Display PDF using PdfRenderer

The class android.graphics.pdf.PdfRenderer enables rendering a PDF document. This example show how to:


MainActivity.java

package com.blogspot.android_er.androidpdf;

import android.graphics.Bitmap;
import android.graphics.pdf.PdfRenderer;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    String targetPdf = "/sdcard/MagPi54.pdf";

    ImageView pdfView;

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

        pdfView = (ImageView)findViewById(R.id.pdfview);

        try {
            openPDF();
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this,
                    "Something Wrong: " + e.toString(),
                    Toast.LENGTH_LONG).show();
        }
    }

    private void openPDF() throws IOException {
        File file = new File(targetPdf);

        ParcelFileDescriptor fileDescriptor = null;
        fileDescriptor = ParcelFileDescriptor.open(
                file, ParcelFileDescriptor.MODE_READ_ONLY);

        //min. API Level 21
        PdfRenderer pdfRenderer = null;
        pdfRenderer = new PdfRenderer(fileDescriptor);

        final int pageCount = pdfRenderer.getPageCount();
        Toast.makeText(this,
                "pageCount = " + pageCount,
                Toast.LENGTH_LONG).show();

        //Display page 0
        PdfRenderer.Page rendererPage = pdfRenderer.openPage(0);
        int rendererPageWidth = rendererPage.getWidth();
        int rendererPageHeight = rendererPage.getHeight();
        Bitmap bitmap = Bitmap.createBitmap(
                rendererPageWidth,
                rendererPageHeight,
                Bitmap.Config.ARGB_8888);
        rendererPage.render(bitmap, null, null,
                PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);

        pdfView.setImageBitmap(bitmap);
        rendererPage.close();

        pdfRenderer.close();
        fileDescriptor.close();
    }
}

layout/activity_main.xml, add a ImageView to display the PDF:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidpdf.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold"/>

    <ImageView
        android:id="@+id/pdfview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

uses-permission of "android.permission.READ_EXTERNAL_STORAGE" is needed in AndroidManifest.xml to read file from sdcard.

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

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

</manifest>

Next:
- Display PDF in assets folder (inside APK)

Related:
- Create PDF using PdfDocument