How I can make compatible my BookPDF.class to `Fragment` for `Navigation Drawer`.

Question

Q1. How I can make compatible my BookPDF.class to Fragment for Navigation Drawer .
Q2. I wanna use Intent intent = new Intent (MainActivity.this, BookPDF.class); to call BookPDF.class, but it won't work.

I'm using "AndroidPdfViewer" project from https://github.com/barteksc/AndroidPdfViewer

This is my MainActivity

public class MainActivity extends AppCompatActivity {

private static Button new_bookpdf;

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

public void onClickButtonListener() {
    new_bookpdf = (Button) findViewById(R.id.but_book);
    new_bookpdf.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent("ahmer.afzal.books.BookPDF");
            startActivity(intent);                
        }
    });
}
}

This is my BookPDF.class

@EActivity(R.layout.activity_pdf)
@OptionsMenu(R.menu.options)
public class BookPDF extends AppCompatActivity implements OnPageChangeListener, OnLoadCompleteListener {
private static final String TAG = BookPDF.class.getSimpleName();
private final static int REQUEST_CODE = 42;
public static final int PERMISSION_CODE = 42042;
public static final String SAMPLE_FILE = "book.pdf";
public static final String READ_EXTERNAL_STORAGE = "android.permission.READ_EXTERNAL_STORAGE";
@ViewById
PDFView pdfView;
@NonConfigurationInstance
Uri uri;
@NonConfigurationInstance
Integer pageNumber = 0;
String pdfFileName;
@OptionsItem(R.id.pickFile)
void pickFile() {
    int permissionCheck = ContextCompat.checkSelfPermission(this, READ_EXTERNAL_STORAGE);
    if (permissionCheck != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{READ_EXTERNAL_STORAGE}, PERMISSION_CODE);
        return;
    }
    launchPicker();
}

void launchPicker() {
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType("application/pdf");
    try {
        startActivityForResult(intent, REQUEST_CODE);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(this, R.string.toast_pick_file_error, Toast.LENGTH_SHORT).show();
    }
}

@AfterViews
void afterViews() {
    if (uri != null) {
        displayFromUri(uri);
    } else {
        displayFromAsset(SAMPLE_FILE);
    }
    setTitle(pdfFileName);
}

private void displayFromAsset(String assetFileName) {
    pdfFileName = assetFileName;
    pdfView.fromAsset(SAMPLE_FILE)
            .defaultPage(pageNumber)
            .onPageChange(this)
            .enableAnnotationRendering(true)
            .onLoad(this)
            .scrollHandle(new DefaultScrollHandle(this))
            .load();
}
private void displayFromUri(Uri uri) {
    pdfFileName = getFileName(uri);
    pdfView.fromUri(uri)
            .defaultPage(pageNumber)
            .onPageChange(this)
            .enableAnnotationRendering(true)
            .onLoad(this)
            .scrollHandle(new DefaultScrollHandle(this))
            .load();
}
@OnActivityResult(REQUEST_CODE)
public void onResult(int resultCode, Intent intent) {
    if (resultCode == RESULT_OK) {
        uri = intent.getData();
        displayFromUri(uri);
    }
}
@Override
public void onPageChanged(int page, int pageCount) {
    pageNumber = page;
    setTitle(String.format("%s %s / %s", "Page Number", page + 1, pageCount));
}
public String getFileName(Uri uri) {
    String result = null;
    if (uri.getScheme().equals("content")) {
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);
        try {
            if (cursor != null && cursor.moveToFirst()) {
                result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }
    if (result == null) {
        result = uri.getLastPathSegment();
    }
    return result;
}
@Override
public void loadComplete(int nbPages) {
    PdfDocument.Meta meta = pdfView.getDocumentMeta();
    Log.e(TAG, "title = " + meta.getTitle());
    Log.e(TAG, "author = " + meta.getAuthor());
    Log.e(TAG, "subject = " + meta.getSubject());
    Log.e(TAG, "keywords = " + meta.getKeywords());
    Log.e(TAG, "creator = " + meta.getCreator());
    Log.e(TAG, "producer = " + meta.getProducer());
    Log.e(TAG, "creationDate = " + meta.getCreationDate());
    Log.e(TAG, "modDate = " + meta.getModDate());
    printBookmarksTree(pdfView.getTableOfContents(), "-");
}

public void printBookmarksTree(List<PdfDocument.Bookmark> tree, String sep) {
    for (PdfDocument.Bookmark b : tree) {
        Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx()));
        if (b.hasChildren()) {
            printBookmarksTree(b.getChildren(), sep + "-");
        }
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
    if (requestCode == PERMISSION_CODE) {
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            launchPicker();
        }
    }
}
}

This is my Manifest.xml

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

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    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>
    <activity
        android:name="BookPDF_"
        android:screenOrientation="sensor">
        <intent-filter>
            <action android:name="ahmer.afzal.books.BookPDF" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>
</application>
</manifest>  

Please help me.

Answer 1

package ahmer.afzal.books;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.annotation.NonNull;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener
{
    private ProgressDialog progressDialog;
    DrawerLayout drawer;
    ActionBarDrawerToggle toggle;

    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();
        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
    }    

    @Override
    public void onBackPressed()
    {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START))
        {
            drawer.closeDrawer(GravityCompat.START);
        }
        else
        {
            super.onBackPressed();
        }
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState)
    {
        super.onPostCreate(savedInstanceState);
        toggle.syncState();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        if (toggle.onOptionsItemSelected(item))
        {
            return true;
        }

        if(item.getItemId() == R.id.action_settings)
        {
            startActivity(new Intent(this, SettingsActivity.class));
        }
        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item)
    {
        int id = item.getItemId();
        if (id == R.id.vocabulary)
        {
            Intent intent = new Intent("com.ahmer.books.BookPDF");
            startActivity(intent);
        }
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}