Java tutorial
/* * Copyright 2013 The Android Open Source Project * * 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 se.dxapps.generic; import java.util.Locale; import se.dxapps.generic.R; import android.app.ActionBar; import android.app.ActionBar.Tab; import android.app.ActionBar.TabListener; import android.app.SearchManager; import android.content.Intent; import android.content.res.Configuration; import android.os.Bundle; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.view.GravityCompat; import android.support.v4.view.ViewPager; import android.support.v4.widget.DrawerLayout; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; /** * This example illustrates a common usage of the DrawerLayout widget * in the Android support library. * <p/> * <p>When a navigation (left) drawer is present, the host activity should detect presses of * the action bar's Up affordance as a signal to open and close the navigation drawer. The * ActionBarDrawerToggle facilitates this behavior. * Items within the drawer should fall into one of two categories:</p> * <p/> * <ul> * <li><strong>View switches</strong>. A view switch follows the same basic policies as * list or tab navigation in that a view switch does not create navigation history. * This pattern should only be used at the root activity of a task, leaving some form * of Up navigation active for activities further down the navigation hierarchy.</li> * <li><strong>Selective Up</strong>. The drawer allows the user to choose an alternate * parent for Up navigation. This allows a user to jump across an app's navigation * hierarchy at will. The application should treat this as it treats Up navigation from * a different task, replacing the current task stack using TaskStackBuilder or similar. * This is the only form of navigation drawer that should be used outside of the root * activity of a task.</li> * </ul> * <p/> * <p>Right side drawers should be used for actions, not navigation. This follows the pattern * established by the Action Bar that navigation should be to the left and actions to the right. * An action should be an operation performed on the current contents of the window, * for example enabling or disabling a data overlay on top of the current content.</p> */ public class MainActivity extends FragmentActivity implements TabListener { /** * The {@link android.support.v4.view.PagerAdapter} that will provide fragments for each of the * three primary sections of the app. We use a {@link android.support.v4.app.FragmentPagerAdapter} * derivative, which will keep every loaded fragment in memory. If this becomes too memory * intensive, it may be best to switch to a {@link android.support.v4.app.FragmentStatePagerAdapter}. */ AppSectionsPagerAdapter mAppSectionsPagerAdapter; /** * The {@link ViewPager} that will display the three primary sections of the app, one at a * time. */ ViewPager mViewPager; private DrawerLayout mDrawerLayout; private ListView mDrawerList; private ActionBarDrawerToggle mDrawerToggle; private CharSequence mDrawerTitle; private CharSequence mTitle; private String[] mPlanetTitles; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final ActionBar actionBar = getActionBar(); // Create the adapter that will return a fragment for each of the three primary sections // of the app. mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager()); mTitle = mDrawerTitle = getTitle(); mPlanetTitles = getResources().getStringArray(R.array.planets_array); 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, mPlanetTitles)); mDrawerList.setOnItemClickListener(new DrawerItemClickListener()); // enable ActionBar app icon to behave as action to toggle nav drawer actionBar.setDisplayHomeAsUpEnabled(true); actionBar.setHomeButtonEnabled(true); // 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) { getActionBar().setTitle(mTitle); invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() } public void onDrawerOpened(View drawerView) { getActionBar().setTitle(mDrawerTitle); invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() } }; mDrawerLayout.setDrawerListener(mDrawerToggle); // if (savedInstanceState == null) { // selectItem(0); // } //ViewPager stuff. // Specify that we will be displaying tabs in the action bar. actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); // Set up the ViewPager, attaching the adapter and setting up a listener for when the // user swipes between sections. mViewPager = (ViewPager) findViewById(R.id.pager); mViewPager.setAdapter(mAppSectionsPagerAdapter); mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { // When swiping between different app sections, select the corresponding tab. // We can also use ActionBar.Tab#select() to do this if we have a reference to the // Tab. actionBar.setSelectedNavigationItem(position); } }); // For each of the sections in the app, add a tab to the action bar. for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) { // Create a tab with text corresponding to the page title defined by the adapter. // Also specify this Activity object, which implements the TabListener interface, as the // listener for when this tab is selected. actionBar.addTab( actionBar.newTab().setText(mAppSectionsPagerAdapter.getPageTitle(i)).setTabListener(this)); } } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.main, menu); return super.onCreateOptionsMenu(menu); } /* Called whenever we call invalidateOptionsMenu() */ @Override public boolean onPrepareOptionsMenu(Menu menu) { // If the nav drawer is open, hide action items related to the content view boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList); menu.findItem(R.id.action_websearch).setVisible(!drawerOpen); return super.onPrepareOptionsMenu(menu); } @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()) { case R.id.action_websearch: // create intent to perform web search for this planet Intent intent = new Intent(Intent.ACTION_WEB_SEARCH); intent.putExtra(SearchManager.QUERY, getActionBar().getTitle()); // catch event that there's no activity to handle intent if (intent.resolveActivity(getPackageManager()) != null) { startActivity(intent); } else { Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show(); } return true; default: return super.onOptionsItemSelected(item); } } /* The click listner 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 //TODO do your hting. // update selected item and title, then close the drawer mDrawerList.setItemChecked(position, true); mDrawerLayout.closeDrawer(mDrawerList); } @Override public void setTitle(CharSequence title) { mTitle = title; getActionBar().setTitle(mTitle); } /** * 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); } /** * Fragment that appears in the "content_frame", shows a planet */ public static class PlanetFragment extends Fragment { public static final String ARG_PLANET_NUMBER = "planet_number"; public PlanetFragment() { // Empty constructor required for fragment subclasses } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_planet, container, false); int i = getArguments().getInt(ARG_PLANET_NUMBER); String planet = getResources().getStringArray(R.array.planets_array)[i]; int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()), "drawable", getActivity().getPackageName()); ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId); getActivity().setTitle(planet); return rootView; } } /** * A {@link FragmentPagerAdapter} that returns a fragment corresponding to one of the primary * sections of the app. */ public static class AppSectionsPagerAdapter extends FragmentPagerAdapter { public AppSectionsPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int i) { //Switch otherwise. // The other sections of the app are dummy placeholders. Fragment fragment = new DummySectionFragment(); Bundle args = new Bundle(); args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, i + 1); fragment.setArguments(args); return fragment; } @Override public int getCount() { return 3; } @Override public CharSequence getPageTitle(int position) { return "Section " + (position + 1); } } /** * A dummy fragment representing a section of the app, but that simply displays dummy text. */ public static class DummySectionFragment extends Fragment { public static final String ARG_SECTION_NUMBER = "section_number"; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_section_dummy, container, false); Bundle args = getArguments(); ((TextView) rootView.findViewById(android.R.id.text1)) .setText(getString(R.string.dummy_section_text, args.getInt(ARG_SECTION_NUMBER))); return rootView; } } @Override public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) { // TODO Auto-generated method stub } @Override public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) { // TODO Auto-generated method stub mViewPager.setCurrentItem(tab.getPosition()); } @Override public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) { // TODO Auto-generated method stub } }