PDF Viewer via Pdf-Reader---Writer in Android

Question

I have to implement PDF viewer library in project I am following https://github.com/bhavyahmehta/Pdf-Reader---Writer/blob/master/Pdf_%20Reader_Writer/README.md In this example they are creating PDF and loading in viewer. Actually I understood how library works Here is the below snippet of code for creating and loading PDF from library:

            @Override
    protected Void doInBackground(Void... params)
    {
    String pdfcontent = generateHelloWorldPDF(); //generating pdf content
    outputToFile("PdfSample.pdf",pdfcontent,"ISO-8859-1"); //passing pdf name and content
        return null;
    }

          private String generateHelloWorldPDF() 
          { //function returns pdf content with pages
        PDFWriter mPDFWriter = new PDFWriter(PaperSize.FOLIO_WIDTH, PaperSize.FOLIO_HEIGHT);


    try {
        // all image formates are supported
        Bitmap i1 = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);   
        mPDFWriter.addImage(40, 60, i1, Transformation.DEGREES_315_ROTATION);
        mPDFWriter.addImage(72, 72, i1);
        mPDFWriter.addImage(200, 400, 135, 75, i1);
        mPDFWriter.addImage(150, 300, 130, 70, i1);
        mPDFWriter.addImageKeepRatio(100, 200, 50, 25, i1);
        mPDFWriter.addImageKeepRatio(50, 100, 30, 25, i1, Transformation.DEGREES_270_ROTATION);
        mPDFWriter.addImageKeepRatio(25, 50, 30, 25, i1);
    } catch (Exception e) {
        e.printStackTrace();
    }

    mPDFWriter.setFont(StandardFonts.SUBTYPE, StandardFonts.TIMES_ROMAN);
    mPDFWriter.addRawContent("row content \n");
    mPDFWriter.addText(70, 50, 12, "hello world");
    mPDFWriter.setFont(StandardFonts.SUBTYPE, StandardFonts.COURIER, StandardFonts.WIN_ANSI_ENCODING);
    mPDFWriter.addRawContent("row content rg\n");
    mPDFWriter.addText(30, 90, 10, "� CRL", Transformation.DEGREES_270_ROTATION);

    mPDFWriter.newPage();
    mPDFWriter.addRawContent("[] 0 d\n");
    mPDFWriter.addRawContent("1 w\n");
    mPDFWriter.addRawContent("0 0 1 RG\n");
    mPDFWriter.addRawContent("0 1 0 rg\n");
    mPDFWriter.addRectangle(40, 50, 280, 50);
    mPDFWriter.addText(85, 75, 18, "Android Docs");

    mPDFWriter.newPage();
    mPDFWriter.setFont(StandardFonts.SUBTYPE, StandardFonts.COURIER_BOLD);
   // mPDFWriter.addText(150, 150, 14, "http://coderesearchlabs.com");
    mPDFWriter.addLine(150, 140, 300, 140);

    String s = mPDFWriter.asString();
    return s;
}


         private void outputToFile(String fileName, String pdfContent, String encoding)        { //function which pushes the file to below path
    //System.out.println("content" +fileName);
   if(isSDPresent)
   {

       try {
                File dir = new File(Environment.getExternalStorageDirectory() + "/pdf_Writer_Reader/");
                if (!dir.exists())
                {
                    dir.mkdirs();
                }

                newFile = new File(dir,fileName);
                if(!newFile.exists())
                {
                    newFile.createNewFile();
                }

               try
               {
                    FileOutputStream pdfFile = new FileOutputStream(newFile);
                    pdfFile.write(pdfContent.getBytes(encoding));               
                    pdfFile.close();
               }
               catch(FileNotFoundException e) {
                Log.e("Ex==",""+e.toString());
               }
       } 
       catch(IOException e)
       {
        Log.e("Ex==",""+e.toString());
       }
   }

can anybody suggest on how to load PDF from sdcard any help will be thankful.

Answer 1

The project you mentioned on GitHub is based on MuPDF library. In the same GitHub project you have an example of reading a pdf in an Activity - MuPDFActivity The part of the Activity which reads the PDF is at the start -

private MuPDFCore openFile(String path)
{
    int lastSlashPos = path.lastIndexOf('/');
    mFileName = new String(lastSlashPos == -1? path : path.substring(lastSlashPos+1));
    System.out.println("Trying to open "+path);
    try
    {
        core = new MuPDFCore(path);
        // New file: drop the old outline data
        OutlineActivityData.set(null);
    }
    catch (Exception e)
    {
        System.out.println(e);
        return null;
    }
    return core;
}

Using the MuPDFCore instance you call

    public static native void drawPage(Bitmap bitmap, int pageW, int pageH, 
int patchX, int patchY,
int patchW, int patchH);

to write the particular page on the bitmap. To know more check the project which has a working sample to display pdfs.