Implement auto backups

app/src/main/AndroidManifest.xml

@@ -5,13 +5,15 @@
     android:versionCode="2"
     android:versionName="1.0.0">
 
-    <uses-permission android:name="android.permission.VIBRATE"/>
+    <uses-permission
+        android:name="android.permission.VIBRATE"/>
 
     <application
         android:name="com.activeandroid.app.Application"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
-        android:theme="@style/AppTheme">
+        android:theme="@style/AppBaseTheme"
+        android:backupAgent=".HabitsBackupAgent">
 
         <meta-data
             android:name="AA_DB_NAME"
@@ -21,6 +23,10 @@
             android:name="AA_DB_VERSION"
             android:value="7"/>
 
+        <meta-data
+            android:name="com.google.android.backup.api_key"
+            android:value="AEdPqrEAAAAI6aeWncbnMNo8E5GWeZ44dlc5cQ7tCROwFhOtiw" />
+
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name">
@@ -30,8 +36,8 @@
             </intent-filter>
         </activity>
 
-        <receiver android:name=".ReminderAlarmReceiver">
-        </receiver>
+        <receiver
+            android:name=".ReminderAlarmReceiver" />
 
         <activity
             android:name=".ShowHabitActivity"

app/src/main/java/org/isoron/helpers/ReplayableActivity.java

@@ -1,6 +1,7 @@
 package org.isoron.helpers;
 
 import android.app.Activity;
+import android.app.backup.BackupManager;
 import android.os.Bundle;
 import android.widget.Toast;
 
@@ -28,6 +29,7 @@ abstract public class ReplayableActivity extends Activity
     public void executeCommand(Command command)
     {
         executeCommand(command, false);
+        BackupManager.dataChanged("org.isoron.uhabits");
     }
 
     protected void undo()

app/src/main/java/org/isoron/uhabits/HabitsBackupAgent.java

@@ -0,0 +1,15 @@
+package org.isoron.uhabits;
+
+import android.app.backup.BackupAgentHelper;
+import android.app.backup.FileBackupHelper;
+import android.app.backup.SharedPreferencesBackupHelper;
+
+public class HabitsBackupAgent extends BackupAgentHelper
+{
+    @Override
+    public void onCreate()
+    {
+        addHelper("preferences", new SharedPreferencesBackupHelper(this, "preferences"));
+        addHelper("database", new FileBackupHelper(this, "../databases/uhabits.db"));
+    }
+}

app/src/main/java/org/isoron/uhabits/dialogs/SettingsFragment.java

@@ -1,12 +1,14 @@
 package org.isoron.uhabits.dialogs;
 
 
+import android.app.backup.BackupManager;
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.preference.PreferenceFragment;
 
 import org.isoron.uhabits.R;
 
-public class SettingsFragment extends PreferenceFragment
+public class SettingsFragment extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener
 {
     @Override
     public void onCreate(Bundle savedInstanceState)
@@ -14,4 +16,26 @@ public class SettingsFragment extends PreferenceFragment
         super.onCreate(savedInstanceState);
         addPreferencesFromResource(R.xml.preferences);
     }
+
+    @Override
+    public void onResume()
+    {
+        super.onResume();
+        getPreferenceManager().getSharedPreferences().
+                registerOnSharedPreferenceChangeListener(this);
+    }
+
+    @Override
+    public void onPause()
+    {
+        getPreferenceManager().getSharedPreferences().
+                unregisterOnSharedPreferenceChangeListener(this);
+        super.onPause();
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
+    {
+        BackupManager.dataChanged("org.isoron.uhabits");
+    }
 }