Java tutorial
/** The MIT License (MIT) Copyright (c) 2013 Valentin Konovalov Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.*/ package ru.valle.safetrade; import android.app.AlertDialog; import android.content.ActivityNotFoundException; import android.content.ClipData; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.graphics.Bitmap; import android.net.Uri; import android.os.AsyncTask; import android.os.Build; import android.os.Bundle; import android.provider.BaseColumns; import android.support.v4.app.FragmentActivity; import android.text.TextUtils; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import com.d_project.qrcode.ErrorCorrectLevel; import com.d_project.qrcode.QRCode; import ru.valle.btc.BTCUtils; import java.io.ByteArrayOutputStream; import java.io.FileOutputStream; import java.util.ArrayList; public class BuyActivity extends FragmentActivity { private long rowId; private AsyncTask<Void, Void, TradeRecord> loadStateTask; private TextView intermediateCodeView; private TextView encryptedPrivateKeyView; private TextView addressView; private TextView confirmationCodeView; private TradeRecord tradeInfo; private TextView balanceView; private static final String TAG = "BuyActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.buy); intermediateCodeView = (TextView) findViewById(R.id.intermediate_code); confirmationCodeView = (TextView) findViewById(R.id.confirmation_code); addressView = (TextView) findViewById(R.id.address); encryptedPrivateKeyView = (TextView) findViewById(R.id.encrypted_private_key); balanceView = (TextView) findViewById(R.id.balance); findViewById(R.id.send_confirmation_code_button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { sendConfirmationCode(); } }); findViewById(R.id.send_encrypted_private_key_button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { sendEncryptedPrivateKey(); } }); findViewById(R.id.deposit_button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (tradeInfo == null || TextUtils.isEmpty(tradeInfo.address)) { new AlertDialog.Builder(BuyActivity.this) .setMessage(getString(R.string.buy_state_still_loading)) .setPositiveButton(android.R.string.ok, null).show(); } else { depositFunds(tradeInfo.address); } } }); findViewById(R.id.show_qr_code_button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (tradeInfo == null || TextUtils.isEmpty(tradeInfo.address)) { new AlertDialog.Builder(BuyActivity.this) .setMessage(getString(R.string.buy_state_still_loading)) .setPositiveButton(android.R.string.ok, null).show(); } else { showQrCode(tradeInfo.address); } } }); rowId = getIntent().getLongExtra(BaseColumns._ID, -1); } private void showQrCode(final String address) { QRCode qr = new QRCode(); qr.setTypeNumber(3); qr.setErrorCorrectLevel(ErrorCorrectLevel.M); qr.addData(address); qr.make(); Bitmap bmp = qr.createImage((int) (300 * getResources().getDisplayMetrics().density)); View view = LayoutInflater.from(this).inflate(R.layout.address_qr_code_popup, null); ((ImageView) view.findViewById(R.id.image)).setImageBitmap(bmp); new AlertDialog.Builder(BuyActivity.this).setTitle(address).setView(view) .setPositiveButton(R.string.copy, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { copyTextToClipboard(address, address); Toast.makeText(BuyActivity.this, getString(R.string.address_copied_to_clipboard), Toast.LENGTH_SHORT).show(); } }).setNegativeButton(android.R.string.cancel, null).show(); } @SuppressWarnings("deprecation") private void copyTextToClipboard(String label, String text) { if (Build.VERSION.SDK_INT >= 11) { android.content.ClipboardManager clipboard = (android.content.ClipboardManager) getSystemService( Context.CLIPBOARD_SERVICE); ClipData clip = ClipData.newPlainText(label, text); clipboard.setPrimaryClip(clip); } else { android.text.ClipboardManager clipboard = (android.text.ClipboardManager) getSystemService( Context.CLIPBOARD_SERVICE); clipboard.setText(text); } } private void depositFunds(final String address) { try { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("bitcoin:" + address)); startActivity(intent); } catch (ActivityNotFoundException e) { new AlertDialog.Builder(BuyActivity.this).setMessage(getString(R.string.no_wallet_installed)) .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { try { Intent intent = new Intent(Intent.ACTION_SEND); intent.putExtra(Intent.EXTRA_TEXT, address); startActivity(intent); } catch (ActivityNotFoundException e) { Toast.makeText(BuyActivity.this, getString(R.string.no_email_clients), Toast.LENGTH_SHORT).show(); } } }).setNegativeButton(android.R.string.cancel, null).show(); } } private void sendEncryptedPrivateKey() { final String encryptedPrivateKey = tradeInfo.encryptedPrivateKey; new AsyncTask<Void, Void, Uri>() { @Override protected Uri doInBackground(Void... params) { try { QRCode qr = new QRCode(); qr.setTypeNumber(5); qr.setErrorCorrectLevel(ErrorCorrectLevel.M); qr.addData(encryptedPrivateKey); qr.make(); Bitmap bmp = qr.createImage(640); ByteArrayOutputStream baos = new ByteArrayOutputStream(); bmp.compress(Bitmap.CompressFormat.PNG, 100, baos); byte[] pngBytes = baos.toByteArray(); if (pngBytes != null && pngBytes.length > 0) { String fileName = BTCUtils.toHex(BTCUtils.doubleSha256(encryptedPrivateKey.getBytes())) + QRCodesProvider.PRIVATE_KEY_FEATURE + QRCodesProvider.FILENAME_SUFFIX; deleteFile(fileName); FileOutputStream fos = openFileOutput(fileName, Context.MODE_PRIVATE); fos.write(pngBytes); fos.close(); return Uri.parse(QRCodesProvider.getUri(fileName)); } } catch (Exception e) { Log.e(TAG, "Unable to create QR code", e); } return null; } @Override protected void onPostExecute(Uri uri) { Intent intent = new Intent(Intent.ACTION_SEND); if (uri != null) { intent.putExtra(Intent.EXTRA_STREAM, uri); } intent.putExtra(Intent.EXTRA_SUBJECT, "Encrypted private key"); intent.putExtra(Intent.EXTRA_TEXT, encryptedPrivateKey); intent.setType("message/rfc822"); try { startActivity(intent); } catch (ActivityNotFoundException ex) { Toast.makeText(BuyActivity.this, getString(R.string.no_email_clients), Toast.LENGTH_SHORT) .show(); } } }.execute(); } @Override protected void onResume() { super.onResume(); if (rowId != -1) { loadState(rowId); } } private void loadState(final long id) { cancelAllTasks(); loadStateTask = new AsyncTask<Void, Void, TradeRecord>() { @Override protected TradeRecord doInBackground(Void... params) { SQLiteDatabase db = DatabaseHelper.getInstance(BuyActivity.this).getReadableDatabase(); Cursor cursor = db.query(DatabaseHelper.TABLE_HISTORY, null, BaseColumns._ID + "=?", new String[] { String.valueOf(id) }, null, null, null); ArrayList<TradeRecord> tradeRecords = DatabaseHelper.readTradeRecords(cursor); return tradeRecords.isEmpty() ? null : tradeRecords.get(0); } @Override protected void onPostExecute(TradeRecord tradeRecord) { tradeInfo = tradeRecord; loadStateTask = null; rowId = tradeRecord.id; encryptedPrivateKeyView.setText(tradeRecord.encryptedPrivateKey); addressView.setText(tradeRecord.address); confirmationCodeView.setText(tradeRecord.confirmationCode); intermediateCodeView.setText(tradeRecord.intermediateCode); MainActivity.updateBalance(BuyActivity.this, id, tradeInfo.address, new Listener<AddressState>() { @Override public void onSuccess(AddressState result) { if (result != null) { balanceView.setText(BTCUtils.formatValue(result.getBalance()) + " BTC"); } } }); } }; if (Build.VERSION.SDK_INT >= 11) { loadStateTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR); } else { loadStateTask.execute(); } } private void cancelAllTasks() { if (loadStateTask != null) { loadStateTask.cancel(true); loadStateTask = null; } } private void sendConfirmationCode() { if (tradeInfo != null) { final String confirmationCode = tradeInfo.confirmationCode; new AsyncTask<Void, Void, Uri>() { @Override protected Uri doInBackground(Void... params) { try { QRCode qr = new QRCode(); qr.setTypeNumber(5); qr.setErrorCorrectLevel(ErrorCorrectLevel.M); qr.addData(confirmationCode); qr.make(); Bitmap bmp = qr.createImage(640); ByteArrayOutputStream baos = new ByteArrayOutputStream(); bmp.compress(Bitmap.CompressFormat.PNG, 100, baos); byte[] pngBytes = baos.toByteArray(); if (pngBytes != null && pngBytes.length > 0) { String fileName = BTCUtils.toHex(BTCUtils.doubleSha256(confirmationCode.getBytes())) + QRCodesProvider.CONFIRMATION_FEATURE + QRCodesProvider.FILENAME_SUFFIX; deleteFile(fileName); FileOutputStream fos = openFileOutput(fileName, Context.MODE_PRIVATE); fos.write(pngBytes); fos.close(); return Uri.parse(QRCodesProvider.getUri(fileName)); } } catch (Exception e) { Log.e(TAG, "Unable to create QR code", e); } return null; } @Override protected void onPostExecute(Uri uri) { Intent intent = new Intent(Intent.ACTION_SEND); if (uri != null) { intent.putExtra(Intent.EXTRA_STREAM, uri); } intent.putExtra(Intent.EXTRA_SUBJECT, "Confirmation code"); intent.putExtra(Intent.EXTRA_TEXT, confirmationCode); intent.setType("message/rfc822"); try { startActivity(intent); } catch (ActivityNotFoundException ex) { Toast.makeText(BuyActivity.this, getString(R.string.no_email_clients), Toast.LENGTH_SHORT) .show(); } } }.execute(); } } }