Refactor to coupler/presenter pattern. Moved framework classes to correct packages

Bug:2579760
Change-Id: Ia0c475e55830aa2d8b13cdb2685fc0981b6f6ade
diff --git a/src/android/app/patterns/Loader.java b/src/android/app/patterns/Loader.java
new file mode 100644
index 0000000..dfc35e9
--- /dev/null
+++ b/src/android/app/patterns/Loader.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * 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 android.app.patterns;
+
+import android.content.Context;
+import android.database.ContentObserver;
+import android.os.Handler;
+
+public abstract class Loader<D> {
+    private int mId;
+    private OnLoadCompleteListener<D> mListener;
+    private Context mContext;
+
+    protected final class ForceLoadContentObserver extends ContentObserver {
+        public ForceLoadContentObserver() {
+            super(new Handler());
+        }
+
+        @Override
+        public boolean deliverSelfNotifications() {
+            return true;
+        }
+
+        @Override
+        public void onChange(boolean selfChange) {
+            forceLoad();
+        }
+    }
+
+    public interface OnLoadCompleteListener<D> {
+        /**
+         * Called on the thread that created the Loader when the load is complete.
+         *
+         * @param loader the loader that completed the load
+         * @param data the result of the load
+         */
+        public void onLoadComplete(Loader loader, D data);
+    }
+
+    /**
+     * Sends the result of the load to the register listener.
+     *
+     * @param data the result of the load
+     */
+    protected void deliverResult(D data) {
+        if (mListener != null) {
+            mListener.onLoadComplete(this, data);
+        }
+    }
+
+    /**
+     * Stores away the application context associated with context. Since Loaders can be used
+     * across multiple activities it's dangerous to store the context directly.
+     *
+     * @param context used to retrieve the application context.
+     */
+    public Loader(Context context) {
+        mContext = context.getApplicationContext();
+    }
+
+    /**
+     * @return an application context retrieved from the Context passed to the constructor.
+     */
+    public Context getContext() {
+        return mContext;
+    }
+
+    /**
+     * @return the ID of this loader
+     */
+    public int getId() {
+        return mId;
+    }
+
+    /**
+     * Registers a class that will receive callbacks when a load is complete. The callbacks will
+     * be called on the UI thread so it's safe to pass the results to widgets.
+     * 
+     * Must be called from the UI thread
+     */
+    public void registerListener(int id, OnLoadCompleteListener<D> listener) {
+        if (mListener != null) {
+            throw new IllegalStateException("There is already a listener registered");
+        }
+        mListener = listener;
+        mId = id;
+    }
+
+    /**
+     * Must be called from the UI thread
+     */
+    public void unregisterListener(OnLoadCompleteListener<D> listener) {
+        if (mListener == null) {
+            throw new IllegalStateException("No listener register");
+        }
+        if (mListener != listener) {
+            throw new IllegalArgumentException("Attempting to unregister the wrong listener");
+        }
+        mListener = null;
+    }
+
+    /**
+     * Starts an asynchronous load of the contacts list data. When the result is ready the callbacks
+     * will be called on the UI thread. If a previous load has been completed and is still valid
+     * the result may be passed to the callbacks immediately. The loader will monitor the source of
+     * the data set and may deliver future callbacks if the source changes. Calling
+     * {@link #stopLoading} will stop the delivery of callbacks. 
+     *
+     * Must be called from the UI thread
+     */
+    public abstract void startLoading();
+
+    /**
+     * Force an asynchronous load. Unlike {@link #startLoading()} this will ignore a previously
+     * loaded data set and load a new one.
+     */
+    public abstract void forceLoad();
+
+    /**
+     * Stops delivery of updates until the next time {@link #startLoading()} is called
+     *
+     * Must be called from the UI thread
+     */
+    public abstract void stopLoading();
+
+    /**
+     * Destroys the loader and frees it's resources, making it unusable.
+     *
+     * Must be called from the UI thread
+     */
+    public abstract void destroy();
+}
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