Java tutorial
/* * Copyright (C) 2014 The Illinois-Indiana Sea Grant * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.iisgcp.waterwalk.activity; import org.iisgcp.waterwalk.R; import org.iisgcp.waterwalk.fragment.AllRoutesFragment; import org.iisgcp.waterwalk.fragment.RoutesGridFragment; import org.iisgcp.waterwalk.fragment.RoutesMapFragment; import org.iisgcp.waterwalk.utils.Constants; import org.iisgcp.waterwalk.utils.HelpDialog; import org.iisgcp.waterwalk.utils.HelpDialog.HelpDialogListener; import android.annotation.TargetApi; import android.os.Bundle; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.content.res.Configuration; import android.os.Build; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.app.DialogFragment; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.support.v7.app.ActionBar; import android.support.v7.app.ActionBarActivity; import android.view.Gravity; import android.view.LayoutInflater; import android.view.MenuItem; import android.view.View; import android.view.WindowManager; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.TextView; public class MainActivity extends ActionBarActivity implements ActionBar.OnNavigationListener, HelpDialogListener { private static final String HELP_DIALOG = "help_dialog"; /** * The serialization (saved instance state) Bundle key representing the * current dropdown position. */ private static final String STATE_SELECTED_NAVIGATION_ITEM = "selected_navigation_item"; private String mTag; private DrawerLayout mDrawerLayout; private ListView mDrawerList; private ActionBarDrawerToggle mDrawerToggle; private String[] mDrawerTitles; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); setContentView(R.layout.activity_main); mDrawerTitles = getResources().getStringArray(R.array.drawer_items); mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); mDrawerList = (ListView) findViewById(R.id.left_drawer); // set a custom shadow that overlays the main content when the drawer opens mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START); // set up the drawer's list view with items and click listener mDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mDrawerTitles)); mDrawerList.setOnItemClickListener(new DrawerItemClickListener()); // Set up the action bar. final ActionBar actionBar = getSupportActionBar(); actionBar.setDisplayShowCustomEnabled(true); actionBar.setDisplayShowTitleEnabled(false); actionBar.setDisplayHomeAsUpEnabled(true); actionBar.setHomeButtonEnabled(true); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST); // Set up the dropdown list navigation in the action bar. actionBar.setListNavigationCallbacks( // Specify a SpinnerAdapter to populate the dropdown list. new ArrayAdapter<String>(getActionBarThemedContextCompat(), android.R.layout.simple_dropdown_item_1line, android.R.id.text1, new String[] { getString(R.string.title_grid), getString(R.string.title_map) }), this); LayoutInflater inflator = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); View view = inflator.inflate(R.layout.actionbar, null); actionBar.setCustomView(view); setTitle(getString(R.string.title_routes)); // ActionBarDrawerToggle ties together the the proper interactions // between the sliding drawer and the action bar app icon mDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */ mDrawerLayout, /* DrawerLayout object */ R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */ R.string.drawer_open, /* "open drawer" description for accessibility */ R.string.drawer_close /* "close drawer" description for accessibility */ ) { public void onDrawerClosed(View view) { if (mDrawerList.getCheckedItemPosition() == 0) { setTitle(mDrawerTitles[0]); getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_LIST); } else { setTitle(mDrawerTitles[1]); getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); } } public void onDrawerOpened(View drawerView) { setTitle(getString(R.string.app_name)); getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); } }; mDrawerLayout.setDrawerListener(mDrawerToggle); if (savedInstanceState == null) { selectItem(0); } SharedPreferences prefs = getPreferences(Context.MODE_PRIVATE); if (!prefs.contains(Constants.INTENT_DRAWER_POSITION)) { mDrawerLayout.closeDrawer(mDrawerList); mDrawerLayout.openDrawer(Gravity.LEFT); showDialog(HELP_DIALOG); } } @Override public void onNewIntent(Intent intent) { super.onNewIntent(intent); if (intent == null) { return; } int position = intent.getIntExtra(Constants.INTENT_DRAWER_POSITION, -1); if (position != -1) { selectItem(position); } setIntent(null); } @Override public void setTitle(CharSequence title) { TextView view = (TextView) findViewById(R.id.title); view.setText(title); } @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH) private Context getActionBarThemedContextCompat() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { return getActionBar().getThemedContext(); } else { return this; } } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { super.onRestoreInstanceState(savedInstanceState); // Restore the previously serialized current dropdown position. if (savedInstanceState.containsKey(STATE_SELECTED_NAVIGATION_ITEM)) { int position = Integer.valueOf(savedInstanceState.getString(STATE_SELECTED_NAVIGATION_ITEM)); if (position == 0 || position == 1) { getSupportActionBar().setSelectedNavigationItem( Integer.valueOf(savedInstanceState.getString(STATE_SELECTED_NAVIGATION_ITEM))); } else { getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); } mTag = savedInstanceState.getString(STATE_SELECTED_NAVIGATION_ITEM); } } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); // Serialize the current dropdown position. outState.putString(STATE_SELECTED_NAVIGATION_ITEM, mTag); } @Override public boolean onNavigationItemSelected(int position, long id) { FragmentManager fragmentManager = getSupportFragmentManager(); Fragment fragment = getSupportFragmentManager().findFragmentByTag(mTag); if (fragment != null) { fragmentManager.beginTransaction().detach(fragment).commit(); } String tag = String.valueOf(position); fragment = getSupportFragmentManager().findFragmentByTag(tag); if (fragment == null) { if (position == 0) { fragment = new RoutesGridFragment(); } else if (position == 1) { fragment = new RoutesMapFragment(); } getSupportFragmentManager().beginTransaction().add(R.id.content, fragment, tag).commit(); } else { fragmentManager.beginTransaction().attach(fragment).commit(); } mTag = tag; return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // The action bar home/up action should open or close the drawer. // ActionBarDrawerToggle will take care of this. if (mDrawerToggle.onOptionsItemSelected(item)) { return true; } // Handle action buttons switch (item.getItemId()) { default: return super.onOptionsItemSelected(item); } } /* The click listener for ListView in the navigation drawer */ private class DrawerItemClickListener implements ListView.OnItemClickListener { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { selectItem(position); } } private void selectItem(int position) { // update the main content by replacing fragments FragmentManager fragmentManager = getSupportFragmentManager(); Fragment fragment = getSupportFragmentManager().findFragmentByTag(mTag); if (fragment != null) { fragmentManager.beginTransaction().detach(fragment).commit(); } if (position == 0) { getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_LIST); // Set up the dropdown list navigation in the action bar. getSupportActionBar().setListNavigationCallbacks( // Specify a SpinnerAdapter to populate the dropdown list. new ArrayAdapter<String>(getActionBarThemedContextCompat(), android.R.layout.simple_dropdown_item_1line, android.R.id.text1, new String[] { getString(R.string.title_grid), getString(R.string.title_map) }), this); setTitle(getString(R.string.title_routes)); } else { getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); String tag = String.valueOf(2); fragment = getSupportFragmentManager().findFragmentByTag(tag); if (fragment == null) { fragment = new AllRoutesFragment(); getSupportFragmentManager().beginTransaction().add(R.id.content, fragment, tag).commit(); } else { fragmentManager.beginTransaction().attach(fragment).commit(); } setTitle(getString(R.string.title_all_stops)); mTag = tag; } // update selected item and title, then close the drawer mDrawerList.setItemChecked(position, true); mDrawerLayout.closeDrawer(mDrawerList); } /** * When using the ActionBarDrawerToggle, you must call it during * onPostCreate() and onConfigurationChanged()... */ @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); // Sync the toggle state after onRestoreInstanceState has occurred. mDrawerToggle.syncState(); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); // Pass any configuration change to the drawer toggls mDrawerToggle.onConfigurationChanged(newConfig); } private void showDialog(String tag) { // in a transaction. We also want to remove any currently showing // dialog, so make our own transaction and take care of that here. FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); Fragment prev = getSupportFragmentManager().findFragmentByTag(tag); if (prev != null) { ft.remove(prev); } Fragment fragment = HelpDialog.newInstance(this, getString(R.string.welcome), getString(R.string.help_text)); ft.add(0, fragment, tag); ft.commit(); } @Override public void onHelpDialogClosed(DialogFragment dialog) { mDrawerLayout.closeDrawer(mDrawerList); SharedPreferences prefs = getPreferences(Context.MODE_PRIVATE); Editor editor = prefs.edit(); editor.putString(Constants.INTENT_DRAWER_POSITION, Constants.INTENT_DRAWER_POSITION); editor.commit(); } }