Initial checkin of AOSP Messaging app.

b/23110861

Change-Id: I9aa980d7569247d6b2ca78f5dcb4502e1eaadb8a

src/com/android/messaging/datamodel/media/BindableMediaRequest.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.messaging.datamodel.media;
+
+import com.android.messaging.datamodel.binding.BindableOnceData;
+import com.android.messaging.datamodel.media.MediaResourceManager.MediaResourceLoadListener;
+
+/**
+ * The {@link MediaRequest} interface is threading-model-blind, allowing the implementations to
+ * be processed synchronously or asynchronously.
+ * This is a {@link MediaRequest} implementation that includes functionalities such as binding and
+ * event callbacks for multi-threaded media request processing.
+ */
+public abstract class BindableMediaRequest<T extends RefCountedMediaResource>
+        extends BindableOnceData
+        implements MediaRequest<T>, MediaResourceLoadListener<T> {
+    private MediaResourceLoadListener<T> mListener;
+
+    public BindableMediaRequest(final MediaResourceLoadListener<T> listener) {
+        mListener = listener;
+    }
+
+    /**
+     * Delegates the media resource callback to the listener. Performs binding check to ensure
+     * the listener is still bound to this request.
+     */
+    @Override
+    public void onMediaResourceLoaded(final MediaRequest<T> request, final T resource,
+            final boolean cached) {
+        if (isBound() && mListener != null) {
+            mListener.onMediaResourceLoaded(request, resource, cached);
+        }
+    }
+
+    /**
+     * Delegates the media resource callback to the listener. Performs binding check to ensure
+     * the listener is still bound to this request.
+     */
+    @Override
+    public void onMediaResourceLoadError(final MediaRequest<T> request, final Exception exception) {
+        if (isBound() && mListener != null) {
+            mListener.onMediaResourceLoadError(request, exception);
+        }
+    }
+
+    @Override
+    protected void unregisterListeners() {
+        mListener = null;
+    }
+}