Track previously selected per-recipient ringtone value.

Fixes #3397
Closes #3477

res/xml/recipient_preferences.xml

@@ -9,7 +9,8 @@
             android:disableDependentsState="true"
             android:persistent="false" />
 
-    <RingtonePreference android:dependency="pref_key_recipient_mute"
+    <org.thoughtcrime.securesms.preferences.AdvancedRingtonePreference
+                        android:dependency="pref_key_recipient_mute"
                         android:key="pref_key_recipient_ringtone"
                         android:title="@string/recipient_preferences__ringtone"
                         android:ringtoneType="notification"

src/org/thoughtcrime/securesms/RecipientPreferenceActivity.java

@@ -12,7 +12,6 @@ import android.os.Handler;
 import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
 import android.preference.Preference;
-import android.preference.RingtonePreference;
 import android.provider.Settings;
 import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
@@ -31,6 +30,7 @@ import org.thoughtcrime.securesms.components.AvatarImageView;
 import org.thoughtcrime.securesms.crypto.MasterSecret;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.RecipientPreferenceDatabase.VibrateState;
+import org.thoughtcrime.securesms.preferences.AdvancedRingtonePreference;
 import org.thoughtcrime.securesms.preferences.ColorPreference;
 import org.thoughtcrime.securesms.recipients.RecipientFactory;
 import org.thoughtcrime.securesms.recipients.Recipients;
@@ -185,7 +185,7 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
 
     private void setSummaries(Recipients recipients) {
       CheckBoxPreference         mutePreference     = (CheckBoxPreference) this.findPreference(PREFERENCE_MUTED);
-      RingtonePreference ringtonePreference = (RingtonePreference) this.findPreference(PREFERENCE_TONE);
+      AdvancedRingtonePreference ringtonePreference = (AdvancedRingtonePreference) this.findPreference(PREFERENCE_TONE);
       ListPreference             vibratePreference  = (ListPreference) this.findPreference(PREFERENCE_VIBRATE);
       ColorPreference            colorPreference    = (ColorPreference) this.findPreference(PREFERENCE_COLOR);
       Preference                 blockPreference    = this.findPreference(PREFERENCE_BLOCK);
@@ -197,6 +197,7 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
 
         if (tone != null) {
           ringtonePreference.setSummary(tone.getTitle(getActivity()));
+          ringtonePreference.setCurrentRingtone(recipients.getRingtone());
         }
       } else {
         ringtonePreference.setSummary(R.string.preferences__default);

src/org/thoughtcrime/securesms/preferences/AdvancedRingtonePreference.java

@@ -0,0 +1,31 @@
+package org.thoughtcrime.securesms.preferences;
+
+import android.content.Context;
+import android.net.Uri;
+import android.preference.RingtonePreference;
+import android.util.AttributeSet;
+
+
+public class AdvancedRingtonePreference extends RingtonePreference {
+
+  private Uri currentRingtone;
+
+  public AdvancedRingtonePreference(Context context, AttributeSet attrs, int defStyleAttr) {
+    super(context, attrs, defStyleAttr);
+  }
+  public AdvancedRingtonePreference(Context context, AttributeSet attrs) {
+    super(context, attrs);
+  }
+  public AdvancedRingtonePreference(Context context) {
+    super(context);
+  }
+
+  @Override
+  protected Uri onRestoreRingtone() {
+    return currentRingtone;
+  }
+
+  public void setCurrentRingtone(Uri uri) {
+    currentRingtone = uri;
+  }
+}