/*
Copyright © 2013-2014, Silent Circle, LLC.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Any redistribution, use, or modification is done solely for personal
benefit and not for any commercial purpose or for monetary gain
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name Silent Circle nor the names of its contributors may
be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL SILENT CIRCLE, LLC BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This implementation is edited version of original Android sources.
*/
/*
* Copyright (C) 2010 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.silentcircle.contacts.utils;
import android.content.Context;
import android.support.v4.content.Loader;
/**
* Extends the standard class to provide the cancellation functions and listener.
*
* @param <D> The result returned when the load is complete
*/
public class ScLoader<D> extends Loader<D> {
OnLoadCanceledListener<D> mOnLoadCanceledListener;
/**
* Interface that is implemented to discover when a Loader has been canceled
* before it finished loading its data. You do not normally need to implement
* this yourself; it is used in the implementation of {@link android.app.LoaderManager}
* to find out when a Loader it is managing has been canceled so that it
* can schedule the next Loader. This interface should only be used if a
* Loader is not being used in conjunction with LoaderManager.
*/
public interface OnLoadCanceledListener<D> {
/**
* Called on the thread that created the Loader when the load is canceled.
*
* @param loader the loader that canceled the load
*/
public void onLoadCanceled(ScLoader<D> loader);
}
/**
* Stores away the application context associated with context.
* Since Loaders can be used across multiple activities it's dangerous to
* store the context directly; always use {@link #getContext()} to retrieve
* the Loader's Context, don't use the constructor argument directly.
* The Context returned by {@link #getContext} is safe to use across
* Activity instances.
*
* @param context used to retrieve the application context.
*/
public ScLoader(Context context) {
super(context);
}
/**
* Informs the registered {@link OnLoadCanceledListener} that the load has been canceled.
* Should only be called by subclasses.
*
* Must be called from the process's main thread.
*/
public void deliverCancellation() {
if (mOnLoadCanceledListener != null) {
mOnLoadCanceledListener.onLoadCanceled(this);
}
}
/**
* Registers a listener that will receive callbacks when a load is canceled.
* The callback will be called on the process's main thread so it's safe to
* pass the results to widgets.
*
* Must be called from the process's main thread.
*
* @param listener The listener to register.
*/
public void registerOnLoadCanceledListener(OnLoadCanceledListener<D> listener) {
if (mOnLoadCanceledListener != null) {
throw new IllegalStateException("There is already a listener registered");
}
mOnLoadCanceledListener = listener;
}
/**
* Unregisters a listener that was previously added with
* {@link #registerOnLoadCanceledListener}.
*
* Must be called from the process's main thread.
*
* @param listener The listener to unregister.
*/
public void unregisterOnLoadCanceledListener(OnLoadCanceledListener<D> listener) {
if (mOnLoadCanceledListener == null) {
throw new IllegalStateException("No listener register");
}
if (mOnLoadCanceledListener != listener) {
throw new IllegalArgumentException("Attempting to unregister the wrong listener");
}
mOnLoadCanceledListener = null;
}
/**
* Attempt to cancel the current load task.
* Must be called on the main thread of the process.
*
* <p>Cancellation is not an immediate operation, since the load is performed
* in a background thread. If there is currently a load in progress, this
* method requests that the load be canceled, and notes this is the case;
* once the background thread has completed its work its remaining state
* will be cleared. If another load request comes in during this time,
* it will be held until the canceled load is complete.
*
* @return Returns <tt>false</tt> if the task could not be canceled,
* typically because it has already completed normally, or
* because {@link #startLoading()} hasn't been called; returns
* <tt>true</tt> otherwise. When <tt>true</tt> is returned, the task
* is still running and the {@link OnLoadCanceledListener} will be called
* when the task completes.
*/
public boolean cancelLoad() {
return onCancelLoad();
}
/**
* Subclasses must implement this to take care of requests to {@link #cancelLoad()}.
* This will always be called from the process's main thread.
*
* @return Returns <tt>false</tt> if the task could not be canceled,
* typically because it has already completed normally, or
* because {@link #startLoading()} hasn't been called; returns
* <tt>true</tt> otherwise. When <tt>true</tt> is returned, the task
* is still running and the {@link OnLoadCanceledListener} will be called
* when the task completes.
*/
protected boolean onCancelLoad() {
return false;
}
}