fix coding style

app/src/main/java/chat/rocket/android/helper/DateTime.java

@@ -7,15 +7,17 @@ import java.util.GregorianCalendar;
 import java.util.TimeZone;
 import timber.log.Timber;
 
+/**
+ * Utility class for converting epoch ms and date-time string.
+ */
 public class DateTime {
   private static final String TAG = DateTime.class.getName();
 
-  private static final SimpleDateFormat sSimpleTimeFormat = new SimpleDateFormat("HH:mm");
-  private static final SimpleDateFormat sSimpleDateFormat = new SimpleDateFormat("yyyy/MM/dd");
-  private static final SimpleDateFormat sSimpleDayFormat = new SimpleDateFormat("MM/dd");
-  private static final SimpleDateFormat sSimpleDayTimeFormat = new SimpleDateFormat("MM/dd HH:mm");
-  private static final SimpleDateFormat sSimpleDateTimeFormat =
-      new SimpleDateFormat("yyyy/MM/dd HH:mm");
+  private static final SimpleDateFormat TIME_FORMAT = new SimpleDateFormat("HH:mm");
+  private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy/MM/dd");
+  private static final SimpleDateFormat DAY_FORMAT = new SimpleDateFormat("MM/dd");
+  private static final SimpleDateFormat DAY_TIME_FORMAT = new SimpleDateFormat("MM/dd HH:mm");
+  private static final SimpleDateFormat DATE_TIME_FORMAT = new SimpleDateFormat("yyyy/MM/dd HH:mm");
 
   /**
    * convert datetime ms to String.
@@ -26,26 +28,26 @@ public class DateTime {
 
     switch (format) {
       case DAY:
-        return sSimpleDayFormat.format(cal.getTime());
+        return DAY_FORMAT.format(cal.getTime());
       case DATE:
-        return sSimpleDateFormat.format(cal.getTime());
+        return DATE_FORMAT.format(cal.getTime());
       case TIME:
-        return sSimpleTimeFormat.format(cal.getTime());
+        return TIME_FORMAT.format(cal.getTime());
       case DATE_TIME:
-        return sSimpleDateTimeFormat.format(cal.getTime());
+        return DATE_TIME_FORMAT.format(cal.getTime());
       case DAY_TIME:
-        return sSimpleDayTimeFormat.format(cal.getTime());
+        return DAY_TIME_FORMAT.format(cal.getTime());
       case AUTO_DAY_TIME: {
         final long curTimeMs = System.currentTimeMillis();
         Calendar cal2 = Calendar.getInstance(TimeZone.getTimeZone("JST"));
         cal2.setTimeInMillis(curTimeMs);
 
-        if (cal.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) && cal.get(Calendar.DAY_OF_YEAR) == cal2
-            .get(Calendar.DAY_OF_YEAR)) {
+        if (cal.get(Calendar.YEAR) == cal2.get(Calendar.YEAR)
+            && cal.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR)) {
           //same day.
-          return sSimpleDayTimeFormat.format(cal.getTime());
+          return DAY_TIME_FORMAT.format(cal.getTime());
         } else {
-          return sSimpleDayFormat.format(cal.getTime());
+          return DAY_FORMAT.format(cal.getTime());
         }
       }
       default:
@@ -59,7 +61,7 @@ public class DateTime {
   public static long fromDateToEpocMs(String dateString) {
     try {
       Calendar cal = new GregorianCalendar();
-      cal.setTime(sSimpleDateFormat.parse(dateString));
+      cal.setTime(DATE_FORMAT.parse(dateString));
       return cal.getTimeInMillis();
     } catch (ParseException exception) {
       Timber.w(exception, "failed to parse date: %s", dateString);
@@ -67,8 +69,10 @@ public class DateTime {
     return 0;
   }
 
+  /**
+   * format.
+   */
   public enum Format {
     DATE, DAY, TIME, DATE_TIME, DAY_TIME, AUTO_DAY_TIME
-
   }
 }
\ No newline at end of file

app/src/main/java/chat/rocket/android/layouthelper/chatroom/MessageViewHolder.java

@@ -12,6 +12,7 @@ import chat.rocket.android.renderer.MessageRenderer;
 import chat.rocket.android.widget.message.RocketChatMessageLayout;
 
 /**
+ * View holder of NORMAL chat message.
  */
 public class MessageViewHolder extends RealmModelViewHolder<PairedMessage> {
   private final ImageView avatar;
@@ -23,6 +24,9 @@ public class MessageViewHolder extends RealmModelViewHolder<PairedMessage> {
   private final View newDayContainer;
   private final TextView newDayText;
 
+  /**
+   * constructor WITH hostname.
+   */
   public MessageViewHolder(View itemView, String hostname) {
     super(itemView);
     avatar = (ImageView) itemView.findViewById(R.id.user_avatar);
@@ -35,6 +39,9 @@ public class MessageViewHolder extends RealmModelViewHolder<PairedMessage> {
     this.hostname = hostname;
   }
 
+  /**
+   * bind the view model.
+   */
   public void bind(PairedMessage pairedMessage) {
     new MessageRenderer(itemView.getContext(), pairedMessage.target)
         .avatarInto(avatar, hostname)

app/src/main/java/chat/rocket/android/layouthelper/chatroom/PairedMessage.java

@@ -15,12 +15,18 @@ public class PairedMessage {
     this.nextSibling = nextSibling;
   }
 
+  /**
+   * Returns true if target and nextSibling has the same date of timestamp.
+   */
   public boolean hasSameDate() {
     return nextSibling != null
         && DateTime.fromEpocMs(nextSibling.getTs(), DateTime.Format.DATE)
         .equals(DateTime.fromEpocMs(target.getTs(), DateTime.Format.DATE));
   }
 
+  /**
+   * Returns true if target and nextSibling are sent by the same user.
+   */
   public boolean hasSameUser() {
     return nextSibling != null
         && nextSibling.getU() != null && target.getU() != null