Java tutorial
/* * The MIT License (MIT) * * Copyright (c) 2014 by cochrane343 * * 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 cochrane343.journal; import android.app.AlertDialog; import android.content.ContentUris; import android.content.ContentValues; import android.content.DialogInterface; import android.content.Intent; import android.content.SharedPreferences; import android.net.Uri; import android.os.Bundle; import android.os.Parcelable; import android.preference.PreferenceManager; import android.support.v4.app.FragmentManager; import android.support.v4.view.ViewPager; import android.support.v7.app.ActionBarActivity; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.widget.CheckBox; import android.widget.Toast; import cochrane343.journal.contentprovider.JournalContract.Expense; import cochrane343.journal.dialogs.ExpenseDialogFragment; import cochrane343.journal.dialogs.ExpenseDialogListener; /** * @author cochrane343 */ public class MainActivity extends ActionBarActivity implements ExpenseEditListener, ExpenseDialogListener { private static final String BUNDLE_KEY_MONTHLY_PAGER_ADAPTER_STATE = "monthlyPagerAdapterState"; private static final String FRAGMENT_TAG_EXPENSE_DIALOG = "expenseDialog"; /** * The view pager used to swipe through months */ private ViewPager viewPager; private MonthlyExpensesPagerAdapter monthlyExpensesPagerAdapter; /* - - - - - Activity Lifecycle - - - - - - - - - - */ @Override protected void onCreate(final Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main_activity); monthlyExpensesPagerAdapter = new MonthlyExpensesPagerAdapter(getSupportFragmentManager()); viewPager = (ViewPager) findViewById(R.id.main_activity_view_pager); viewPager.setAdapter(monthlyExpensesPagerAdapter); if (savedInstanceState != null) { final Parcelable monthlyPagerAdapterState = savedInstanceState .getParcelable(BUNDLE_KEY_MONTHLY_PAGER_ADAPTER_STATE); monthlyExpensesPagerAdapter.restoreState(monthlyPagerAdapterState, getClassLoader()); } else { viewPager.setCurrentItem(DateTimeHelper.getMonthsSinceEpoch()); } } /** * Inflates the menu of this activity and adds action items to the action bar. */ @Override public boolean onCreateOptionsMenu(final Menu menu) { final MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.activity_main_actions, menu); return super.onCreateOptionsMenu(menu); } @Override public void onSaveInstanceState(final Bundle savedInstanceState) { savedInstanceState.putParcelable(BUNDLE_KEY_MONTHLY_PAGER_ADAPTER_STATE, monthlyExpensesPagerAdapter.saveState()); super.onSaveInstanceState(savedInstanceState); } /* - - - - - Expense Edit Listener - - - - - - - - - - */ @Override public void onAddExpense(final String description, final long costInCents, final long category) { final int selectedMonth = viewPager.getCurrentItem(); final boolean selectedMonthIsCurrentMonth = selectedMonth == DateTimeHelper.getMonthsSinceEpoch(); if (selectedMonthIsCurrentMonth) { addExpenseToCurrentMonth(description, costInCents, category); } else { if (shouldShowPastExpenseWarning()) { // TODO Consider refactoring into separate method final LayoutInflater inflater = LayoutInflater.from(this); final View warningLayout = inflater.inflate(R.layout.past_expense_warning, null); final CheckBox doNotAskAgainCheckbox = (CheckBox) warningLayout .findViewById(R.id.do_not_show_again); final AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setView(warningLayout).setTitle(R.string.label_past_expense) .setMessage(R.string.label_past_expense_message) .setPositiveButton(R.string.label_yes_add_to_past, new DialogInterface.OnClickListener() { public void onClick(final DialogInterface dialog, final int which) { if (doNotAskAgainCheckbox.isChecked()) { setShowPastExpenseWarning(false); } addExpenseToEndOfSelectedMonth(description, costInCents, category); } }) .setNegativeButton(R.string.label_no_add_to_current, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { if (doNotAskAgainCheckbox.isChecked()) { setShowPastExpenseWarning(false); } addExpenseToCurrentMonth(description, costInCents, category); } }).show(); } else { addExpenseToEndOfSelectedMonth(description, costInCents, category); } } } /** * Adds a new expense with a current timestamp. * Used to add expenses to the ongoing month. * @since 0.11.0 */ private void addExpenseToCurrentMonth(final String description, final long costInCents, final long category) { final long currentTimestamp = DateTimeHelper.getNow().getMillis(); addExpense(description, costInCents, category, currentTimestamp); } /** * Adds a new expense with the end of the currently selected month as timestamp. * Used to add expenses to past months. * @since 0.11.0 */ private void addExpenseToEndOfSelectedMonth(final String description, final long costInCents, final long category) { final int selectedMonth = viewPager.getCurrentItem(); final long endOfSelectedMonthTimestamp = DateTimeHelper.getEndOfMonth(selectedMonth).getMillis(); addExpense(description, costInCents, category, endOfSelectedMonthTimestamp); } /** * @since 0.11.0 */ private void addExpense(final String description, final long costInCents, final long category, final long timestamp) { final ContentValues newExpense = getContentValues(description, costInCents, category); newExpense.put(Expense._TIMESTAMP, timestamp); getContentResolver().insert(Expense.EXPENSES_URI, newExpense); Toast.makeText(this, R.string.toast_added_expense, Toast.LENGTH_SHORT).show(); } @Override public void onUpdateExpense(final long expenseId, final String description, final long costInCents, final long category) { final ContentValues newExpense = getContentValues(description, costInCents, category); final Uri uri = ContentUris.withAppendedId(Expense.EXPENSES_URI, expenseId); getContentResolver().update(uri, newExpense, null, null); Toast.makeText(this, R.string.toast_updated_expense, Toast.LENGTH_SHORT).show(); } private ContentValues getContentValues(final String description, final long costInCents, final long category) { final ContentValues newExpense = new ContentValues(); newExpense.put(Expense._DESCRIPTION, description); newExpense.put(Expense._COST, costInCents); newExpense.put(Expense._CATEGORY, category); return newExpense; } @Override public void onDeleteExpense(final long expenseId) { final Uri uri = ContentUris.withAppendedId(Expense.EXPENSES_URI, expenseId); getContentResolver().delete(uri, null, null); } /* - - - - - User Interface Callbacks - - - - - - - - - - */ /** * Handles presses on the action bar items. */ @Override public boolean onOptionsItemSelected(final MenuItem item) { switch (item.getItemId()) { case R.id.action_add_expense: showExpenseDialogForCreate(); return true; case R.id.action_settings: startActivity(new Intent(getApplicationContext(), SettingsActivity.class)); return true; default: return super.onOptionsItemSelected(item); } } /** * Callback method invoked when the activity has detected the user's press of the * back key. Forwards the event to the currently displayed {@link MonthlyExpensesFragment}. * Propagates the event further if the fragment does not consume it. * Used to allow the user to navigate from single category display back to the * category overview. */ @Override public void onBackPressed() { final MonthlyExpensesFragment currentFragment = (MonthlyExpensesFragment) monthlyExpensesPagerAdapter .instantiateItem(viewPager, viewPager.getCurrentItem()); final boolean backPressConsumed = currentFragment.onBackPressed(); if (!backPressConsumed) { super.onBackPressed(); } ; } /* - - - - - Expense Dialog - - - - - - - - - - */ @Override public void showExpenseDialogForCreate() { final FragmentManager fragmentManager = getSupportFragmentManager(); final ExpenseDialogFragment expenseDialog = ExpenseDialogFragment.newInstanceForCreate(); expenseDialog.show(fragmentManager, FRAGMENT_TAG_EXPENSE_DIALOG); } @Override public void showExpenseDialogForEdit(final long expenseId) { final FragmentManager fragmentManager = getSupportFragmentManager(); final ExpenseDialogFragment expenseDialog = ExpenseDialogFragment.newInstanceForEdit(expenseId); expenseDialog.show(fragmentManager, FRAGMENT_TAG_EXPENSE_DIALOG); } /* - - - - - Settings - - - - - - - - - - */ /** * Changes the setting for showing a warning when adding an expense to a past month. * @param shouldShowPastExpenseWarning true to enable the warning or false to disable it * @since 0.11.0 */ private void setShowPastExpenseWarning(final boolean shouldShowPastExpenseWarning) { final SharedPreferences defaultPreferences = PreferenceManager.getDefaultSharedPreferences(this); final SharedPreferences.Editor editor = defaultPreferences.edit(); final String preferenceKey = getString(R.string.preference_key_show_past_expense_warning); editor.putBoolean(preferenceKey, shouldShowPastExpenseWarning); editor.commit(); } /** * @return true if showing a warning when adding an expense to a past month is enabled - * false if the warning is disabled * @since 0.11.0 */ private boolean shouldShowPastExpenseWarning() { final SharedPreferences defaultPreferences = PreferenceManager.getDefaultSharedPreferences(this); final String preferenceKey = getString(R.string.preference_key_show_past_expense_warning); final String preferenceDefaultString = getString(R.string.preference_default_show_past_expense_warning); final boolean preferenceDefault = Boolean.parseBoolean(preferenceDefaultString); return defaultPreferences.getBoolean(preferenceKey, preferenceDefault); } }