I have some slides with ViewPager that shows application help and I want to show it in DrawerLayout too.
this is HelpActivity.class:
public class HelpActivity extends Activity {
private ViewPager viewPager;
private MyViewPagerAdapter myViewPagerAdapter;
private LinearLayout dotsLayout;
private TextView[] dots;
private int[] layouts;
private Button btnSkip, btnNext;
private PrefManager prefManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Checking for first time launch - before calling setContentView()
prefManager = new PrefManager(this);
if (!prefManager.isFirstTimeLaunch()) {
launchHomeScreen();
finish();
}
// Making notification bar transparent
if (Build.VERSION.SDK_INT >= 21) {
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
}
setContentView(R.layout.fragment_help);
viewPager = (ViewPager) findViewById(R.id.view_pager);
dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
btnSkip = (Button) findViewById(R.id.btn_skip);
btnNext = (Button) findViewById(R.id.btn_next);
// layouts of all welcome sliders
// add few more layouts if you want
layouts = new int[]{
R.layout.welcome_1,
R.layout.welcome_2,
R.layout.welcome_3,
R.layout.welcome_4,
R.layout.welcome_5,
R.layout.welcome_6,
R.layout.welcome_7};
// adding bottom dots
addBottomDots(0);
// making notification bar transparent
changeStatusBarColor();
myViewPagerAdapter = new MyViewPagerAdapter();
viewPager.setAdapter(myViewPagerAdapter);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
btnSkip.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
launchHomeScreen();
}
});
btnNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// checking for last page
// if last page home screen will be launched
int current = getItem(+1);
if (current < layouts.length) {
// move to next screen
viewPager.setCurrentItem(current);
} else {
launchHomeScreen();
}
}
});
}
private void addBottomDots(int currentPage) {
dots = new TextView[layouts.length];
int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);
dotsLayout.removeAllViews();
for (int i = 0; i < dots.length; i++) {
dots[i] = new TextView(this);
dots[i].setText(Html.fromHtml("•"));
dots[i].setTextSize(35);
dots[i].setTextColor(colorsInactive[currentPage]);
dotsLayout.addView(dots[i]);
}
if (dots.length > 0)
dots[currentPage].setTextColor(colorsActive[currentPage]);
}
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
private void launchHomeScreen() {
prefManager.setFirstTimeLaunch(false);
startActivity(new Intent(HelpActivity.this, MainActivity.class));
finish();
}
// viewpager change listener
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
addBottomDots(position);
// changing the next button text 'NEXT' / 'GOT IT'
if (position == layouts.length - 1) {
// last page. make button text to GOT IT
btnNext.setText(/*getString(R.string.start)*/ "Start");
btnSkip.setVisibility(View.GONE);
} else {
// still pages are left
btnNext.setText(/*getString(R.string.next)*/ "Next");
btnSkip.setVisibility(View.VISIBLE);
}
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
};
/**
* Making notification bar transparent
*/
private void changeStatusBarColor() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
window.setStatusBarColor(Color.TRANSPARENT);
}
}
/**
* View pager adapter
*/
public class MyViewPagerAdapter extends PagerAdapter {
private LayoutInflater layoutInflater;
public MyViewPagerAdapter() {
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(layouts[position], container, false);
container.addView(view);
return view;
}
#Override
public int getCount() {
return layouts.length;
}
#Override
public boolean isViewFromObject(View view, Object obj) {
return view == obj;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
View view = (View) object;
container.removeView(view);
}
}
}
this is PrefManager.class:
public class PrefManager {
SharedPreferences pref;
SharedPreferences.Editor editor;
Context _context;
// shared pref mode
int PRIVATE_MODE = 0;
// Shared preferences file name
private static final String PREF_NAME = "stand up-welcome";
private static final String IS_FIRST_TIME_LAUNCH = "IsFirstTimeLaunch";
public PrefManager(Context context) {
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
public void setFirstTimeLaunch(boolean isFirstTime) {
editor.putBoolean(IS_FIRST_TIME_LAUNCH, isFirstTime);
editor.commit();
}
public boolean isFirstTimeLaunch() {
return pref.getBoolean(IS_FIRST_TIME_LAUNCH, true);
}
}
and I use this code for defining it to drawerLayout:
public void selectDrawerItem(MenuItem menuItem) {
if (menuItem.getItemId()== R.id.nav_item_help) {
//startActivityForResult(new Intent(this,HelpActivity.class),1000);
startActivity(new Intent(MainActivity.this,HelpActivity.class));
}
with clicking on help in drawer, nothing shows. what should I do?
This is MainActivity.class:
ublic class MainActivity extends AppCompatActivity {
public DrawerLayout drawerLayout;
public Toolbar toolbar;
public NavigationView navigationView;
public ActionBarDrawerToggle actionBarDrawerToggle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentTransaction tx = getSupportFragmentManager().beginTransaction();
tx.replace(R.id.flContent, new HomeFragment());
tx.commit();
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//drawer layout
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
actionBarDrawerToggle= setupDrawerToggle();
drawerLayout.setDrawerListener(actionBarDrawerToggle);
//navigation view
navigationView= (NavigationView) findViewById(R.id.nvView);
// Setup drawer view
setupDrawerContent(navigationView);
actionBarDrawerToggle.syncState();
// default item of navigation view
// navigationView.getMenu().getItem(0).setChecked(true);
navigationView.setCheckedItem(R.id.nav_item_home);
}//onCreate
private ActionBarDrawerToggle setupDrawerToggle() {
return new ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close);
}
private void setupDrawerContent(NavigationView navigationView) {
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
selectDrawerItem(menuItem);
return true;
}
});
}
public void selectDrawerItem(MenuItem menuItem) {
if (menuItem.getItemId()==R.id.nav_item_setting){
startActivityForResult(new Intent(this, SettingActivity.class), 1002);
}
if (menuItem.getItemId()== R.id.nav_item_help) {
//startActivityForResult(new Intent(this,HelpActivity.class),1000);
startActivity(new Intent(MainActivity.this,HelpActivity.class));
}
// Create a new fragment and specify the fragment to show based on nav item clicked
android.support.v4.app.Fragment fragment = null /*new android.support.v4.app.Fragment()*/;
Class fragmentClass = null;
switch(menuItem.getItemId()) {
case R.id.nav_item_home:
fragmentClass = HomeFragment.class;
break;
case R.id.nav_item_knowledge:
fragmentClass = HomeFragment.class;
break;
/* case R.id.nav_item_help:
fragmentClass = HelpActivity.class;
break;*/
case R.id.nav_item_about:
fragmentClass =AboutFragment.class;
break;
default:
fragmentClass = HomeFragment.class;
break;
} try {
fragment = (android.support.v4.app.Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
// Insert the fragment by replacing any existing fragment
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.flContent);
if(currentFragment==null){
fragmentManager.beginTransaction().add(R.id.flContent, fragment).commit();
}else{
fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
}
// Highlight the selected item has been done by NavigationView
menuItem.setChecked(true);
// Set action bar title
setTitle(menuItem.getTitle());
// Close the navigation drawer
drawerLayout.closeDrawers();
}
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggles
actionBarDrawerToggle.onConfigurationChanged(newConfig);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (actionBarDrawerToggle.onOptionsItemSelected(item)) {
return true;
} return super.onOptionsItemSelected(item);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState); // `onPostCreate` called when activity start-up is complete after `onStart()`
}
#Override
public void onBackPressed() {
MainActivity.this.finish();
}
}
in your xml:
<android.support.design.widget.NavigationView
android:id="#+id/navigation_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="right"
android:background="#drawable/background_drawer"
app:headerLayout="#layout/nav_header"
app:itemIconTint="#color/colorPrimary"
app:menu="#menu/menu_navigation" />
you have to add help options in your menu_navigation
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group android:checkableBehavior="single">
<item
android:id="#+id/nav_item_help"
android:icon="#drawable/profile_icon"
android:title="Help" />
</group>
</menu>
Also in your MainActivity:
public void selectDrawerItem(MenuItem menuItem) {
// Create a new fragment and specify the fragment to show based on nav item clicked
android.support.v4.app.Fragment fragment = null /*new android.support.v4.app.Fragment()*/;
Class fragmentClass = null;
switch(menuItem.getItemId()) {
case R.id.nav_item_setting:
Intent i = new Intent(MainActivity.this, SettingActivity.class);
startActivity(i);
break;
case R.id.nav_item_help:
Intent i = new Intent(MainActivity.this, HelpActivity.class);
startActivity(i);
break;
case R.id.nav_item_home:
fragmentClass = HomeFragment.class;
break;
case R.id.nav_item_knowledge:
fragmentClass = HomeFragment.class;
break;
/* case R.id.nav_item_help:
fragmentClass = HelpActivity.class;
break;*/
case R.id.nav_item_about:
fragmentClass =AboutFragment.class;
break;
default:
fragmentClass = HomeFragment.class;
break;
} try {
fragment = (android.support.v4.app.Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
// Insert the fragment by replacing any existing fragment
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.flContent);
if(currentFragment==null){
fragmentManager.beginTransaction().add(R.id.flContent, fragment).commit();
}else{
fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
}
// Highlight the selected item has been done by NavigationView
menuItem.setChecked(true);
// Set action bar title
setTitle(menuItem.getTitle());
// Close the navigation drawer
drawerLayout.closeDrawers();
}
In your preference manager:
public void setFirstTimeLaunch(boolean isFirstTime) {
Editor editor = pref.edit();
editor.putBoolean(IS_FIRST_TIME_LAUNCH, isFirstTime);
editor.commit();
}
difference between startactivity and startActivityForResult is:
1. startActvity():
startActivity() will start the activity you want to start without worrying about getting any result from new child activity started by startActivity to parent activity.
2. startAcitvityForResult():
startAcitvityForResult() starts another activity from your activity and it expect to get some data from newly started child activity by startAcitvityForResult() and return that to parent activity.
see this blog:https://malikshafique.wordpress.com/2012/06/14/android-startactivity-and-startactivityforresult/
Related
I am receiving the following crash reports from fabric.io (mainly after I added a SettingsActivity which can be loaded from my SlidingMenue to my App):
The code of to post the pendingRunnable has not been changed recently, anyway it started to receive the exceptions.
Fatal Exception: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1842)
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1860)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:650)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:609)
at my.app.ui.activity.MainActivity$2.run(MainActivity.java:271)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5530)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:733)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:623)
This is my MainActivity.java
public class MainActivity extends AppCompatActivity implements MyAppFragment.OnListFragmentInteractionListener, AsyncResponse {
private MyAppDatabaseHandler myAppDatabaseHandler;
private SharedPreferences sharedpreferences;
private SharedPreferences defaultPrefs;
private FragmentA fragmentA;
public static boolean activityVisible = true;
private boolean isAttached;
private NavigationView navigationView;
private DrawerLayout drawer;
private View navHeader;
private Toolbar toolbar;
// index to identify current nav menu item
private static int navItemIndex = 0;
public static String CURRENT_TAG = MyAppConstants.TAG_A;
// toolbar titles respected to selected nav menu item
private String[] activityTitles;
// flag to load home fragment when user presses back key
private boolean shouldLoadHomeFragOnBackPress = true;
private Handler mHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.myAppDatabaseHandler= MyAppDatabaseHandler.getInstance(this);
defaultPrefs = PreferenceManager.getDefaultSharedPreferences(this);
sharedpreferences = getSharedPreferences(MyAppConstants.PREFERENCES, Context.MODE_PRIVATE);
setContentView(R.layout.activity_main);
fragmentA = new FragmentA();
// Init UI
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mHandler = new Handler();
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
navigationView = (NavigationView) findViewById(R.id.nav_view);
// load toolbar titles from string resources
activityTitles = getResources().getStringArray(R.array.sliding_menu_item_activity_titles);
// load nav menu header data
loadNavHeader();
// initializing navigation menu
setUpNavigationView();
if (savedInstanceState == null) {
navItemIndex = 0;
CURRENT_TAG = MyAppConstants.TAG_A;
loadNextFragment();
}
}
/***
* Load navigation menu header information
* like background image, profile image
* name, website, notifications action view (dot)
*/
private void loadNavHeader() {
// Init NavigationHeader
}
/***
* Returns respected fragment that user
* selected from navigation menu
*/
private void loadNextFragment() {
// if user select the current navigation menu again, don't do anything
// just close the navigation drawer
if (getSupportFragmentManager().findFragmentByTag( CURRENT_TAG) != null && navItemIndex != 4) {
drawer.closeDrawers();
return;
}
if (navItemIndex == 4) {
startActivity(new Intent(MainActivity.this, SettingsActivity.class));
} else {
// set toolbar title
setToolbarTitle();
// Sometimes, when fragment has huge data, screen seems hanging
// when switching between navigation menus
// So using runnable, the fragment is loaded with cross fade effect
// This effect can be seen in GMail app
Runnable mPendingRunnable = new Runnable() {
#Override
public void run() {
// update the activity_main_header_with_item content by replacing fragments
Fragment fragment = getNextFragment();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out);
fragmentTransaction.replace(R.id.frame, fragment, CURRENT_TAG);
fragmentTransaction.commit();
}
};
// If mPendingRunnable is not null, then add to the message queue
if (mPendingRunnable != null) {
mHandler.post(mPendingRunnable);
}
}
//Closing drawer on item click
drawer.closeDrawers();
// refresh toolbar menu
invalidateOptionsMenu();
}
private Fragment getNextFragment() {
switch (navItemIndex) {
case 0:
// home
return this.fragmentA;
case 1:
FragmentB fragmentB = new FragmentB();
return fragmentB;
case 2:
// About Fragment
AboutFragment aboutFragment = new AboutFragment();
return aboutFragment;
case 3:
// Licence Fragment
LicenceFragment licenceFragment = new LicenceFragment();
return licenceFragment;
default:
return this.fragmentA;
}
}
private void setToolbarTitle() {
getSupportActionBar().setTitle(activityTitles[navItemIndex]);
}
private void setUpNavigationView() {
//Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
// This method will trigger on item Click of navigation menu
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
//Check to see which item was being clicked and perform appropriate action
switch (menuItem.getItemId()) {
//Replacing the activity_main_header_with_item content with ContentFragment Which is our Inbox View;
case R.id.nav_home:
navItemIndex = 0;
CURRENT_TAG = MyAppConstants.TAG_A;
break;
case R.id.nav_recently:
navItemIndex = 1;
CURRENT_TAG = MyAppConstants.TAG_B;
break;
case R.id.nav_about_us:
navItemIndex = 2;
CURRENT_TAG = MyAppConstants.TAG_ABOUT;
break;
case R.id.nav_licences:
navItemIndex = 3;
CURRENT_TAG = MyAppConstants.TAG_LICENCES;
break;
case R.id.nav_settings:
navItemIndex = 4;
// do not set CURRENT_TAG
break;
default:
navItemIndex = 0;
}
loadNextFragment();
return true;
}
});
ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.openDrawer, R.string.closeDrawer) {
#Override
public void onDrawerClosed(View drawerView) {
// Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
super.onDrawerClosed(drawerView);
}
#Override
public void onDrawerOpened(View drawerView) {
// Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank
super.onDrawerOpened(drawerView);
}
};
//Setting the actionbarToggle to drawer layout
drawer.setDrawerListener(actionBarDrawerToggle);
//calling sync state is necessary or else your hamburger icon wont show up
actionBarDrawerToggle.syncState();
}
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawers();
return;
}
// This code loads home fragment when back key is pressed
// when user is in other fragment than home
if (shouldLoadHomeFragOnBackPress && CURRENT_TAG != MyAppConstants.TAG_A) {
// checking if user is on other navigation menu
// rather than home
if (navItemIndex != 0) {
navItemIndex = 0;
CURRENT_TAG = MyAppConstants.TAG_A;
loadNextFragment();
return;
}
}
finish();
super.onBackPressed();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main_header_with_item, menu);
// Disable Player Icon in case no player is found on device
Intent intent = Intent.makeMainSelectorActivity(Intent.ACTION_MAIN, MyAppConstants.MUSIC_APP);
List<ResolveInfo> activities = getPackageManager().queryIntentActivities(intent, 0);
if(activities == null || activities.size() <= 0) {
MenuItem player = menu.findItem(R.id.player);
if(player != null){
player.setVisible(false);
}
}
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
public void notifyOnDelete(View v) {
myAppDatabaseHandler.deleteAll();
}
#Override
public void onListFragmentInteraction(Song item) {
}
#Override
public void processFinish(String output) {
if (isAttached) {
...
}
}
#Override
public void onAttachedToWindow() {
isAttached = true;
super.onAttachedToWindow();
}
#Override
public void onDetachedFromWindow() {
isAttached = false;
super.onDetachedFromWindow();
}
#Override
public void onResume() {
activityVisible = true;
updateFragmentA();
super.onResume();
}
#Override
public void onPause() {
activityVisible = false;
super.onPause();
}
#Override
protected void onDestroy() {
super.onDestroy();
}
#Override
protected void onStart() {
super.onStart();
}
public void updateFragmentA() {
if (CURRENT_TAG == MyAppConstants.TAG_A) {
Timber.i( "updating FragmentA");
fragmentA.swap();
}
}
}
Any ideas about the cause of this issue?
Try this first setContentView(R.layout.activity_main); than perform your action
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.myAppDatabaseHandler= MyAppDatabaseHandler.getInstance(this);
defaultPrefs = PreferenceManager.getDefaultSharedPreferences(this);
sharedpreferences = getSharedPreferences(MyAppConstants.PREFERENCES, Context.MODE_PRIVATE);
i try create app on fragment, but i have some error:
FATAL EXCEPTION: main Process: pl.pionas.zabawa, PID: 3074
java.lang.NullPointerException
at pl.pionas.zabawa.Fragments.HomeFragment.initializeListViewPromo(HomeFragment.java:77)
at pl.pionas.zabawa.Fragments.HomeFragment.OnTaskCompletedArticlesPromo(HomeFragment.java:71)
at pl.pionas.zabawa.AsyncTasks.ArticlesPromoAsyncTask$1.onResponse(ArticlesPromoAsyncTask.java:70)
at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:68)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
This error is when i change class fragment (example go to LoginFragment.class) and orientation.
My MainMenuActivity.class:
public class MainActivity extends AppCompatActivity {
private DrawerLayout mDrawer;
private Toolbar toolbar;
private NavigationView nvDrawer;
private ActionBarDrawerToggle drawerToggle;
private Fragment fragment = null;
private Boolean restore = false;
private String mTitle;
FragmentManager fragmentManager;
private Boolean action = false;
String tag = null;
private int prev;
private ArrayList<MenuFragment> mapMenu = new ArrayList<MenuFragment>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getSupportFragmentManager();
if (savedInstanceState != null) {
fragment = fragmentManager.getFragment(savedInstanceState, "currentFragment");
restore = savedInstanceState.getBoolean("restore");
mTitle = savedInstanceState.getString("mTitle");
mapMenu = savedInstanceState.getParcelableArrayList("mapMenu");
tag = fragment.getTag();
} else {
fragment = new HomeFragment();
mapMenu.add(new MenuFragment(getString(R.string.app_name), 0));
restore = false;
mTitle = getString(R.string.app_name);
tag = mTitle;
}
if (fragment != null) {
fragmentManager.beginTransaction().replace(R.id.flContent, fragment, tag).addToBackStack(tag).commit();
if (restore) {
fragmentManager.findFragmentByTag(tag);
} else {
fragmentManager.beginTransaction().replace(R.id.flContent, fragment, tag).addToBackStack(tag).commit();
}
}
// Set a Toolbar to replace the ActionBar.
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle(mTitle);
// Find our drawer view
mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerToggle = new ActionBarDrawerToggle(this, mDrawer, toolbar, R.string.drawer_open, R.string.drawer_close);
// Tie DrawerLayout events to the ActionBarToggle
mDrawer.addDrawerListener(drawerToggle);
nvDrawer = (NavigationView) findViewById(R.id.nvView);
View headerLayout = nvDrawer.inflateHeaderView(R.layout.nav_header);
// We can now look up items within the header if needed
ImageView ivHeaderPhoto = (ImageView) headerLayout.findViewById(R.id.imageView);
Drawable myDrawable = ResourcesCompat.getDrawable(getResources(), R.drawable.logo, null);
ivHeaderPhoto.setImageDrawable(myDrawable);
// Setup drawer view
setupDrawerContent(nvDrawer);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
switch (item.getItemId()) {
case android.R.id.home:
mDrawer.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
// `onPostCreate` called when activity start-up is complete after `onStart()`
// NOTE! Make sure to override the method with only a single `Bundle` argument
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
drawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggles
drawerToggle.onConfigurationChanged(newConfig);
}
private void setupDrawerContent(NavigationView navigationView) {
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
selectDrawerItem(menuItem);
return true;
}
});
}
public void selectDrawerItem(MenuItem menuItem) {
int menuId = menuItem.getItemId();
if (prev == menuId) {
mDrawer.closeDrawers();
return;
}
prev = menuId;
createNewFragment(menuId, true);
}
private void createNewFragment(int menuId, boolean add) { // Create a new fragment and specify the fragment to show based on nav item clicked
Class fragmentClass;
action = true;
int position = 0;
switch (menuId) {
case R.id.nav_login:
fragmentClass = LoginFragment.class;
mTitle = getString(R.string.menu_login);
position = 1;
break;
case R.id.nav_articles:
fragmentClass = CategoryFragment.class;
mTitle = getString(R.string.menu_articles);
position = 2;
break;
default:
fragmentClass = HomeFragment.class;
mTitle = APP_NAME;
break;
}
if (add) {
mapMenu.add(new MenuFragment(mTitle, menuId));
}
try {
fragment = (Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
tag = mTitle;
if (action) {
// Insert the fragment by replacing any existing fragment
fragmentManager.beginTransaction().replace(R.id.flContent, fragment, tag).addToBackStack(tag).commit();
// Highlight the selected item has been done by NavigationView
nvDrawer.getMenu().getItem(position).setChecked(true);
}
// Set action bar title
getSupportActionBar().setTitle(mTitle);
// Close the navigation drawer
mDrawer.closeDrawers();
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean("restore", true);
outState.putParcelableArrayList("mapMenu", mapMenu);
outState.putString("mTitle", getSupportActionBar().getTitle().toString());
getSupportFragmentManager().putFragment(outState, "currentFragment", fragment);
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
int i = mapMenu.size();
if (i > 1) {
mapMenu.remove(i - 1);
MenuFragment menuFragment = mapMenu.get((i - 2));
tag = menuFragment.getTitle();
createNewFragment(menuFragment.getMenuPosition(), false);
} else {
MainActivity.this.finish();
}
}
} }
My HomeFragment.class:
public class HomeFragment extends Fragment implements OnTaskCompletedArticlesLastAdded {
private ListView listViewLastAdded;
private ArrayList<Article> articleLastAddedList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ArticlesLastAddedAsyncTask articlesLastAddedAsyncTask = new ArticlesLastAddedAsyncTask(getContext(), this);
articlesLastAddedAsyncTask.execute();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
listViewLastAdded = (ListView) rootView.findViewById(R.id.listViewLastAdded);
return rootView;
}
#Override
public void OnTaskCompletedArticlesLastAdded(ArrayList<Article> articleList) {
articleLastAddedList = articleList;
initializeListLastAdded();
}
private void initializeListLastAdded() {
ArticlesListAdapter adapter = new ArticlesListAdapter(getContext(), articleLastAddedList);
listViewLastAdded.setAdapter(adapter);
}
}
What i do wrong?
Thanks for help.
If you don't want Android to restart the activity when screen is rotated (this destroys your fragment and causes NULLPointer exception) you can add
android:configChanges="orientation|screenSize"
inside the activity tag in your Androidmanifest.xml
I'm writing an app for school and everything works fine when I run the app in the emulator.
The problem is when I connect my phone through usb and run the app on the phone.
Whenever I do something which requires the mListener (in any fragment in the whole app), I get a nullpointerexception on my mListener.
I have searched but have not found a solution or similar problem.
I have the problem in all of my fragments, but I will just show 1 fragment here:
Code of a fragment:
public class QuizFragment extends Fragment {
private OnFragmentQuizInteractionListener mListener;
List<Vraag> quesList;
int qid=0;
Vraag currentQ;
TextView txtQuestion;
RadioButton rda, rdb, rdc;
Button butNext;
TextView txtResult;
Button btnToonAntwoord;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
getActivity().setTitle("Quiz");
final View view = inflater.inflate(R.layout.quiz_layout, container, false);
//btnStart = (Button) getActivity().findViewById(R.id.btnStart);
//btnStart.setOnClickListener(new View.OnClickListener() {
// #Override
// public void onClick(View v) {
// mListener.initQuiz();
// }
//});
//reset the score to 0
mListener.resetScore();
qid=0;
QuizDbHelper db=new QuizDbHelper(view.getContext());
quesList=db.getAllQuestions();
currentQ=quesList.get(qid);
txtQuestion=(TextView) view.findViewById(R.id.textView1);
rda=(RadioButton)view.findViewById(R.id.radio0);
rdb=(RadioButton)view.findViewById(R.id.radio1);
rdc=(RadioButton)view.findViewById(R.id.radio2);
//zet de radiobuttons klaar om geklikt te worden.
rda.setEnabled(true);
rdb.setEnabled(true);
rdc.setEnabled(true);
butNext=(Button)view.findViewById(R.id.btnNext);
btnToonAntwoord=(Button)view.findViewById(R.id.btnToonAntwoord);
txtResult = (TextView) view.findViewById(R.id.resultTextview);
setQuestionView(view);
setOnClickListeners(view);
return view;
}
private void setOnClickListeners(View v){
final View thisView = v;
butNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(qid<8){
//zet de radiobuttons klaar om geklikt te worden.
rda.setEnabled(true);
rdb.setEnabled(true);
rdc.setEnabled(true);
//zet het resultaat terug op niets
txtResult.setText("");
//Wanneer het goed is, voeg 1 bij de score bij
RadioGroup grp = (RadioGroup) thisView.findViewById(R.id.radioGroup1);
RadioButton answer = (RadioButton) thisView.findViewById(grp.getCheckedRadioButtonId());
if (currentQ.getANSWER().equals(checkChecked(answer.getId()))) {
mListener.incrementScore();
}
currentQ=quesList.get(qid);
setQuestionView(thisView);
}else{
//ga naar het eindscherm met het resultaat.
mListener.navigeerEindscore();
}
}
});
btnToonAntwoord.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
RadioGroup grp = (RadioGroup) thisView.findViewById(R.id.radioGroup1);
RadioButton answer = (RadioButton) thisView.findViewById(grp.getCheckedRadioButtonId());
//toon de juiste boodschap aan de hand van het antwoord die gegeven is.
if (currentQ.getANSWER().equals(checkChecked(answer.getId()))) {
txtResult.setText(currentQ.getGoedeFeedback());
}else{
txtResult.setText(currentQ.getSlechteFeedback());
}
//zet de radiobuttons klaar om geklikt te worden.
rda.setEnabled(false);
rdb.setEnabled(false);
rdc.setEnabled(false);
}
});
}
private String checkChecked(int id) {
if(id == R.id.radio0){
return "A";
}else if(id == R.id.radio1){
return "B";
}else{
return "C";
}
}
private void setQuestionView(View v)
{
txtQuestion.setText(currentQ.getQUESTION());
rda.setText(currentQ.getOPTA());
rdb.setText(currentQ.getOPTB());
rdc.setText(currentQ.getOPTC());
qid++;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentQuizInteractionListener) {
mListener = (OnFragmentQuizInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnResultFragmentInteractionListener");
}
}
public interface OnFragmentQuizInteractionListener {
void incrementScore();
void resetScore();
void navigeerEindscore();
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
mainActivity:
{
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener,DashboardFragment.OnFragmentLoginInteractionListener,LoginFragment.OnFragmentLoginInteractionListener, RegistratieFragment.OnFragmentRegistratieInteractionListener,QuizFragment.OnFragmentQuizInteractionListener, ResultFragment.OnResultFragmentInteractionListener{
private FragmentManager fragmentManager;
public int quizScore;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils.onActivityCreateSetTheme(this);
setContentView(R.layout.activity_main);
quizScore = 0;
SharedPreferences pref = PreferenceManager
.getDefaultSharedPreferences(this);
String themeName = pref.getString("Theme1", "Blauw");
//toolbar ophalen
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
Log.i("huidige preferences", themeName);
//toolbar instellen
setSupportActionBar(toolbar);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
/**if (themeName.equals("Blauw")) {
setTheme(R.style.AppTheme_blauw);
Log.i("MyActivity", "in blauw");
} else if (themeName.equals("Groen")) {
this.setTheme(R.style.AppTheme_groen);
Log.i("MyActivity", "in groen");
} else if (themeName.equals("Roze")) {
this.setTheme(R.style.AppTheme_roze);
Log.i("MyActivity", "in roze");
}**/
fragmentManager = getFragmentManager();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
fragmentManager.beginTransaction().replace(R.id.content_frame, new DashboardFragment()).commit();
}
//backknop werkt hoe hij moet werken
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
int count = getFragmentManager().getBackStackEntryCount();
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
if (count == 0) {
super.onBackPressed();
//additional code
} else {
getFragmentManager().popBackStack();
}
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, 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.
switch (item.getItemId()) {
case R.id.action_settings:
fragmentManager.beginTransaction().replace(R.id.content_frame, new InstellingenFragment()).commit();
return true;
}
return super.onOptionsItemSelected(item);
}
//region dashboard
public void MijnProfielClicked() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new MijnProfielFragment())
.addToBackStack("MijnProfiel")
.commit();
}
public void AlarmClicked() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new PilAlarmFragment())
.addToBackStack("Pilalarm")
.commit();
}
public void KalenderClicked() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new MenstruatieFragment())
.addToBackStack("Kalender")
.commit();
}
//endregion
//Navigatiemethodes LOGIN
public void Login() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new DashboardFragment())
.addToBackStack("Login")
.commit();
}
//Navigatiemethodes REGISTREREN
public void Registreer() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new DashboardFragment())
.addToBackStack("Registreer")
.commit();
}
public void Annuleren() {
getFragmentManager().beginTransaction().replace(R.id.content_frame, new LoginFragment())
.addToBackStack("Registreer")
.commit();
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
switch (item.getItemId()) {
case R.id.nav_dashboard_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new DashboardFragment()).addToBackStack("dashboard").commit();
break;
case R.id.nav_mijnprofiel_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new MijnProfielFragment()).addToBackStack("mijnprofiel").commit();
break;
case R.id.nav_categorieen_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new CategorieenFragment()).addToBackStack("categorieen").commit();
break;
case R.id.nav_pilalarm_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new PilAlarmFragment()).addToBackStack("pilalarm").commit();
break;
case R.id.nav_menstruatie_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new MenstruatieFragment()).addToBackStack("menstruatie").commit();
break;
case R.id.nav_quiz_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new QuizFragment()).addToBackStack("quiz").commit();
break;
case R.id.nav_instellingen_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new InstellingenFragment()).addToBackStack("instellingen").commit();
break;
case R.id.nav_partners_layout:
fragmentManager.beginTransaction().replace(R.id.content_frame, new PartnersFragment()).addToBackStack("partners").commit();
break;
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
//region Partner onclick listeners
public void onVivesPartner_clicked(View view) {
// Perform action on click
goToUrl("http://www.vives.be/");
}
public void onSensoaPartner_clicked(View view) {
// Perform action on click
goToUrl("http://www.sensoa.be/");
}
public void onUgentPartner_clicked(View view) {
// Perform action on click
goToUrl("http://www.ugent.be/");
}
public void onUCCVPartner_clicked(View view) {
// Perform action on click
goToUrl("http://www.ucvvgent.be/nl/");
}
public void onOnePartner_clicked(View view) {
// Perform action on click
goToUrl("http://www.one.be//");
}
private void goToUrl(String url) {
Uri uriUrl = Uri.parse(url);
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);
startActivity(launchBrowser);
}
//endregion
//region quizfragment
#Override
public void incrementScore() {
quizScore++;
}
#Override
public void resetScore() {
quizScore = 0;
}
#Override
public void navigeerEindscore() {
fragmentManager.beginTransaction().replace(R.id.content_frame, new ResultFragment()).commit();
}
#Override
public int getScore() {
return quizScore;
}
//endregion
The error I'm getting (doesn't matter what fragment, it's always nullpointerexception on the mlistener)
java.lang.NullPointerException: Attempt to invoke interface method 'void be.vives.pwo_kinderwens.Quiz.QuizFragment$OnFragmentQuizInteractionListener.resetScore()' on a null object reference
at be.vives.pwo_kinderwens.Quiz.QuizFragment.onCreateView(QuizFragment.java:55)
at android.app.Fragment.performCreateView(Fragment.java:2053)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:894)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.app.BackStackRecord.run(BackStackRecord.java:834)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1452)
at android.app.FragmentManagerImpl$1.run(FragmentManager.java:447)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5294)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
The problem is that your mListener is not implemented.
I would try the following:
I would add a method to QuizFragment like :
public void setFragmentQuizInteractionListener(OnFragmentQuizInteractionListener mListener)
{
this.mListener = mListener;
}
And then
case R.id.nav_quiz_layout:
QuizFragment quizFragment = new QuizFragment();
quizFragment.setFragmentQuizInteractionListener(this);
fragmentManager.beginTransaction().replace(R.id.content_frame, quizFragment ).addToBackStack("quiz").commit();
break;
And drop the onAttach() method.
Probably not the nicest way but worth a try.
You need to override
public void onAttach (Activity activity)
instead of
public void onAttach (Context context)
The latter was included in API level 23, so previous versions of Android will not call it.
See onAttach (Activity activity)
Use onAttach method in Fragment. Check Fragment Lifecycle
Context context;
#Override
public void onAttach(Context context) {
super.onAttach(context);
this.context=context;
}
I have a Navigation Drawer with Navigation View, there are four tabs, one of them is a fragment, which includes ViewPager, ie is a host for the other fragments. Everything works fine, but when switched from fragment with ViewPager any other fragment of NavigationDrawer shows nothing. Checked logs, onCreate, onCreateView these fragments are called, but why does not display... Who knows why?
NavigationDrawer
public class NavigationDrawerHost extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListener {
//буду использовать эту активность как хост под все фрагменты, чтобы верно работал мой drawer!
public static String WHERE_FROM = NavigationDrawerHost.class.getSimpleName();
public static Toolbar toolbar;
public static ProgressBar progressBar;
private DrawerLayout drawer;
private NavigationView navigationView;
private ActionBarDrawerToggle drawerToggle;
private int navItemId;
private static final String NAV_ITEM_ID = "NAV_ITEM_ID";
private TextView userFirstNameTextView, userLastNameTextView;
private ImageView userPhotoImageView;
private VKAccessToken access_token; //токен это информация о правах доступа
private VKApiUser user; //текущий пользователь
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.navigation_drawer_host);
progressBar = (ProgressBar) findViewById(R.id.progressBar);
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
// Find the toolbar view inside the activity layout
toolbar = (Toolbar) findViewById(R.id.toolbar);
// Set a Toolbar to replace the ActionBar.
setSupportActionBar(toolbar);
//setTitle(R.string.drawer_menu_posts);
// load saved navigation state if present
if (null == savedInstanceState) {
navItemId = R.id.posts_fragment;
} else {
navItemId = savedInstanceState.getInt(NAV_ITEM_ID);
}
// Find our drawer view
navigationView = (NavigationView) findViewById(R.id.nvView);
navigationView.setNavigationItemSelectedListener(this);
// select the correct nav menu item
navigationView.getMenu().findItem(navItemId).setChecked(true);
// если хотим добавить какие-то элементы в наш header,
// то нужно добавить их в layout, а затем инициализировать нижеприведенным способом
// Inflate the header view at runtime
View headerLayout = navigationView.inflateHeaderView(R.layout.nav_header);
// We can now look up items within the header if needed
userFirstNameTextView = (TextView) headerLayout.findViewById(R.id.user_first_name);
userLastNameTextView = (TextView) headerLayout.findViewById(R.id.user_last_name);
userPhotoImageView = (ImageView) headerLayout.findViewById(R.id.user_photo);
drawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.drawer_open, R.string.drawer_close);
// Tie DrawerLayout events to the ActionBarToggle
drawer.setDrawerListener(drawerToggle);
drawerToggle.syncState();
selectItem(navItemId);
}
#Override
protected void onSaveInstanceState(final Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(NAV_ITEM_ID, navItemId);
}
// Menu icons are inflated just as they were with actionbar
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_exit:
//quitDialog();
VKSdk.logout();
finish();
return true;
default:
return drawerToggle.onOptionsItemSelected(item) || super.onOptionsItemSelected(item);
}
}
// Make sure this is the method with just `Bundle` as the signature
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
drawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggles
drawerToggle.onConfigurationChanged(newConfig);
}
private void selectItem(final int itemId) {
// perform the actual navigation logic, updating the main content fragment etc
// Create a new fragment and specify the planet to show based on position
Fragment fragment = null;
Class fragmentClass = null;
switch (itemId) {
case R.id.posts_fragment:
fragmentClass = PostsFragment.class;
fragment = new PostsFragment();
break;
case R.id.albums_fragment:
fragmentClass = FragmentTest.class;
fragment = new FragmentTest();
break;
case R.id.friends_fragment:
fragmentClass = FragmentTest.class;
fragment = new FragmentTest();
break;
case R.id.likes_fragment:
fragmentClass = LikesFragment.class;
fragment = new LikesFragment();
break;
/*default:
fragmentClass = PostsFragment.class;*/
}
/*try {
fragment = (Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}*/
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.fragment_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
drawer.closeDrawers();
}
#Override
public boolean onNavigationItemSelected(final MenuItem item) {
// update highlighted item in the navigation menu
item.setChecked(true);
setTitle(item.getTitle());
navItemId = item.getItemId();
// allow some time after closing the drawer before performing real navigation
// so the user can see what is happening
drawer.closeDrawer(GravityCompat.START);
selectItem(item.getItemId());
return true;
}
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
quitDialog();
} else {
getSupportFragmentManager().popBackStack();
}
}
private void quitDialog() {
AlertDialog.Builder quitDialog = new AlertDialog.Builder(this);
quitDialog.setTitle("Вы хотите выйти?");
quitDialog.setPositiveButton("Да", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
//стираем БД
Delete.tables(PostTable.class, PictureTable.class, PostTableMyLikes.class, PictureTableMyLikes.class);
FlowManager.getDatabase(WallDatabase.DB_NAME).reset(NavigationDrawerHost.this);
FlowManager.getDatabase(WallDatabaseMyLikes.DB_NAME).reset(NavigationDrawerHost.this);
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
});
quitDialog.setNegativeButton("Нет",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
});
quitDialog.show();
}
}
ViewPager host for fragments, which needs to display through ViewPager
//этот фрагмент является хостом для MyLikesFragment и FriendLikesFragment, так же тут содержатся табы
public class LikesFragment extends Fragment {
public static String WHERE_FROM_FRIENDS_LIKES = LikesFragment.class.getSimpleName() + "_FRIENDSLIKES";
private ViewPager viewPager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.likes_fragment, container, false);
TabLayout tabLayout = (TabLayout) v.findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Мои лайки"));
tabLayout.addTab(tabLayout.newTab().setText("Лайки друзей"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
viewPager = (ViewPager) v.findViewById(R.id.view_pager);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
viewPager.setAdapter(new LikesPagerAdapter(getChildFragmentManager()));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
return v;
}
public static class LikesPagerAdapter extends FragmentPagerAdapter {
public LikesPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return 2;
}
//сделано так, чтобы передавать те аргументы, от которых будет зависеть функционал фрагмента
#Override
public Fragment getItem(int position) {
return (position == 0) ? new MyLikesPostsFragment() : new PostsFragment();
}
#Override
public CharSequence getPageTitle(int position) {
return (position == 0) ? "Мои лайки" : "Лайки друзей";
}
}
}
P.S. And after going to the same fragment ViewPager select several items in drawer, this should not be
The problem was that I called adapter.notifyDataSetChanged() in the main thread and onPostExecute() in AsyncTask. My carelessness...
I've been searching and thinking how to implement the desire behaviour that I want when switching back and forth between fragments when using a Navigation Drawer. Actually the documentation says:
When using fragments in your app, individual FragmentTransaction objects may represent context changes that should be added to the back stack. For example, if you are implementing a master/detail flow on a handset by swapping out fragments, you should ensure that pressing the Back button on a detail screen returns the user to the master screen
So in my app I have a MainActivity that controls everything and a navigation layout within you can change between predefined options. This is the view when you launch the app
When you click on an item in the navigation drawer it opens a new fragment that replaces the main_content as follows:
At this point the behaviour is the correct one, so if you want to change the options you need to open the navigation drawer again to toggle between the menu options.
This is the Main Activity (notice that there is no Drawer Toggle)
MainActivity.java
public class MainActivity extends AppCompatActivity {
ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout drawerLayout;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSnackBarView = findViewById(R.id.myCoordinatorLayout);
setToolbar(); // Set Toolbar como action bar
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
if (navigationView != null) {
setupDrawerContent(navigationView);
}
drawerTitle = getResources().getString(R.string.app_name);
if (savedInstanceState == null) {
selectItem(drawerTitle, mCurrentSelectedPosition);
}
}
private void setToolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final ActionBar ab = getSupportActionBar();
if (ab != null) {
// Poner ícono del drawer toggle
ab.setHomeAsUpIndicator(R.drawable.ic_menu);
ab.setDisplayHomeAsUpEnabled(true);
}
}
private void setupDrawerContent(final NavigationView navigationView) {
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
// Marcar item presionado
menuItem.setChecked(true);
// Crear nuevo fragmento
String title = menuItem.getTitle().toString();
int id = menuItem.getItemId();
selectItem(title, id);
return true;
}
}
);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!drawerLayout.isDrawerOpen(GravityCompat.START)) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
drawerLayout.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
private void selectItem(String title, int id) {
Bundle args = new Bundle();
args.putString(PlaceholderFragment.ARG_SECTION_TITLE, title);
Fragment fragment = PlaceholderFragment.newInstance(title);
fragment.setArguments(args);
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment)
.commit();
switch (id) {
case R.id.nav_localizacion:
//Snackbar.make(mSnackBarView, R.string.menu_localization, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 0;
LocalizacionFragment fragment_localizacion = new LocalizacionFragment();
// fragmentManager = getSupportFragmentManager();
Snackbar.make(mSnackBarView, R.string.menu_localization, Snackbar.LENGTH_SHORT).show();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment_localizacion)
.commit();
break;
case R.id.nav_productos:
Snackbar.make(mSnackBarView, R.string.menu_productos, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 1;
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment)
.commit();
break;
case R.id.nav_consejos:
Snackbar.make(mSnackBarView, R.string.menu_consejos, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 3;
ConsejosFragment fragment_consejo = new ConsejosFragment();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment_consejo)
.commit();
break;
default:
break;
}
drawerLayout.closeDrawers(); // Cerrar drawer
setTitle(title); // título actual
}
}
I don't use the hamburger icon because it hides under the Navigation Layout, but here is the thing. When you click on "Recetas" in the recycle view it open a new fragment (replace) but now I want to show the up caret icon and give proper back navigation to my app.
Here is the code of the "Consejos" fragment class
Consejos.java
public class ConsejosFragment extends Fragment {
RecyclerView mRecycler;
ConsejosAdapter mAdapter;
FragmentActivity mActivity;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
this.mActivity = (FragmentActivity) activity;
setRetainInstance(true);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
List items = new ArrayList();
items.add(new ConsejosInfo("Recetas", R.drawable.icon_recetas));
/* Inflamos el layout */
View v = inflater.inflate(R.layout.consejos_layout_recycler, container, false);
/* Obtenemos el Recycle */
mRecycler = (RecyclerView) v.findViewById(R.id.recycler_consejos);
/* Creamos el adaptador */
mAdapter = new ConsejosAdapter(mActivity, items);
/* Set click en adapter */
return v;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mRecycler.setHasFixedSize(true);
mRecycler.setLayoutManager(new LinearLayoutManager(getActivity()));
mRecycler.setAdapter(mAdapter);
}
}
And this is the adapter that the Recyclerview use and handles the click on the item inside:
Adapter.java
public class ConsejosAdapter extends RecyclerView.Adapter<ConsejosAdapter.ConsejosViewHolder> {
private List<ConsejosInfo> _items = new ArrayList<ConsejosInfo>();
private final FragmentActivity mActivity;
private Context context;
public ConsejosAdapter(FragmentActivity mActivity, List<ConsejosInfo> items) {
this._items = items;
this.mActivity = mActivity;
}
#Override
public int getItemCount() {
return _items.size();
}
#Override
public ConsejosViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cardview_consejos, viewGroup, false);
return new ConsejosViewHolder(v);
}
#Override
public void onBindViewHolder(ConsejosViewHolder viewHolder, int position) {
viewHolder.imagen.setImageResource(_items.get(position).get_imagen());
viewHolder.nombre.setText(_items.get(position).get_nombre());
}
public class ConsejosViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public ImageView imagen;
public TextView nombre;
public ConsejosViewHolder(final View itemView) {
super(itemView);
imagen = (ImageView) itemView.findViewById(R.id.consejos_imagen);
nombre = (TextView) itemView.findViewById(R.id.consejos_nombre);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
RecetasFragment recetasFragment = new RecetasFragment();
FragmentManager fragmentManager = mActivity.getSupportFragmentManager();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, recetasFragment)
.addToBackStack(null)
.commit();
}
}
}
In the Consejos Adapter I added to backstack the fragment before calling the new fragment (inside fragment) and that changes the behaviour of the back button, so before this if you press the back button is closes the app but now it takes you to the Consejos fragment, but now I want to add the up caret and make the exactly same operation as when you click the back button but I don't know how to achieve it.
Please feel free to ask for more code
Thank you very much
I will give you the full answer:
We will use the interfaces to communicate with the MainActivity from RecetasFragment so we can enable and disable navigation back button.
RecetasFragment class:
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* Created by hema on 8/19/2015.
*/
public class RecetasFragment extends Fragment {
private CommunicateWithActivity mWithActivity;
public RecetasFragment() {
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mWithActivity = (CommunicateWithActivity) activity; // MainActivity must implement CommunicateWithActivity interface.
mWithActivity.enableNavigationBack(true); // We enable navigation back here.
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement CommunicateWithActivity");
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_recetas, container, false);
}
#Override
public void onDestroy() {
super.onDestroy();
mWithActivity.enableNavigationBack(false); // We disable navigation back here, restore menu icon.
}
public interface CommunicateWithActivity {
void enableNavigationBack(boolean enable);// we will implement this method in MainActivity class.
}
}
And in MainActivity class we will implement CommunicateWithActivity interface, Modify your MainActivity class (only required modifications):
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class MainActivity extends AppCompatActivity implements RecetasFragment.CommunicateWithActivity {
private Toolbar mToolbar;
private DrawerLayout drawerLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
mToolbar.setNavigationIcon(R.drawable.ic_menu);
mSnackBarView = findViewById(R.id.myCoordinatorLayout);
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
if (navigationView != null) {
setupDrawerContent(navigationView);
}
drawerTitle = getResources().getString(R.string.app_name);
if (savedInstanceState == null) {
selectItem(drawerTitle, mCurrentSelectedPosition);
}
}
private void setupDrawerContent(final NavigationView navigationView) {
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
// Marcar item presionado
menuItem.setChecked(true);
// Crear nuevo fragmento
String title = menuItem.getTitle().toString();
int id = menuItem.getItemId();
selectItem(title, id);
return true;
}
}
);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!drawerLayout.isDrawerOpen(GravityCompat.START)) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
drawerLayout.openDrawer(GravityCompat.START);
return true;
}
return super.onOptionsItemSelected(item);
}
private void selectItem(String title, int id) {
Bundle args = new Bundle();
args.putString(PlaceholderFragment.ARG_SECTION_TITLE, title);
Fragment fragment = PlaceholderFragment.newInstance(title);
fragment.setArguments(args);
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment)
.commit();
switch (id) {
case R.id.nav_localizacion:
//Snackbar.make(mSnackBarView, R.string.menu_localization, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 0;
LocalizacionFragment fragment_localizacion = new LocalizacionFragment();
// fragmentManager = getSupportFragmentManager();
Snackbar.make(mSnackBarView, R.string.menu_localization, Snackbar.LENGTH_SHORT).show();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment_localizacion)
.commit();
break;
case R.id.nav_productos:
Snackbar.make(mSnackBarView, R.string.menu_productos, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 1;
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment)
.commit();
break;
case R.id.nav_consejos:
Snackbar.make(mSnackBarView, R.string.menu_consejos, Snackbar.LENGTH_SHORT).show();
mCurrentSelectedPosition = 3;
ConsejosFragment fragment_consejo = new ConsejosFragment();
fragmentManager
.beginTransaction()
.replace(R.id.main_content, fragment_consejo)
.commit();
break;
default:
break;
}
drawerLayout.closeDrawers(); // Cerrar drawer
setTitle(title); // título actual
}
#Override
public void enableNavigationBack(boolean enable) {
if(enable) {
// We enable the navigation back button here
mToolbar.setNavigationIcon(R.drawable.abc_ic_ab_back_mtrl_am_alpha);
mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// On navigation back button clicked.
if(getSupportFragmentManager().getBackStackEntryCount() > 0) { // Check if there is fragments in BackStack.
getSupportFragmentManager().popBackStack(); // PopBackStack.
} else {
// You can implement this part as you want.
return;
}
}
});
} else {
mToolbar.setNavigationIcon(R.drawable.ic_menu);
mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(drawerLayout != null) {
drawerLayout.openDrawer(Gravity.LEFT);
}
}
});
}
}
}
Please let me know if there is something you don't understand.