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 com.redmahbub.perfectnavigationdrawer; import java.util.Locale; import android.app.Activity; import android.app.SearchManager; import android.content.Intent; import android.content.res.Configuration; import android.os.Bundle; import android.service.textservice.SpellCheckerService.Session; 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.FragmentTransaction; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.util.Log; 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.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 { private DrawerLayout mDrawerLayout; private ListView mDrawerList; private ActionBarDrawerToggle mDrawerToggle; private CharSequence mDrawerTitle; private CharSequence mTitle; private String[] mPlanetTitles; private static final int MERCURY = 0; private static final int VENUS = 1; private static final int EARTH = 2; private static final int MARS = 3; private static final int JUPITER = 4; private static final int SATURN = 5; private static final int URANUS = 6; private static final int NEPTUNE = 7; private static final int TOTAL_NUM_FRAGMENT = 8; private Fragment[] fragments = new Fragment[TOTAL_NUM_FRAGMENT]; private static int CURRENT_VISIBLE_FRAGMENT; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); 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 getActionBar().setDisplayHomeAsUpEnabled(true); getActionBar().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); FragmentManager fm = getSupportFragmentManager(); fragments[MERCURY] = fm.findFragmentById(R.id.mercuryFragment); fragments[VENUS] = fm.findFragmentById(R.id.venusFragment); fragments[EARTH] = fm.findFragmentById(R.id.earthFragment); fragments[MARS] = fm.findFragmentById(R.id.marsFragment); fragments[JUPITER] = fm.findFragmentById(R.id.jupiterFragment); fragments[SATURN] = fm.findFragmentById(R.id.saturnFragment); fragments[URANUS] = fm.findFragmentById(R.id.uranusFragment); fragments[NEPTUNE] = fm.findFragmentById(R.id.neptuneFragment); FragmentTransaction ft = fm.beginTransaction(); for (int i = 0; i < TOTAL_NUM_FRAGMENT; i++) if (fragments[i] != null) ft.hide(fragments[i]); // Check for null to avoid exception ft.commit(); if (savedInstanceState == null) { Log.d("DEBUG_TAG", "savedInstanceState is NULL"); selectItem(MERCURY); } else { CURRENT_VISIBLE_FRAGMENT = savedInstanceState.getInt("CURRENT_VISIBLE_FRAGMENT"); Log.d("DEBUG_TAG", "CURRENT_VISIBLE_FRAGMENT = " + CURRENT_VISIBLE_FRAGMENT); selectItem(CURRENT_VISIBLE_FRAGMENT); } } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); Log.d("DEBUG_TAG", "onSaveInstanceState() of MainActivity"); outState.putInt("CURRENT_VISIBLE_FRAGMENT", CURRENT_VISIBLE_FRAGMENT); } @Override protected void onRestoreInstanceState(Bundle savedInstanceState) { super.onRestoreInstanceState(savedInstanceState); Log.d("DEBUG_TAG", "onRestoreInstanceState() of MainActivity"); } @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 /* Fragment fragment = new PlanetFragment(); Bundle args = new Bundle(); args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position); fragment.setArguments(args); */ /* FragmentManager fragmentManager = getFragmentManager(); Fragment fragment; if(position == 0) { //if(mercuryFragment == null) mercuryFragment = new MercuryFragment(); mercuryFragment = (MercuryFragment) fragmentManager.findFragmentByTag("MERCURY"); if(mercuryFragment == null) { mercuryFragment = new MercuryFragment(); //fragmentManager.beginTransaction().add(mercuryFragment, "MERCURY").commit(); } fragmentManager.beginTransaction().replace(R.id.content_frame, mercuryFragment).commit(); } else if(position == 1) { //if(venusFragment == null) venusFragment = new VenusFragment(); venusFragment = (VenusFragment) fragmentManager.findFragmentByTag("VENUS"); if(venusFragment == null) { Log.d("DEBUG_TAG", "venusFragment is null"); venusFragment = new VenusFragment(); //fragmentManager.beginTransaction().add(venusFragment, "VENUS").commit(); } fragmentManager.beginTransaction().replace(R.id.content_frame, venusFragment, "VENUS").commit(); } */ switch (position) { case MERCURY: showFragment(MERCURY, false); break; case VENUS: showFragment(VENUS, false); break; case EARTH: showFragment(EARTH, false); break; case MARS: showFragment(MARS, false); break; case JUPITER: showFragment(JUPITER, false); break; case SATURN: showFragment(SATURN, false); break; case URANUS: showFragment(URANUS, false); break; case NEPTUNE: showFragment(NEPTUNE, false); break; default: break; } //if(position == MERCURY) showFragment(MERCURY, false); //else if(position == VENUS) showFragment(VENUS, false); //FragmentManager fragmentManager = getFragmentManager(); //fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit(); // update selected item and title, then close the drawer mDrawerList.setItemChecked(position, true); setTitle(mPlanetTitles[position]); mDrawerLayout.closeDrawer(mDrawerList); } private void showFragment(int fragmentIndex, boolean addToBackStack) { FragmentManager fm = getSupportFragmentManager(); FragmentTransaction ft = fm.beginTransaction(); ft.hide(fragments[CURRENT_VISIBLE_FRAGMENT]); ft.show(fragments[fragmentIndex]); CURRENT_VISIBLE_FRAGMENT = fragmentIndex; /* for (int i = 0; i < fragments.length; i++) { if (i == fragmentIndex) { transaction.show(fragments[i]); /* if (Session.getActiveSession().isClosed()) { mDrawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED); } } else { transaction.hide(fragments[i]); } } */ if (addToBackStack) { ft.addToBackStack(null); } ft.commit(); } @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 void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setRetainInstance(true); } @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); Log.d("DEBUG_TAG", "Running onCreateView()"); return rootView; } } }