1 files changed, 68 insertions, 0 deletions
diff --git a/library/src/main/java/com/bumptech/glide/load/resource/FileToStreamDecoder.java b/library/src/main/java/com/bumptech/glide/load/resource/FileToStreamDecoder.java
new file mode 100644
index 00000000..907c7746
--- /dev/null
+++ b/library/src/main/java/com/bumptech/glide/load/resource/FileToStreamDecoder.java
@@ -0,0 +1,68 @@
+package com.bumptech.glide.load.resource;
+
+import com.bumptech.glide.load.ResourceDecoder;
+import com.bumptech.glide.load.engine.Resource;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * A decoder that wraps an InputStream decoder to allow it to decode from a file.
+ * @param <T> The type of resource that the wrapped InputStream decoder decodes.
+ */
+public class FileToStreamDecoder<T> implements ResourceDecoder<File, T> {
+    private static final FileOpener DEFAULT_FILE_OPENER = new DefaultFileOpener();
+
+    private ResourceDecoder<InputStream, T> streamDecoder;
+    private final FileOpener fileOpener;
+
+    public FileToStreamDecoder(ResourceDecoder<InputStream, T> streamDecoder) {
+        this(streamDecoder, DEFAULT_FILE_OPENER);
+    }
+
+    // Exposed for testing.
+    FileToStreamDecoder(ResourceDecoder<InputStream, T> streamDecoder, FileOpener fileOpener) {
+        this.streamDecoder = streamDecoder;
+        this.fileOpener = fileOpener;
+    }
+
+    @Override
+    public Resource<T> decode(File source, int width, int height) throws IOException {
+        InputStream is = null;
+        Resource<T> result = null;
+        try {
+            is = fileOpener.open(source);
+            result = streamDecoder.decode(is, width, height);
+        } finally {
+            if (is != null) {
+                try {
+                    is.close();
+                } catch (IOException e) {
+                    // Do nothing.
+                }
+            }
+
+        }
+        return result;
+    }
+
+    @Override
+    public String getId() {
+        return "";
+    }
+
+    interface FileOpener {
+        public InputStream open(File file) throws FileNotFoundException;
+    }
+
+    private static class DefaultFileOpener implements FileOpener {
+
+        @Override
+        public InputStream open(File file) throws FileNotFoundException {
+            return new FileInputStream(file);
+        }
+    }
+}