ac.robinson.bettertogether.api.messaging.PluginConnectionDelegate.java Source code

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Here is the source code for ac.robinson.bettertogether.api.messaging.PluginConnectionDelegate.java

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/*
 * Copyright (C) 2017 The Better Together Toolkit
 *
 * 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 ac.robinson.bettertogether.api.messaging;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.content.LocalBroadcastManager;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

/**
 * For more direct integration with your app, use this connection helper class to send and receive messages. You must first
 * initialise, providing a {@link PluginMessageCallback} for message handling, then call {@link #onCreate(Bundle)} to register
 * the helper, {@link #onSaveInstanceState(Bundle)} to handle screen rotation, and {@link #onDestroy()} to clean up.
 * <p>
 * See {@link ac.robinson.bettertogether.api.BasePluginActivity} for a reference implementation.
 */
public class PluginConnectionDelegate {

    private final Context mContext;
    private final PluginMessageCallback mMessageCallback;

    public interface PluginMessageCallback {
        void onMessageReceived(@NonNull BroadcastMessage message);
    }

    public PluginConnectionDelegate(@NonNull Context context, @NonNull PluginMessageCallback callback) {
        mContext = context;
        mMessageCallback = callback;
    }

    public void onCreate(@SuppressWarnings("UnusedParameters") @Nullable Bundle savedInstanceState) {
        // note: savedInstanceState is passed for potential future usage; unused for now
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(PluginIntent.ACTION_STOP_PLUGIN);
        intentFilter.addAction(PluginIntent.ACTION_MESSAGE_RECEIVED);
        LocalBroadcastManager.getInstance(mContext).registerReceiver(mLocalBroadcastReceiver, intentFilter);
    }

    @SuppressWarnings("EmptyMethod")
    public void onSaveInstanceState(@SuppressWarnings("UnusedParameters") Bundle outState) {
        // note: saved state is passed for potential future usage; unused for now
    }

    public void onDestroy() {
        LocalBroadcastManager.getInstance(mContext).unregisterReceiver(mLocalBroadcastReceiver);
    }

    @SuppressFBWarnings("ANDROID_BROADCAST")
    public void sendMessage(@NonNull BroadcastMessage message) {
        Intent intent = new Intent();
        intent.setAction(PluginIntent.ACTION_MESSAGE_RECEIVED);
        intent.setClassName(PluginIntent.HOST_PACKAGE, PluginIntent.MESSAGE_RECEIVER);
        intent.putExtra(PluginIntent.KEY_BROADCAST_MESSAGE, message);

        // note: source is only necessary for internal plugins - it may be removed at a later date
        intent.putExtra(PluginIntent.EXTRA_SOURCE, PluginMessageCallback.class.getPackage().toString());

        mContext.sendBroadcast(intent);
    }

    private final BroadcastReceiver mLocalBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            // note: source is only necessary for internal plugins - it may be removed at a later date
            if (PluginMessageCallback.class.getPackage().toString()
                    .equals(intent.getStringExtra(PluginIntent.EXTRA_SOURCE))) {
                return; // ignore this message - its source is us
            }

            switch (intent.getAction()) {
            case PluginIntent.ACTION_STOP_PLUGIN:
                if (mContext instanceof Activity) {
                    ((Activity) mContext).finish();
                }
                break;

            case PluginIntent.ACTION_MESSAGE_RECEIVED:
                BroadcastMessage message = (BroadcastMessage) intent
                        .getSerializableExtra(PluginIntent.KEY_BROADCAST_MESSAGE);
                mMessageCallback.onMessageReceived(message);
                break;

            default:
                break;
            }
        }
    };
}