Develop Reference

Implementing proper back navigation and home button handling using Toolbar in Android

I am using a single activity and multiple fragments(screenshot attached) within the same activity to provide a seamless navigation. But after implementing the latest toolbar and navigation view, it seems hard to handle the navigation and home buttons. I am having trouble with the following things.
Managing the Hamburger/Back button at left top. Toggling the icon and functionality to Menu and Back nav.
Page title - Changing the page titles whenever a fragment in pushed and popped.
I have tried several things like overriding onBackPressed(), setHomeAsUpIndicator, popping fragments manually. Earlier i was using ActionBarDrawer toggle to handle this but it is failing somehow now. I checked the google samples they seem to use separate activities at most of the places.
Can anyone guide me how to implement a proper back navigation to handle the NavigationView, Back button in inner fragments and page titles? I am using AppCompatActivity, android.app.Fragment, NavigationView and Toolbar.

It's much easier to illustrate with some sort of division of responsibility for your Activity and Fragment.
Problem 1: Managing the Hamburger/Back button at left top. Toggling the icon and functionality to Menu and Back nav.
From the illustration, the solution should be encapsulated by the Activity, which will look something like this:
public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawer;
private ActionBar mActionBar;
private boolean mToolBarNavigationListenerIsRegistered = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mActionBar = getSupportActionBar();
mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
mDrawer.addDrawerListener(mDrawerToggle);
mDrawerToggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
// On orientation change savedInstanceState will not be null.
// Use this to show hamburger or up icon based on fragment back stack.
if(savedInstanceState != null){
resolveUpButtonWithFragmentStack();
} else {
// You probably want to add your ListFragment here.
}
}
#Override
public void onBackPressed() {
if (mDrawer.isDrawerOpen(GravityCompat.START)) {
mDrawer.closeDrawer(GravityCompat.START);
} else {
int backStackCount = getSupportFragmentManager().getBackStackEntryCount();
if (backStackCount >= 1) {
getSupportFragmentManager().popBackStack();
// Change to hamburger icon if at bottom of stack
if(backStackCount == 1){
showUpButton(false);
}
} else {
super.onBackPressed();
}
}
}
#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.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
} else if (id == android.R.id.home) {
// Home/Up logic handled by onBackPressed implementation
onBackPressed();
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
// Navigation drawer item selection logic goes here
mDrawer.closeDrawer(GravityCompat.START);
return true;
}
private void replaceFragment() {
/**
* Your fragment replacement logic goes here
* e.g.
* FragmentTransaction ft = getFragmentManager().beginTransaction();
* String tag = "MyFragment";
* ft.replace(R.id.content, MyFragment.newInstance(tag), tag).addToBackStack(null).commit();
*/
// The part that changes the hamburger icon to the up icon
showUpButton(true);
}
private void resolveUpButtonWithFragmentStack() {
showUpButton(getSupportFragmentManager().getBackStackEntryCount() > 0);
}
private void showUpButton(boolean show) {
// To keep states of ActionBar and ActionBarDrawerToggle synchronized,
// when you enable on one, you disable on the other.
// And as you may notice, the order for this operation is disable first, then enable - VERY VERY IMPORTANT.
if(show) {
// Remove hamburger
mDrawerToggle.setDrawerIndicatorEnabled(false);
// Show back button
mActionBar.setDisplayHomeAsUpEnabled(true);
// when DrawerToggle is disabled i.e. setDrawerIndicatorEnabled(false), navigation icon
// clicks are disabled i.e. the UP button will not work.
// We need to add a listener, as in below, so DrawerToggle will forward
// click events to this listener.
if(!mToolBarNavigationListenerIsRegistered) {
mDrawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
mToolBarNavigationListenerIsRegistered = true;
}
} else {
// Remove back button
mActionBar.setDisplayHomeAsUpEnabled(false);
// Show hamburger
mDrawerToggle.setDrawerIndicatorEnabled(true);
// Remove the/any drawer toggle listener
mDrawerToggle.setToolbarNavigationClickListener(null);
mToolBarNavigationListenerIsRegistered = false;
}
// So, one may think "Hmm why not simplify to:
// .....
// getSupportActionBar().setDisplayHomeAsUpEnabled(enable);
// mDrawer.setDrawerIndicatorEnabled(!enable);
// ......
// To re-iterate, the order in which you enable and disable views IS important #dontSimplify.
}
}
Problem 2: Page title - Changing the page titles whenever a fragment in pushed and popped.
Essentially, this can be handled in the onStart for each Fragment i.e. your ListFragment, DetailsFragment and CommentsFragment look something like this:
#Override
public void onStart() {
super.onStart();
// where mText is the title you want on your toolbar/actionBar
getActivity().setTitle(mText);
}
Probably worth having setRetainInstance(true) in the onCreate of your fragments as well.

tl;dr
Watch this:
https://youtu.be/ANpBWIT3vlU
Clone this:
https://github.com/shredderskelton/androidtemplate.
This is a really common problem and one that I've overcome by creating a kind of template project which I use whenever I start a new Android project. The idea is to abstract as much of the logic that handles the back button, the 'hamburger' indicator and fragment management into reusable classes:
Start by creating a BaseActivity and BaseFragment class. This is where you are going to as much of the reusable code as possible.
Lets start with your BaseActivity
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
fragmentManager = getSupportFragmentManager();
fragmentHandler = new AddFragmentHandler(fragmentManager);
fragmentManager.addOnBackStackChangedListener(backStackListener);
}
The FragmentManager is the key to owning the back stack, so you need to listen for changes to the back stack from here. The AddFramentHandler is a little class I cooked up to make it easier to add Fragments, from Fragments. More on that later.
#Override
public void onBackPressed() {
if (sendBackPressToDrawer()) {
//the drawer consumed the backpress
return;
}
if (sendBackPressToFragmentOnTop()) {
// fragment on top consumed the back press
return;
}
//let the android system handle the back press, usually by popping the fragment
super.onBackPressed();
//close the activity if back is pressed on the root fragment
if (fragmentManager.getBackStackEntryCount() == 0) {
finish();
}
}
onBackPressed is where most of the magic happens. You notice the plain text formatting of the methods.. I'm a huge Clean Code fan - if you need to write comments, your code isn't clean. Basically you need to really have a central place where you can run to when you're not sure why a back button press is not happening the way you expect. This method is that place.
private void syncDrawerToggleState() {
ActionBarDrawerToggle drawerToggle = getDrawerToggle();
if (getDrawerToggle() == null) {
return;
}
if (fragmentManager.getBackStackEntryCount() > 1) {
drawerToggle.setDrawerIndicatorEnabled(false);
drawerToggle.setToolbarNavigationClickListener(navigationBackPressListener); //pop backstack
} else {
drawerToggle.setDrawerIndicatorEnabled(true);
drawerToggle.setToolbarNavigationClickListener(drawerToggle.getToolbarNavigationClickListener()); //open nav menu drawer
}
}
This is the other key part of the BaseActivity. Basically this method checks whether you are at the root fragment and sets up the indicator accordingly. Notice that it changes the listener depending on how many fragments are in the back stack.
Then there is the BaseFragment:
#Override
public void onResume() {
super.onResume();
getActivity().setTitle(getTitle());
}
protected abstract String getTitle();
The code above shows how the title is handled by the fragments.

Try something like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
if (getSupportActionBar()!=null) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
final ActionBarDrawerToggle drawerToggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(drawerToggle);
drawerToggle.syncState();
final View.OnClickListener originalToolbarListener = drawerToggle.getToolbarNavigationClickListener();
final View.OnClickListener navigationBackPressListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
getFragmentManager().popBackStack();
}
};
getFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
if (getFragmentManager().getBackStackEntryCount() > 0) {
drawerToggle.setDrawerIndicatorEnabled(false);
drawerToggle.setToolbarNavigationClickListener(navigationBackPressListener);
} else {
drawerToggle.setDrawerIndicatorEnabled(true);
drawerToggle.setToolbarNavigationClickListener(originalToolbarListener);
}
}
});
// Though below steps are not related but I have included to show drawer close on Navigation Item click.
navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
/**
* handle item clicks using id
*/
drawer.closeDrawer(GravityCompat.START);
return true;
}
});
}
Handle the drawer state onBackPressed:
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
To reload previous fragment on back press, always add the fragment transaction to back stack like this:
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
SomeFragment fragmentToBeLoaded = new SomeFragment();
fragmentTransaction.replace(R.id.fragment_container, fragmentToBeLoaded,
fragmentToBeLoaded.getName());
fragmentTransaction.addToBackStack(fragmentToBeLoaded.getName());
fragmentTransaction.commit();
To dynamically change the page title, you can call this from every Fragments onStart or onResume method:
#Override
public void onStart() {
super.onStart();
getActivity().setTitle("Title for fragment");
}
Note: I have considered standard layout declaration and thus I have not included any layouts.

"Page title - Changing the page titles whenever a fragment in pushed and popped"
When you remove a fragment, there is the method isRemoving(). It helps to change title back.
#Override
public void onStop() {
super.onStop();
if (isRemoving()) {
// Change your title here
}
}
"functionality to Menu and Back nav"
Suggestion: we have to rely on the default android navigation system. If we use addToBackStack() for our fragments, in theory we don't have to override onBackPressed() at all.
"App does not redefine the expected function of a system icon (such as the Back button)."
"App supports standard system Back button navigation and does not make use of any custom, on-screen "Back button" prompts."
Core App Quality: https://developer.android.com/distribute/essentials/quality/core.html
"Managing the Hamburger/Back button at left top"
I suggest to use activity instead of 'MainActivityDetailFragment' to avoid complication.

Add this in your MainActivity where you are calling Fragments. getBackStackEntryCount() Return number of fragments in the back stack. where the fragment on the bottom of the stack has index 0. popBackStack() Pop the top Fragment off the back stack
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
if (getSupportFragmentManager().getBackStackEntryCount() == 1) {
getSupportFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
}
return true;
}
And in your Fragment where you want to go back use this function
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
getActivity().onBackPressed();
}
return true;
}

Ok, after a lot of tests I finally succeeded to setup a good navigation. I needed exactly the same as you, the only difference is that I am using v4 Fragments, but I don't think this will change anything here.
I am not using ActionBarDrawerToggle since the latest examples from Google do not use this component anymore.
The solution below also works for deep navigation: parent activity --> fragment --> fragment etc.
The only change needed in the Fragments is to change the title:
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
getActivity().setTitle(R.string.targets);
}
In the parent Activity onCreate method, I initialize the following:
mNavigationView = (NavigationView) findViewById(R.id.navigation_view);
setupDrawerContent(mNavigationView);
final Toolbar toolbar = (Toolbar) findViewById(R.id.drawer_toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_menu_24);// Set the hamburger icon
getSupportActionBar().setDisplayHomeAsUpEnabled(true);// Set home button pressable
// Handle the changes on the actionbar
getSupportFragmentManager().addOnBackStackChangedListener(
new FragmentManager.OnBackStackChangedListener() {
public void onBackStackChanged() {
// When no more fragments to remove, we display back the hamburger icon and the original activity title
if (getSupportFragmentManager().getBackStackEntryCount() <= 0) {
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_menu_24);
setTitle(R.string.app_name);
}
// Else displays the back arrow
else {
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_arrow_back_24);
}
}
});
Here is now the code to handle the action on the Home button:
#Override
public boolean onOptionsItemSelected(MenuItem item){
// Close the soft keyboard right away
Tools.setSoftKeyboardVisible(mViewPager, false);
switch (item.getItemId()) {
case android.R.id.home:
// When no more fragments to remove, open the navigation drawer
if (getSupportFragmentManager().getBackStackEntryCount() <= 0) {
mDrawerLayout.openDrawer(GravityCompat.START);
}
// Removes the latest fragment
else {
getSupportFragmentManager().popBackStack();
}
return true;
}
return super.onOptionsItemSelected(item);
}
And finally the code to handle the back press action:
#Override
public void onBackPressed() {
// When no more fragments to remove, closes the activity
if (getSupportFragmentManager().getBackStackEntryCount() <= 0) {
super.onBackPressed();
}
// Else removes the latest fragment
else {
getSupportFragmentManager().popBackStack();
}
}
NOTE: I am using an AppCompatActivity, a NavigationView and the theme Theme.AppCompat.Light.NoActionBar.

Up navigation in `AppCompatActivity` with `Fragments`

I am trying to set up proper navigation in my application, which replaces Fragments in a main content area, so I have only one single Activity. I have one main Fragment and several subFragments, for example a Fragment for preferences. Everything works fine when using the back button, but I want to implement the up navigation including icon in addition to this. I am using the ActionBar fetched with Activity.getSupportActionBar() together with a Toolbar from appcompat and an ActionBarDrawerToggle.
I followed this tutorial when setting up my Drawer in the first place.
Current behavior:
When I start the app, the list/drawer icon is shown in the left part of the ActionBar. When I click this, the Drawer opens and I can select items. Sub Fragments are replaced into my content and the back button pops the stack, taking me back to the previous Fragment.
Missing behavior:
The list/drawer icon in the top left is never replaced by the back arrow icon and I cannot figure out how to implement this properly. The Drawer is always pulled out when clicking the list/drawer icon, no matter which Fragment I am in.
What have I tried:
I tried following this answer. It kinda works, meaning that the back arrow icon is set in the sub Fragments, but clicking the back arrow still opens the Drawer instead of providing up navigation. Also, when using the back button to go "up", the list/drawer icon is replaced by nothing.
I also tried following this answer. Here, the desired ActionBar behavior/look is implemented in the onCreate() method of the various Fragments. Using this I could get the back arrow up, but still the Drawer is pulled when clicking the arrow.
Various other minor things and hacks.
My questions:
What is wrong in my code below?
Is it correct/normal to use the combination ActionBar, Toolbar and ActionBarDrawerToggle to implement the Drawer navigation together with up navigation?
MyActivity.onCreate():
#Override
protected void onCreate(Bundle savedInstanceState)
{
// Other stuff
// Setup drawer.
mDrawerFragment = (DrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.mm_navigation_drawer);
mDrawerFragment.initialize(this, (DrawerLayout)findViewById(R.id.mm_drawer_layout), toolbar);
}
DrawerFragment class
public class DrawerFragment extends Fragment
{
private MyActivity mMyActivity;
private MyActionBarDrawerToggle mMyBarDrawerToggle;
private DrawerLayout mDrawerLayout;
private FragmentDrawerListener mFragmentDrawerListener;
private View mContainerView;
public void initialize(MyActivity myActivity, final DrawerLayout drawerLayout, final Toolbar toolbar)
{
mMyActivity = myActivity;
mFragmentDrawerListener = mMyActivity;
mContainerView = myActivity.findViewById(R.id.mm_navigation_drawer);
mMyActionBarDrawerToggle = new MyActionBarDrawerToggle(myActivity, drawerLayout, toolbar, R.string.mm_drawer_open, R.string.mm_drawer_close);
mDrawerLayout = drawerLayout;
mDrawerLayout.setDrawerListener(mMyActionBarDrawerToggle);
mDrawerLayout.post(new Runnable()
{
#Override
public void run()
{
mMyActionBarDrawerToggle.syncState();
}
});
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, final ViewGroup container, Bundle savedInstanceState)
{
// Not relevant, just create and return the View.
}
}
MyActivity.onDrawerItemSelected()
The implementation of the interface FragmentDrawerListener is done in the MyActivity class. It simply replaces the content area with other Fragments, using FragmentTransactions.
#Override
public void onDrawerItemSelected(View view, int postion)
{
switch (postion)
{
case DrawerAdapter.ITEM_FILTERED_RECIPES:
showFilteredRecipesFragment();
break;
case DrawerAdapter.ITEM_SELECTED_RECIPES:
showSelectedRecipesFragment();
break;
case DrawerAdapter.ITEM_SHOPPING_LIST:
showShoppingListFragment();
break;
case DrawerAdapter.ITEM_SETTINGS:
showSettingsFragment();
break;
case DrawerAdapter.ITEM_ABOUT:
showAboutFragment();
break;
}
}
MyActionBarDrawerToggle class
public class MyActionBarDrawerToggle extends ActionBarDrawerToggle
{
private MyActivity mMyActivity;
private Toolbar mToolbar;
public MyActionBarDrawerToggle(Activity activity, DrawerLayout drawerLayout, Toolbar toolbar, int openDrawerContentDescRes, int closeDrawerContentDescRes)
{
super(activity, drawerLayout, toolbar, openDrawerContentDescRes, closeDrawerContentDescRes);
mMyActivity = (MyActivity) activity;
mToolbar = toolbar;
}
#Override
public void onDrawerOpened(View drawerView)
{
super.onDrawerOpened(drawerView);
mMyActivity.invalidateOptionsMenu();
}
#Override
public void onDrawerClosed(View drawerView)
{
super.onDrawerClosed(drawerView);
mMyActivity.invalidateOptionsMenu();
}
#Override
public void onDrawerSlide(View drawerView, float slideOffset)
{
super.onDrawerSlide(drawerView, slideOffset);
mToolbar.setAlpha(1 - slideOffset / 2);
}
}
The DrawerFragment is inflated in the main layout using a simple, static Fragment instance like this:
<fragment
android:id="#+id/my_navigation_drawer"
android:name="com.my.company.gui.drawer.DrawerFragment"
android:layout_width="#dimen/my_nav_drawer_width"
android:layout_height="match_parent"
android:layout_gravity="start"
app:layout="#layout/my_drawer_navigation_fragment"
tools:layout="#layout/my_drawer_navigation_fragment">
</fragment>

If you're using material design for you app, then it is expected that you use the Toolbar to replace the Actionbar in your activity. You will still maintain your ActionBarDrawerToggle and functionality will remain the same.
As for your fragments, as long as they are 'housed' by the same activtiy (i.e the activity with the drawer), changing fragments will not cause the drawer toggle to change the back arrow. It will only change if you navigate to a new activity. Only then will the main activity be treated as home and with the other activities having a back arrow to navigate back

How change Actionbar title by switching between Fragments

I have an application with two fragments when the application starts the Actionbar title is the one of the first fragment. But when I'm going to the second Fragment the title doesn't change.
So how do I change the ActionBar title?
This is my code:
public class ClientList extends Fragment {
#Override
public void onResume() {
super.onResume();
String title;
title = getResources().getString(R.string.client_title);
ActionBarActivity action = ((EmployeeActivity)getActivity());
action.getSupportActionBar().setTitle(title);
}
#Override
public void onDestroyView() {
super.onDestroyView();
String title2;
title2 = getResources().getString(R.string.action_settings);
ActionBarActivity action = ((EmployeeActivity)getActivity());
action.getSupportActionBar().setTitle(title2);
}
}

so if you say you cannot reach the method from onCreateView, so this is your solution I think:
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.my_fragment,
container, false);
getActivity().setTitle("Title");
return view;
}
Because if you return before you call setTitle() you cannot reach it, that's true.
Hope it helps.

You can set your action bar title inside onCreate(if activity)/onCreateView(if fragment) method as getSupportActionBar().setTitle("Your Title");

Whenever you switch from one fragment to another fragment you can set the title in ActionBar. This can be done on onCreateView(...) of a fragment. Advisable try to change the name in Activity in which you are trying to load the fragment.
To do so ....
If you are using appcompat library
ActionBar actionBar = getSupportActionBar();
actionBar.setTitle(" your title ");
If you are not using appcompat library
ActionBar actionBar = getActionBar();
actionBar.setTitle(" your title ");

This should work:
getActivity().setTitle(YOUR_TITLE);
Call it from your Fragment when you wanted to set.

Android Navigation Drawer Show Up Indicator for Lower Level Fragments

I have some issues switching navigation drawer functionality to up functionality at lower level fragment. I have read this thread to manage to show the up indicator. But when pressing the button, it'll open up the navigation drawer instead of going back to previous fragment. And I can't set action bar title in EditUserFragment to "Edit Profile".
I'm using the navigation drawer template available in Android Studio.
I have three levels:
MainActivity with navigation drawer that consists of Home and Profile items
UserFragment titled with "Profile" that has an option item that'll bring up EditUserFragment
EditUserFragment (lower level fragment) is triggered by UserFragment
MainActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerToggle = new ActionBarDrawerToggle(this, drawerLayout,
R.drawable.ic_launcher, R.string.navigation_drawer_open,
R.string.navigation_drawer_close);
}
#Override
public void onBackPressed() {
super.onBackPressed();
// this won't change the drawer indicator back
drawerToggle.setDrawerIndicatorEnabled(true);
// this works
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);
}
public void onSectionAttached(int number) {
// Show the corresponding title on the action bar when clicked and open corresponding
// fragments.
Fragment fragment = null;
switch (number) {
case 1:
mTitle = getString(R.string.title_home);
break;
case 2:
mTitle = getString(R.string.title_profile);
fragment = new UserFragment();
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, fragment).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!mNavigationDrawerFragment.isDrawerOpen()) {
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.main, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
public void restoreActionBar() {
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setTitle(mTitle);
}
public void setActionBarTitle(String title){
getActionBar().setTitle(title);
Log.d("Title 2", getActionBar().getTitle().toString());
}
onBackPressed is working partially (commented in code) when I pressed back button on phone (not up button on action bar).
UserFragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
setHasOptionsMenu(true);
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_profile, container, false);
drawerLayout = (DrawerLayout) getActivity().findViewById(R.id.drawer_layout);
drawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout,
R.drawable.ic_launcher, R.string.navigation_drawer_open,
R.string.navigation_drawer_close);
return view;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.action_edit:
drawerToggle.setDrawerIndicatorEnabled(false);
// Disable sliding from edge to open drawer
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED);
getFragmentManager().beginTransaction()
.replace(R.id.container, new EditUserFragment())
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.addToBackStack(null)
.commit();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
EditUserFragment
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
getActivity().getActionBar().setDisplayHomeAsUpEnabled(true);
((MainActivity) getActivity()).setActionBarTitle("Edit Profile");
Log.d("Title", getActivity().getActionBar().getTitle().toString());
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Get item selected and deal with it
Log.d("KEY: ", String.valueOf(item.getItemId()));
switch (item.getItemId()) {
case android.R.id.home:
Log.d("EditUserFragment", "I'm here");
getActivity().onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
getActivity().getActionBar().setDisplayHomeAsUpEnabled(true); works as expected that up caret is showing instead of drawer; though when tapping it, it's opening up drawer instead of going back to previous fragment. In addition, the code under case android.R.id.home is never executed.
And I try to set action bar title to "Edit Profile" from "Profile". The log shows me "Edit Profile", but the actual running app shows me "Profile" for some reason.
What I want to achieve is be able to go back to UserFragment from EditUserFragment by tapping the up indicator (right now the up indicator is opening up navigation drawer). And show correct title in EditUserFragment.
Any help is greatly appreciated!!

After days of analyzing, I discovered that the problem is I am using the built-in navigation drawer activity when creating it. The built-in separate the tasks into two. MainActivity and NavigationDrawerFragment. Thus, the drawerToggle I have in MainActivity is not the same as the real one in NavigationDrawerFragment.
Oroginally, MainActivty calls NavigationDrawerFragment to setup all the things needed for navigation drawer. I SOLVED this by implementing navigation drawer in my MainActivity, so I'll have only one drawerToggle. Though, I still can't find the way to make it work if I have everything (the navigation drawer variables) in NavigationDrawerFragment rather than MainActivity. If anyone knows the answer to that, feel free to leave a comment!

Switching between Android Navigation Drawer image and Up caret when using fragments

When using the Navigation Drawer the Android devs are recommending that in the ActionBar "only those screens that are represented in the Navigation Drawer should actually have the Navigation Drawer image" and that "all other screens have the traditional up carat."
See here for details: http://youtu.be/F5COhlbpIbY
I'm using one activity to control multiple levels of fragments and can get the Navigation Drawer image to display and function at all levels.
When creating lower level fragments I can call the ActionBarDrawerToggle setDrawerIndicatorEnabled(false) to hide the Navigation Drawer image and have the Up caret displayed
LowerLevelFragment lowFrag = new LowerLevelFragment();
//disable the toggle menu and show up carat
theDrawerToggle.setDrawerIndicatorEnabled(false);
getSupportFragmentManager().beginTransaction().replace(R.id.frag_layout,
lowFrag, "lowerFrag").addToBackStack(null).commit();
The problem I'm having is when I navigate back to the top level fragments the Up carat still shows instead of the original Navigation Drawer image. Any suggestions on how to "refresh" the ActionBar on the top level fragments to re-display the Navigation Drawer image?
Solution
Tom's suggestion worked for me. Here’s what I did:
MainActivity
This activity controls all fragments in the app.
When preparing new fragments to replace others, I set the DrawerToggle setDrawerIndicatorEnabled(false) like this:
LowerLevelFragment lowFrag = new LowerLevelFragment();
//disable the toggle menu and show up carat
theDrawerToggle.setDrawerIndicatorEnabled(false);
getSupportFragmentManager().beginTransaction().replace(R.id.frag_layout,
lowFrag).addToBackStack(null).commit();
Next, in an override of onBackPressed, I reverted the above by setting the DrawerToggle to setDrawerIndicatorEnabled(true) like this:
#Override
public void onBackPressed() {
super.onBackPressed();
// turn on the Navigation Drawer image;
// this is called in the LowerLevelFragments
setDrawerIndicatorEnabled(true)
}
In the LowerLevelFragments
In the fragments I modified onCreate and onOptionsItemSelected like this:
In onCreate added setHasOptionsMenu(true) to enable configuring the options menu. Also set setDisplayHomeAsUpEnabled(true) to enable the < in the actionbar:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// needed to indicate that the fragment would
// like to add items to the Options Menu
setHasOptionsMenu(true);
// update the actionbar to show the up carat/affordance
getActivity().getActionBar().setDisplayHomeAsUpEnabled(true);
}
Then in onOptionsItemSelected whenever the < is pressed it calls the onBackPressed() from the activity to move up one level in the hierarchy and display the Navigation Drawer Image:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Get item selected and deal with it
switch (item.getItemId()) {
case android.R.id.home:
//called when the up affordance/carat in actionbar is pressed
getActivity().onBackPressed();
return true;
…
}

It's easy as 1-2-3.
If you want to achieve:
1) Drawer Indicator - when no fragments are in the Back Stack or the Drawer is opened
2) Arrow - when some Fragments are in the Back Stack
private FragmentManager.OnBackStackChangedListener
mOnBackStackChangedListener = new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
syncActionBarArrowState();
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mDrawerToggle = new ActionBarDrawerToggle(
this,
mDrawerLayout,
R.drawable.ic_navigation_drawer,
0,
0
) {
public void onDrawerClosed(View view) {
syncActionBarArrowState();
}
public void onDrawerOpened(View drawerView) {
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
getSupportFragmentManager().addOnBackStackChangedListener(mOnBackStackChangedListener);
}
#Override
protected void onDestroy() {
getSupportFragmentManager().removeOnBackStackChangedListener(mOnBackStackChangedListener);
super.onDestroy();
}
private void syncActionBarArrowState() {
int backStackEntryCount =
getSupportFragmentManager().getBackStackEntryCount();
mDrawerToggle.setDrawerIndicatorEnabled(backStackEntryCount == 0);
}
3) Both indicators to act according to their shape
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.isDrawerIndicatorEnabled() &&
mDrawerToggle.onOptionsItemSelected(item)) {
return true;
} else if (item.getItemId() == android.R.id.home &&
getSupportFragmentManager().popBackStackImmediate()) {
return true;
} else {
return super.onOptionsItemSelected(item);
}
}
P.S. See Creating a Navigation Drawer on Android Developers on other tips about the 3-lines indicator behavior.

You have written that, to implement lower-level fragments, you are replacing the existing fragment, as opposed to implementing the lower-level fragment in a new activity.
I would think that you would then have to implement the back functionality manually: when the user pressed back you have code that pops the stack (e.g. in Activity::onBackPressed override). So, wherever you do that, you can reverse the setDrawerIndicatorEnabled.

I've used next thing:
getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
if(getSupportFragmentManager().getBackStackEntryCount() > 0){
mDrawerToggle.setDrawerIndicatorEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
else {
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
}
});

If your up action bar button doesn't work, don't forget to add the listener :
// Navigation back icon listener
mDrawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
I've got some trouble implementing a drawer navigation with a home button, everything worked except the action buton.

Try handling the Home item selection in the MainActivity depending on the state of the DrawerToggle. This way you don't have to add same code to every fragment.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Only handle with DrawerToggle if the drawer indicator is enabled.
if (mDrawerToggle.isDrawerIndicatorEnabled() &&
mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch (item.getItemId()) {
// Handle home button in non-drawer mode
case android.R.id.home:
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}

FOLLOW UP
The solution given by #dzeikei is neat, but it can be extended, when using fragments, to automatically handle setting back the drawer indicator when the backstack is empty.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Only handle with DrawerToggle if the drawer indicator is enabled.
if (mDrawerToggle.isDrawerIndicatorEnabled() &&
mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch (item.getItemId()) {
// Handle home button in non-drawer mode
case android.R.id.home:
// Use getSupportFragmentManager() to support older devices
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.popBackStack();
// Make sure transactions are finished before reading backstack count
fragmentManager.executePendingTransactions();
if (fragmentManager.getBackStackEntryCount() < 1){
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
EDIT
For the question of #JJD.
The fragments are held/managed in an activity. The above code is written once in that activity, but only handle the up caret for the onOptionsItemSelected.
In one of my apps I also needed to handle the behavior of the up caret when the back button was pressed. This can be handle by overriding onBackPressed.
#Override
public void onBackPressed() {
// Use getSupportFragmentManager() to support older devices
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.executePendingTransactions();
if (fragmentManager.getBackStackEntryCount() < 1){
super.onBackPressed();
} else {
fragmentManager.executePendingTransactions();
fragmentManager.popBackStack();
fragmentManager.executePendingTransactions();
if (fragmentManager.getBackStackEntryCount() < 1){
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
}
};
Note the code duplication between onOptionsItemSelected and onBackPressed which can be avoided by creating a method and calling that method in both places.
Also note I add two more times executePendingTransactions which in my case was required or else I had sometimes strange behaviors of the up caret.

I created an interface for the hosting activity to update the view state of the hamburger menu. For top level fragments I set the toggle to true and for fragments for which I want to display the up < arrow I set the toggle to false.
public class SomeFragment extends Fragment {
public interface OnFragmentInteractionListener {
public void showDrawerToggle(boolean showDrawerToggle);
}
private OnFragmentInteractionListener mListener;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
this.mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString() + " must implement OnFragmentInteractionListener");
}
}
#Override
public void onResume() {
super.onResume();
mListener.showDrawerToggle(false);
}
}
Then in my Activity ...
public class MainActivity extends Activity implements SomeFragment.OnFragmentInteractionListener {
private ActionBarDrawerToggle mDrawerToggle;
public void showDrawerToggle(boolean showDrawerIndicator) {
mDrawerToggle.setDrawerIndicatorEnabled(showDrawerIndicator);
}
}

This answer was working but there was a little problem with it.
The getSupportActionBar().setDisplayHomeAsUpEnabled(false) was not called explicitly and it was causing drawer icon to be hidden even when there were no items in the backstack so changing the setActionBarArrowDependingOnFragmentsBackStack() method worked for me.
private void setActionBarArrowDependingOnFragmentsBackStack() {
int backStackEntryCount = getSupportFragmentManager()
.getBackStackEntryCount();
// If there are no items in the back stack
if (backStackEntryCount == 0) {
// Please make sure that UP CARAT is Hidden otherwise Drawer icon
// wont display
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
// Display the Drawer Icon
mDrawerToggle.setDrawerIndicatorEnabled(true);
} else {
// Show the Up carat
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// Hide the Drawer Icon
mDrawerToggle.setDrawerIndicatorEnabled(false);
}
}

Logic is clear.
Show back button if fragment back stack is clear.
Show material hamburger-back animation if fragment stack is not clear.
getSupportFragmentManager().addOnBackStackChangedListener(
new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
syncActionBarArrowState();
}
}
);
private void syncActionBarArrowState() {
int backStackEntryCount = getSupportFragmentManager().getBackStackEntryCount();
mNavigationDrawerFragment.setDrawerIndicatorEnabled(backStackEntryCount == 0);
}
//add these in Your NavigationDrawer fragment class
public void setDrawerIndicatorEnabled(boolean flag){
ActionBar actionBar = getActionBar();
if (!flag) {
mDrawerToggle.setDrawerIndicatorEnabled(false);
actionBar.setDisplayHomeAsUpEnabled(true);
mDrawerToggle.setHomeAsUpIndicator(getColoredArrow());
} else {
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
mDrawerToggle.syncState();
getActivity().supportInvalidateOptionsMenu();
}
//download back button from this(https://www.google.com/design/icons/) website and add to your project
private Drawable getColoredArrow() {
Drawable arrowDrawable = ContextCompat.getDrawable(getActivity(), R.drawable.ic_arrow_back_black_24dp);
Drawable wrapped = DrawableCompat.wrap(arrowDrawable);
if (arrowDrawable != null && wrapped != null) {
// This should avoid tinting all the arrows
arrowDrawable.mutate();
DrawableCompat.setTint(wrapped, Color.GRAY);
}
return wrapped;
}

If you take a look at the GMAIL app and come here to search for the carret/affordance icon..
I would ask you to do this, none of the above answer was clear. i was able to modify the accepted answer.
NavigationDrawer --> Listview contains subfragments.
subfragments will be listed like this
firstFragment == position 0 ---> this will have subfragments --> fragment
secondFragment
thirdFragment and so forth....
In firstFragment you have other fragment.
Call this on DrawerActivity
getFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
if (getFragmentManager().getBackStackEntryCount() > 0) {
mDrawerToggle.setDrawerIndicatorEnabled(false);
} else {
mDrawerToggle.setDrawerIndicatorEnabled(true);
}
}
});
and in fragment
setHasOptionsMenu(true);
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Get item selected and deal with it
switch (item.getItemId()) {
case android.R.id.home:
//called when the up affordance/carat in actionbar is pressed
activity.onBackPressed();
return true;
}
return false;
}
On the OnBackPressed Drawer activity method set the drawer toggle to true to enable navigation list icon again.
Thanks,
Pusp

You can look at this little example!
https://github.com/oskarko/NavDrawerExample

IMO, using onNavigateUp() (as shown here) in riwnodennyk's or Tom's solution is cleaner and seems to work better. Just replace the onOptionsItemSelected code with this:
#Override
public boolean onSupportNavigateUp() {
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
// handle up navigation
return true;
} else {
return super.onSupportNavigateUp();
}
}