android - How do I display the calendar date on the top of chat messages?

Question

I am working on a chat application but I am struggling to figure out how to display the calendar date on the top of chat messages; for example, something like this:

Another image with timestamps:

As you see in the example, the date is displayed on top of a fresh new batch of text messages. I would like to do the same, just for a batch of messages related to a specific date. Say if I have messages for October 19, it shows October 19 on top followed by messages for October 20 and so on... Here's the working sample code similar to mine:

http://www.codeproject.com/Tips/897826/Designing-Android-Chat-Bubble-Chat-UI

The construction of the code is same as mine except for the date being displayed on top which is something I am stuck on. I have my timestamps showing for every message, I just want to display the date in the format "Monday, October 19, 2015" for the batch of messages; just once on top, from October 19, and likewise calendar dates for past and future messages, as shown in the image. Any clues? Thanks!

Answer 1

As far as I understand you want to show time/date only for certain group of messages and not for each message. So here is how to do that. Precondition: I assume each message item has time stamp based on which we will do our grouping Idea: we will need each list item to have timeview:TextView element and we will show and hide that element based on it's position and TS (time stamp) Example:

item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="@color/white"
              android:orientation="vertical"
              android:padding="@dimen/padding_small">

    <TextView
        android:id="@+id/timeText"
        style="@style/DefaultText"
        android:paddingBottom="@dimen/padding_small"
        android:paddingRight="@dimen/padding_small"
        android:paddingTop="@dimen/padding_small"
        android:text="@string/hello_world"
        android:textSize="@dimen/font_size_small_10"/>

    <TextView
        android:id="@+id/textView"
        style="@style/DefaultText"
        android:layout_width="wrap_content"
        android:background="@drawable/bg_gray_rounded"
        android:paddingBottom="@dimen/padding_extra_small"
        android:paddingLeft="@dimen/padding_small"
        android:paddingRight="@dimen/padding_small"
        android:paddingTop="@dimen/padding_extra_small"
        android:textColor="@color/gray"
        android:textSize="@dimen/font_size_md"/>

</LinearLayout>

ChatRecyclerAdapter.java

public class ChatEGRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    public static class TextViewHolder extends RecyclerView.ViewHolder {
        public TextView textView;
        public TextView timeText;
        public TextViewHolder(View v) {
            super(v);
            timeText = (TextView) v.findViewById(R.id.timeText);
            textView = (TextView) v.findViewById(R.id.textView);
        }
    }

    private final List<Message> messages;


    public ChatEGRecyclerAdapter(List<Message> messages) {
        this.messages = messages;
    }


    // Create new views (invoked by the layout manager)
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item, parent, false);
        return new TextViewHolder(v);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
        final Message m = messages.get(position);
        final Context context = viewHolder.itemView.getContext();

        TextViewHolder holder = (TextViewHolder)viewHolder;
        holder.textView.setVisibility(View.VISIBLE);
        holder.textView.setText(m.getText());

        long previousTs = 0;
        if(position>1){
            Message pm = messages.get(position-1);
            previousTs = pm.getTimeStamp();
        }
        setTimeTextVisibility(m.getTimeStamp(), previousTs, holder.timeText);
    }

    private void setTimeTextVisibility(long ts1, long ts2, TextView timeText){

        if(ts2==0){
            timeText.setVisibility(View.VISIBLE);
            timeText.setText(Utils.formatDayTimeHtml(ts1));
        }else {
            Calendar cal1 = Calendar.getInstance();
            Calendar cal2 = Calendar.getInstance();
            cal1.setTimeInMillis(ts1);
            cal2.setTimeInMillis(ts2);

            boolean sameMonth = cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) &&
                    cal1.get(Calendar.MONTH) == cal2.get(Calendar.MONTH);

            if(sameMonth){
                timeText.setVisibility(View.GONE);
                timeText.setText("");
            }else {
                timeText.setVisibility(View.VISIBLE);
                timeText.setText(Utils.formatDayTimeHtml(ts2));
            }

        }
    }


    @Override
    public int getItemCount() {
        return messages.size();
    }

}

what left is to create your RecylcerView and give it this adapter