Java tutorial
/* * Copyright 2011-2013 the original author or authors. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.feathercoin.wallet.feathercoin.ui; import java.math.BigInteger; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android.database.Cursor; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.v4.app.Fragment; import android.support.v4.app.LoaderManager; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.AsyncTaskLoader; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import com.feathercoin.wallet.feathercoin.Constants; import com.feathercoin.wallet.feathercoin.ExchangeRatesProvider; import com.feathercoin.wallet.feathercoin.WalletApplication; import com.feathercoin.wallet.feathercoin.util.ThrottelingWalletChangeListener; import com.feathercoin.wallet.feathercoin.util.WalletUtils; import com.google.feathercoin.core.Wallet; import com.google.feathercoin.core.Wallet.BalanceType; import de.schildbach.wallet.feathercoin.R; /** * @author Andreas Schildbach */ public final class WalletBalanceFragment extends Fragment { private WalletApplication application; private AbstractWalletActivity activity; private Wallet wallet; private SharedPreferences prefs; private LoaderManager loaderManager; private CurrencyTextView viewBalance; private CurrencyTextView viewBalanceLocal; private boolean showLocalBalance; private BigInteger balance = null; private ExchangeRatesProvider.ExchangeRate exchangeRate = null; private static final int ID_BALANCE_LOADER = 0; private static final int ID_RATE_LOADER = 1; @Override public void onAttach(final Activity activity) { super.onAttach(activity); this.activity = (AbstractWalletActivity) activity; this.application = (WalletApplication) activity.getApplication(); this.wallet = application.getWallet(); this.prefs = PreferenceManager.getDefaultSharedPreferences(activity); this.loaderManager = getLoaderManager(); showLocalBalance = getResources().getBoolean(R.bool.show_local_balance); } @Override public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) { final View view = inflater.inflate(R.layout.wallet_balance_fragment, container, false); final boolean showExchangeRatesOption = getResources().getBoolean(R.bool.show_exchange_rates_option); if (showExchangeRatesOption) { view.setOnClickListener(new OnClickListener() { public void onClick(final View v) { startActivity(new Intent(getActivity(), ExchangeRatesActivity.class)); } }); } else { view.setEnabled(false); } return view; } @Override public void onViewCreated(final View view, final Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); viewBalance = (CurrencyTextView) view.findViewById(R.id.wallet_balance); viewBalance.setPrefix(Constants.CURRENCY_CODE_FEATHERCOIN); viewBalanceLocal = (CurrencyTextView) view.findViewById(R.id.wallet_balance_local); viewBalanceLocal.setPrecision(Constants.LOCAL_PRECISION); viewBalanceLocal.setInsignificantRelativeSize(1); viewBalanceLocal.setStrikeThru(Constants.TEST); } @Override public void onResume() { super.onResume(); loaderManager.initLoader(ID_BALANCE_LOADER, null, balanceLoaderCallbacks); loaderManager.initLoader(ID_RATE_LOADER, null, rateLoaderCallbacks); updateView(); } @Override public void onPause() { loaderManager.destroyLoader(ID_RATE_LOADER); loaderManager.destroyLoader(ID_BALANCE_LOADER); super.onPause(); } private void updateView() { if (!showLocalBalance) viewBalanceLocal.setVisibility(View.GONE); if (balance != null) { viewBalance.setVisibility(View.VISIBLE); viewBalance.setPrecision(Integer.parseInt( prefs.getString(Constants.PREFS_KEY_FTC_PRECISION, Integer.toString(Constants.FTC_PRECISION)))); viewBalance.setAmount(balance); if (showLocalBalance) { if (exchangeRate != null) { final BigInteger localValue = WalletUtils.localValue(balance, exchangeRate.rate); viewBalanceLocal.setVisibility(View.VISIBLE); viewBalanceLocal.setPrefix(Constants.PREFIX_ALMOST_EQUAL_TO + exchangeRate.currencyCode); viewBalanceLocal.setAmount(localValue); viewBalanceLocal.setTextColor(getResources().getColor(R.color.fg_less_significant)); } else { viewBalanceLocal.setVisibility(View.INVISIBLE); } } } else { viewBalance.setVisibility(View.INVISIBLE); } } private static class BalanceLoader extends AsyncTaskLoader<BigInteger> { private final Wallet wallet; private BalanceLoader(final Context context, final Wallet wallet) { super(context); this.wallet = wallet; } @Override protected void onStartLoading() { super.onStartLoading(); wallet.addEventListener(walletChangeListener); forceLoad(); } @Override protected void onStopLoading() { wallet.removeEventListener(walletChangeListener); walletChangeListener.removeCallbacks(); super.onStopLoading(); } @Override public BigInteger loadInBackground() { return wallet.getBalance(BalanceType.ESTIMATED); } private final ThrottelingWalletChangeListener walletChangeListener = new ThrottelingWalletChangeListener() { @Override public void onThrotteledWalletChanged() { forceLoad(); } }; } private final LoaderCallbacks<BigInteger> balanceLoaderCallbacks = new LoaderManager.LoaderCallbacks<BigInteger>() { public Loader<BigInteger> onCreateLoader(final int id, final Bundle args) { return new BalanceLoader(activity, wallet); } public void onLoadFinished(final Loader<BigInteger> loader, final BigInteger balance) { WalletBalanceFragment.this.balance = balance; updateView(); } public void onLoaderReset(final Loader<BigInteger> loader) { } }; private static class RateLoader extends CursorLoader implements OnSharedPreferenceChangeListener { private final SharedPreferences prefs; public RateLoader(final Context context) { super(context, ExchangeRatesProvider.contentUri(context.getPackageName()), null, ExchangeRatesProvider.KEY_CURRENCY_CODE, null, null); prefs = PreferenceManager.getDefaultSharedPreferences(context); onCurrencyChange(); } @Override protected void onStartLoading() { super.onStartLoading(); prefs.registerOnSharedPreferenceChangeListener(this); forceLoad(); } @Override protected void onStopLoading() { prefs.unregisterOnSharedPreferenceChangeListener(this); super.onStopLoading(); } public void onSharedPreferenceChanged(final SharedPreferences sharedPreferences, final String key) { if (Constants.PREFS_KEY_EXCHANGE_CURRENCY.equals(key)) { cancelLoad(); onCurrencyChange(); forceLoad(); } } private void onCurrencyChange() { final String exchangeCurrency = prefs.getString(Constants.PREFS_KEY_EXCHANGE_CURRENCY, Constants.DEFAULT_EXCHANGE_CURRENCY); setSelectionArgs(new String[] { exchangeCurrency }); } } private final LoaderCallbacks<Cursor> rateLoaderCallbacks = new LoaderManager.LoaderCallbacks<Cursor>() { public Loader<Cursor> onCreateLoader(final int id, final Bundle args) { return new RateLoader(activity); } public void onLoadFinished(final Loader<Cursor> loader, final Cursor data) { if (data != null) { data.moveToFirst(); exchangeRate = ExchangeRatesProvider.getExchangeRate(data); updateView(); } } public void onLoaderReset(final Loader<Cursor> loader) { } }; }