Add preference to disable the SMS channel all together.

1) If the SMS fallback preference is disabled, no outgoing
   messages will succeed via the SMS transport.

2) If the SMS fallback preference is disabled, "mirroring" the
   SMS db state when not the default system SMS app is disabled.

res/values/strings.xml

@@ -678,6 +678,8 @@
     <string name="preferences__use_the_data_channel_for_communication_with_other_textsecure_users">
         Use the data channel for communication with other TextSecure users
     </string>
+    <string name="preferences__allow_sms_fallback">Allow SMS Fallback</string>
+    <string name="preferences__send_and_receive_sms_messages_when_push_is_not_available">Send and receive SMS messages when push is not available</string>
                                     
     <!-- **************************************** -->
     <!-- menus -->

res/xml/preferences.xml

@@ -16,16 +16,22 @@
                     android:title="@string/preferences__make_default_sms_app"
                     android:summary="@string/preferences__make_textsecure_the_default_sms_mms_app" />
 
-        <CheckBoxPreference android:defaultValue="false"
+        <!--<CheckBoxPreference android:defaultValue="false"-->
-                            android:key="pref_delivery_report_sms"
+                            <!--android:key="pref_delivery_report_sms"-->
-                            android:summary="@string/preferences__request_a_delivery_report_for_each_sms_message_you_send"
+                            <!--android:summary="@string/preferences__request_a_delivery_report_for_each_sms_message_you_send"-->
-                            android:title="@string/preferences__sms_delivery_reports" />
+                            <!--android:title="@string/preferences__sms_delivery_reports" />-->
 
         <CheckBoxPreference android:defaultValue="false"
                             android:key="pref_toggle_push_messaging"
                             android:title="@string/preferences__use_data_channel"
                             android:summary="@string/preferences__use_the_data_channel_for_communication_with_other_textsecure_users"/>
 
+        <CheckBoxPreference android:defaultValue="true"
+                            android:enabled="false"
+                            android:key="pref_allow_sms_traffic_out"
+                            android:title="@string/preferences__allow_sms_fallback"
+                            android:summary="@string/preferences__send_and_receive_sms_messages_when_push_is_not_available"/>
+
     </PreferenceCategory>
     <PreferenceCategory android:title="@string/preferences__notifications">
         <CheckBoxPreference android:key="pref_key_enable_notifications"

src/org/thoughtcrime/securesms/ApplicationPreferencesActivity.java

@@ -100,6 +100,7 @@ public class ApplicationPreferencesActivity extends PassphraseRequiredSherlockPr
 
     initializeIdentitySelection();
     initializePlatformSpecificOptions();
+    initializeSmsFallbackOption();
     initializePushMessagingToggle();
 
     this.findPreference(TextSecurePreferences.CHANGE_PASSPHRASE_PREF)
@@ -178,7 +179,7 @@ public class ApplicationPreferencesActivity extends PassphraseRequiredSherlockPr
   }
 
   private void initializePlatformSpecificOptions() {
-    PreferenceGroup generalCategory = (PreferenceGroup)findPreference("general_category");
+    PreferenceGroup    generalCategory    = (PreferenceGroup) findPreference("general_category");
     Preference         defaultPreference  = findPreference(KITKAT_DEFAULT_PREF);
 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
@@ -198,6 +199,29 @@ public class ApplicationPreferencesActivity extends PassphraseRequiredSherlockPr
     }
   }
 
+  private void initializeSmsFallbackOption() {
+    CheckBoxPreference allowSmsPreference =
+        (CheckBoxPreference) findPreference(TextSecurePreferences.ALLOW_SMS_FALLBACK_PREF);
+
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+      if (Util.isDefaultSmsProvider(this) || !TextSecurePreferences.isPushRegistered(this)) {
+        allowSmsPreference.setEnabled(false);
+        allowSmsPreference.setChecked(true);
+      } else {
+        allowSmsPreference.setEnabled(true);
+      }
+    } else {
+      if (TextSecurePreferences.isInterceptAllMmsEnabled(this) ||
+          TextSecurePreferences.isInterceptAllSmsEnabled(this))
+      {
+        allowSmsPreference.setEnabled(false);
+        allowSmsPreference.setChecked(true);
+      } else {
+        allowSmsPreference.setEnabled(true);
+      }
+    }
+  }
+
   private void initializeEditTextSummary(final EditTextPreference preference) {
     if (preference.getText() == null) {
       preference.setSummary("Not set");
@@ -268,6 +292,10 @@ public class ApplicationPreferencesActivity extends PassphraseRequiredSherlockPr
       dynamicTheme.onResume(this);
     } else if (key.equals(TextSecurePreferences.LANGUAGE_PREF)) {
       dynamicLanguage.onResume(this);
+    } else if (key.equals(TextSecurePreferences.ALL_MMS_PREF) ||
+               key.equals(TextSecurePreferences.ALL_SMS_PREF))
+    {
+      initializeSmsFallbackOption();
     }
   }
 

src/org/thoughtcrime/securesms/service/MmsListener.java

@@ -20,14 +20,12 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
-import android.preference.PreferenceManager;
 import android.provider.Telephony;
 import android.util.Log;
 
-import org.thoughtcrime.securesms.ApplicationPreferencesActivity;
 import org.thoughtcrime.securesms.protocol.WirePrefix;
-import org.thoughtcrime.securesms.util.Util;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
+import org.thoughtcrime.securesms.util.Util;
 
 import ws.com.google.android.mms.pdu.GenericPdu;
 import ws.com.google.android.mms.pdu.NotificationInd;
@@ -52,7 +50,8 @@ public class MmsListener extends BroadcastReceiver {
       return false;
     }
 
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ||
+    if ((Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT &&
+         TextSecurePreferences.isSmsFallbackEnabled(context)) ||
         TextSecurePreferences.isInterceptAllMmsEnabled(context))
     {
       return true;

src/org/thoughtcrime/securesms/service/SmsListener.java

@@ -110,7 +110,8 @@ public class SmsListener extends BroadcastReceiver {
       return false;
     }
 
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ||
+    if ((Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT &&
+         TextSecurePreferences.isSmsFallbackEnabled(context)) ||
         TextSecurePreferences.isInterceptAllSmsEnabled(context))
     {
       return true;
@@ -120,7 +121,6 @@ public class SmsListener extends BroadcastReceiver {
   }
 
   private boolean isChallenge(Context context, Intent intent) {
-    SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
     String messageBody = getSmsMessageBodyFromIntent(intent);
 
     if (messageBody == null)

src/org/thoughtcrime/securesms/transport/SmsTransport.java

@@ -48,6 +48,12 @@ public class SmsTransport extends BaseTransport {
   }
 
   public void deliver(SmsMessageRecord message) throws UndeliverableMessageException {
+    if (TextSecurePreferences.isPushRegistered(context) &&
+        !TextSecurePreferences.isSmsFallbackEnabled(context))
+    {
+      throw new UndeliverableMessageException("SMS Transport is not enabled!");
+    }
+
     if (message.isSecure() || message.isKeyExchange() || message.isEndSession()) {
       deliverSecureMessage(message);
     } else {

src/org/thoughtcrime/securesms/transport/UniversalTransport.java

@@ -214,6 +214,12 @@ public class UniversalTransport {
       return false;
     }
 
+    if (TextSecurePreferences.isPushRegistered(context) &&
+        !TextSecurePreferences.isSmsFallbackEnabled(context))
+    {
+      return false;
+    }
+
     Directory directory = Directory.getInstance(context);
     return directory.isSmsFallbackSupported(destination);
   }

src/org/thoughtcrime/securesms/util/TextSecurePreferences.java

@@ -44,6 +44,11 @@ public class TextSecurePreferences {
   private static final String IN_THREAD_NOTIFICATION_PREF      = "pref_key_inthread_notifications";
 
   private static final String LOCAL_REGISTRATION_ID_PREF       = "pref_local_registration_id";
+  public  static final String ALLOW_SMS_FALLBACK_PREF          = "pref_allow_sms_traffic_out";
+
+  public static boolean isSmsFallbackEnabled(Context context) {
+    return getBooleanPreference(context, ALLOW_SMS_FALLBACK_PREF, true);
+  }
 
   public static int getLocalRegistrationId(Context context) {
     return getIntegerPreference(context, LOCAL_REGISTRATION_ID_PREF, 0);
@@ -175,7 +180,7 @@ public class TextSecurePreferences {
   }
 
   public static boolean isSmsDeliveryReportsEnabled(Context context) {
-    return getBooleanPreference(context, SMS_DELIVERY_REPORT_PREF, false);
+    return getBooleanPreference(context, SMS_DELIVERY_REPORT_PREF, true);
   }
 
   public static boolean hasPromptedPushRegistration(Context context) {