Part 4 – GET Request

Dependencies + instructions:

developer.android.com/topic/libraries/support-library/packages.html#v7-cardview

developer.android.com/topic/libraries/support-library/packages.html#v7-recyclerview

developer.android.com/training/volley/index.html

square.github.io/picasso/

Pixabay API:

pixabay.com/api/docs/

package com.codinginflow.recylerviewjsonexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    private ExampleAdapter mExampleAdapter;
    private ArrayList<ExampleItem> mExampleList;
    private RequestQueue mRequestQueue;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRecyclerView = findViewById(R.id.recycler_view);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        mExampleList = new ArrayList<>();

        mRequestQueue = Volley.newRequestQueue(this);
        parseJSON();
    }

    private void parseJSON() {
        String url = "https://pixabay.com/api/?key=5303976-fd6581ad4ac165d1b75cc15b3&q=kitten&image_type=photo&pretty=true";

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            JSONArray jsonArray = response.getJSONArray("hits");

                            for (int i = 0; i < jsonArray.length(); i++) {
                                JSONObject hit = jsonArray.getJSONObject(i);

                                String creatorName = hit.getString("user");
                                String imageUrl = hit.getString("webformatURL");
                                int likeCount = hit.getInt("likes");

                                mExampleList.add(new ExampleItem(imageUrl, creatorName, likeCount));
                            }

                            mExampleAdapter = new ExampleAdapter(MainActivity.this, mExampleList);
                            mRecyclerView.setAdapter(mExampleAdapter);

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
            }
        });

        mRequestQueue.add(request);
    }
}

package com.codinginflow.recylerviewjsonexample;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.squareup.picasso.Picasso;

import java.util.ArrayList;


public class ExampleAdapter extends RecyclerView.Adapter<ExampleAdapter.ExampleViewHolder> {
    private Context mContext;
    private ArrayList<ExampleItem> mExampleList;

    public ExampleAdapter(Context context, ArrayList<ExampleItem> exampleList) {
        mContext = context;
        mExampleList = exampleList;
    }

    @Override
    public ExampleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(mContext).inflate(R.layout.example_item, parent, false);
        return new ExampleViewHolder(v);
    }

    @Override
    public void onBindViewHolder(ExampleViewHolder holder, int position) {
        ExampleItem currentItem = mExampleList.get(position);

        String imageUrl = currentItem.getImageUrl();
        String creatorName = currentItem.getCreator();
        int likeCount = currentItem.getLikeCount();

        holder.mTextViewCreator.setText(creatorName);
        holder.mTextViewLikes.setText("Likes: " + likeCount);
        Picasso.with(mContext).load(imageUrl).fit().centerInside().into(holder.mImageView);
    }

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

    public class ExampleViewHolder extends RecyclerView.ViewHolder {
        public ImageView mImageView;
        public TextView mTextViewCreator;
        public TextView mTextViewLikes;

        public ExampleViewHolder(View itemView) {
            super(itemView);
            mImageView = itemView.findViewById(R.id.image_view);
            mTextViewCreator = itemView.findViewById(R.id.text_view_creator);
            mTextViewLikes = itemView.findViewById(R.id.text_view_likes);
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="8dp"
    app:cardCornerRadius="8dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="16dp">

        <ImageView
            android:id="@+id/image_view"
            android:layout_width="match_parent"
            android:layout_height="200dp"
            android:src="@mipmap/ic_launcher" />

        <TextView
            android:id="@+id/text_view_creator"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Creator Name"
            android:textColor="@android:color/black"
            android:textSize="20sp" />

        <TextView
            android:id="@+id/text_view_likes"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Like: " />

    </LinearLayout>

</android.support.v7.widget.CardView>

package com.codinginflow.recylerviewjsonexample;

public class ExampleItem {
    private String mImageUrl;
    private String mCreator;
    private int mLikes;

    public ExampleItem(String imageUrl, String creator, int likes) {
        mImageUrl = imageUrl;
        mCreator = creator;
        mLikes = likes;
    }

    public String getImageUrl() {
        return mImageUrl;
    }

    public String getCreator() {
        return mCreator;
    }

    public int getLikeCount() {
        return mLikes;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codinginflow.recylerviewjsonexample">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.codinginflow.recylerviewjsonexample.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/darker_gray" />

</RelativeLayout>