Android PDF Viewer library [closed]

Answer 1

Firstly to view a pdf in android you have to convert the pdf into images then display them to the user. (i am going to use a webview)

So to do this we need this library. It is my edited version of this git.

After you have imported the library into your project you need to create your activity.

The XML:

The java onCreate:

//Imports:
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.view.ViewTreeObserver;
import android.webkit.WebView;
import com.sun.pdfview.PDFFile;
import com.sun.pdfview.PDFImage;
import com.sun.pdfview.PDFPage;
import com.sun.pdfview.PDFPaint;
import net.sf.andpdf.nio.ByteBuffer;
import net.sf.andpdf.refs.HardReference;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;

//Globals:
private WebView wv;
private int ViewSize = 0;

//OnCreate Method:
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //Settings
    PDFImage.sShowImages = true; // show images
    PDFPaint.s_doAntiAlias = true; // make text smooth
    HardReference.sKeepCaches = true; // save images in cache

    //Setup webview
    wv = (WebView)findViewById(R.id.webView1);
    wv.getSettings().setBuiltInZoomControls(true);//show zoom buttons
    wv.getSettings().setSupportZoom(true);//allow zoom
    //get the width of the webview
    wv.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener()
    {
        @Override
        public void onGlobalLayout()
        {
            ViewSize = wv.getWidth();
            wv.getViewTreeObserver().removeGlobalOnLayoutListener(this);
        }
    });

    pdfLoadImages();//load images
}

Load Images:

private void pdfLoadImages()
{
    try
    {
        // run async
        new AsyncTask()
                {
                    // create and show a progress dialog
                    ProgressDialog progressDialog = ProgressDialog.show(MainActivity.this, "", "Opening...");

                    @Override
                    protected void onPostExecute(Void result)
                    {
                        //after async close progress dialog
                        progressDialog.dismiss();
                    }

                    @Override
                    protected Void doInBackground(Void... params)
                    {
                        try
                        {
                            // select a document and get bytes
                            File file = new File(Environment.getExternalStorageDirectory().getPath()+"/randompdf.pdf");
                            RandomAccessFile raf = new RandomAccessFile(file, "r");
                            FileChannel channel = raf.getChannel();
                            ByteBuffer bb = ByteBuffer.NEW(channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size()));
                            raf.close();
                            // create a pdf doc
                            PDFFile pdf = new PDFFile(bb);
                            //Get the first page from the pdf doc
                            PDFPage PDFpage = pdf.getPage(1, true);
                            //create a scaling value according to the WebView Width
                            final float scale = ViewSize / PDFpage.getWidth() * 0.95f;
                            //convert the page into a bitmap with a scaling value
                            Bitmap page = PDFpage.getImage((int)(PDFpage.getWidth() * scale), (int)(PDFpage.getHeight() * scale), null, true, true);
                            //save the bitmap to a byte array
                            ByteArrayOutputStream stream = new ByteArrayOutputStream();
                            page.compress(Bitmap.CompressFormat.PNG, 100, stream);
                            stream.close();
                            byte[] byteArray = stream.toByteArray();
                            //convert the byte array to a base64 string
                            String base64 = Base64.encodeToString(byteArray, Base64.DEFAULT);
                            //create the html + add the first image to the html
                            String html = "
";
                            //loop through the rest of the pages and repeat the above
                            for(int i = 2; i <= pdf.getNumPages(); i++)
                            {
                                PDFpage = pdf.getPage(i, true);
                                page = PDFpage.getImage((int)(PDFpage.getWidth() * scale), (int)(PDFpage.getHeight() * scale), null, true, true);
                                stream = new ByteArrayOutputStream();
                                page.compress(Bitmap.CompressFormat.PNG, 100, stream);
                                stream.close();
                                byteArray = stream.toByteArray();
                                base64 = Base64.encodeToString(byteArray, Base64.DEFAULT);
                                html += "
";
                            }
                            html += "";
                            //load the html in the webview
                            wv.loadDataWithBaseURL("", html, "text/html","UTF-8", "");
                    }
                    catch (Exception e)
                    {
                        Log.d("CounterA", e.toString());
                    }
                        return null;
                    }
                }.execute();
                System.gc();// run GC
    }
    catch (Exception e)
    {
        Log.d("error", e.toString());
    }
}