Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Android Build a Self-Destructing Message Android App Retrieving and Viewing Messages Creating a Custom List Adapter for Messages

jenyufu
jenyufu
3,311 Points

Don't know what I'm doing wrong but nothing shows up in the Inbox list

All I see in my messages is "No new messages" Here is my code.

package com.joinedit.ribbitpractice;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.parse.ParseObject;

import java.util.List;

/**
 * Created by yofu1 on 9/25/2015.
 */
public class MessageAdapter extends ArrayAdapter<ParseObject> {

    protected Context mContext;
    protected List<ParseObject> mMessages;

    //7.4 create custom layout for messages
    public MessageAdapter(Context context, List<ParseObject> messages) {
        super(context, R.layout.message_item);
        mContext = context;
        mMessages = messages;
    }


    //7.4 Override getView() in order to use a custom list adapter.
    // for  adapters for fragments, the adapter called a certain method to get an appropriate fragment.
    // And then it went ahead and adapted it and put it in the view.
    //This adapter, which is going to be attached to a list view,
    // is going to call a method, called getView,
    // and it's going to create the view, inflate it into a layout and then attach it into the list view.
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        //7.4 we want to do getView as efficiently as possible because the more efficient we are in this method, the faster it will perform
        ViewHolder holder;

        //RecyclerView (recycle views if it already exists.)
        if (convertView == null) { //if the view holder does not exist: create new holders
            convertView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
            holder = new ViewHolder();
            holder.iconImageView = (ImageView) convertView.findViewById(R.id.messageIcon); //if you do (ImageView)findViewById(R.id.messageIcon) it will be RED error. need "convertView." in front
            //^  find view by ID is an activity method.
            //But we can call it from the convert view because in this  instance, we want to get it for the layout for this view.
            //Because we're not attached to the activity yet.

            //do the same thing for TextView holder:
            holder.nameLabel = (TextView) convertView.findViewById(R.id.senderLabel);
            convertView.setTag(holder);
        } else { // else if it already exits: reuse the old holders
            holder = (ViewHolder)convertView.getTag(); //.getTag() method gets the holder that was already created
        }

        //7.4 Now that we have the view, get the ParseObject that correspond to each item on the list:
        ParseObject message = mMessages.get(position); //get the positon of the message

        //7.4 change icon of the message in layout based on message type
        if (message.getString(ParseConstants.KEY_FILE_TYPE).equals(ParseConstants.TYPE_IMAGE)){ //if image file type ".equals" image then:

            holder.iconImageView.setImageResource(R.drawable.ic_action_picture); //set message Icon

        } else { //else set it to image icon for video:

            holder.iconImageView.setImageResource(R.drawable.ic_action_play_over_video);

        }
        holder.nameLabel.setText(message.getString(ParseConstants.KEY_SENDER_NAME)); //set message sender name



        return convertView;
    }

    //7.4 Create a ViewHolder class to use viewHolder (android convention)
    private static class ViewHolder {
        //7.4 a very simple class that just includes the data that is going to be displayed in the custom layout.
        ImageView iconImageView;
        TextView nameLabel;

    }
}

2 Answers

jenyufu
jenyufu
3,311 Points

Nvrm, solved it:

super(context, R.layout.message_item, messages); //<-I forgot the ",messages" part
Peter Kazimir
Peter Kazimir
5,277 Points

thanks! you saved me a lot of time by posting this!