How to use your library about android-pdf-viewer-library HOT 5 OPEN

private ImageButton refreshButton;
private Button fireCreationButton;
private EditText fireCreationPath;
private TextView logTextView;
private ImageView previewImageView;

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

    refreshButton = (ImageButton) findViewById(R.id.refreshButton);
    fireCreationButton = (Button) findViewById(R.id.fireCreation);
    fireCreationButton.setEnabled(false);
    fireCreationPath = (EditText) findViewById(R.id.filePathEt);
    logTextView = (TextView) findViewById(R.id.logTv);
    previewImageView = (ImageView) findViewById(R.id.preview);

    final String externalDir = Environment.getExternalStorageDirectory().getAbsolutePath();
    final String fileName = externalDir + File.separator + "PDF-render_Test.pdf";
    fireCreationPath.setText(fileName);
    refreshButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            String filePath = fireCreationPath.getText().toString();
            File file = new File(filePath);
            if (null == file || !file.exists() || !file.canRead()){
                fireCreationPath.setError("The specified file does not exists or is not readable!");
                fireCreationButton.setEnabled(false);
                fireCreationPath.requestFocus();
            }else{
                fireCreationPath.setError(null);
                fireCreationButton.setEnabled(true);
            }
        }
    });

    fireCreationButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            logTextView.setText("Firing preview creation process...\n");
            String filePath = fireCreationPath.getText().toString();
            long startTime = System.currentTimeMillis();
            boolean result = processPreview(filePath);
            long endTime = System.currentTimeMillis(); 
            long delta = endTime - startTime;
            String elapsed =  DateUtils.formatElapsedTime(delta/1000);
            String resultText ="File '" + filePath + "' had a preview result of " + result; 
            logAndTrace(resultText);
            String finishText ="Finished creation of thumbnails in " + elapsed +" seconds"; 
            logAndTrace(finishText );
        }
    });
}

private boolean processPreview(String fullFilePath) {
    logAndTrace("File is : " + fullFilePath);
    int slash = fullFilePath.lastIndexOf(File.separator);
    String externalDir = fullFilePath.substring(0,slash);
    String pdfFileName = fullFilePath.substring(slash+1);
    logAndTrace("External dir is: " + externalDir + ", fileName is: "+pdfFileName);

    try {
        File f = new File(fullFilePath);
        if (!f.exists()){
            Log.e(TAG, "File '" + f.getAbsolutePath() + "' not found");
            throw new FileNotFoundException("The file does not exists");
        }
        long len = f.length();
        if (len == 0) {
            Log.e(TAG, "File '" + f.getAbsolutePath() + "' has no length");
            throw new IllegalArgumentException("File has no length");
        }
        // first open the file for random access
        RandomAccessFile raf = new RandomAccessFile(f, "r");
        // extract a file channel
        FileChannel channel = raf.getChannel();

        // now memory-map a byte-buffer
        //java.nio.ByteBuffer b1 = new java.nio.channels.FileChannel
        ByteBuffer bb = ByteBuffer.NEW(channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size()));
        // create a PDFFile from the data
        PDFFile mPdfFile = new PDFFile(bb);
        // draw the first page to an image
        PDFPage page = mPdfFile.getPage(1, true);
        // get the width and height for the doc at the default zoom

        logAndTrace("page");
        float width = page.getWidth();//*0.1f;
        float height = page.getHeight();//*0.1f;

        logAndTrace("pagesize");
        RectF clip = null;
        Bitmap pageImage = page.getImage((int) (width), (int) (height), clip, true, true);
        if(null==pageImage){
            logAndTrace("Image is null");
        }else{
            logAndTrace("Image is not null");
        }
        previewImageView.setImageBitmap(pageImage);
        OutputStream fOut = null;
        File file = new File(externalDir, pdfFileName + "_thumb.png");
        fOut = new FileOutputStream(file);
        logAndTrace("Image will be saved to:" + file.getAbsolutePath());
        pageImage.compress(Bitmap.CompressFormat.PNG, 99, fOut);
        fOut.flush();
        fOut.close();
        raf.close();

        // Add to mediastore
        MediaStore.Images.Media.insertImage(getContentResolver(), file.getAbsolutePath(), file.getName(), file.getName());
        //MediaStore.Images.Media.insertImage(getContentResolver(), pageImage, pdfFileName + "_thumb.png", pdfFileName + "_thumb.png");
        return true;
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
        return false;
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        return false;
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Log.e(TAG,"Exception while writing to device! "+e.getMessage());
        return false;
    } catch (NullPointerException np){
        Log.e(TAG, "Null pointer exception writing image!"+ np.getMessage());
        return false;
    }
}

private void logAndTrace(String message){
    if (null != logTextView){
        logTextView.append(message+"\n\n");
    }
    Log.d(TAG,message);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_launcher, menu);
    return true;
}