Java tutorial
/* DroidBeard - a free, open-source Android app for managing SickBeard Copyright (C) 2014 Robert Carr 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.rastating.droidbeard.fragments; import android.app.ActionBar; import android.app.Activity; import android.app.Fragment; import android.content.SharedPreferences; import android.content.res.Configuration; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; 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.rastating.droidbeard.entities.NavigationAction; import com.rastating.droidbeard.R; import com.rastating.droidbeard.adapters.NavigationActionAdapter; /** * 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#Interaction"> * 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"; /** * 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; private DrawerLayout mDrawerLayout; private ListView mDrawerListView; private View mFragmentContainerView; private boolean mFromSavedInstanceState; private boolean mUserLearnedDrawer; private int mCurrentPosition; private NavigationActionAdapter mAdapter; public NavigationDrawerFragment() { } private void setSelectedPosition(int position) { mCurrentPosition = position; if (mAdapter != null) { mAdapter.setSelectedPosition(position); } } private int getSelectedPosition() { return mCurrentPosition; } @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); if (savedInstanceState != null) { setSelectedPosition(savedInstanceState.getInt(STATE_SELECTED_POSITION)); mFromSavedInstanceState = true; selectItem(getSelectedPosition(), false); } else { // Select either the default item (0) or the last selected item. selectItem(getSelectedPosition(), true); } } @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); } private NavigationAction[] createNavigationActions() { return new NavigationAction[] { new NavigationAction(R.drawable.glyph_video_camera_333333_64, R.drawable.glyph_video_camera_838383_64, getString(R.string.title_shows)), new NavigationAction(R.drawable.glyph_calendar_333333_64, R.drawable.glyph_calendar_838383_64, getString(R.string.title_coming_episodes)), new NavigationAction(R.drawable.glyph_history_333333_64, R.drawable.glyph_history_838383_64, getString(R.string.title_history)), new NavigationAction(R.drawable.glyph_file_text_o_333333_64, R.drawable.glyph_file_text_o_838383_64, getString(R.string.title_logs)) }; } @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, true); } }); mAdapter = new NavigationActionAdapter(getActionBar().getThemedContext(), getActivity().getLayoutInflater(), R.layout.navigation_list_item, createNavigationActions()); mDrawerListView.setAdapter(mAdapter); mDrawerListView.setItemChecked(getSelectedPosition(), true); if (savedInstanceState != null) { selectItem(getSelectedPosition(), false); } return mDrawerListView; } 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; // 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; } getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu() } @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(); } getActivity().invalidateOptionsMenu(); // calls onPrepareOptionsMenu() } }; // 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); } private void selectItem(int position, boolean triggerCallback) { setSelectedPosition(position); if (mDrawerListView != null) { mDrawerListView.setItemChecked(position, true); } if (mDrawerLayout != null) { mDrawerLayout.closeDrawer(mFragmentContainerView); } if (mCallbacks != null && triggerCallback) { 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, getSelectedPosition()); } @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) { if (mDrawerToggle.onOptionsItemSelected(item)) { return true; } return 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.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); actionBar.setTitle(R.string.app_name); } private ActionBar getActionBar() { return getActivity().getActionBar(); } /** * Callbacks interface that all activities using this fragment must implement. */ public static interface NavigationDrawerCallbacks { /** * Called when an item in the navigation drawer is selected. */ void onNavigationDrawerItemSelected(int position); } }