/*
* Copyright 2015 Google Inc. All Rights Reserved.
*
* 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.examples.abelanav2.ui;
import android.app.Activity;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v4.app.Fragment;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
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.ListView;
import com.examples.abelanav2.R;
import com.examples.abelanav2.ui.utils.DrawerListAdapter;
import com.examples.abelanav2.ui.utils.NavItem;
import java.util.ArrayList;
/**
* Fragment used for managing interactions for and presentation of a navigation
* drawer.
* See the <a href=
* "https://developer.android.com/design/patterns/navigation-drawer.html">
* design guidelines</a> for a complete explanation of the behaviors implemented
* here.
*/
public class NavigationDrawerFragment extends Fragment {
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION
= "selected_navigation_drawer_position";
/**
* 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";
/**
* The navigation drawer items.
*/
private ArrayList<NavItem> mNavItems = new ArrayList<>();
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mDrawerToggle;
/**
* The navigation drawer layout.
*/
private DrawerLayout mDrawerLayout;
/**
* The navigation drawer ListView.
*/
private ListView mDrawerListView;
/**
* The fragment container view.
*/
private View mFragmentContainerView;
/**
* The currently selected item.
*/
private int mCurrentSelectedPosition = 0;
/**
* Indicates if the drawer was restored or not.
*/
private boolean mFromSavedInstanceState;
/**
* Indicates if the user has understood that the application uses a drawer.
*/
private boolean mUserLearnedDrawer;
/**
* Constructor.
*/
public NavigationDrawerFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNavItems.add(new NavItem(getString(R.string.title_section1),
R.drawable.ic_home_black_24dp));
mNavItems.add(new NavItem(getString(R.string.title_section2),
R.drawable.ic_file_upload_black_24dp));
mNavItems.add(new NavItem(getString(R.string.title_section3),
R.drawable.ic_image_black_24dp));
mNavItems.add(new NavItem(getString(R.string.title_section4),
R.drawable.ic_favorite_black_24dp));
mNavItems.add(new NavItem("New Section", -1));
mNavItems.add(new NavItem(getString(R.string.title_sign_out),
R.drawable.ic_exit_to_app_black_24dp));
// 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);
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState
.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
// Select either the default item (0) or the last selected item.
selectItem(mCurrentSelectedPosition);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Indicate that this fragment would like to influence the set of
// actions in the action bar.
setHasOptionsMenu(true);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mDrawerListView = (ListView) inflater.inflate(
R.layout.fragment_navigation_drawer, container, false);
mDrawerListView
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
selectItem(position);
}
});
DrawerListAdapter adapter = new DrawerListAdapter(getActivity()
.getApplicationContext(), mNavItems);
mDrawerListView.setAdapter(adapter);
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
mDrawerListView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
return mDrawerListView;
}
/**
* Indicates whether the drawer is open or not.
* @return a boolean indicating whether the drawer is open or not.
*/
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 setUp(int fragmentId, DrawerLayout drawerLayout) {
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
GravityCompat.START);
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
mDrawerToggle = new ActionBarDrawerToggle(
getActivity(), // host Activity
mDrawerLayout, // DrawerLayout object
R.string.navigation_drawer_open, // "open drawer" description
R.string.navigation_drawer_close // "close drawer"
) {
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
if (!isAdded()) {
return;
}
getActivity().supportInvalidateOptionsMenu();
}
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if (!isAdded()) {
return;
}
if (!mUserLearnedDrawer) {
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true)
.apply();
}
getActivity().supportInvalidateOptionsMenu();
}
};
if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
mDrawerLayout.openDrawer(mFragmentContainerView);
}
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mDrawerToggle);
}
/**
* Called when an item is selected.
* @param position the item position in the list.
*/
private void selectItem(int position) {
mCurrentSelectedPosition = position;
if (mDrawerListView != null) {
mDrawerListView.setItemChecked(position, true);
}
if (mDrawerLayout != null) {
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null) {
mCallbacks.onNavigationDrawerItemSelected(position);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallbacks = (NavigationDrawerCallbacks) activity;
} catch (ClassCastException e) {
throw new ClassCastException(
"Activity must implement NavigationDrawerCallbacks.");
}
}
@Override
public void onDetach() {
super.onDetach();
mCallbacks = null;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mDrawerToggle.onConfigurationChanged(newConfig);
}
@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()) {
inflater.inflate(R.menu.global, menu);
showGlobalContextActionBar();
}
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
return mDrawerToggle.onOptionsItemSelected(item)
|| super.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.setTitle(R.string.app_name);
}
/**
* @return the ActionBar.
*/
private ActionBar getActionBar() {
return ((AppCompatActivity) getActivity()).getSupportActionBar();
}
/**
* Callbacks interface that all activities using this fragment must
* implement.
*/
public interface NavigationDrawerCallbacks {
/**
* Called when an item in the navigation drawer is selected.
* @param position the position in the list.
*/
void onNavigationDrawerItemSelected(int position);
}
}