added pagination with recyclerview

PagingnationInRecyclerview/.gitignore

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+*.iml
+.gradle
+/local.properties
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild

PagingnationInRecyclerview/app/.gitignore

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+/build

PagingnationInRecyclerview/app/build.gradle

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+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 27
+    defaultConfig {
+        applicationId "velmm.com.pagingnationinrecyclerview"
+        minSdkVersion 15
+        targetSdkVersion 27
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'com.android.support:appcompat-v7:27.1.1'
+    implementation 'com.android.support.constraint:constraint-layout:1.1.2'
+    implementation 'com.android.support:recyclerview-v7:27.1.1'
+    implementation 'com.android.support:cardview-v7:27.1.1'
+    implementation 'com.squareup.retrofit2:retrofit:2.1.0'
+    implementation 'com.squareup.retrofit2:converter-gson:2.1.0'
+    implementation 'com.github.bumptech.glide:glide:4.7.1'
+
+
+}

PagingnationInRecyclerview/app/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

PagingnationInRecyclerview/app/src/androidTest/java/velmm/com/pagingnationinrecyclerview/ExampleInstrumentedTest.java

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+package velmm.com.pagingnationinrecyclerview;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("velmm.com.pagingnationinrecyclerview", appContext.getPackageName());
+    }
+}

PagingnationInRecyclerview/app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="velmm.com.pagingnationinrecyclerview">
+
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
+    <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>

PagingnationInRecyclerview/app/src/main/java/velmm/com/pagingnationinrecyclerview/MainActivity.java

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+package velmm.com.pagingnationinrecyclerview;
+
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+import android.widget.ProgressBar;
+
+import java.util.List;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+import velmm.com.pagingnationinrecyclerview.api.ClientApi;
+import velmm.com.pagingnationinrecyclerview.api.MovieService;
+import velmm.com.pagingnationinrecyclerview.model.Movie;
+
+public class MainActivity extends AppCompatActivity {
+
+    private PaginationAdapter paginationAdapter;
+    private MovieService movieService;
+    private ProgressBar progressBar;
+    private static final int PAGE_START = 1;
+    private boolean isLoading = false;
+    private boolean isLastPage = false;
+    private int TOTAL_PAGES = 5;
+    private int currentPage = PAGE_START;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+        RecyclerView recyclerView = findViewById(R.id.recyclerview);
+        progressBar = findViewById(R.id.progressbar);
+
+        movieService = ClientApi.getClient().create(MovieService.class);
+        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
+        paginationAdapter = new PaginationAdapter(this);
+        recyclerView.setLayoutManager(linearLayoutManager);
+        recyclerView.setAdapter(paginationAdapter);
+
+        recyclerView.addOnScrollListener(new PaginationScrollListener(linearLayoutManager) {
+            @Override
+            protected void loadMoreItems() {
+                isLoading = true;
+                currentPage += 1;
+                loadNextPage();
+            }
+
+            @Override
+            public boolean isLastPage() {
+                return isLastPage;
+            }
+
+            @Override
+            public boolean isLoading() {
+                return isLoading;
+            }
+        });
+
+        loadFirstPage();
+    }
+
+    private void loadNextPage() {
+
+        movieService.getMovies().enqueue(new Callback<List<Movie>>() {
+            @Override
+            public void onResponse(Call<List<Movie>> call, Response<List<Movie>> response) {
+                paginationAdapter.removeLoadingFooter();
+                isLoading = false;
+
+                List<Movie> results = response.body();
+                paginationAdapter.addAll(results);
+
+                if (currentPage != TOTAL_PAGES) paginationAdapter.addLoadingFooter();
+                else isLastPage = true;
+            }
+
+            @Override
+            public void onFailure(Call<List<Movie>> call, Throwable t) {
+                t.printStackTrace();
+            }
+        });
+    }
+
+
+    private void loadFirstPage() {
+
+        movieService.getMovies().enqueue(new Callback<List<Movie>>() {
+            @Override
+            public void onResponse(Call<List<Movie>> call, Response<List<Movie>> response) {
+                List<Movie> results = response.body();
+                progressBar.setVisibility(View.GONE);
+                paginationAdapter.addAll(results);
+
+                if (currentPage <= TOTAL_PAGES) paginationAdapter.addLoadingFooter();
+                else isLastPage = true;
+            }
+
+            @Override
+            public void onFailure(Call<List<Movie>> call, Throwable t) {
+
+            }
+
+        });
+    }
+
+}

PagingnationInRecyclerview/app/src/main/java/velmm/com/pagingnationinrecyclerview/PaginationAdapter.java

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+package velmm.com.pagingnationinrecyclerview;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+import android.support.v7.widget.RecyclerView;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+
+import com.bumptech.glide.Glide;
+import com.bumptech.glide.request.RequestOptions;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import velmm.com.pagingnationinrecyclerview.model.Movie;
+
+public class PaginationAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
+
+    private Context context;
+    private List<Movie> movieList;
+    private static final int LOADING = 0;
+    private static final int ITEM = 1;
+    private boolean isLoadingAdded = false;
+
+    public PaginationAdapter(Context context) {
+        this.context = context;
+        movieList = new LinkedList<>();
+    }
+
+    public void setMovieList(List<Movie> movieList) {
+        this.movieList = movieList;
+    }
+
+    @NonNull
+    @Override
+    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        RecyclerView.ViewHolder viewHolder = null;
+        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
+
+        switch (viewType) {
+            case ITEM:
+                View viewItem = inflater.inflate(R.layout.item_list, parent, false);
+                viewHolder = new MovieViewHolder(viewItem);
+                break;
+            case LOADING:
+                View viewLoading = inflater.inflate(R.layout.item_progress, parent, false);
+                viewHolder = new LoadingViewHolder(viewLoading);
+                break;
+        }
+        return viewHolder;
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
+
+        Movie movie = movieList.get(position);
+        switch (getItemViewType(position)) {
+            case ITEM:
+                MovieViewHolder movieViewHolder = (MovieViewHolder) holder;
+                movieViewHolder.movieTitle.setText(movie.getTitle());
+                Glide.with(context).load(movie.getImageUrl()).apply(RequestOptions.centerCropTransform()).into(movieViewHolder.movieImage);
+                break;
+
+            case LOADING:
+                LoadingViewHolder loadingViewHolder = (LoadingViewHolder) holder;
+                loadingViewHolder.progressBar.setVisibility(View.VISIBLE);
+                break;
+        }
+    }
+
+    @Override
+    public int getItemCount() {
+        return movieList == null ? 0 : movieList.size();
+    }
+
+    @Override
+    public int getItemViewType(int position) {
+        return (position == movieList.size() - 1 && isLoadingAdded) ? LOADING : ITEM;
+    }
+
+    public void addLoadingFooter() {
+        isLoadingAdded = true;
+        add(new Movie());
+    }
+
+    public void removeLoadingFooter() {
+        isLoadingAdded = false;
+
+        int position = movieList.size() - 1;
+        Movie result = getItem(position);
+
+        if (result != null) {
+            movieList.remove(position);
+            notifyItemRemoved(position);
+        }
+    }
+
+    public void add(Movie movie) {
+        movieList.add(movie);
+        notifyItemInserted(movieList.size() - 1);
+    }
+
+    public void addAll(List<Movie> moveResults) {
+        for (Movie result : moveResults) {
+            add(result);
+        }
+    }
+
+    public Movie getItem(int position) {
+        return movieList.get(position);
+    }
+
+
+    public class MovieViewHolder extends RecyclerView.ViewHolder {
+
+        private TextView movieTitle;
+        private ImageView movieImage;
+
+        public MovieViewHolder(View itemView) {
+            super(itemView);
+            movieTitle = (TextView) itemView.findViewById(R.id.movie_title);
+            movieImage = (ImageView) itemView.findViewById(R.id.movie_poster);
+        }
+    }
+
+    public class LoadingViewHolder extends RecyclerView.ViewHolder {
+
+        private ProgressBar progressBar;
+
+        public LoadingViewHolder(View itemView) {
+            super(itemView);
+            progressBar = (ProgressBar) itemView.findViewById(R.id.loadmore_progress);
+
+        }
+    }
+
+
+}