com.android.transmart.PlaceActivity.java Source code

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/*
 * Copyright 2011 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 com.android.transmart;

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

import com.android.transmart.UI.fragments.CheckinFragment;
import com.android.transmart.UI.fragments.PlaceDetailFragment;
import com.android.transmart.UI.fragments.PlaceListFragment;
import com.android.transmart.location.LocationConstants;
import com.android.transmart.location.PlatformSpecific;
import com.android.transmart.receivers.LocationChangedReceiver;
import com.android.transmart.receivers.NewCheckinReceiver;
import com.android.transmart.receivers.PassiveLocReceiver;
import com.android.transmart.services.EclairPlacesUpdateService;
import com.android.transmart.services.PlacesUpdateService;
import com.android.transmart.utils.ILastLocationFinder;
import com.android.transmart.utils.LocUpdateRequest;
import com.android.transmart.utils.SharedPref;

/**
 * Main application Activity. Used for all application UI, including pre/post Honeycomb 
 * and tablet / phone variations using different layouts. The {@link PlaceDetailFragment},
 * {@link PlaceListFragment}, and {@link CheckinFragment} are all managed from within this Activity.
 * 
 * Because the list, detail, and checkin functionality is encapsulated within their respective
 * Fragments, this Activity serves as a container for each fragment, and the coordinator of their
 * interaction. This Activity also manages the menu, listens for checkins, and manages location updates when the 
 * Application is active.
 * 
 * TODO Update the menu and functionality to support your enhanced UI
 * TODO and service-specific features and requirements
 */
public class PlaceActivity extends FragmentActivity {

    protected static String TAG = "PlaceActivity";

    // TODO (RETO) Add "refreshing" icons when stuff is blank or refreshing.

    protected PackageManager packageManager;
    protected NotificationManager notificationManager;
    protected LocationManager locationManager;

    //  protected boolean followLocationChanges = true;
    protected SharedPreferences prefs;
    protected Editor prefsEditor;
    protected SharedPref sharedPreferenceSaver;

    protected Criteria criteria;
    protected ILastLocationFinder lastLocationFinder;
    protected LocUpdateRequest locationUpdateRequester;
    protected PendingIntent locationListenerPendingIntent;
    protected PendingIntent locationListenerPassivePendingIntent;

    protected PlaceListFragment placeListFragment;
    protected CheckinFragment checkinFragment;
    protected PlaceDetailFragment placeDetailFragment;

    protected IntentFilter newCheckinFilter;
    protected ComponentName newCheckinReceiverName;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Inflate the layout
        setContentView(R.layout.nearby);

        // Get a handle to the Fragments
        placeListFragment = (PlaceListFragment) getSupportFragmentManager().findFragmentById(R.id.list_fragment);
        checkinFragment = (CheckinFragment) getSupportFragmentManager().findFragmentById(R.id.checkin_fragment);

        // Get references to the managers
        packageManager = getPackageManager();
        notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // Get a reference to the Shared Preferences and a Shared Preference Editor.
        prefs = getSharedPreferences(LocationConstants.SHARED_PREFERENCE_FILE, Context.MODE_PRIVATE);
        prefsEditor = prefs.edit();

        // Instantiate a SharedPreferenceSaver class based on the available platform version.
        // This will be used to save shared preferences
        sharedPreferenceSaver = PlatformSpecific.getSharedPreferenceSaver(this);

        // Save that we've been run once.
        prefsEditor.putBoolean(LocationConstants.SP_KEY_RUN_ONCE, true);
        sharedPreferenceSaver.savePreferences(prefsEditor, false);

        // Specify the Criteria to use when requesting location updates while the application is Active
        criteria = new Criteria();
        if (LocationConstants.USE_GPS_WHEN_ACTIVITY_VISIBLE)
            criteria.setAccuracy(Criteria.ACCURACY_FINE);
        else
            criteria.setPowerRequirement(Criteria.POWER_LOW);

        // Setup the location update Pending Intents
        Intent activeIntent = new Intent(this, LocationChangedReceiver.class);
        locationListenerPendingIntent = PendingIntent.getBroadcast(this, 0, activeIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);

        Intent passiveIntent = new Intent(this, PassiveLocReceiver.class);
        locationListenerPassivePendingIntent = PendingIntent.getBroadcast(this, 0, passiveIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);

        // Instantiate a LastLocationFinder class.
        // This will be used to find the last known location when the application starts.
        lastLocationFinder = PlatformSpecific.getLastLocationFinder(this);
        lastLocationFinder.setChangedLocationListener(oneShotLastLocationUpdateListener);

        // Instantiate a Location Update Requester class based on the available platform version.
        // This will be used to request location updates.
        locationUpdateRequester = PlatformSpecific.getLocationUpdateRequester(locationManager);

        // Create an Intent Filter to listen for checkins
        newCheckinReceiverName = new ComponentName(this, NewCheckinReceiver.class);
        newCheckinFilter = new IntentFilter(LocationConstants.NEW_CHECKIN_ACTION);

        // Check to see if an Place ID has been specified in the launch Intent.
        // If so, we should display the details for the specified venue.
        if (getIntent().hasExtra(LocationConstants.EXTRA_KEY_ID)) {
            Intent intent = getIntent();
            String key = intent.getStringExtra(LocationConstants.EXTRA_KEY_ID);
            if (key != null) {
                selectDetail(null, key);
                // Remove the ID from the Intent (so that a resume doesn't reselect).
                intent.removeExtra(LocationConstants.EXTRA_KEY_ID);
                setIntent(intent);
            }
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        // Commit shared preference that says we're in the foreground.
        prefsEditor.putBoolean(LocationConstants.EXTRA_KEY_IN_BACKGROUND, false);
        sharedPreferenceSaver.savePreferences(prefsEditor, false);

        // Disable the Manifest Checkin Receiver when the Activity is visible.
        // The Manifest Checkin Receiver is designed to run only when the Application
        // isn't active to notify the user of pending checkins that have succeeded 
        // (usually through a Notification). 
        // When the Activity is visible we capture checkins through the checkinReceiver.
        packageManager.setComponentEnabledSetting(newCheckinReceiverName,
                PackageManager.COMPONENT_ENABLED_STATE_DISABLED, PackageManager.DONT_KILL_APP);

        // Register the checkinReceiver to listen for checkins while the Activity is visible.
        registerReceiver(checkinReceiver, newCheckinFilter);

        // Cancel notifications.
        notificationManager.cancel(LocationConstants.CHECKIN_NOTIFICATION);

        // Update the CheckinFragment with the last checkin.
        updateCheckinFragment(prefs.getString(LocationConstants.SP_KEY_LAST_CHECKIN_ID, null));

        // Get the last known location (and optionally request location updates) and
        // update the place list.
        boolean followLocationChanges = prefs.getBoolean(LocationConstants.SP_KEY_FOLLOW_LOCATION_CHANGES, true);
        getLocationAndUpdatePlaces(followLocationChanges);
    }

    @Override
    protected void onPause() {
        // Commit shared preference that says we're in the background.
        prefsEditor.putBoolean(LocationConstants.EXTRA_KEY_IN_BACKGROUND, true);
        sharedPreferenceSaver.savePreferences(prefsEditor, false);

        // Enable the Manifest Checkin Receiver when the Activity isn't active.
        // The Manifest Checkin Receiver is designed to run only when the Application
        // isn't active to notify the user of pending checkins that have succeeded 
        // (usually through a Notification). 
        packageManager.setComponentEnabledSetting(newCheckinReceiverName,
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED, PackageManager.DONT_KILL_APP);

        // Unregister the checkinReceiver when the Activity is inactive.
        unregisterReceiver(checkinReceiver);

        // Stop listening for location updates when the Activity is inactive.
        disableLocationUpdates();

        super.onPause();
    }

    /**
     * Find the last known location (using a {@link LastLocationFinder}) and updates the
     * place list accordingly.
     * @param updateWhenLocationChanges Request location updates
     */
    protected void getLocationAndUpdatePlaces(boolean updateWhenLocationChanges) {
        // This isn't directly affecting the UI, so put it on a worker thread.
        AsyncTask<Void, Void, Void> findLastLocationTask = new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... params) {
                // Find the last known location, specifying a required accuracy of within the min distance between updates
                // and a required latency of the minimum time required between updates.
                Location lastKnownLocation = lastLocationFinder.getLastBestLocation(LocationConstants.MAX_DISTANCE,
                        System.currentTimeMillis() - LocationConstants.MAX_TIME);

                // Update the place list based on the last known location within a defined radius.
                // Note that this is *not* a forced update. The Place List Service has settings to
                // determine how frequently the underlying web service should be pinged. This function  
                // is called everytime the Activity becomes active, so we don't want to flood the server
                // unless the location has changed or a minimum latency or distance has been covered.
                // TODO Modify the search radius based on user settings?
                updatePlaces(lastKnownLocation, LocationConstants.DEFAULT_RADIUS, false);
                return null;
            }
        };
        findLastLocationTask.execute();

        // If we have requested location updates, turn them on here.
        toggleUpdatesWhenLocationChanges(updateWhenLocationChanges);
    }

    /**
     * Choose if we should receive location updates. 
     * @param updateWhenLocationChanges Request location updates
     */
    protected void toggleUpdatesWhenLocationChanges(boolean updateWhenLocationChanges) {
        // Save the location update status in shared preferences
        prefsEditor.putBoolean(LocationConstants.SP_KEY_FOLLOW_LOCATION_CHANGES, updateWhenLocationChanges);
        sharedPreferenceSaver.savePreferences(prefsEditor, true);

        // Start or stop listening for location changes
        if (updateWhenLocationChanges)
            requestLocationUpdates();
        else
            disableLocationUpdates();
    }

    /**
     * Start listening for location updates.
     */
    protected void requestLocationUpdates() {
        // Normal updates while activity is visible.
        locationUpdateRequester.requestLocationUpdates(LocationConstants.MAX_TIME, LocationConstants.MAX_DISTANCE,
                criteria, locationListenerPendingIntent);

        // Passive location updates from 3rd party apps when the Activity isn't visible.
        locationUpdateRequester.requestPassiveLocationUpdates(LocationConstants.PASSIVE_MAX_TIME,
                LocationConstants.PASSIVE_MAX_DISTANCE, locationListenerPassivePendingIntent);

        // Register a receiver that listens for when the provider I'm using has been disabled. 
        IntentFilter intentFilter = new IntentFilter(LocationConstants.ACTIVE_LOCATION_UPDATE_PROVIDER_DISABLED);

        registerReceiver(locProviderDisabledReceiver, intentFilter);

        // Register a receiver that listens for when a better provider than I'm using becomes available.
        String bestProvider = locationManager.getBestProvider(criteria, false);
        String bestAvailableProvider = locationManager.getBestProvider(criteria, true);
        if (bestProvider != null && !bestProvider.equals(bestAvailableProvider)) {
            locationManager.requestLocationUpdates(bestProvider, 0, 0, bestInactiveLocationProviderListener,
                    getMainLooper());
        }
    }

    /**
     * Stop listening for location updates
     */
    protected void disableLocationUpdates() {
        unregisterReceiver(locProviderDisabledReceiver);
        locationManager.removeUpdates(locationListenerPendingIntent);
        locationManager.removeUpdates(bestInactiveLocationProviderListener);
        if (isFinishing())
            lastLocationFinder.cancel();
        if (LocationConstants.DISABLE_PASSIVE_LOCATION_WHEN_USER_EXIT && isFinishing())
            locationManager.removeUpdates(locationListenerPassivePendingIntent);
    }

    /**
     * One-off location listener that receives updates from the {@link LastLocationFinder}.
     * This is triggered where the last known location is outside the bounds of our maximum
     * distance and latency.
     */
    protected LocationListener oneShotLastLocationUpdateListener = new LocationListener() {
        public void onLocationChanged(Location l) {
            updatePlaces(l, LocationConstants.DEFAULT_RADIUS, true);
        }

        public void onProviderDisabled(String provider) {
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
        }

        public void onProviderEnabled(String provider) {
        }
    };

    /**
     * If the best Location Provider (usually GPS) is not available when we request location
     * updates, this listener will be notified if / when it becomes available. It calls 
     * requestLocationUpdates to re-register the location listeners using the better Location
     * Provider.
     */
    protected LocationListener bestInactiveLocationProviderListener = new LocationListener() {
        public void onLocationChanged(Location l) {
        }

        public void onProviderDisabled(String provider) {
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
        }

        public void onProviderEnabled(String provider) {
            // Re-register the location listeners using the better Location Provider.
            requestLocationUpdates();
        }
    };

    /**
     * If the Location Provider we're using to receive location updates is disabled while the 
     * app is running, this Receiver will be notified, allowing us to re-register our Location
     * Receivers using the best available Location Provider is still available.
     */
    protected BroadcastReceiver locProviderDisabledReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            boolean providerDisabled = !intent.getBooleanExtra(LocationManager.KEY_PROVIDER_ENABLED, false);
            // Re-register the location listeners using the best available Location Provider.
            if (providerDisabled)
                requestLocationUpdates();
        }
    };

    /**
     * Update the list of nearby places centered on the specified Location, within the specified radius.
     * This will start the {@link PlacesUpdateService} that will poll the underlying web service.
     * @param location Location
     * @param radius Radius (meters)
     * @param forceRefresh Force Refresh
     */
    protected void updatePlaces(Location location, int radius, boolean forceRefresh) {
        if (location != null) {
            Log.d(TAG, "Updating place list.");
            // Start the PlacesUpdateService. Note that we use an action rather than specifying the 
            // class directly. That's because we have different variations of the Service for different
            // platform versions.
            Intent updateServiceIntent = new Intent(this,
                    LocationConstants.SUPPORTS_ECLAIR ? EclairPlacesUpdateService.class
                            : PlacesUpdateService.class);
            //Intent updateServiceIntent = new Intent(this, PlacesUpdateService.class);
            updateServiceIntent.putExtra(LocationConstants.EXTRA_KEY_LOCATION, location);
            updateServiceIntent.putExtra(LocationConstants.EXTRA_KEY_RADIUS, radius);
            updateServiceIntent.putExtra(LocationConstants.EXTRA_KEY_FORCEREFRESH, forceRefresh);
            startService(updateServiceIntent);
        } else
            Log.d(TAG, "Updating place list for: No Previous Location Found");
    }

    /**
     * Updates (or displays) the venue detail Fragment when a venue is selected
     * (normally by clicking a place on the Place List.
     * @param reference Place Reference
     * @param id Place Identifier
     */
    public void selectDetail(String reference, String id) {
        // If the layout includes a single "main fragment container" then
        // we want to hide the List Fragment and display the Detail Fragment.
        // A back-button click should reverse this operation.
        // This is the phone-portrait mode.
        if (findViewById(R.id.main_fragment_container) != null) {
            placeDetailFragment = PlaceDetailFragment.newInstance(reference, id);
            FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction ft = fragmentManager.beginTransaction();
            ft.addToBackStack(null);
            if (checkinFragment != null)
                ft.hide(checkinFragment);
            ft.hide(placeListFragment);
            ft.replace(R.id.main_fragment_container, placeDetailFragment);
            ft.show(placeDetailFragment);
            ft.commit();
            // Otherwise the Detail Fragment is already visible and we can
            // Simply replace the previous Fragment with a new one for the
            // selected Place.
        } else {
            placeDetailFragment = PlaceDetailFragment.newInstance(reference, id);
            FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction ft = fragmentManager.beginTransaction();
            ft.disallowAddToBackStack();
            ft.replace(R.id.detail_fragment_container, placeDetailFragment);
            ft.commit();
        }
    }

    /**
     * Receiver that listens for checkins when the Activity is visible.
     * It should update the Checkin Fragment with the details for the
     * last venue checked in to.
     */
    protected BroadcastReceiver checkinReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String id = intent.getStringExtra(LocationConstants.EXTRA_KEY_ID);
            if (id != null)
                updateCheckinFragment(id);
        }
    };

    /**
     * Request that the {@link CheckinFragment} UI be updated
     * with the details corresponding to the specified ID.
     * @param id Place Identifier
     */
    public void updateCheckinFragment(String id) {
        if (id != null) {
            checkinFragment.setPlaceId(id);

            if (placeDetailFragment != null)
                placeDetailFragment.checkedIn(id);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.nearby_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle item selection
        switch (item.getItemId()) {
        case R.id.refresh:
            // Request the last known location.
            Location lastKnownLocation = lastLocationFinder.getLastBestLocation(LocationConstants.MAX_DISTANCE,
                    System.currentTimeMillis() - LocationConstants.MAX_TIME);
            // Force an update
            updatePlaces(lastKnownLocation, LocationConstants.DEFAULT_RADIUS, true);
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }
}