try/catch around backup service, get backup update status and save the

summary off.

res/values/strings.xml

@@ -465,8 +465,16 @@ Skipped %d tasks.\n
         <string name="prefs_deadlineTime_desc"># of days from now to set new deadlines</string>
 
         <string name="prefs_backup_title">Automatic Backups</string>
+        
+        <!--  backup summary when there is no backup message -->
         <string name="prefs_backup_desc">Perform daily backups to sdcard.</string>
         
+        <!--  backup failure message (%s -> error message) -->
+        <string name="prefs_backup_desc_failure">Backup failed: %s</string>
+        
+        <!--  backup success message (%s -> date) -->
+        <string name="prefs_backup_desc_success">Latest backup: %s</string>
+        
         <string name="displayedFields_PrefScreen_Title">Displayed Fields</string>
         <string name="displayedFields_PrefScreen_Desc">Select the fields to show in task list</string>
         

src/com/timsu/astrid/activities/EditPreferences.java

@@ -20,11 +20,13 @@
 package com.timsu.astrid.activities;
 
 import android.os.Bundle;
+import android.preference.Preference;
 import android.preference.PreferenceActivity;
 
 import com.flurry.android.FlurryAgent;
 import com.timsu.astrid.R;
 import com.timsu.astrid.utilities.Constants;
+import com.timsu.astrid.utilities.Preferences;
 
 /**
  * Displays the preference screen for users to edit their preferences
@@ -38,6 +40,11 @@ public class EditPreferences extends PreferenceActivity {
         super.onCreate(savedInstanceState);
 
         addPreferencesFromResource(R.xml.preferences);
+
+        Preference backupPreference = findPreference(getString(R.string.p_backup));
+        String backupSummary = Preferences.getBackupSummary(this);
+        if(backupSummary != null && backupPreference != null)
+            backupPreference.setSummary(backupSummary);
     }
 
     @Override

src/com/timsu/astrid/utilities/BackupService.java

@@ -2,6 +2,7 @@ package com.timsu.astrid.utilities;
 
 import java.io.File;
 import java.io.FilenameFilter;
+import java.util.Date;
 
 import android.app.AlarmManager;
 import android.app.PendingIntent;
@@ -10,6 +11,8 @@ import android.content.Context;
 import android.content.Intent;
 import android.os.IBinder;
 
+import com.timsu.astrid.R;
+
 /**
  * Inspired heavily by SynchronizationService
  */
@@ -44,10 +47,20 @@ public class BackupService extends Service {
         if (!Preferences.isBackupEnabled(ctx)) {
             return;
         }
+        try {
             deleteOldBackups();
             TasksXmlExporter exporter = new TasksXmlExporter(true);
             exporter.setContext(ctx);
             exporter.exportTasks();
+            Preferences.setBackupSummary(ctx,
+                    ctx.getString(R.string.prefs_backup_desc_success,
+                            DateUtilities.getFormattedDate(ctx.getResources(), new Date())));
+        } catch (Exception e) {
+            // unable to backup.
+            Preferences.setBackupSummary(ctx,
+                    ctx.getString(R.string.prefs_backup_desc_failure,
+                            e.getMessage()));
+        }
     }
 
     public static void scheduleService(Context ctx) {

src/com/timsu/astrid/utilities/Preferences.java

@@ -1,15 +1,16 @@
 package com.timsu.astrid.utilities;
 
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.Editor;
 import android.content.res.Resources;
 import android.net.Uri;
 import android.preference.PreferenceManager;
-import com.timsu.astrid.R;
 
-import java.text.SimpleDateFormat;
-import java.util.Date;
+import com.timsu.astrid.R;
 
 public class Preferences {
 
@@ -24,6 +25,7 @@ public class Preferences {
     private static final String P_LOCALE_LAST_NOTIFY = "locnot";
     private static final String P_DID_ANDROID_AND_ME_SURVEY = "aamsurvey";
     private static final String P_TASK_KILLER_HELP = "taskkiller";
+    private static final String P_BACKUP_ERROR = "backupError";
 
     // pref values
     public static final int ICON_SET_PINK = 0;
@@ -62,6 +64,9 @@ public class Preferences {
         if (!prefs.contains(r.getString(R.string.p_backup))) {
             editor.putBoolean(r.getString(R.string.p_backup), true);
         }
+        if (!prefs.contains(P_BACKUP_ERROR)) {
+            editor.putString(P_BACKUP_ERROR, null);
+        }
 
         setVisibilityPreferences(prefs, editor, r);
 
@@ -281,11 +286,26 @@ public class Preferences {
     }
 
     // --- backup preferences
+
     public static boolean isBackupEnabled(Context context) {
         Resources r = context.getResources();
         return getPrefs(context).getBoolean(r.getString(R.string.p_backup), true);
     }
 
+    /**
+     * @return error when doing backup, empty string if successful, or null
+     *         if no backup has been attempted
+     */
+    public static String getBackupSummary(Context context) {
+        return getPrefs(context).getString(P_BACKUP_ERROR, null);
+    }
+
+    public static void setBackupSummary(Context context, String newValue) {
+        Editor editor = getPrefs(context).edit();
+        editor.putString(P_BACKUP_ERROR, newValue);
+        editor.commit();
+    }
+
     // --- synchronization preferences
 
     /** RTM authentication token, or null if doesn't exist */