Added Android Beam support to allow sharing sessions using NFC, in all

activities showing sessions.

AndroidManifest.xml

@@ -9,6 +9,7 @@
         android:targetSdkVersion="19" />
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.NFC" />
 
     <!-- Permissions required for alarms -->
     <uses-permission android:name="android.permission.WAKE_LOCK" />
@@ -46,7 +47,15 @@
                 android:value=".activities.MainActivity" />
         </activity>
         <activity android:name=".activities.TrackScheduleEventActivity" />
-        <activity android:name=".activities.EventDetailsActivity" />
+        <activity android:name=".activities.EventDetailsActivity" >
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data android:mimeType="application/be.digitalia.fosdem" />
+            </intent-filter>
+        </activity>
         <activity android:name=".activities.PersonInfoActivity" />
         <activity
             android:name=".activities.SearchResultActivity"

res/values/strings.xml

@@ -51,6 +51,7 @@
 
     <!-- Errors -->
     <string name="error_title">Error</string>
+    <string name="event_not_found_error">Unable to load the session details.\nMake sure the database has been updated to the latest version.</string>
     <string name="schedule_loading_error">An error occurred while updating the schedule. Please try again later.</string>
     <string name="search_length_error">The minimum search text length is 3 chars.</string>
 

src/be/digitalia/fosdem/activities/EventDetailsActivity.java

@@ -5,17 +5,20 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
-import android.support.v4.app.TaskStackBuilder;
 import android.support.v4.app.LoaderManager.LoaderCallbacks;
 import android.support.v4.app.NavUtils;
+import android.support.v4.app.TaskStackBuilder;
 import android.support.v4.content.Loader;
 import android.support.v7.app.ActionBarActivity;
 import android.view.MenuItem;
+import android.widget.Toast;
 import be.digitalia.fosdem.R;
 import be.digitalia.fosdem.db.DatabaseManager;
 import be.digitalia.fosdem.fragments.EventDetailsFragment;
 import be.digitalia.fosdem.loaders.LocalCacheLoader;
 import be.digitalia.fosdem.model.Event;
+import be.digitalia.fosdem.utils.NfcUtils;
+import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 
 /**
  * Displays a single event passed either as a complete Parcelable object in extras or as an id in data.
@@ -23,7 +26,7 @@ import be.digitalia.fosdem.model.Event;
  * @author Christophe Beyls
  * 
  */
-public class EventDetailsActivity extends ActionBarActivity implements LoaderCallbacks<Event> {
+public class EventDetailsActivity extends ActionBarActivity implements LoaderCallbacks<Event>, CreateNfcAppDataCallback {
 
 	public static final String EXTRA_EVENT = "event";
 
@@ -38,11 +41,11 @@ public class EventDetailsActivity extends ActionBarActivity implements LoaderCal
 
 		getSupportActionBar().setTitle(R.string.event_details);
 
-		event = getIntent().getParcelableExtra(EXTRA_EVENT);
+		Event event = getIntent().getParcelableExtra(EXTRA_EVENT);
 
 		if (event != null) {
 			// The event has been passed as parameter, it can be displayed immediately
-			initActionBar();
+			initEvent(event);
 			if (savedInstanceState == null) {
 				Fragment f = EventDetailsFragment.newInstance(event);
 				getSupportFragmentManager().beginTransaction().add(R.id.content, f).commit();
@@ -54,11 +57,14 @@ public class EventDetailsActivity extends ActionBarActivity implements LoaderCal
 	}
 
 	/**
-	 * Initialize event-related ActionBar configuration after the event has been loaded.
+	 * Initialize event-related configuration after the event has been loaded.
 	 */
-	private void initActionBar() {
+	private void initEvent(Event event) {
+		this.event = event;
 		// Enable up navigation only after getting the event details
 		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+		// Enable Android Beam
+		NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
 	}
 
 	@Override
@@ -83,6 +89,11 @@ public class EventDetailsActivity extends ActionBarActivity implements LoaderCal
 		return false;
 	}
 
+	@Override
+	public byte[] createNfcAppData() {
+		return String.valueOf(event.getId()).getBytes();
+	}
+
 	private static class EventLoader extends LocalCacheLoader<Event> {
 
 		private final long eventId;
@@ -100,23 +111,32 @@ public class EventDetailsActivity extends ActionBarActivity implements LoaderCal
 
 	@Override
 	public Loader<Event> onCreateLoader(int id, Bundle args) {
-		return new EventLoader(this, Long.parseLong(getIntent().getDataString()));
+		Intent intent = getIntent();
+		String eventIdString;
+		if (NfcUtils.hasAppData(intent)) {
+			// NFC intent
+			eventIdString = new String(NfcUtils.extractAppData(intent));
+		} else {
+			// Normal in-app intent
+			eventIdString = intent.getDataString();
+		}
+		return new EventLoader(this, Long.parseLong(eventIdString));
 	}
 
 	@Override
 	public void onLoadFinished(Loader<Event> loader, Event data) {
 		if (data == null) {
 			// Event not found, quit
+			Toast.makeText(this, getString(R.string.event_not_found_error), Toast.LENGTH_LONG).show();
 			finish();
 			return;
 		}
 
-		event = data;
-		initActionBar();
+		initEvent(data);
 
 		FragmentManager fm = getSupportFragmentManager();
 		if (fm.findFragmentById(R.id.content) == null) {
-			Fragment f = EventDetailsFragment.newInstance(event);
+			Fragment f = EventDetailsFragment.newInstance(data);
 			fm.beginTransaction().add(R.id.content, f).commitAllowingStateLoss();
 		}
 	}

src/be/digitalia/fosdem/activities/TrackScheduleActivity.java

@@ -16,6 +16,8 @@ import be.digitalia.fosdem.fragments.TrackScheduleListFragment;
 import be.digitalia.fosdem.model.Day;
 import be.digitalia.fosdem.model.Event;
 import be.digitalia.fosdem.model.Track;
+import be.digitalia.fosdem.utils.NfcUtils;
+import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 
 /**
  * Track Schedule container, works in both single pane and dual pane modes.
@@ -23,7 +25,7 @@ import be.digitalia.fosdem.model.Track;
  * @author Christophe Beyls
  * 
  */
-public class TrackScheduleActivity extends ActionBarActivity implements TrackScheduleListFragment.Callbacks {
+public class TrackScheduleActivity extends ActionBarActivity implements TrackScheduleListFragment.Callbacks, CreateNfcAppDataCallback {
 
 	public static final String EXTRA_DAY = "day";
 	public static final String EXTRA_TRACK = "track";
@@ -33,6 +35,7 @@ public class TrackScheduleActivity extends ActionBarActivity implements TrackSch
 	private Day day;
 	private Track track;
 	private boolean isTabletLandscape;
+	private Event lastSelectedEvent;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
@@ -72,6 +75,19 @@ public class TrackScheduleActivity extends ActionBarActivity implements TrackSch
 			}
 		}
 		trackScheduleListFragment.setSelectionEnabled(isTabletLandscape);
+
+		if (isTabletLandscape) {
+			// Enable Android Beam
+			NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
+		}
+	}
+
+	@Override
+	public byte[] createNfcAppData() {
+		if (lastSelectedEvent == null) {
+			return null;
+		}
+		return String.valueOf(lastSelectedEvent.getId()).getBytes();
 	}
 
 	@Override
@@ -88,6 +104,8 @@ public class TrackScheduleActivity extends ActionBarActivity implements TrackSch
 	public void onEventSelected(int position, Event event) {
 		if (isTabletLandscape) {
 			// Tablet mode: Show event details in the right pane fragment
+			lastSelectedEvent = event;
+
 			FragmentManager fm = getSupportFragmentManager();
 			EventDetailsFragment currentFragment = (EventDetailsFragment) fm.findFragmentById(R.id.event);
 			if (event != null) {

src/be/digitalia/fosdem/activities/TrackScheduleEventActivity.java

@@ -2,6 +2,7 @@ package be.digitalia.fosdem.activities;
 
 import android.database.Cursor;
 import android.os.Bundle;
+import android.provider.BaseColumns;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentStatePagerAdapter;
@@ -18,6 +19,8 @@ import be.digitalia.fosdem.fragments.EventDetailsFragment;
 import be.digitalia.fosdem.loaders.TrackScheduleLoader;
 import be.digitalia.fosdem.model.Day;
 import be.digitalia.fosdem.model.Track;
+import be.digitalia.fosdem.utils.NfcUtils;
+import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 
 import com.viewpagerindicator.PageIndicator;
 
@@ -27,7 +30,7 @@ import com.viewpagerindicator.PageIndicator;
  * @author Christophe Beyls
  * 
  */
-public class TrackScheduleEventActivity extends ActionBarActivity implements LoaderCallbacks<Cursor> {
+public class TrackScheduleEventActivity extends ActionBarActivity implements LoaderCallbacks<Cursor>, CreateNfcAppDataCallback {
 
 	public static final String EXTRA_DAY = "day";
 	public static final String EXTRA_TRACK = "track";
@@ -69,6 +72,9 @@ public class TrackScheduleEventActivity extends ActionBarActivity implements Loa
 		bar.setTitle(R.string.event_details);
 		bar.setSubtitle(track.getName());
 
+		// Enable Android Beam
+		NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
+
 		setCustomProgressVisibility(true);
 		getSupportLoaderManager().initLoader(EVENTS_LOADER_ID, null, this);
 	}
@@ -77,6 +83,18 @@ public class TrackScheduleEventActivity extends ActionBarActivity implements Loa
 		progress.setVisibility(isVisible ? View.VISIBLE : View.GONE);
 	}
 
+	@Override
+	public byte[] createNfcAppData() {
+		if (adapter.getCount() == 0) {
+			return null;
+		}
+		long eventId = adapter.getItemId(pager.getCurrentItem());
+		if (eventId == -1L) {
+			return null;
+		}
+		return String.valueOf(eventId).getBytes();
+	}
+
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		switch (item.getItemId()) {
@@ -145,5 +163,12 @@ public class TrackScheduleEventActivity extends ActionBarActivity implements Loa
 			cursor.moveToPosition(position);
 			return EventDetailsFragment.newInstance(DatabaseManager.toEvent(cursor));
 		}
+
+		public long getItemId(int position) {
+			if (!cursor.moveToPosition(position)) {
+				return -1L;
+			}
+			return cursor.getLong(cursor.getColumnIndexOrThrow(BaseColumns._ID));
+		}
 	}
 }

src/be/digitalia/fosdem/utils/NfcReceiverUtils.java

@@ -0,0 +1,28 @@
+package be.digitalia.fosdem.utils;
+
+import android.annotation.TargetApi;
+import android.content.Intent;
+import android.nfc.NdefMessage;
+import android.nfc.NfcAdapter;
+import android.os.Build;
+import android.os.Parcelable;
+
+/**
+ * NFC helper methods for receiving data sent by NfcSenderUtils. This class wraps API 10+ code.
+ * 
+ * @author Christophe Beyls
+ * 
+ */
+@TargetApi(Build.VERSION_CODES.GINGERBREAD_MR1)
+class NfcReceiverUtils {
+
+	public static boolean hasAppData(Intent intent) {
+		return NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction());
+	}
+
+	public static byte[] extractAppData(Intent intent) {
+		Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
+		NdefMessage msg = (NdefMessage) rawMsgs[0];
+		return msg.getRecords()[0].getPayload();
+	}
+}

src/be/digitalia/fosdem/utils/NfcSenderUtils.java

@@ -0,0 +1,51 @@
+package be.digitalia.fosdem.utils;
+
+import java.nio.charset.Charset;
+
+import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.nfc.NdefMessage;
+import android.nfc.NdefRecord;
+import android.nfc.NfcAdapter;
+import android.nfc.NfcEvent;
+import android.nfc.NfcAdapter.CreateNdefMessageCallback;
+import android.os.Build;
+
+/**
+ * NFC helper methods for Android Beam foreground push. This class wraps API 14+ code.
+ * 
+ * @author Christophe Beyls
+ * 
+ */
+@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
+class NfcSenderUtils {
+
+	public static boolean setAppDataPushMessageCallbackIfAvailable(Activity activity, final CreateNfcAppDataCallback callback) {
+		NfcAdapter adapter = NfcAdapter.getDefaultAdapter(activity);
+		if (adapter == null) {
+			return false;
+		}
+		final String packageName = activity.getPackageName();
+		adapter.setNdefPushMessageCallback(new CreateNdefMessageCallback() {
+
+			@Override
+			public NdefMessage createNdefMessage(NfcEvent event) {
+				byte[] appData = callback.createNfcAppData();
+				if (appData == null) {
+					return null;
+				}
+				NdefRecord[] records = new NdefRecord[] { createMimeRecord("application/" + packageName, appData),
+						NdefRecord.createApplicationRecord(packageName) };
+				return new NdefMessage(records);
+			}
+
+		}, activity);
+		return true;
+	}
+
+	private static NdefRecord createMimeRecord(String mimeType, byte[] payload) {
+		byte[] mimeBytes = mimeType.getBytes(Charset.forName("US-ASCII"));
+		return new NdefRecord(NdefRecord.TNF_MIME_MEDIA, mimeBytes, new byte[0], payload);
+	}
+}

src/be/digitalia/fosdem/utils/NfcUtils.java

@@ -0,0 +1,67 @@
+package be.digitalia.fosdem.utils;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Build;
+
+/**
+ * NFC helper methods compatible with all API levels.
+ * 
+ * @author Christophe Beyls
+ * 
+ */
+public class NfcUtils {
+
+	/**
+	 * Implement this interface to create application-specific data to be shared through Android Beam.
+	 */
+	public interface CreateNfcAppDataCallback {
+		/**
+		 * 
+		 * @return The app data, or null if no data is currently available for sharing.
+		 */
+		public byte[] createNfcAppData();
+	}
+
+	/**
+	 * Call this method in an Activity, between onCreate() and onDestroy(), to make its content sharable using Android Beam if available. MIME type of the data
+	 * to share will be "application/" followed by the app's package name. Declare it in your Manifest's intent filters as the data type with an action of
+	 * android.nfc.action.NDEF_DISCOVERED to handle the NFC Intents on the receiver side.
+	 * 
+	 * @param activity
+	 * @param callback
+	 * @return true if NFC is available and the content was made available, false if not.
+	 */
+	public static boolean setAppDataPushMessageCallbackIfAvailable(Activity activity, final CreateNfcAppDataCallback callback) {
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
+			return NfcSenderUtils.setAppDataPushMessageCallbackIfAvailable(activity, callback);
+		}
+		return false;
+	}
+
+	/**
+	 * Determines if the intent contains NFC NDEF application-specific data to be extracted.
+	 * 
+	 * @param intent
+	 * @return
+	 */
+	public static boolean hasAppData(Intent intent) {
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD_MR1) {
+			return NfcReceiverUtils.hasAppData(intent);
+		}
+		return false;
+	}
+
+	/**
+	 * Extracts application-specific data sent through NFC from an intent. You must first ensure that the intent contains NFC data by calling hasAppData().
+	 * 
+	 * @param intent
+	 * @return The extracted data
+	 */
+	public static byte[] extractAppData(Intent intent) {
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD_MR1) {
+			return NfcReceiverUtils.extractAppData(intent);
+		}
+		return null;
+	}
+}