Java tutorial
/* 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 com.mobile.syslogng.monitor; import java.util.ArrayList; import android.app.Activity; import android.app.Fragment; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.content.res.Configuration; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListView; public class MainActivity extends Activity implements IMainActivity { private String APP_NAME; private DrawerLayout mDrawerLayout; private ListView mDrawerList; private ActionBarDrawerToggle mDrawerToggle; private CharSequence mDrawerTitle; private CharSequence mTitle; private String[] menuItems; public Integer stackCount = 0; public static final String FRAGMENT_POS = "fragment_pos"; public static final int WELCOME_FRAGMENT_POS = 0; public static final int IMPORT_CERTIFICATE_FRAGMENT_POS = 1; public static final int SYSLOGNG_FRAGMENT_POS = 2; public static final int MONITORED_SYSLOGNG_FRAGMENT_POS = 3; public static final int ABOUT_FRAGMENT_POS = 4; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); APP_NAME = getApplicationContext().getString(R.string.app_title); FileManager fManager = new FileManager(getApplicationContext()); fManager.createCertificateDirectory(); mTitle = getTitle(); mDrawerTitle = APP_NAME; menuItems = getResources().getStringArray(R.array.menu_array); mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); mDrawerList = (ListView) findViewById(R.id.left_drawer); mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START); mDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, menuItems)); mDrawerList.setOnItemClickListener(new DrawerItemClickListener()); getActionBar().setDisplayHomeAsUpEnabled(true); getActionBar().setHomeButtonEnabled(true); mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.drawable.ic_drawer, R.string.drawer_open, R.string.drawer_close) { public void onDrawerClosed(View view) { getActionBar().setTitle(mTitle); invalidateOptionsMenu(); } public void onDrawerOpened(View drawerView) { getActionBar().setTitle(mDrawerTitle); invalidateOptionsMenu(); } }; mDrawerLayout.setDrawerListener(mDrawerToggle); if (savedInstanceState == null) { SQLiteManager sManager = new SQLiteManager(getApplicationContext()); ArrayList<Syslogng> savedData = sManager.getSyslogngs(); if (savedData.isEmpty()) { loadFragment(WELCOME_FRAGMENT_POS); } else { loadFragment(MONITORED_SYSLOGNG_FRAGMENT_POS); } } } @Override public boolean onCreateOptionsMenu(Menu menu) { return super.onCreateOptionsMenu(menu); } @Override public boolean onPrepareOptionsMenu(Menu menu) { return super.onPrepareOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { if (mDrawerToggle.onOptionsItemSelected(item)) { return true; } return false; } private class DrawerItemClickListener implements ListView.OnItemClickListener { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { loadFragment(position); } } private void loadFragment(int position) { switch (position) { case WELCOME_FRAGMENT_POS: setFragment(new WelcomeFragment(this, getApplicationContext()), position, "fragment_welcome_tag"); break; case IMPORT_CERTIFICATE_FRAGMENT_POS: setFragment(new ImportCertificateFragment(this, getApplicationContext()), position, "fragment_importcert_tag"); break; case SYSLOGNG_FRAGMENT_POS: setFragment(new SyslogngFragment(this, getApplicationContext(), null), position, "fragment_addsyslogng_tag"); break; case MONITORED_SYSLOGNG_FRAGMENT_POS: setFragment(new MonitoredSyslogngFragment(this, getApplicationContext()), position, "fragment_monitored_syslogng_tag"); break; case ABOUT_FRAGMENT_POS: setFragment(new AboutFragment(this, getApplicationContext()), position, "fragment_about_tag"); default: break; } setTitle(menuItems[position]); } public void setFragment(Fragment fragment, Integer position, String tag) { updateDrawer(position); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction transaction = fragmentManager.beginTransaction(); Bundle args = new Bundle(); args.putInt(MainActivity.FRAGMENT_POS, position); fragment.setArguments(args); String cTag = "empty"; Fragment currentFragment = fragmentManager.findFragmentById(R.id.container); if (currentFragment != null) { cTag = currentFragment.getTag(); if (!cTag.equals(tag)) { if (currentFragment instanceof WelcomeFragment || currentFragment instanceof MonitoredSyslogngFragment || currentFragment instanceof AboutFragment) { stackCount = 0; transaction.addToBackStack(cTag); stackCount++; } else { if (stackCount < 2) { transaction.addToBackStack(cTag); stackCount++; } } } } transaction.replace(R.id.container, fragment, tag).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); mDrawerToggle.syncState(); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); mDrawerToggle.onConfigurationChanged(newConfig); } public void updateDrawer(Integer position) { mDrawerList.setItemChecked(position, true); mDrawerLayout.closeDrawer(mDrawerList); } private String checkFragment() { String currentFragment = null; Fragment importFragment = getFragmentManager().findFragmentByTag("fragment_importcert_tag"); Fragment addSyslogngFragment = getFragmentManager().findFragmentByTag("fragment_addsyslogng_tag"); if ((importFragment != null && importFragment.isVisible())) { currentFragment = importFragment.getTag(); } else if (addSyslogngFragment != null && addSyslogngFragment.isVisible()) { currentFragment = addSyslogngFragment.getTag(); } return currentFragment; } @Override public void onBackPressed() { String currentFragmentTag = checkFragment(); if (currentFragmentTag != null) { popBackFragment(currentFragmentTag); updateDrawer(getFragmentPosition()); } else { finish(); } } private Integer getFragmentPosition() { Fragment fragment = getFragmentManager().findFragmentById(R.id.container); if (fragment instanceof ImportCertificateFragment) { return IMPORT_CERTIFICATE_FRAGMENT_POS; } if (fragment instanceof SyslogngFragment) { return SYSLOGNG_FRAGMENT_POS; } if (fragment instanceof WelcomeFragment) { return WELCOME_FRAGMENT_POS; } if (fragment instanceof MonitoredSyslogngFragment) { return MONITORED_SYSLOGNG_FRAGMENT_POS; } if (fragment instanceof AboutFragment) { return ABOUT_FRAGMENT_POS; } return -1; } private void popBackFragment(String removalFragmentTag) { Fragment currentFragment = getFragmentManager().findFragmentById(R.id.container); if (currentFragment.getTag().equals(getFragmentManager() .getBackStackEntryAt(getFragmentManager().getBackStackEntryCount() - 1).getName())) { getFragmentManager().popBackStack(); FragmentTransaction transaction = getFragmentManager().beginTransaction(); transaction.remove(currentFragment).commit(); getFragmentManager().executePendingTransactions(); } getFragmentManager().popBackStack(); Fragment removalFragment = getFragmentManager().findFragmentByTag(removalFragmentTag); FragmentTransaction transaction = getFragmentManager().beginTransaction(); transaction.remove(removalFragment).commit(); getFragmentManager().executePendingTransactions(); } }