I have a simple fragment with this code:
private BottomNavigationView.OnNavigationItemSelectedListener navListener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem menuItem) {
Fragment selectedFragment= null;
switch (menuItem.getItemId()){
case R.id.nav_home:
selectedFragment= new HomeFragment();
setTitle("Beranda");
break;
case R.id.nav_message:
selectedFragment= new MessageFragment();
setTitle("Pesan");
break;
case R.id.nav_transaction:
selectedFragment= new TransactionFragment();
setTitle("Transaksi");
break;
case R.id.nav_profile:
selectedFragment= new ProfileFragment();
setTitle("Profil");
if(sessionLevel.equals("admin")){
setTitle("Admin");
}
break;
}
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, selectedFragment).commit();
return true;
}
};
Most of the fragment are just some kind of holder for Intent Activity. And the Activity itself doesnt have some fancy code.
The problem is that when i do Intent on Profile menu and then press back, the fragment shown is HomeActivity but the selected button is Profile.
I dont know about the other 2 fragment since im not there yet, but probably they do the same thing.
You can do this like the following:
#Override
public void onBackPressed() {
super.onBackPressed();
Fragment frag = YourActivity.this.getSupportFragmentManager().findFragmentById(R.id.fragment_container);
if(frag!=null && frag instanceof yourFragment)
{}
}
The following will give you count
int count = getSupportFragmentManager().getBackStackEntryCount();
You can make condition, If count is great than 1 then have more than 1 fragments else you have atleast 1 fragment and that will be last fragment. If count 0 then no more fragment available on stack as all have been poped out of stack.
Create an interface:
public interface IOnBackPressed {
boolean onBackPressed();
}
In Fragment implement IOnBackPressed like:
public class FAQFragment extends Fragment implements IOnBackPressed {
public boolean onBackPressed() {
return false
}
}
On Main Activity Backpress use
#Override
public void onBackPressed(){
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
getSupportFragmentManager().popBackStack();
}
}
Related
I tried many methods to save instances but I am confused how to save instances in backstack because no one described how to use it if there multiple fragments.my code in mainactivity below:
bottomNavigationView.setOnItemSelectedListener(item -> {
switch (item.getItemId()){
case R.id.home:
loadFragment(new HomeFragment(),0);
break;
case R.id.create:
loadFragment(new CreateFragment(),1);
break;
case R.id.profile:
loadFragment(new ProfileFragment(),1);
break;
}
return true;
});
public void loadFragment(Fragment fragment,int flag){
FragmentManager fragmentManager=getSupportFragmentManager();
FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();
if(flag==0){
fragmentTransaction.add(R.id.frame_layout,fragment);
fragmentManager.popBackStack(ROOT_FRAGMENT_TAG,FragmentManager.POP_BACK_STACK_INCLUSIVE);
fragmentTransaction.addToBackStack(ROOT_FRAGMENT_TAG);
}
else {
fragmentTransaction.replace(R.id.frame_layout,fragment);
fragmentTransaction.addToBackStack(null);
}
fragmentTransaction.commit();
}
I suggest you to make your Fragment Classes Singleton.
private static MyFragment fragment;
public static MyFragment getInstance() {
if (fragment == null) {
fragment = new MyFragment();
}
return fragment;
}
then use getInstance() method to instantiate your fragment
I have trouble finding a good example on how to swipe between fragments with help of bottom navigatiom bar. Since FragmentStatePagerAdapter is deprecated and a new ViewPager2 is now recommended instead of the old ViewPager I want to use ViewPager2 and FragmentStateAdapter in my code instead. I have found an example of how to combine BottomNavigationBar and ViewPager here and I want to do something similar. My code have many similarities to the one in the example with the only difference that I have my code in a fragment instead of an activity. Here is a picture of how my FrontendFragment display look like. I can switch between the views using the bottomnavigationbar but I also want to be able to swipe between the views. Can someone help me or at least direct me on the right way? Here is my code:
FragmentPagerAdapter Class:
public class FragmentPagerAdapter extends FragmentStateAdapter {
private static final int mFragmentCount = 5;
public FragmentPagerAdapter(#NonNull Fragment fragment) {
super(fragment);
}
#NonNull
#Override
public Fragment createFragment(int position) {
switch (position){
case 0:
return new HomeFragment();
case 1:
return new SearchFragment();
case 2:
return new AddFragment();
case 3:
return new MessageFragment();
case 4:
return new ProfileFragment();
}
return null;
}
#Override
public int getItemCount() {
return mFragmentCount;
}
}
FrontendFragment Class:
public class FrontendFragment extends Fragment implements BottomNavigationView.OnNavigationItemSelectedListener{
private BottomNavigationView mBottomNavigationView;
private ViewPager2 mViewPager2;
private FragmentPagerAdapter mFragmentPagerAdapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_frontend, container, false);
loadFragment(new HomeFragment());
mBottomNavigationView = v.findViewById(R.id.bottomNavigationBar);
mBottomNavigationView.setOnNavigationItemSelectedListener(this);
return v;
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.home_icon:
selectedFragment = new HomeFragment();
break;
case R.id.search_icon:
selectedFragment = new SearchFragment();
break;
case R.id.add_icon:
selectedFragment = new AddFragment();
break;
case R.id.message_icon:
selectedFragment = new MessageFragment();
break;
case R.id.profile_icon:
selectedFragment = new ProfileFragment();
break;
}
return loadFragment(selectedFragment);
}
private boolean loadFragment(Fragment selectedFragment) {
if(selectedFragment != null){
MainActivity.sFm.beginTransaction().replace(R.id.relLayoutMiddle, selectedFragment).commit();
return true;
}
return false;
}
}
Thanks in advance!
As I'm already using BottomNav with ViewPager2 in one of my app, I can help.
Your code is partially correct which means your FragmentPagerAdapter is fine, but not your FrontEndFragment.
See, the FragmentPagerAdapter has to be set to a ViewPager2 as
//this here is the FrontEndFragment
mViewPager2.setAdapter(new FragmentPagerAdapter(this));
Then, You don't have to do the FragmentTransaction at all, you just have to change the ViewPager2's current item position through the BottomNavigationBar as
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.home_icon:
mViewPager2.setCurrentItem(0);
break;
case R.id.search_icon:
mViewPager2.setCurrentItem(1);
break;
case R.id.add_icon:
mViewPager2.setCurrentItem(2);
break;
case R.id.message_icon:
mViewPager2.setCurrentItem(3);
break;
case R.id.profile_icon:
mViewPager2.setCurrentItem(4);
break;
}
return false;
}
This is all, you don't have to deal with Fragments at all apart from the FragmentPagerAdapter. Also, don't forget to remove the loadFragment(new HomeFragment()); which is not required, nor the function loadFragment() is required.
(Optional), Furthermore, if you want to disable the Swipe Action of the ViewPager2 and want the Fragments to be selected based on the Selected BottomNav item only, then you can set setUserInputEnabled() property of ViewPager2 as false.
Next, to set the BottomNavigationBar's item as selected based on the swipe of the ViewPager2, what you've to do is,
Create a global var
MenuItem previousMenuItem;
Then, set a default item (first) to be selected of BottomNav on activity start as
mBottomNavigationView.getMenu().getItem(0).setChecked(true);
Finally, set an OnPageSelected() callback on ViewPager2 to update the selected Menu Item as:
mViewPager2.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
super.onPageScrolled(position, positionOffset, positionOffsetPixels);
}
#Override
public void onPageSelected(int position) {
super.onPageSelected(position);
if (previousMenuItem != null) {
previousMenuItem.setChecked(false);
}
else {
mBottomNavigationView.getMenu().getItem(0).setChecked(false);
}
mBottomNavigationView.getMenu().getItem(position).setChecked(true);
previousMenuItem = mBottomNavigationView.getMenu().getItem(position);
}
#Override
public void onPageScrollStateChanged(int state) {
super.onPageScrollStateChanged(state);
}
});
What you're doing here is that you're setting default item to previousMenuItem and then on swiping to a different page, deselecting the previousMenuItem and selecting the new one, which means updating the BottomNav based on ViewPager's current item. This is the complete code you require to acheive your objective.
If you want to swipe between views, a simple solution would be to store all views in your parent view, but set all layouts for views except the initial view to android:visibility="gone". Make sure to set the initial view layout to android:visibility="visible" though. Now on you button clicks, you will have to implement onClick such that they turn on/ off view visibilities accordingly. For example, store views in order and control them via array index. But the whole thing you're trying to do is generally not a good design pattern in my opinion.
Why don't you load another Activity onClick instead of crowding your single activity? This will cause load time issues. Even if the views are non-visible, it's just an overall hassle to maintain all that in one place.
In my application I have NavigationView and into this NavigationView I have set menu for open some fragments!
<android.support.design.widget.NavigationView
android:id="#+id/nav_view"
android:layout_width="320dip"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#000"
android:fitsSystemWindows="true"
app:headerLayout="#layout/tester_drawer_header"
app:itemIconTint="#fff"
app:itemTextColor="#fff"
app:menu="#menu/tester_drawer_main"/>
I want when click on this menu open one fragment and I want when go to nested fragments and press onBack button open first fragment not open backStack fragments!
I write below codes, but after click on back button back fragments from backStack, but I want just open first fragment!
MyActivity codes:
public class TesterDashboardActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tester_dashboard);
loadFragment(new TesterTestListFragment(), userName);
}
#Override
public void onBackPressed() {
fragmentBackCount = getSupportFragmentManager().getBackStackEntryCount();
if (fragmentBackCount <= 1) {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
//finishAffinity();
super.onBackPressed();
}
} else {
getSupportFragmentManager().popBackStack();
}
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.nav_home:
loadFragment(new TesterTestListFragment(), userName);
break;
case R.id.nav_billing:
loadFragment(new TesterFinanceFragment(), context.getString(R.string.menu_billing));
break;
case R.id.nav_edit_profile:
loadFragment(new TesterProfileFilterEditFragment(), context.getString(R.string.menu_edit_profile));
break;
case R.id.nav_bank:
loadFragment(new TesterShebaFragment(), context.getString(R.string.menu_bank));
break;
case R.id.nav_report:
loadFragment(new TesterReportsFragment(), context.getString(R.string.menu_report));
break;
case R.id.nav_setting:
loadFragment(new TesterSettingFragment(), context.getString(R.string.menu_setting));
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
public void loadFragment(Fragment fragment, String toolbarTitle) {
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fm.beginTransaction();
fragmentTransaction.replace(R.id.testerFragment, fragment,TAG_FRAGMENT);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
toolbar.setTitle(toolbarTitle);
}
How can I fix it?
In your code I found when the fragmentBackCount>1 you just call getSupportFragmentManager().popBackStack(); once, so you will see top fragment on backstack.
I think you should call getSupportFragmentManager().popBackStack();, fragmentBackCount-1 time to reach the first fragmnet
else {
for(int i=0;i<fragmentBackCount-1;i++)
getSupportFragmentManager().popBackStack();
}
When you are transitioning between Fragments, call addToBackStack() as part of your
FragmentTransaction:
FragmentTransaction tx = fragmentManager.beginTransation();
tx.replace( R.id.fragment, new MyFragment() ).addToBackStack( "tag" ).commit();
I'm making an app that has launches with a Swiping Tabs Fragment, but I also want to have a Preferences menu using Fragment Transaction. When I press the Settings button in my app, the preferences menu does appear and is interactive, but the layout seems to be transparent showing the Tabs below. Is there anything that can be done to fix this, or is there a better method?
Code that calls the Preferences Menu from the Options:
public boolean onOptionsItemSelected(final MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
getFragmentManager().popBackStackImmediate();
break;
case R.id.logout:
FirebaseAuth.getInstance().signOut();
finish();
startActivity(new Intent(this, Activity_Main.class));
break;
case R.id.action_settings:
getFragmentManager().beginTransaction()
.replace(android.R.id.content, new Fragment_Settings()).addToBackStack(null)
.commit();
break;
}
return true;
}
Code that calls Tabs Fragments:
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public android.support.v4.app.Fragment getItem(int index) {
switch (index) {
case 0:
// Top Rated fragment activity
return new Fragment_Flower();
case 1:
// Games fragment activity
return new Fragment_Overview();
}
return null;
}
#Override
public int getCount() {
// get item count - equal to number of tabs
return 2;
}
}
Initialising Transaction in onCreate:
startService(new Intent(this, SensorListener.class));
if (b == null) {
// Create new fragment and transaction
Fragment newFragment = new Fragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
//Replace whatever is in the fragment_container view with this
// fragment,
// and add the transaction to the back stack
transaction.replace(android.R.id.content, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
Any help will be greatly appreciated!
Just set background color in your layout file. It may avoid transparent backgound.
I have this problem with Google's Navigation Drawer where starting the activity specified in the first case (case 0) in my selectItem method breaks and returns to the previous activity.
private class DrawerItemClickListener implements ListView.OnItemClickListener {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
switch(position) {
case 0:
// Placing any startActivity here will load the activity
// but immediately return to the calling activity.
parent.startActivity(new Intent(parent, Dashboard.class));
break;
case 1:
parent.startActivity(new Intent(parent, Card.class));
break;
}
}
But if I put mDrawerLayout.closeDrawer(mDrawerList); or any other code, it'll work normally.
There are no errors reported when the called activity is closed and no exception is thrown. Any thoughts?
I tried reproducing this and it will not resolve parent. Do you have it declared somewhere else ?
What class are you using this in both Activities and Fragments can use startActivity() without the need for parent.startActivity()
Can you post the complete class?
This works for ok for me.
private void selectItem(int position) {
switch (position) {
case 0:
// goto home screen
Log.d(TAG, "Showing Home");
startActivity(new Intent(this, SettingsActivity.class));
break;
case 1:
// Show Editor
Log.d(TAG, "Showing Editor");
break;
default:
break;
}
}