1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/home/SimpleCursorLoader.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,126 @@
1.4 +/*
1.5 + * This is an adapted version of Android's original CursorLoader
1.6 + * without all the ContentProvider-specific bits.
1.7 + *
1.8 + * Copyright (C) 2011 The Android Open Source Project
1.9 + *
1.10 + * Licensed under the Apache License, Version 2.0 (the "License");
1.11 + * you may not use this file except in compliance with the License.
1.12 + * You may obtain a copy of the License at
1.13 + *
1.14 + * http://www.apache.org/licenses/LICENSE-2.0
1.15 + *
1.16 + * Unless required by applicable law or agreed to in writing, software
1.17 + * distributed under the License is distributed on an "AS IS" BASIS,
1.18 + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
1.19 + * See the License for the specific language governing permissions and
1.20 + * limitations under the License.
1.21 + */
1.22 +
1.23 +package org.mozilla.gecko.home;
1.24 +
1.25 +import android.content.Context;
1.26 +import android.database.Cursor;
1.27 +import android.support.v4.content.AsyncTaskLoader;
1.28 +
1.29 +abstract class SimpleCursorLoader extends AsyncTaskLoader<Cursor> {
1.30 + final ForceLoadContentObserver mObserver;
1.31 + Cursor mCursor;
1.32 +
1.33 + public SimpleCursorLoader(Context context) {
1.34 + super(context);
1.35 + mObserver = new ForceLoadContentObserver();
1.36 + }
1.37 +
1.38 + /**
1.39 + * Loads the target cursor for this loader. This method is called
1.40 + * on a worker thread.
1.41 + */
1.42 + protected abstract Cursor loadCursor();
1.43 +
1.44 + /* Runs on a worker thread */
1.45 + @Override
1.46 + public Cursor loadInBackground() {
1.47 + Cursor cursor = loadCursor();
1.48 +
1.49 + if (cursor != null) {
1.50 + // Ensure the cursor window is filled
1.51 + cursor.getCount();
1.52 + cursor.registerContentObserver(mObserver);
1.53 + }
1.54 +
1.55 + return cursor;
1.56 + }
1.57 +
1.58 + /* Runs on the UI thread */
1.59 + @Override
1.60 + public void deliverResult(Cursor cursor) {
1.61 + if (isReset()) {
1.62 + // An async query came in while the loader is stopped
1.63 + if (cursor != null) {
1.64 + cursor.close();
1.65 + }
1.66 +
1.67 + return;
1.68 + }
1.69 +
1.70 + Cursor oldCursor = mCursor;
1.71 + mCursor = cursor;
1.72 +
1.73 + if (isStarted()) {
1.74 + super.deliverResult(cursor);
1.75 + }
1.76 +
1.77 + if (oldCursor != null && oldCursor != cursor && !oldCursor.isClosed()) {
1.78 + oldCursor.close();
1.79 + }
1.80 + }
1.81 +
1.82 + /**
1.83 + * Starts an asynchronous load of the list data. When the result is ready the callbacks
1.84 + * will be called on the UI thread. If a previous load has been completed and is still valid
1.85 + * the result may be passed to the callbacks immediately.
1.86 + *
1.87 + * Must be called from the UI thread
1.88 + */
1.89 + @Override
1.90 + protected void onStartLoading() {
1.91 + if (mCursor != null) {
1.92 + deliverResult(mCursor);
1.93 + }
1.94 +
1.95 + if (takeContentChanged() || mCursor == null) {
1.96 + forceLoad();
1.97 + }
1.98 + }
1.99 +
1.100 + /**
1.101 + * Must be called from the UI thread
1.102 + */
1.103 + @Override
1.104 + protected void onStopLoading() {
1.105 + // Attempt to cancel the current load task if possible.
1.106 + cancelLoad();
1.107 + }
1.108 +
1.109 + @Override
1.110 + public void onCanceled(Cursor cursor) {
1.111 + if (cursor != null && !cursor.isClosed()) {
1.112 + cursor.close();
1.113 + }
1.114 + }
1.115 +
1.116 + @Override
1.117 + protected void onReset() {
1.118 + super.onReset();
1.119 +
1.120 + // Ensure the loader is stopped
1.121 + onStopLoading();
1.122 +
1.123 + if (mCursor != null && !mCursor.isClosed()) {
1.124 + mCursor.close();
1.125 + }
1.126 +
1.127 + mCursor = null;
1.128 + }
1.129 +}
1.130 \ No newline at end of file
