Java tutorial
/* * Copyright (C) 2013 * * This file is part of Messic. * * 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 org.messic.android.activities; import java.util.Locale; import org.messic.android.R; import org.messic.android.activities.fragments.ExploreFragment; import org.messic.android.activities.fragments.PlayQueueFragment; import org.messic.android.activities.fragments.PlaylistFragment; import org.messic.android.activities.fragments.RandomFragment; import android.app.ActionBar; import android.app.Activity; import android.app.Fragment; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.os.Bundle; import android.support.v13.app.FragmentPagerAdapter; import android.support.v4.view.ViewPager; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; public class BaseActivity extends Activity implements ActionBar.TabListener { /** * The {@link android.support.v4.view.PagerAdapter} that will provide fragments for each of the sections. We use a * {@link 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.v13.app.FragmentStatePagerAdapter}. */ SectionsPagerAdapter mSectionsPagerAdapter; /** * The {@link ViewPager} that will host the section contents. */ ViewPager mViewPager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_base); // Set up the action bar. final ActionBar actionBar = getActionBar(); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); // Create the adapter that will return a fragment for each of the three // primary sections of the activity. mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager()); // Set up the ViewPager with the sections adapter. mViewPager = (ViewPager) findViewById(R.id.pager); mViewPager.setAdapter(mSectionsPagerAdapter); // When swiping between different sections, select the corresponding // tab. We can also use ActionBar.Tab#select() to do this if we have // a reference to the Tab. mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { actionBar.setSelectedNavigationItem(position); } }); // For each of the sections in the app, add a tab to the action bar. for (int i = 0; i < mSectionsPagerAdapter.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 callback (listener) for when // this tab is selected. actionBar .addTab(actionBar.newTab().setText(mSectionsPagerAdapter.getPageTitle(i)).setTabListener(this)); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.base2, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { // When the given tab is selected, switch to the corresponding page in // the ViewPager. mViewPager.setCurrentItem(tab.getPosition()); } public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { } public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { } /** * A {@link FragmentPagerAdapter} that returns a fragment corresponding to one of the sections/tabs/pages. */ public class SectionsPagerAdapter extends FragmentPagerAdapter { public SectionsPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { if (position == 0) { return new RandomFragment(); } else if (position == 1) { return new ExploreFragment(); } else if (position == 2) { return new PlaylistFragment(); } else if (position == 4) { return new PlayQueueFragment(); } // getItem is called to instantiate the fragment for the given page. // Return a PlaceholderFragment (defined as a static inner class below). return PlaceholderFragment.newInstance(position + 1); } @Override public int getCount() { // Show 5 total pages. return 5; } @Override public CharSequence getPageTitle(int position) { Locale l = Locale.getDefault(); switch (position) { case 0: return getString(R.string.title_section_random).toUpperCase(l); case 1: return getString(R.string.title_section_explore).toUpperCase(l); case 2: return getString(R.string.title_section_playlist).toUpperCase(l); case 3: return getString(R.string.title_section_downloaded).toUpperCase(l); case 4: return getString(R.string.title_section_queue).toUpperCase(l); } return null; } } /** * A placeholder fragment containing a simple view. */ public static class PlaceholderFragment extends Fragment { /** * The fragment argument representing the section number for this fragment. */ private static final String ARG_SECTION_NUMBER = "section_number"; /** * Returns a new instance of this fragment for the given section number. */ public static PlaceholderFragment newInstance(int sectionNumber) { PlaceholderFragment fragment = new PlaceholderFragment(); Bundle args = new Bundle(); args.putInt(ARG_SECTION_NUMBER, sectionNumber); fragment.setArguments(args); return fragment; } public PlaceholderFragment() { } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_base, container, false); return rootView; } } }