.glide.load.data.FileDescriptorLocalUriFetcher;
 
 /**
  * A {@link ModelLoader} For translating {@link Uri} models for local uris into {@link ParcelFileDescriptor} data.
@@ -45,4 +46,9 @@ public class FileDescriptorUriLoader extends UriLoader<ParcelFileDescriptor> imp
     protected DataFetcher<ParcelFileDescriptor> getLocalUriFetcher(Context context, Uri uri) {
         return new FileDescriptorLocalUriFetcher(context, uri);
     }
+
+    @Override
+    protected DataFetcher<ParcelFileDescriptor> getAssetPathFetcher(Context context, String assetPath) {
+        return new FileDescriptorAssetPathFetcher(context.getApplicationContext().getAssets(), assetPath);
+    }
 }

library/src/main/java/com/bumptech/glide/load/model/stream/StreamUriLoader.java

@@ -3,13 +3,14 @@ package com.bumptech.glide.load.model.stream;
 import android.content.Context;
 import android.net.Uri;
 import com.bumptech.glide.Glide;
+import com.bumptech.glide.load.data.DataFetcher;
+import com.bumptech.glide.load.data.StreamAssetPathFetcher;
+import com.bumptech.glide.load.data.StreamLocalUriFetcher;
 import com.bumptech.glide.load.model.GenericLoaderFactory;
 import com.bumptech.glide.load.model.GlideUrl;
 import com.bumptech.glide.load.model.ModelLoader;
 import com.bumptech.glide.load.model.ModelLoaderFactory;
 import com.bumptech.glide.load.model.UriLoader;
-import com.bumptech.glide.load.data.DataFetcher;
-import com.bumptech.glide.load.data.StreamLocalUriFetcher;
 
 import java.io.InputStream;
 
@@ -48,4 +49,9 @@ public class StreamUriLoader extends UriLoader<InputStream> implements StreamMod
     protected DataFetcher<InputStream> getLocalUriFetcher(Context context, Uri uri) {
         return new StreamLocalUriFetcher(context, uri);
     }
+
+    @Override
+    protected DataFetcher<InputStream> getAssetPathFetcher(Context context, String assetPath) {
+        return new StreamAssetPathFetcher(context.getApplicationContext().getAssets(), assetPath);
+    }
 }