Java tutorial
/* * Copyright 2014 Jacopo Aliprandi, Dario Archetti * * This file is part of SPF. * * SPF is free software: you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License as published by the Free * Software Foundation, either version 3 of the License, or (at your option) * any later version. * * SPF 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 Lesser General Public License for * more details. * * You should have received a copy of the GNU Lesser General Public License * along with SPF. If not, see <http://www.gnu.org/licenses/>. * */ package it.polimi.spf.app.navigation; import it.polimi.spf.app.R; import android.app.ActionBar; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.content.SharedPreferences; import android.content.res.Configuration; import android.os.Bundle; import android.preference.PreferenceManager; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; /** * Subclass of {@link NavigationFragment} to handle the navigation within the * main activity with a {@link NavigationDrawerFragment} layout. * "https://developer.android.com/design/patterns/navigation-drawer.html#Interaction" * > design guidelines</a> for a complete explanation of the behaviors * implemented here. */ public class NavigationDrawerFragment extends NavigationFragment { /** * Per the design guidelines, you should show the drawer on launch until the * user manually expands it. This shared preference tracks this. */ private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned"; /** * Helper component that ties the action bar to the navigation drawer. */ private ActionBarDrawerToggle mDrawerToggle; private DrawerLayout mDrawerLayout; private View mFragmentContainerView; private boolean mFromSavedInstanceState; private boolean mUserLearnedDrawer; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Read in the flag indicating whether or not the user has demonstrated // awareness of the // drawer. See PREF_USER_LEARNED_DRAWER for details. SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity()); mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false); mFromSavedInstanceState = savedInstanceState != null; } public boolean isDrawerOpen() { return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView); } /** * Users of this fragment must call this method to set up the navigation * drawer interactions. * * @param fragmentId * The android:id of this fragment in its activity's layout. * @param drawerLayout * The DrawerLayout containing this fragment's UI. */ public void setUpDrawer(int fragmentId, DrawerLayout drawerLayout) { mFragmentContainerView = getActivity().findViewById(fragmentId); mDrawerLayout = drawerLayout; // 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 ActionBar actionBar = getActionBar(); actionBar.setDisplayHomeAsUpEnabled(true); actionBar.setHomeButtonEnabled(true); // ActionBarDrawerToggle ties together the the proper interactions // between the navigation drawer and the action bar app icon. mDrawerToggle = new ActionBarDrawerToggle(getActivity(), /* host Activity */ mDrawerLayout, /* DrawerLayout object */ R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */ R.string.navigation_drawer_open, /* * "open drawer" description for * accessibility */ R.string.navigation_drawer_close /* * "close drawer" description for * accessibility */ ) { @Override public void onDrawerClosed(View drawerView) { super.onDrawerClosed(drawerView); if (!isAdded()) { return; } // calls onPrepareOptionsMenu() getActivity().invalidateOptionsMenu(); } @Override public void onDrawerOpened(View drawerView) { super.onDrawerOpened(drawerView); if (!isAdded()) { return; } if (!mUserLearnedDrawer) { // The user manually opened the drawer; store this flag to // prevent auto-showing // the navigation drawer automatically in the future. mUserLearnedDrawer = true; SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity()); sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply(); } // calls onPrepareOptionsMenu() getActivity().invalidateOptionsMenu(); } }; // If the user hasn't 'learned' about the drawer, open it to introduce // them to the drawer, // per the navigation drawer design guidelines. if (!mUserLearnedDrawer && !mFromSavedInstanceState) { mDrawerLayout.openDrawer(mFragmentContainerView); } // Defer code dependent on restoration of previous instance state. mDrawerLayout.post(new Runnable() { @Override public void run() { mDrawerToggle.syncState(); } }); mDrawerLayout.setDrawerListener(mDrawerToggle); } @Override protected void selectItem(int position, boolean replace) { if (mDrawerLayout == null) { return; } mDrawerLayout.closeDrawer(mFragmentContainerView); super.selectItem(position, replace); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); // Forward the new configuration the drawer toggle component. mDrawerToggle.onConfigurationChanged(newConfig); } @Override public boolean hasOptionsMenu() { return isDrawerOpen(); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { // If the drawer is open, show the global app actions in the action bar. // See also // showGlobalContextActionBar, which controls the top-left area of the // action bar. if (mDrawerLayout != null && isDrawerOpen()) { showGlobalContextActionBar(); return; } } @Override public boolean onOptionsItemSelected(MenuItem item) { return mDrawerToggle.onOptionsItemSelected(item); } /** * Per the navigation drawer design guidelines, updates the action bar to * show the global app 'context', rather than just what's in the current * screen. */ private void showGlobalContextActionBar() { ActionBar actionBar = getActionBar(); actionBar.setDisplayShowTitleEnabled(true); //actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); actionBar.setTitle(R.string.app_name); } }