Android : 06-Notifications: add

1 files changed, 217 insertions, 0 deletions

diff --git a/Android/06-Notifications/Notifications/src/course/labs/notificationslab/DownloaderTask.java b/Android/06-Notifications/Notifications/src/course/labs/notificationslab/DownloaderTask.java
new file mode 100644
index 0000000..b792b38
--- /dev/null
+++ b/Android/06-Notifications/Notifications/src/course/labs/notificationslab/DownloaderTask.java
@@ -0,0 +1,217 @@
+package course.labs.notificationslab;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.net.URL;
+
+import android.app.Activity;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+import android.util.Log;
+import android.widget.RemoteViews;
+
+public class DownloaderTask extends AsyncTask<String, Void, String[]> {
+
+    private static final int SIM_NETWORK_DELAY = 5000;
+    private static final String TAG = "Lab-Notifications";
+    private final int MY_NOTIFICATION_ID = 11151990;
+    private String mFeeds[] = new String[3];
+    private MainActivity mParentActivity;
+    private Context mApplicationContext;
+
+    // Change this variable to false if you do not have a stable network
+    // connection
+    private static final boolean HAS_NETWORK_CONNECTION = true;
+
+    // Raw feed file IDs used if you do not have a stable connection
+    public static final int txtFeeds[] = { R.raw.tswift, R.raw.rblack, R.raw.lgaga };
+
+    // Constructor
+    public DownloaderTask(MainActivity parentActivity) {
+        super();
+        mParentActivity = parentActivity;
+        mApplicationContext = parentActivity.getApplicationContext();
+    }
+
+    @Override
+    protected String[] doInBackground(String... urlParameters) {
+        log("Entered doInBackground()");
+        return download(urlParameters);
+    }
+
+    private String[] download(String urlParameters[]) {
+
+        boolean downloadCompleted = false;
+
+        try {
+
+            for (int idx = 0; idx < urlParameters.length; idx++) {
+
+                URL url = new URL(urlParameters[idx]);
+                try {
+                    Thread.sleep(SIM_NETWORK_DELAY);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+                InputStream inputStream;
+                BufferedReader in;
+
+                // Alternative for students without
+                // a network connection
+                if (HAS_NETWORK_CONNECTION) {
+                    inputStream = url.openStream();
+                    in = new BufferedReader(new InputStreamReader(inputStream));
+                } else {
+                    inputStream = mApplicationContext.getResources().openRawResource(txtFeeds[idx]);
+                    in = new BufferedReader(new InputStreamReader(inputStream));
+                }
+
+                String readLine;
+                StringBuffer buf = new StringBuffer();
+
+                while ((readLine = in.readLine()) != null) {
+                    buf.append(readLine);
+                }
+
+                mFeeds[idx] = buf.toString();
+
+                if (null != in) {
+                    in.close();
+                }
+            }
+
+            downloadCompleted = true;
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        log("Tweet Download Completed:" + downloadCompleted);
+
+        notify(downloadCompleted);
+
+        return mFeeds;
+    }
+
+    // Call back to the MainActivity to update the feed display
+    @Override
+    protected void onPostExecute(String[] result) {
+        super.onPostExecute(result);
+
+        if (mParentActivity != null) {
+            mParentActivity.setRefreshed(result);
+        }
+
+    }
+
+    // If necessary, notifies the user that the tweet downloads are complete.
+    // Sends an ordered broadcast back to the BroadcastReceiver in MainActivity
+    // to determine whether the notification is necessary.
+    private void notify(final boolean success) {
+        log("Entered notify()");
+        final Intent restartMainActivtyIntent = new Intent(mApplicationContext, MainActivity.class);
+        restartMainActivtyIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+        if (success) {
+            // Save tweets to a file
+            saveTweetsToFile();
+        }
+
+        // Sends an ordered broadcast to determine whether MainActivity is
+        // active and in the foreground. Creates a new BroadcastReceiver
+        // to receive a result indicating the state of MainActivity
+
+        // The Action for this broadcast Intent is MainActivity.DATA_REFRESHED_ACTION
+        // The result Activity.RESULT_OK, indicates that MainActivity is active and
+        // in the foreground.
+        mApplicationContext.sendOrderedBroadcast(
+                new Intent(MainActivity.DATA_REFRESHED_ACTION), null, new BroadcastReceiver() {
+
+                    final String failMsg = "Download has failed. Please retry Later.";
+                    final String successMsg = "Download completed successfully.";
+
+                    @Override
+                    public void onReceive(Context context, Intent intent) {
+
+                        log("Entered result receiver's onReceive() method");
+
+                        // TODO: Check whether the result code is RESULT_OK
+
+                        if (/*change this*/ true) {
+
+                            // TODO:  If so, create a PendingIntent using the
+                            // restartMainActivityIntent and set its flags
+                            // to FLAG_UPDATE_CURRENT
+
+                            final PendingIntent pendingIntent = null;
+
+                            // Uses R.layout.custom_notification for the
+                            // layout of the notification View. The xml
+                            // file is in res/layout/custom_notification.xml
+                            RemoteViews mContentView = new RemoteViews(
+                                    mApplicationContext.getPackageName(),
+                                    R.layout.custom_notification);
+
+                            // TODO: Set the notification View's text to
+                            // reflect whether or the download completed
+                            // successfully
+
+                            // TODO: Use the Notification.Builder class to
+                            // create the Notification. You will have to set
+                            // several pieces of information. You can use
+                            // android.R.drawable.stat_sys_warning
+                            // for the small icon. You should also setAutoCancel(true).
+
+                            Notification.Builder notificationBuilder = null;
+
+                            // TODO: Send the notification
+
+                            log("Notification Area Notification sent");
+                        }
+                    }
+                }, null, 0, null, null);
+    }
+
+    // Saves the tweets to a file
+    private void saveTweetsToFile() {
+        PrintWriter writer = null;
+        try {
+            FileOutputStream fos = mApplicationContext.openFileOutput(
+                    MainActivity.TWEET_FILENAME, Context.MODE_PRIVATE);
+            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
+                            fos)));
+
+            for (String s : mFeeds) {
+                writer.println(s);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (null != writer) {
+                writer.close();
+            }
+        }
+    }
+
+    // Simplified log output method
+    private void log(String msg) {
+        try {
+            Thread.sleep(500);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        Log.i(TAG, msg);
+    }
+}