Android Open Source - nfc-reader-app Main Activity

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License

The source code is released under:

Copyright (c) 2014, University of Washington All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions...

Java Source Code

/**
 * /*from   ww  w.  ja  v  a2  s  . c om*/
 *   Modified the application, so it doesn't get reopened each time tag is connected
 * The screenshot conversion verified to work
 * 
 * the folder where screenshots are saved might change. (currently path is hardcoded for sdcard/screenshots/) 
 * 
 * This application doesn't take screenshots itself. It uses third party application: 
 * screenshot (by KasterSoft). Set the image to bmp format (no compression) 
 * It is possible to extract images from the frame buffer on rooted phone but I found it problematic. 
 * 
 * Tested on Galaxy Nexus (Samsung) and Nexus S (Samsung)
 */

package com.example.nfc_eink_demo;

///////////////////////////////////////////////////////////////////////////////
// IMPORTS
///////////////////////////////////////////////////////////////////////////////

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ShortBuffer;

import com.example.nfc_eink_demo.R;
import com.example.nfc_eink_demo.R.id;
import com.example.nfc_eink_demo.R.layout;
import com.example.nfc_eink_demo.R.menu;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.Matrix;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.IsoDep;

import android.os.Bundle;
import android.os.Environment;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.provider.Settings;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends Activity {

  ///////////////////////////////////////////////////////////////////////////////
  //CONSTANTS
  ///////////////////////////////////////////////////////////////////////////////
  private static final String TAG = "NFCWriteTag"; // Used in debugging?


  ///////////////////////////////////////////////////////////////////////////////
  // FIELDS
  ///////////////////////////////////////////////////////////////////////////////


  public TextView myStatusTextView;
  public IsoDep isoDep;
  
  private NfcAdapter mNfcAdapter; // Represents phone's NFC transceiver
  private IntentFilter[] mWriteTagFilters; 
  private PendingIntent mNfcPendingIntent; 
  private Context context;
  private ImageView mImage; 
  private byte[] imageBuffer; // Global for storing image data to relay to tag
  private PowerManager mPowerManager;
  private WakeLock mWakeLock;
  private SendFileToWISP fileSender;
  

  
  ///////////////////////////////////////////////////////////////////////////////
  // METHODS
  ///////////////////////////////////////////////////////////////////////////////

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

    context = getApplicationContext();
    
    mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);
    
    mWakeLock = mPowerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, getClass().getName());

    myStatusTextView = (TextView) findViewById(R.id.myStatusTextView);

    mImage = (ImageView) findViewById(R.id.imageView1);

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);

    mNfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
        getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP
            | Intent.FLAG_ACTIVITY_CLEAR_TOP), 0);

    IntentFilter discovery = new IntentFilter(
        NfcAdapter.ACTION_TAG_DISCOVERED);
    
    fileSender = new SendFileToWISP(this);

    // Intent filters for writing to a tag
    mWriteTagFilters = new IntentFilter[] { discovery };

    retrieveScreenShot();
    Log.d(TAG, "START");
  }

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

  /**
   * 
   */
  @Override
  protected void onResume() {
    super.onResume();
    
    mWakeLock.acquire(); // Keep the phone awake while app is active

    if (mNfcAdapter != null) {
      if (!mNfcAdapter.isEnabled()) {
        Intent setnfc = new Intent(Settings.ACTION_WIRELESS_SETTINGS);
        startActivity(setnfc);
      }
      mNfcAdapter.enableForegroundDispatch(this, mNfcPendingIntent,
          mWriteTagFilters, null);
    } else {
      Toast.makeText(context, "Sorry, No NFC Adapter found.",
          Toast.LENGTH_SHORT).show();
    }// end if

  }// on resume end

  /**
   * 
   */
  @Override
  protected void onPause() {
    super.onPause();
    
    mWakeLock.release(); // Let the phone go to sleep
    
    if (mNfcAdapter != null)
      mNfcAdapter.disableForegroundDispatch(this);
  }

  /**
   * 
   */
  @Override
  protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    Log.d(TAG, "onNewIntent Called");
    if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())) {
      // validate that this tag can be written....
      myStatusTextView.setText("tag detected");
      Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
      Log.d(TAG, detectedTag.toString());
      Log.d(TAG, detectedTag.getTechList().toString());

      this.isoDep = IsoDep.get(detectedTag);

      // Have the background task send the image
      fileSender.execute(imageBuffer);

    }// end if

  }// end onNewIntent



  /**
   * Convert screenshot or image to the eink format
   * 
   * @todo optimize this function
   */
  public void retrieveScreenShot() {

    // Find the latest file
    // Delete the info.txt file and config.dat to avoid
    File dir = new File("/sdcard/screenshots");
    File f = new File("/sdcard/screenshots/info.txt");
    f.delete();
    File g = new File("/sdcard/screenshots/config.dat");
    g.delete();

    // Find the last modified file, presumably with the latest image
    File[] files = dir.listFiles();
    if (files.length == 0) {
      Log.d("TEST", "No files");
    }

    File lastModifiedFile = files[0];

    for (int i = 1; i < files.length; i++) {
      if (lastModifiedFile.lastModified() < files[i].lastModified()) {

        lastModifiedFile = files[i];
      }
    }

    Log.d("TEST", lastModifiedFile.toString());

    Bitmap image;
    Bitmap image_rotated;
    Bitmap image_rotated_resized;
    Bitmap image_rotated_resized_monochrome;
    image = BitmapFactory.decodeFile(lastModifiedFile.toString());
    image_rotated = ImageManipulation.rotate(image, 90);
    image_rotated_resized = ImageManipulation.getResizedBitmap(
        image_rotated, 176, 264);

    image_rotated_resized_monochrome = ImageManipulation
        .createBlackAndWhite(image_rotated_resized);

    mImage.setImageBitmap(ImageManipulation.rotate(
        image_rotated_resized_monochrome, 270)); // Update the screen
    // with the new
    // image

    int bytes = image_rotated_resized_monochrome.getRowBytes()
        * image_rotated_resized_monochrome.getHeight();

    ByteBuffer buffer = ByteBuffer.allocate(bytes);
    image_rotated_resized_monochrome.copyPixelsToBuffer(buffer);
    byte[] array = buffer.array();
    Log.d("TEST", "Array length: " + Integer.toString(array.length));
    String foo = "";

    String test = "";
    int count = 0;
    int count_bytes = 0;
    byte[] image_array = new byte[33 * image_rotated_resized_monochrome.getHeight()];

    // TODO Rewrite the following more efficiently (Without string conversion and int parsing, etc)

    // For each line in the image
    for (int m = 0; m < image_rotated_resized_monochrome.getHeight(); m++) {

      // For each pixel of each line
      for (int i = 0; i < image_rotated_resized_monochrome.getWidth(); i++) {

        if (image_rotated_resized_monochrome.getPixel(i, m) == -1) {
          test = test.concat("0");

        }// end if
        else {
          test = test.concat("1");
        }// end else

        count++;

        // Assemble a byte
        if (count == 8) {

          count = 0;
          test = Utilities.reverse(test);
          // Log.d("TEST", "teststring: " + test);
          byte numberByte = (byte) Integer.parseInt(test, 2);
          // System.out.println(numberByte);
          image_array[count_bytes] = numberByte;
          // numberByte.toString();
          count_bytes++;
          test = "";
        }// end if

      }// end for
    }// end for

    Log.d("TEST", Integer.toString(count_bytes));
    imageBuffer = image_array;
    Log.d("TEST", Integer.toString(foo.length()));

    foo = Utilities.getHexParsed(image_array);
    try {
      // TODO Don't use hardcoded /sdcard/ path, or any hardcoded path here!
      BufferedWriter out = new BufferedWriter(new FileWriter(
          "/sdcard/byteArrayImage.txt"));
      out.write(foo);
      out.close();
    } catch (IOException e) {
    }

  }// end takescreenshot

};// end class

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